Home Explore Help
Register Sign In
caner
/
test-ffmpeg
1
0
Fork 0
Files Issues 0 Pull Requests 0 Wiki
Branch: master
Branches Tags
test-ffmpeg
/
ffmpeg-4.4-essentials_build
/
doc
/
ffmpeg-utils.html

ffmpeg-utils.html 44 KB
Permalink History Raw

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890891892893894895896897898899900901902903904905906907908909910911912913914915916917918919920921922923924925926927928929930931932933934935936937938939940941942943944945946947948949950951952953954955956957958959960961962963964965966967968969970971972973974975976977978979980981982983984985986987988989990991992993994995996997998999100010011002100310041005100610071008100910101011101210131014101510161017101810191020102110221023102410251026102710281029103010311032103310341035103610371038103910401041104210431044104510461047104810491050105110521053105410551056105710581059106010611062106310641065106610671068106910701071107210731074107510761077107810791080108110821083108410851086108710881089109010911092109310941095109610971098109911001101110211031104110511061107110811091110111111121113111411151116111711181119112011211122112311241125112611271128112911301131113211331134113511361137113811391140114111421143114411451146114711481149115011511152115311541155115611571158115911601161116211631164116511661167116811691170117111721173117411751176117711781179118011811182118311841185118611871188118911901191119211931194119511961197119811991200120112021203120412051206120712081209121012111212121312141215121612171218121912201221122212231224122512261227122812291230123112321233123412351236123712381239124012411242124312441245124612471248124912501251125212531254125512561257125812591260126112621263126412651266126712681269127012711272127312741275127612771278127912801281128212831284128512861287128812891290129112921293129412951296129712981299130013011302130313041305130613071308130913101311131213131314131513161317131813191320132113221323132413251326132713281329133013311332133313341335133613371338133913401341134213431344134513461347134813491350135113521353135413551356135713581359136013611362136313641365136613671368136913701371137213731374137513761377137813791380138113821383138413851386138713881389139013911392139313941395139613971398139914001401140214031404140514061407140814091410141114121413141414151416141714181419142014211422142314241425142614271428142914301431143214331434143514361437143814391440144114421443144414451446144714481449145014511452145314541455145614571458145914601461146214631464146514661467146814691470147114721473147414751476147714781479148014811482148314841485 
  1. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    2. 

  2. <html>
    3. 

  3. <!-- Created by GNU Texinfo 6.7, http://www.gnu.org/software/texinfo/ -->
    4. 

  4.   <head>
    5. 

  5.     <meta charset="utf-8">
    6. 

  6.     <title>
    7. 

  7.       FFmpeg Utilities Documentation
    8. 

  8.     </title>
    9. 

  9.     <meta name="viewport" content="width=device-width,initial-scale=1.0">
    10. 

  10.     <link rel="stylesheet" type="text/css" href="bootstrap.min.css">
    11. 

  11.     <link rel="stylesheet" type="text/css" href="style.min.css">
    12. 

  12.   </head>
    13. 

  13.   <body>
    14. 

  14.     <div class="container">
    15. 

  15.       <h1>
    16. 

  16.       FFmpeg Utilities Documentation
    17. 

  17.       </h1>
    18. 

  18. <div align="center">
    19. 

  19. </div>
    20. 

  20. 

  21. 

  22. <a name="SEC_Top"></a>
    23. 

  23. 

  24. <span id="SEC_Contents"></span>
    25. 

  25. <h2 class="contents-heading">Table of Contents</h2>
    26. 

  26. 

  27. <div class="contents">
    28. 

  28. 

  29. <ul class="no-bullet">
    30. 

  30.   <li><a id="toc-Description" href="#Description">1 Description</a></li>
    31. 

  31.   <li><a id="toc-Syntax" href="#Syntax">2 Syntax</a>
    32. 

  32.   <ul class="no-bullet">
    33. 

  33.     <li><a id="toc-Quoting-and-escaping" href="#Quoting-and-escaping">2.1 Quoting and escaping</a>
    34. 

  34.     <ul class="no-bullet">
    35. 

  35.       <li><a id="toc-Examples" href="#Examples">2.1.1 Examples</a></li>
    36. 

  36.     </ul></li>
    37. 

  37.     <li><a id="toc-Date" href="#Date">2.2 Date</a></li>
    38. 

  38.     <li><a id="toc-Time-duration" href="#Time-duration">2.3 Time duration</a>
    39. 

  39.     <ul class="no-bullet">
    40. 

  40.       <li><a id="toc-Examples-1" href="#Examples-1">2.3.1 Examples</a></li>
    41. 

  41.     </ul></li>
    42. 

  42.     <li><a id="toc-Video-size" href="#Video-size">2.4 Video size</a></li>
    43. 

  43.     <li><a id="toc-Video-rate" href="#Video-rate">2.5 Video rate</a></li>
    44. 

  44.     <li><a id="toc-Ratio" href="#Ratio">2.6 Ratio</a></li>
    45. 

  45.     <li><a id="toc-Color" href="#Color">2.7 Color</a></li>
    46. 

  46.     <li><a id="toc-Channel-Layout" href="#Channel-Layout">2.8 Channel Layout</a></li>
    47. 

  47.   </ul></li>
    48. 

  48.   <li><a id="toc-Expression-Evaluation" href="#Expression-Evaluation">3 Expression Evaluation</a></li>
    49. 

  49.   <li><a id="toc-See-Also" href="#See-Also">4 See Also</a></li>
    50. 

  50.   <li><a id="toc-Authors" href="#Authors">5 Authors</a></li>
    51. 

  51. </ul>
    52. 

  52. </div>
    53. 

  53. 

  54. 

  55. <a name="Description"></a>
    56. 

  56. <h2 class="chapter">1 Description<span class="pull-right"><a class="anchor hidden-xs" href="#Description" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Description" aria-hidden="true">TOC</a></span></h2>
    57. 

  57. 

  58. <p>This document describes some generic features and utilities provided
    59. 

  59. by the libavutil library.
    60. 

  60. </p>
    61. 

  61. 

  62. <a name="Syntax"></a>
    63. 

  63. <h2 class="chapter">2 Syntax<span class="pull-right"><a class="anchor hidden-xs" href="#Syntax" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Syntax" aria-hidden="true">TOC</a></span></h2>
    64. 

  64. 

  65. <p>This section documents the syntax and formats employed by the FFmpeg
    66. 

  66. libraries and tools.
    67. 

  67. </p>
    68. 

  68. <span id="quoting_005fand_005fescaping"></span><a name="Quoting-and-escaping"></a>
    69. 

  69. <h3 class="section">2.1 Quoting and escaping<span class="pull-right"><a class="anchor hidden-xs" href="#Quoting-and-escaping" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Quoting-and-escaping" aria-hidden="true">TOC</a></span></h3>
    70. 

  70. 

  71. <p>FFmpeg adopts the following quoting and escaping mechanism, unless
    72. 

  72. explicitly specified. The following rules are applied:
    73. 

  73. </p>
    74. 

  74. <ul>
    75. 

  75. <li> &lsquo;<samp>'</samp>&rsquo; and &lsquo;<samp>\</samp>&rsquo; are special characters (respectively used for
    76. 

  76. quoting and escaping). In addition to them, there might be other
    77. 

  77. special characters depending on the specific syntax where the escaping
    78. 

  78. and quoting are employed.
    79. 

  79. 

  80. </li><li> A special character is escaped by prefixing it with a &lsquo;<samp>\</samp>&rsquo;.
    81. 

  81. 

  82. </li><li> All characters enclosed between &lsquo;<samp>''</samp>&rsquo; are included literally in the
    83. 

  83. parsed string. The quote character &lsquo;<samp>'</samp>&rsquo; itself cannot be quoted,
    84. 

  84. so you may need to close the quote and escape it.
    85. 

  85. 

  86. </li><li> Leading and trailing whitespaces, unless escaped or quoted, are
    87. 

  87. removed from the parsed string.
    88. 

  88. </li></ul>
    89. 

  89. 

  90. <p>Note that you may need to add a second level of escaping when using
    91. 

  91. the command line or a script, which depends on the syntax of the
    92. 

  92. adopted shell language.
    93. 

  93. </p>
    94. 

  94. <p>The function <code>av_get_token</code> defined in
    95. 

  95. <samp>libavutil/avstring.h</samp> can be used to parse a token quoted or
    96. 

  96. escaped according to the rules defined above.
    97. 

  97. </p>
    98. 

  98. <p>The tool <samp>tools/ffescape</samp> in the FFmpeg source tree can be used
    99. 

  99. to automatically quote or escape a string in a script.
    100. 

  100. </p>
    101. 

  101. <a name="Examples"></a>
    102. 

  102. <h4 class="subsection">2.1.1 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples" aria-hidden="true">TOC</a></span></h4>
    103. 

  103. 

  104. <ul>
    105. 

  105. <li> Escape the string <code>Crime d'Amour</code> containing the <code>'</code> special
    106. 

  106. character:
    107. 

  107. <div class="example">
    108. 

  108. <pre class="example">Crime d\'Amour
    109. 

  109. </pre></div>
    110. 

  110. 

  111. </li><li> The string above contains a quote, so the <code>'</code> needs to be escaped
    112. 

  112. when quoting it:
    113. 

  113. <div class="example">
    114. 

  114. <pre class="example">'Crime d'\''Amour'
    115. 

  115. </pre></div>
    116. 

  116. 

  117. </li><li> Include leading or trailing whitespaces using quoting:
    118. 

  118. <div class="example">
    119. 

  119. <pre class="example">'  this string starts and ends with whitespaces  '
    120. 

  120. </pre></div>
    121. 

  121. 

  122. </li><li> Escaping and quoting can be mixed together:
    123. 

  123. <div class="example">
    124. 

  124. <pre class="example">' The string '\'string\'' is a string '
    125. 

  125. </pre></div>
    126. 

  126. 

  127. </li><li> To include a literal &lsquo;<samp>\</samp>&rsquo; you can use either escaping or quoting:
    128. 

  128. <div class="example">
    129. 

  129. <pre class="example">'c:\foo' can be written as c:\\foo
    130. 

  130. </pre></div>
    131. 

  131. </li></ul>
    132. 

  132. 

  133. <span id="date-syntax"></span><a name="Date"></a>
    134. 

  134. <h3 class="section">2.2 Date<span class="pull-right"><a class="anchor hidden-xs" href="#Date" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Date" aria-hidden="true">TOC</a></span></h3>
    135. 

  135. 

  136. <p>The accepted syntax is:
    137. 

  137. </p><div class="example">
    138. 

  138. <pre class="example">[(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...]]])|(HHMMSS[.m...]]]))[Z]
    139. 

  139. now
    140. 

  140. </pre></div>
    141. 

  141. 

  142. <p>If the value is &quot;now&quot; it takes the current time.
    143. 

  143. </p>
    144. 

  144. <p>Time is local time unless Z is appended, in which case it is
    145. 

  145. interpreted as UTC.
    146. 

  146. If the year-month-day part is not specified it takes the current
    147. 

  147. year-month-day.
    148. 

  148. </p>
    149. 

  149. <span id="time-duration-syntax"></span><a name="Time-duration"></a>
    150. 

  150. <h3 class="section">2.3 Time duration<span class="pull-right"><a class="anchor hidden-xs" href="#Time-duration" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Time-duration" aria-hidden="true">TOC</a></span></h3>
    151. 

  151. 

  152. <p>There are two accepted syntaxes for expressing time duration.
    153. 

  153. </p>
    154. 

  154. <div class="example">
    155. 

  155. <pre class="example">[-][<var>HH</var>:]<var>MM</var>:<var>SS</var>[.<var>m</var>...]
    156. 

  156. </pre></div>
    157. 

  157. 

  158. <p><var>HH</var> expresses the number of hours, <var>MM</var> the number of minutes
    159. 

  159. for a maximum of 2 digits, and <var>SS</var> the number of seconds for a
    160. 

  160. maximum of 2 digits. The <var>m</var> at the end expresses decimal value for
    161. 

  161. <var>SS</var>.
    162. 

  162. </p>
    163. 

  163. <p><em>or</em>
    164. 

  164. </p>
    165. 

  165. <div class="example">
    166. 

  166. <pre class="example">[-]<var>S</var>+[.<var>m</var>...][s|ms|us]
    167. 

  167. </pre></div>
    168. 

  168. 

  169. <p><var>S</var> expresses the number of seconds, with the optional decimal part
    170. 

  170. <var>m</var>.  The optional literal suffixes &lsquo;<samp>s</samp>&rsquo;, &lsquo;<samp>ms</samp>&rsquo; or &lsquo;<samp>us</samp>&rsquo;
    171. 

  171. indicate to interpret the value as seconds, milliseconds or microseconds,
    172. 

  172. respectively.
    173. 

  173. </p>
    174. 

  174. <p>In both expressions, the optional &lsquo;<samp>-</samp>&rsquo; indicates negative duration.
    175. 

  175. </p>
    176. 

  176. <a name="Examples-1"></a>
    177. 

  177. <h4 class="subsection">2.3.1 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-1" aria-hidden="true">TOC</a></span></h4>
    178. 

  178. 

  179. <p>The following examples are all valid time duration:
    180. 

  180. </p>
    181. 

  181. <dl compact="compact">
    182. 

  182. <dt>&lsquo;<samp>55</samp>&rsquo;</dt>
    183. 

  183. <dd><p>55 seconds
    184. 

  184. </p>
    185. 

  185. </dd>
    186. 

  186. <dt>&lsquo;<samp>0.2</samp>&rsquo;</dt>
    187. 

  187. <dd><p>0.2 seconds
    188. 

  188. </p>
    189. 

  189. </dd>
    190. 

  190. <dt>&lsquo;<samp>200ms</samp>&rsquo;</dt>
    191. 

  191. <dd><p>200 milliseconds, that&rsquo;s 0.2s
    192. 

  192. </p>
    193. 

  193. </dd>
    194. 

  194. <dt>&lsquo;<samp>200000us</samp>&rsquo;</dt>
    195. 

  195. <dd><p>200000 microseconds, that&rsquo;s 0.2s
    196. 

  196. </p>
    197. 

  197. </dd>
    198. 

  198. <dt>&lsquo;<samp>12:03:45</samp>&rsquo;</dt>
    199. 

  199. <dd><p>12 hours, 03 minutes and 45 seconds
    200. 

  200. </p>
    201. 

  201. </dd>
    202. 

  202. <dt>&lsquo;<samp>23.189</samp>&rsquo;</dt>
    203. 

  203. <dd><p>23.189 seconds
    204. 

  204. </p></dd>
    205. 

  205. </dl>
    206. 

  206. 

  207. <span id="video-size-syntax"></span><a name="Video-size"></a>
    208. 

  208. <h3 class="section">2.4 Video size<span class="pull-right"><a class="anchor hidden-xs" href="#Video-size" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Video-size" aria-hidden="true">TOC</a></span></h3>
    209. 

  209. <p>Specify the size of the sourced video, it may be a string of the form
    210. 

  210. <var>width</var>x<var>height</var>, or the name of a size abbreviation.
    211. 

  211. </p>
    212. 

  212. <p>The following abbreviations are recognized:
    213. 

  213. </p><dl compact="compact">
    214. 

  214. <dt>&lsquo;<samp>ntsc</samp>&rsquo;</dt>
    215. 

  215. <dd><p>720x480
    216. 

  216. </p></dd>
    217. 

  217. <dt>&lsquo;<samp>pal</samp>&rsquo;</dt>
    218. 

  218. <dd><p>720x576
    219. 

  219. </p></dd>
    220. 

  220. <dt>&lsquo;<samp>qntsc</samp>&rsquo;</dt>
    221. 

  221. <dd><p>352x240
    222. 

  222. </p></dd>
    223. 

  223. <dt>&lsquo;<samp>qpal</samp>&rsquo;</dt>
    224. 

  224. <dd><p>352x288
    225. 

  225. </p></dd>
    226. 

  226. <dt>&lsquo;<samp>sntsc</samp>&rsquo;</dt>
    227. 

  227. <dd><p>640x480
    228. 

  228. </p></dd>
    229. 

  229. <dt>&lsquo;<samp>spal</samp>&rsquo;</dt>
    230. 

  230. <dd><p>768x576
    231. 

  231. </p></dd>
    232. 

  232. <dt>&lsquo;<samp>film</samp>&rsquo;</dt>
    233. 

  233. <dd><p>352x240
    234. 

  234. </p></dd>
    235. 

  235. <dt>&lsquo;<samp>ntsc-film</samp>&rsquo;</dt>
    236. 

  236. <dd><p>352x240
    237. 

  237. </p></dd>
    238. 

  238. <dt>&lsquo;<samp>sqcif</samp>&rsquo;</dt>
    239. 

  239. <dd><p>128x96
    240. 

  240. </p></dd>
    241. 

  241. <dt>&lsquo;<samp>qcif</samp>&rsquo;</dt>
    242. 

  242. <dd><p>176x144
    243. 

  243. </p></dd>
    244. 

  244. <dt>&lsquo;<samp>cif</samp>&rsquo;</dt>
    245. 

  245. <dd><p>352x288
    246. 

  246. </p></dd>
    247. 

  247. <dt>&lsquo;<samp>4cif</samp>&rsquo;</dt>
    248. 

  248. <dd><p>704x576
    249. 

  249. </p></dd>
    250. 

  250. <dt>&lsquo;<samp>16cif</samp>&rsquo;</dt>
    251. 

  251. <dd><p>1408x1152
    252. 

  252. </p></dd>
    253. 

  253. <dt>&lsquo;<samp>qqvga</samp>&rsquo;</dt>
    254. 

  254. <dd><p>160x120
    255. 

  255. </p></dd>
    256. 

  256. <dt>&lsquo;<samp>qvga</samp>&rsquo;</dt>
    257. 

  257. <dd><p>320x240
    258. 

  258. </p></dd>
    259. 

  259. <dt>&lsquo;<samp>vga</samp>&rsquo;</dt>
    260. 

  260. <dd><p>640x480
    261. 

  261. </p></dd>
    262. 

  262. <dt>&lsquo;<samp>svga</samp>&rsquo;</dt>
    263. 

  263. <dd><p>800x600
    264. 

  264. </p></dd>
    265. 

  265. <dt>&lsquo;<samp>xga</samp>&rsquo;</dt>
    266. 

  266. <dd><p>1024x768
    267. 

  267. </p></dd>
    268. 

  268. <dt>&lsquo;<samp>uxga</samp>&rsquo;</dt>
    269. 

  269. <dd><p>1600x1200
    270. 

  270. </p></dd>
    271. 

  271. <dt>&lsquo;<samp>qxga</samp>&rsquo;</dt>
    272. 

  272. <dd><p>2048x1536
    273. 

  273. </p></dd>
    274. 

  274. <dt>&lsquo;<samp>sxga</samp>&rsquo;</dt>
    275. 

  275. <dd><p>1280x1024
    276. 

  276. </p></dd>
    277. 

  277. <dt>&lsquo;<samp>qsxga</samp>&rsquo;</dt>
    278. 

  278. <dd><p>2560x2048
    279. 

  279. </p></dd>
    280. 

  280. <dt>&lsquo;<samp>hsxga</samp>&rsquo;</dt>
    281. 

  281. <dd><p>5120x4096
    282. 

  282. </p></dd>
    283. 

  283. <dt>&lsquo;<samp>wvga</samp>&rsquo;</dt>
    284. 

  284. <dd><p>852x480
    285. 

  285. </p></dd>
    286. 

  286. <dt>&lsquo;<samp>wxga</samp>&rsquo;</dt>
    287. 

  287. <dd><p>1366x768
    288. 

  288. </p></dd>
    289. 

  289. <dt>&lsquo;<samp>wsxga</samp>&rsquo;</dt>
    290. 

  290. <dd><p>1600x1024
    291. 

  291. </p></dd>
    292. 

  292. <dt>&lsquo;<samp>wuxga</samp>&rsquo;</dt>
    293. 

  293. <dd><p>1920x1200
    294. 

  294. </p></dd>
    295. 

  295. <dt>&lsquo;<samp>woxga</samp>&rsquo;</dt>
    296. 

  296. <dd><p>2560x1600
    297. 

  297. </p></dd>
    298. 

  298. <dt>&lsquo;<samp>wqsxga</samp>&rsquo;</dt>
    299. 

  299. <dd><p>3200x2048
    300. 

  300. </p></dd>
    301. 

  301. <dt>&lsquo;<samp>wquxga</samp>&rsquo;</dt>
    302. 

  302. <dd><p>3840x2400
    303. 

  303. </p></dd>
    304. 

  304. <dt>&lsquo;<samp>whsxga</samp>&rsquo;</dt>
    305. 

  305. <dd><p>6400x4096
    306. 

  306. </p></dd>
    307. 

  307. <dt>&lsquo;<samp>whuxga</samp>&rsquo;</dt>
    308. 

  308. <dd><p>7680x4800
    309. 

  309. </p></dd>
    310. 

  310. <dt>&lsquo;<samp>cga</samp>&rsquo;</dt>
    311. 

  311. <dd><p>320x200
    312. 

  312. </p></dd>
    313. 

  313. <dt>&lsquo;<samp>ega</samp>&rsquo;</dt>
    314. 

  314. <dd><p>640x350
    315. 

  315. </p></dd>
    316. 

  316. <dt>&lsquo;<samp>hd480</samp>&rsquo;</dt>
    317. 

  317. <dd><p>852x480
    318. 

  318. </p></dd>
    319. 

  319. <dt>&lsquo;<samp>hd720</samp>&rsquo;</dt>
    320. 

  320. <dd><p>1280x720
    321. 

  321. </p></dd>
    322. 

  322. <dt>&lsquo;<samp>hd1080</samp>&rsquo;</dt>
    323. 

  323. <dd><p>1920x1080
    324. 

  324. </p></dd>
    325. 

  325. <dt>&lsquo;<samp>2k</samp>&rsquo;</dt>
    326. 

  326. <dd><p>2048x1080
    327. 

  327. </p></dd>
    328. 

  328. <dt>&lsquo;<samp>2kflat</samp>&rsquo;</dt>
    329. 

  329. <dd><p>1998x1080
    330. 

  330. </p></dd>
    331. 

  331. <dt>&lsquo;<samp>2kscope</samp>&rsquo;</dt>
    332. 

  332. <dd><p>2048x858
    333. 

  333. </p></dd>
    334. 

  334. <dt>&lsquo;<samp>4k</samp>&rsquo;</dt>
    335. 

  335. <dd><p>4096x2160
    336. 

  336. </p></dd>
    337. 

  337. <dt>&lsquo;<samp>4kflat</samp>&rsquo;</dt>
    338. 

  338. <dd><p>3996x2160
    339. 

  339. </p></dd>
    340. 

  340. <dt>&lsquo;<samp>4kscope</samp>&rsquo;</dt>
    341. 

  341. <dd><p>4096x1716
    342. 

  342. </p></dd>
    343. 

  343. <dt>&lsquo;<samp>nhd</samp>&rsquo;</dt>
    344. 

  344. <dd><p>640x360
    345. 

  345. </p></dd>
    346. 

  346. <dt>&lsquo;<samp>hqvga</samp>&rsquo;</dt>
    347. 

  347. <dd><p>240x160
    348. 

  348. </p></dd>
    349. 

  349. <dt>&lsquo;<samp>wqvga</samp>&rsquo;</dt>
    350. 

  350. <dd><p>400x240
    351. 

  351. </p></dd>
    352. 

  352. <dt>&lsquo;<samp>fwqvga</samp>&rsquo;</dt>
    353. 

  353. <dd><p>432x240
    354. 

  354. </p></dd>
    355. 

  355. <dt>&lsquo;<samp>hvga</samp>&rsquo;</dt>
    356. 

  356. <dd><p>480x320
    357. 

  357. </p></dd>
    358. 

  358. <dt>&lsquo;<samp>qhd</samp>&rsquo;</dt>
    359. 

  359. <dd><p>960x540
    360. 

  360. </p></dd>
    361. 

  361. <dt>&lsquo;<samp>2kdci</samp>&rsquo;</dt>
    362. 

  362. <dd><p>2048x1080
    363. 

  363. </p></dd>
    364. 

  364. <dt>&lsquo;<samp>4kdci</samp>&rsquo;</dt>
    365. 

  365. <dd><p>4096x2160
    366. 

  366. </p></dd>
    367. 

  367. <dt>&lsquo;<samp>uhd2160</samp>&rsquo;</dt>
    368. 

  368. <dd><p>3840x2160
    369. 

  369. </p></dd>
    370. 

  370. <dt>&lsquo;<samp>uhd4320</samp>&rsquo;</dt>
    371. 

  371. <dd><p>7680x4320
    372. 

  372. </p></dd>
    373. 

  373. </dl>
    374. 

  374. 

  375. <span id="video-rate-syntax"></span><a name="Video-rate"></a>
    376. 

  376. <h3 class="section">2.5 Video rate<span class="pull-right"><a class="anchor hidden-xs" href="#Video-rate" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Video-rate" aria-hidden="true">TOC</a></span></h3>
    377. 

  377. 

  378. <p>Specify the frame rate of a video, expressed as the number of frames
    379. 

  379. generated per second. It has to be a string in the format
    380. 

  380. <var>frame_rate_num</var>/<var>frame_rate_den</var>, an integer number, a float
    381. 

  381. number or a valid video frame rate abbreviation.
    382. 

  382. </p>
    383. 

  383. <p>The following abbreviations are recognized:
    384. 

  384. </p><dl compact="compact">
    385. 

  385. <dt>&lsquo;<samp>ntsc</samp>&rsquo;</dt>
    386. 

  386. <dd><p>30000/1001
    387. 

  387. </p></dd>
    388. 

  388. <dt>&lsquo;<samp>pal</samp>&rsquo;</dt>
    389. 

  389. <dd><p>25/1
    390. 

  390. </p></dd>
    391. 

  391. <dt>&lsquo;<samp>qntsc</samp>&rsquo;</dt>
    392. 

  392. <dd><p>30000/1001
    393. 

  393. </p></dd>
    394. 

  394. <dt>&lsquo;<samp>qpal</samp>&rsquo;</dt>
    395. 

  395. <dd><p>25/1
    396. 

  396. </p></dd>
    397. 

  397. <dt>&lsquo;<samp>sntsc</samp>&rsquo;</dt>
    398. 

  398. <dd><p>30000/1001
    399. 

  399. </p></dd>
    400. 

  400. <dt>&lsquo;<samp>spal</samp>&rsquo;</dt>
    401. 

  401. <dd><p>25/1
    402. 

  402. </p></dd>
    403. 

  403. <dt>&lsquo;<samp>film</samp>&rsquo;</dt>
    404. 

  404. <dd><p>24/1
    405. 

  405. </p></dd>
    406. 

  406. <dt>&lsquo;<samp>ntsc-film</samp>&rsquo;</dt>
    407. 

  407. <dd><p>24000/1001
    408. 

  408. </p></dd>
    409. 

  409. </dl>
    410. 

  410. 

  411. <span id="ratio-syntax"></span><a name="Ratio"></a>
    412. 

  412. <h3 class="section">2.6 Ratio<span class="pull-right"><a class="anchor hidden-xs" href="#Ratio" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Ratio" aria-hidden="true">TOC</a></span></h3>
    413. 

  413. 

  414. <p>A ratio can be expressed as an expression, or in the form
    415. 

  415. <var>numerator</var>:<var>denominator</var>.
    416. 

  416. </p>
    417. 

  417. <p>Note that a ratio with infinite (1/0) or negative value is
    418. 

  418. considered valid, so you should check on the returned value if you
    419. 

  419. want to exclude those values.
    420. 

  420. </p>
    421. 

  421. <p>The undefined value can be expressed using the &quot;0:0&quot; string.
    422. 

  422. </p>
    423. 

  423. <span id="color-syntax"></span><a name="Color"></a>
    424. 

  424. <h3 class="section">2.7 Color<span class="pull-right"><a class="anchor hidden-xs" href="#Color" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Color" aria-hidden="true">TOC</a></span></h3>
    425. 

  425. 

  426. <p>It can be the name of a color as defined below (case insensitive match) or a
    427. 

  427. <code>[0x|#]RRGGBB[AA]</code> sequence, possibly followed by @ and a string
    428. 

  428. representing the alpha component.
    429. 

  429. </p>
    430. 

  430. <p>The alpha component may be a string composed by &quot;0x&quot; followed by an
    431. 

  431. hexadecimal number or a decimal number between 0.0 and 1.0, which
    432. 

  432. represents the opacity value (&lsquo;<samp>0x00</samp>&rsquo; or &lsquo;<samp>0.0</samp>&rsquo; means completely
    433. 

  433. transparent, &lsquo;<samp>0xff</samp>&rsquo; or &lsquo;<samp>1.0</samp>&rsquo; completely opaque). If the alpha
    434. 

  434. component is not specified then &lsquo;<samp>0xff</samp>&rsquo; is assumed.
    435. 

  435. </p>
    436. 

  436. <p>The string &lsquo;<samp>random</samp>&rsquo; will result in a random color.
    437. 

  437. </p>
    438. 

  438. <p>The following names of colors are recognized:
    439. 

  439. </p><dl compact="compact">
    440. 

  440. <dt>&lsquo;<samp>AliceBlue</samp>&rsquo;</dt>
    441. 

  441. <dd><p>0xF0F8FF
    442. 

  442. </p></dd>
    443. 

  443. <dt>&lsquo;<samp>AntiqueWhite</samp>&rsquo;</dt>
    444. 

  444. <dd><p>0xFAEBD7
    445. 

  445. </p></dd>
    446. 

  446. <dt>&lsquo;<samp>Aqua</samp>&rsquo;</dt>
    447. 

  447. <dd><p>0x00FFFF
    448. 

  448. </p></dd>
    449. 

  449. <dt>&lsquo;<samp>Aquamarine</samp>&rsquo;</dt>
    450. 

  450. <dd><p>0x7FFFD4
    451. 

  451. </p></dd>
    452. 

  452. <dt>&lsquo;<samp>Azure</samp>&rsquo;</dt>
    453. 

  453. <dd><p>0xF0FFFF
    454. 

  454. </p></dd>
    455. 

  455. <dt>&lsquo;<samp>Beige</samp>&rsquo;</dt>
    456. 

  456. <dd><p>0xF5F5DC
    457. 

  457. </p></dd>
    458. 

  458. <dt>&lsquo;<samp>Bisque</samp>&rsquo;</dt>
    459. 

  459. <dd><p>0xFFE4C4
    460. 

  460. </p></dd>
    461. 

  461. <dt>&lsquo;<samp>Black</samp>&rsquo;</dt>
    462. 

  462. <dd><p>0x000000
    463. 

  463. </p></dd>
    464. 

  464. <dt>&lsquo;<samp>BlanchedAlmond</samp>&rsquo;</dt>
    465. 

  465. <dd><p>0xFFEBCD
    466. 

  466. </p></dd>
    467. 

  467. <dt>&lsquo;<samp>Blue</samp>&rsquo;</dt>
    468. 

  468. <dd><p>0x0000FF
    469. 

  469. </p></dd>
    470. 

  470. <dt>&lsquo;<samp>BlueViolet</samp>&rsquo;</dt>
    471. 

  471. <dd><p>0x8A2BE2
    472. 

  472. </p></dd>
    473. 

  473. <dt>&lsquo;<samp>Brown</samp>&rsquo;</dt>
    474. 

  474. <dd><p>0xA52A2A
    475. 

  475. </p></dd>
    476. 

  476. <dt>&lsquo;<samp>BurlyWood</samp>&rsquo;</dt>
    477. 

  477. <dd><p>0xDEB887
    478. 

  478. </p></dd>
    479. 

  479. <dt>&lsquo;<samp>CadetBlue</samp>&rsquo;</dt>
    480. 

  480. <dd><p>0x5F9EA0
    481. 

  481. </p></dd>
    482. 

  482. <dt>&lsquo;<samp>Chartreuse</samp>&rsquo;</dt>
    483. 

  483. <dd><p>0x7FFF00
    484. 

  484. </p></dd>
    485. 

  485. <dt>&lsquo;<samp>Chocolate</samp>&rsquo;</dt>
    486. 

  486. <dd><p>0xD2691E
    487. 

  487. </p></dd>
    488. 

  488. <dt>&lsquo;<samp>Coral</samp>&rsquo;</dt>
    489. 

  489. <dd><p>0xFF7F50
    490. 

  490. </p></dd>
    491. 

  491. <dt>&lsquo;<samp>CornflowerBlue</samp>&rsquo;</dt>
    492. 

  492. <dd><p>0x6495ED
    493. 

  493. </p></dd>
    494. 

  494. <dt>&lsquo;<samp>Cornsilk</samp>&rsquo;</dt>
    495. 

  495. <dd><p>0xFFF8DC
    496. 

  496. </p></dd>
    497. 

  497. <dt>&lsquo;<samp>Crimson</samp>&rsquo;</dt>
    498. 

  498. <dd><p>0xDC143C
    499. 

  499. </p></dd>
    500. 

  500. <dt>&lsquo;<samp>Cyan</samp>&rsquo;</dt>
    501. 

  501. <dd><p>0x00FFFF
    502. 

  502. </p></dd>
    503. 

  503. <dt>&lsquo;<samp>DarkBlue</samp>&rsquo;</dt>
    504. 

  504. <dd><p>0x00008B
    505. 

  505. </p></dd>
    506. 

  506. <dt>&lsquo;<samp>DarkCyan</samp>&rsquo;</dt>
    507. 

  507. <dd><p>0x008B8B
    508. 

  508. </p></dd>
    509. 

  509. <dt>&lsquo;<samp>DarkGoldenRod</samp>&rsquo;</dt>
    510. 

  510. <dd><p>0xB8860B
    511. 

  511. </p></dd>
    512. 

  512. <dt>&lsquo;<samp>DarkGray</samp>&rsquo;</dt>
    513. 

  513. <dd><p>0xA9A9A9
    514. 

  514. </p></dd>
    515. 

  515. <dt>&lsquo;<samp>DarkGreen</samp>&rsquo;</dt>
    516. 

  516. <dd><p>0x006400
    517. 

  517. </p></dd>
    518. 

  518. <dt>&lsquo;<samp>DarkKhaki</samp>&rsquo;</dt>
    519. 

  519. <dd><p>0xBDB76B
    520. 

  520. </p></dd>
    521. 

  521. <dt>&lsquo;<samp>DarkMagenta</samp>&rsquo;</dt>
    522. 

  522. <dd><p>0x8B008B
    523. 

  523. </p></dd>
    524. 

  524. <dt>&lsquo;<samp>DarkOliveGreen</samp>&rsquo;</dt>
    525. 

  525. <dd><p>0x556B2F
    526. 

  526. </p></dd>
    527. 

  527. <dt>&lsquo;<samp>Darkorange</samp>&rsquo;</dt>
    528. 

  528. <dd><p>0xFF8C00
    529. 

  529. </p></dd>
    530. 

  530. <dt>&lsquo;<samp>DarkOrchid</samp>&rsquo;</dt>
    531. 

  531. <dd><p>0x9932CC
    532. 

  532. </p></dd>
    533. 

  533. <dt>&lsquo;<samp>DarkRed</samp>&rsquo;</dt>
    534. 

  534. <dd><p>0x8B0000
    535. 

  535. </p></dd>
    536. 

  536. <dt>&lsquo;<samp>DarkSalmon</samp>&rsquo;</dt>
    537. 

  537. <dd><p>0xE9967A
    538. 

  538. </p></dd>
    539. 

  539. <dt>&lsquo;<samp>DarkSeaGreen</samp>&rsquo;</dt>
    540. 

  540. <dd><p>0x8FBC8F
    541. 

  541. </p></dd>
    542. 

  542. <dt>&lsquo;<samp>DarkSlateBlue</samp>&rsquo;</dt>
    543. 

  543. <dd><p>0x483D8B
    544. 

  544. </p></dd>
    545. 

  545. <dt>&lsquo;<samp>DarkSlateGray</samp>&rsquo;</dt>
    546. 

  546. <dd><p>0x2F4F4F
    547. 

  547. </p></dd>
    548. 

  548. <dt>&lsquo;<samp>DarkTurquoise</samp>&rsquo;</dt>
    549. 

  549. <dd><p>0x00CED1
    550. 

  550. </p></dd>
    551. 

  551. <dt>&lsquo;<samp>DarkViolet</samp>&rsquo;</dt>
    552. 

  552. <dd><p>0x9400D3
    553. 

  553. </p></dd>
    554. 

  554. <dt>&lsquo;<samp>DeepPink</samp>&rsquo;</dt>
    555. 

  555. <dd><p>0xFF1493
    556. 

  556. </p></dd>
    557. 

  557. <dt>&lsquo;<samp>DeepSkyBlue</samp>&rsquo;</dt>
    558. 

  558. <dd><p>0x00BFFF
    559. 

  559. </p></dd>
    560. 

  560. <dt>&lsquo;<samp>DimGray</samp>&rsquo;</dt>
    561. 

  561. <dd><p>0x696969
    562. 

  562. </p></dd>
    563. 

  563. <dt>&lsquo;<samp>DodgerBlue</samp>&rsquo;</dt>
    564. 

  564. <dd><p>0x1E90FF
    565. 

  565. </p></dd>
    566. 

  566. <dt>&lsquo;<samp>FireBrick</samp>&rsquo;</dt>
    567. 

  567. <dd><p>0xB22222
    568. 

  568. </p></dd>
    569. 

  569. <dt>&lsquo;<samp>FloralWhite</samp>&rsquo;</dt>
    570. 

  570. <dd><p>0xFFFAF0
    571. 

  571. </p></dd>
    572. 

  572. <dt>&lsquo;<samp>ForestGreen</samp>&rsquo;</dt>
    573. 

  573. <dd><p>0x228B22
    574. 

  574. </p></dd>
    575. 

  575. <dt>&lsquo;<samp>Fuchsia</samp>&rsquo;</dt>
    576. 

  576. <dd><p>0xFF00FF
    577. 

  577. </p></dd>
    578. 

  578. <dt>&lsquo;<samp>Gainsboro</samp>&rsquo;</dt>
    579. 

  579. <dd><p>0xDCDCDC
    580. 

  580. </p></dd>
    581. 

  581. <dt>&lsquo;<samp>GhostWhite</samp>&rsquo;</dt>
    582. 

  582. <dd><p>0xF8F8FF
    583. 

  583. </p></dd>
    584. 

  584. <dt>&lsquo;<samp>Gold</samp>&rsquo;</dt>
    585. 

  585. <dd><p>0xFFD700
    586. 

  586. </p></dd>
    587. 

  587. <dt>&lsquo;<samp>GoldenRod</samp>&rsquo;</dt>
    588. 

  588. <dd><p>0xDAA520
    589. 

  589. </p></dd>
    590. 

  590. <dt>&lsquo;<samp>Gray</samp>&rsquo;</dt>
    591. 

  591. <dd><p>0x808080
    592. 

  592. </p></dd>
    593. 

  593. <dt>&lsquo;<samp>Green</samp>&rsquo;</dt>
    594. 

  594. <dd><p>0x008000
    595. 

  595. </p></dd>
    596. 

  596. <dt>&lsquo;<samp>GreenYellow</samp>&rsquo;</dt>
    597. 

  597. <dd><p>0xADFF2F
    598. 

  598. </p></dd>
    599. 

  599. <dt>&lsquo;<samp>HoneyDew</samp>&rsquo;</dt>
    600. 

  600. <dd><p>0xF0FFF0
    601. 

  601. </p></dd>
    602. 

  602. <dt>&lsquo;<samp>HotPink</samp>&rsquo;</dt>
    603. 

  603. <dd><p>0xFF69B4
    604. 

  604. </p></dd>
    605. 

  605. <dt>&lsquo;<samp>IndianRed</samp>&rsquo;</dt>
    606. 

  606. <dd><p>0xCD5C5C
    607. 

  607. </p></dd>
    608. 

  608. <dt>&lsquo;<samp>Indigo</samp>&rsquo;</dt>
    609. 

  609. <dd><p>0x4B0082
    610. 

  610. </p></dd>
    611. 

  611. <dt>&lsquo;<samp>Ivory</samp>&rsquo;</dt>
    612. 

  612. <dd><p>0xFFFFF0
    613. 

  613. </p></dd>
    614. 

  614. <dt>&lsquo;<samp>Khaki</samp>&rsquo;</dt>
    615. 

  615. <dd><p>0xF0E68C
    616. 

  616. </p></dd>
    617. 

  617. <dt>&lsquo;<samp>Lavender</samp>&rsquo;</dt>
    618. 

  618. <dd><p>0xE6E6FA
    619. 

  619. </p></dd>
    620. 

  620. <dt>&lsquo;<samp>LavenderBlush</samp>&rsquo;</dt>
    621. 

  621. <dd><p>0xFFF0F5
    622. 

  622. </p></dd>
    623. 

  623. <dt>&lsquo;<samp>LawnGreen</samp>&rsquo;</dt>
    624. 

  624. <dd><p>0x7CFC00
    625. 

  625. </p></dd>
    626. 

  626. <dt>&lsquo;<samp>LemonChiffon</samp>&rsquo;</dt>
    627. 

  627. <dd><p>0xFFFACD
    628. 

  628. </p></dd>
    629. 

  629. <dt>&lsquo;<samp>LightBlue</samp>&rsquo;</dt>
    630. 

  630. <dd><p>0xADD8E6
    631. 

  631. </p></dd>
    632. 

  632. <dt>&lsquo;<samp>LightCoral</samp>&rsquo;</dt>
    633. 

  633. <dd><p>0xF08080
    634. 

  634. </p></dd>
    635. 

  635. <dt>&lsquo;<samp>LightCyan</samp>&rsquo;</dt>
    636. 

  636. <dd><p>0xE0FFFF
    637. 

  637. </p></dd>
    638. 

  638. <dt>&lsquo;<samp>LightGoldenRodYellow</samp>&rsquo;</dt>
    639. 

  639. <dd><p>0xFAFAD2
    640. 

  640. </p></dd>
    641. 

  641. <dt>&lsquo;<samp>LightGreen</samp>&rsquo;</dt>
    642. 

  642. <dd><p>0x90EE90
    643. 

  643. </p></dd>
    644. 

  644. <dt>&lsquo;<samp>LightGrey</samp>&rsquo;</dt>
    645. 

  645. <dd><p>0xD3D3D3
    646. 

  646. </p></dd>
    647. 

  647. <dt>&lsquo;<samp>LightPink</samp>&rsquo;</dt>
    648. 

  648. <dd><p>0xFFB6C1
    649. 

  649. </p></dd>
    650. 

  650. <dt>&lsquo;<samp>LightSalmon</samp>&rsquo;</dt>
    651. 

  651. <dd><p>0xFFA07A
    652. 

  652. </p></dd>
    653. 

  653. <dt>&lsquo;<samp>LightSeaGreen</samp>&rsquo;</dt>
    654. 

  654. <dd><p>0x20B2AA
    655. 

  655. </p></dd>
    656. 

  656. <dt>&lsquo;<samp>LightSkyBlue</samp>&rsquo;</dt>
    657. 

  657. <dd><p>0x87CEFA
    658. 

  658. </p></dd>
    659. 

  659. <dt>&lsquo;<samp>LightSlateGray</samp>&rsquo;</dt>
    660. 

  660. <dd><p>0x778899
    661. 

  661. </p></dd>
    662. 

  662. <dt>&lsquo;<samp>LightSteelBlue</samp>&rsquo;</dt>
    663. 

  663. <dd><p>0xB0C4DE
    664. 

  664. </p></dd>
    665. 

  665. <dt>&lsquo;<samp>LightYellow</samp>&rsquo;</dt>
    666. 

  666. <dd><p>0xFFFFE0
    667. 

  667. </p></dd>
    668. 

  668. <dt>&lsquo;<samp>Lime</samp>&rsquo;</dt>
    669. 

  669. <dd><p>0x00FF00
    670. 

  670. </p></dd>
    671. 

  671. <dt>&lsquo;<samp>LimeGreen</samp>&rsquo;</dt>
    672. 

  672. <dd><p>0x32CD32
    673. 

  673. </p></dd>
    674. 

  674. <dt>&lsquo;<samp>Linen</samp>&rsquo;</dt>
    675. 

  675. <dd><p>0xFAF0E6
    676. 

  676. </p></dd>
    677. 

  677. <dt>&lsquo;<samp>Magenta</samp>&rsquo;</dt>
    678. 

  678. <dd><p>0xFF00FF
    679. 

  679. </p></dd>
    680. 

  680. <dt>&lsquo;<samp>Maroon</samp>&rsquo;</dt>
    681. 

  681. <dd><p>0x800000
    682. 

  682. </p></dd>
    683. 

  683. <dt>&lsquo;<samp>MediumAquaMarine</samp>&rsquo;</dt>
    684. 

  684. <dd><p>0x66CDAA
    685. 

  685. </p></dd>
    686. 

  686. <dt>&lsquo;<samp>MediumBlue</samp>&rsquo;</dt>
    687. 

  687. <dd><p>0x0000CD
    688. 

  688. </p></dd>
    689. 

  689. <dt>&lsquo;<samp>MediumOrchid</samp>&rsquo;</dt>
    690. 

  690. <dd><p>0xBA55D3
    691. 

  691. </p></dd>
    692. 

  692. <dt>&lsquo;<samp>MediumPurple</samp>&rsquo;</dt>
    693. 

  693. <dd><p>0x9370D8
    694. 

  694. </p></dd>
    695. 

  695. <dt>&lsquo;<samp>MediumSeaGreen</samp>&rsquo;</dt>
    696. 

  696. <dd><p>0x3CB371
    697. 

  697. </p></dd>
    698. 

  698. <dt>&lsquo;<samp>MediumSlateBlue</samp>&rsquo;</dt>
    699. 

  699. <dd><p>0x7B68EE
    700. 

  700. </p></dd>
    701. 

  701. <dt>&lsquo;<samp>MediumSpringGreen</samp>&rsquo;</dt>
    702. 

  702. <dd><p>0x00FA9A
    703. 

  703. </p></dd>
    704. 

  704. <dt>&lsquo;<samp>MediumTurquoise</samp>&rsquo;</dt>
    705. 

  705. <dd><p>0x48D1CC
    706. 

  706. </p></dd>
    707. 

  707. <dt>&lsquo;<samp>MediumVioletRed</samp>&rsquo;</dt>
    708. 

  708. <dd><p>0xC71585
    709. 

  709. </p></dd>
    710. 

  710. <dt>&lsquo;<samp>MidnightBlue</samp>&rsquo;</dt>
    711. 

  711. <dd><p>0x191970
    712. 

  712. </p></dd>
    713. 

  713. <dt>&lsquo;<samp>MintCream</samp>&rsquo;</dt>
    714. 

  714. <dd><p>0xF5FFFA
    715. 

  715. </p></dd>
    716. 

  716. <dt>&lsquo;<samp>MistyRose</samp>&rsquo;</dt>
    717. 

  717. <dd><p>0xFFE4E1
    718. 

  718. </p></dd>
    719. 

  719. <dt>&lsquo;<samp>Moccasin</samp>&rsquo;</dt>
    720. 

  720. <dd><p>0xFFE4B5
    721. 

  721. </p></dd>
    722. 

  722. <dt>&lsquo;<samp>NavajoWhite</samp>&rsquo;</dt>
    723. 

  723. <dd><p>0xFFDEAD
    724. 

  724. </p></dd>
    725. 

  725. <dt>&lsquo;<samp>Navy</samp>&rsquo;</dt>
    726. 

  726. <dd><p>0x000080
    727. 

  727. </p></dd>
    728. 

  728. <dt>&lsquo;<samp>OldLace</samp>&rsquo;</dt>
    729. 

  729. <dd><p>0xFDF5E6
    730. 

  730. </p></dd>
    731. 

  731. <dt>&lsquo;<samp>Olive</samp>&rsquo;</dt>
    732. 

  732. <dd><p>0x808000
    733. 

  733. </p></dd>
    734. 

  734. <dt>&lsquo;<samp>OliveDrab</samp>&rsquo;</dt>
    735. 

  735. <dd><p>0x6B8E23
    736. 

  736. </p></dd>
    737. 

  737. <dt>&lsquo;<samp>Orange</samp>&rsquo;</dt>
    738. 

  738. <dd><p>0xFFA500
    739. 

  739. </p></dd>
    740. 

  740. <dt>&lsquo;<samp>OrangeRed</samp>&rsquo;</dt>
    741. 

  741. <dd><p>0xFF4500
    742. 

  742. </p></dd>
    743. 

  743. <dt>&lsquo;<samp>Orchid</samp>&rsquo;</dt>
    744. 

  744. <dd><p>0xDA70D6
    745. 

  745. </p></dd>
    746. 

  746. <dt>&lsquo;<samp>PaleGoldenRod</samp>&rsquo;</dt>
    747. 

  747. <dd><p>0xEEE8AA
    748. 

  748. </p></dd>
    749. 

  749. <dt>&lsquo;<samp>PaleGreen</samp>&rsquo;</dt>
    750. 

  750. <dd><p>0x98FB98
    751. 

  751. </p></dd>
    752. 

  752. <dt>&lsquo;<samp>PaleTurquoise</samp>&rsquo;</dt>
    753. 

  753. <dd><p>0xAFEEEE
    754. 

  754. </p></dd>
    755. 

  755. <dt>&lsquo;<samp>PaleVioletRed</samp>&rsquo;</dt>
    756. 

  756. <dd><p>0xD87093
    757. 

  757. </p></dd>
    758. 

  758. <dt>&lsquo;<samp>PapayaWhip</samp>&rsquo;</dt>
    759. 

  759. <dd><p>0xFFEFD5
    760. 

  760. </p></dd>
    761. 

  761. <dt>&lsquo;<samp>PeachPuff</samp>&rsquo;</dt>
    762. 

  762. <dd><p>0xFFDAB9
    763. 

  763. </p></dd>
    764. 

  764. <dt>&lsquo;<samp>Peru</samp>&rsquo;</dt>
    765. 

  765. <dd><p>0xCD853F
    766. 

  766. </p></dd>
    767. 

  767. <dt>&lsquo;<samp>Pink</samp>&rsquo;</dt>
    768. 

  768. <dd><p>0xFFC0CB
    769. 

  769. </p></dd>
    770. 

  770. <dt>&lsquo;<samp>Plum</samp>&rsquo;</dt>
    771. 

  771. <dd><p>0xDDA0DD
    772. 

  772. </p></dd>
    773. 

  773. <dt>&lsquo;<samp>PowderBlue</samp>&rsquo;</dt>
    774. 

  774. <dd><p>0xB0E0E6
    775. 

  775. </p></dd>
    776. 

  776. <dt>&lsquo;<samp>Purple</samp>&rsquo;</dt>
    777. 

  777. <dd><p>0x800080
    778. 

  778. </p></dd>
    779. 

  779. <dt>&lsquo;<samp>Red</samp>&rsquo;</dt>
    780. 

  780. <dd><p>0xFF0000
    781. 

  781. </p></dd>
    782. 

  782. <dt>&lsquo;<samp>RosyBrown</samp>&rsquo;</dt>
    783. 

  783. <dd><p>0xBC8F8F
    784. 

  784. </p></dd>
    785. 

  785. <dt>&lsquo;<samp>RoyalBlue</samp>&rsquo;</dt>
    786. 

  786. <dd><p>0x4169E1
    787. 

  787. </p></dd>
    788. 

  788. <dt>&lsquo;<samp>SaddleBrown</samp>&rsquo;</dt>
    789. 

  789. <dd><p>0x8B4513
    790. 

  790. </p></dd>
    791. 

  791. <dt>&lsquo;<samp>Salmon</samp>&rsquo;</dt>
    792. 

  792. <dd><p>0xFA8072
    793. 

  793. </p></dd>
    794. 

  794. <dt>&lsquo;<samp>SandyBrown</samp>&rsquo;</dt>
    795. 

  795. <dd><p>0xF4A460
    796. 

  796. </p></dd>
    797. 

  797. <dt>&lsquo;<samp>SeaGreen</samp>&rsquo;</dt>
    798. 

  798. <dd><p>0x2E8B57
    799. 

  799. </p></dd>
    800. 

  800. <dt>&lsquo;<samp>SeaShell</samp>&rsquo;</dt>
    801. 

  801. <dd><p>0xFFF5EE
    802. 

  802. </p></dd>
    803. 

  803. <dt>&lsquo;<samp>Sienna</samp>&rsquo;</dt>
    804. 

  804. <dd><p>0xA0522D
    805. 

  805. </p></dd>
    806. 

  806. <dt>&lsquo;<samp>Silver</samp>&rsquo;</dt>
    807. 

  807. <dd><p>0xC0C0C0
    808. 

  808. </p></dd>
    809. 

  809. <dt>&lsquo;<samp>SkyBlue</samp>&rsquo;</dt>
    810. 

  810. <dd><p>0x87CEEB
    811. 

  811. </p></dd>
    812. 

  812. <dt>&lsquo;<samp>SlateBlue</samp>&rsquo;</dt>
    813. 

  813. <dd><p>0x6A5ACD
    814. 

  814. </p></dd>
    815. 

  815. <dt>&lsquo;<samp>SlateGray</samp>&rsquo;</dt>
    816. 

  816. <dd><p>0x708090
    817. 

  817. </p></dd>
    818. 

  818. <dt>&lsquo;<samp>Snow</samp>&rsquo;</dt>
    819. 

  819. <dd><p>0xFFFAFA
    820. 

  820. </p></dd>
    821. 

  821. <dt>&lsquo;<samp>SpringGreen</samp>&rsquo;</dt>
    822. 

  822. <dd><p>0x00FF7F
    823. 

  823. </p></dd>
    824. 

  824. <dt>&lsquo;<samp>SteelBlue</samp>&rsquo;</dt>
    825. 

  825. <dd><p>0x4682B4
    826. 

  826. </p></dd>
    827. 

  827. <dt>&lsquo;<samp>Tan</samp>&rsquo;</dt>
    828. 

  828. <dd><p>0xD2B48C
    829. 

  829. </p></dd>
    830. 

  830. <dt>&lsquo;<samp>Teal</samp>&rsquo;</dt>
    831. 

  831. <dd><p>0x008080
    832. 

  832. </p></dd>
    833. 

  833. <dt>&lsquo;<samp>Thistle</samp>&rsquo;</dt>
    834. 

  834. <dd><p>0xD8BFD8
    835. 

  835. </p></dd>
    836. 

  836. <dt>&lsquo;<samp>Tomato</samp>&rsquo;</dt>
    837. 

  837. <dd><p>0xFF6347
    838. 

  838. </p></dd>
    839. 

  839. <dt>&lsquo;<samp>Turquoise</samp>&rsquo;</dt>
    840. 

  840. <dd><p>0x40E0D0
    841. 

  841. </p></dd>
    842. 

  842. <dt>&lsquo;<samp>Violet</samp>&rsquo;</dt>
    843. 

  843. <dd><p>0xEE82EE
    844. 

  844. </p></dd>
    845. 

  845. <dt>&lsquo;<samp>Wheat</samp>&rsquo;</dt>
    846. 

  846. <dd><p>0xF5DEB3
    847. 

  847. </p></dd>
    848. 

  848. <dt>&lsquo;<samp>White</samp>&rsquo;</dt>
    849. 

  849. <dd><p>0xFFFFFF
    850. 

  850. </p></dd>
    851. 

  851. <dt>&lsquo;<samp>WhiteSmoke</samp>&rsquo;</dt>
    852. 

  852. <dd><p>0xF5F5F5
    853. 

  853. </p></dd>
    854. 

  854. <dt>&lsquo;<samp>Yellow</samp>&rsquo;</dt>
    855. 

  855. <dd><p>0xFFFF00
    856. 

  856. </p></dd>
    857. 

  857. <dt>&lsquo;<samp>YellowGreen</samp>&rsquo;</dt>
    858. 

  858. <dd><p>0x9ACD32
    859. 

  859. </p></dd>
    860. 

  860. </dl>
    861. 

  861. 

  862. <span id="channel-layout-syntax"></span><a name="Channel-Layout"></a>
    863. 

  863. <h3 class="section">2.8 Channel Layout<span class="pull-right"><a class="anchor hidden-xs" href="#Channel-Layout" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Channel-Layout" aria-hidden="true">TOC</a></span></h3>
    864. 

  864. 

  865. <p>A channel layout specifies the spatial disposition of the channels in
    866. 

  866. a multi-channel audio stream. To specify a channel layout, FFmpeg
    867. 

  867. makes use of a special syntax.
    868. 

  868. </p>
    869. 

  869. <p>Individual channels are identified by an id, as given by the table
    870. 

  870. below:
    871. 

  871. </p><dl compact="compact">
    872. 

  872. <dt>&lsquo;<samp>FL</samp>&rsquo;</dt>
    873. 

  873. <dd><p>front left
    874. 

  874. </p></dd>
    875. 

  875. <dt>&lsquo;<samp>FR</samp>&rsquo;</dt>
    876. 

  876. <dd><p>front right
    877. 

  877. </p></dd>
    878. 

  878. <dt>&lsquo;<samp>FC</samp>&rsquo;</dt>
    879. 

  879. <dd><p>front center
    880. 

  880. </p></dd>
    881. 

  881. <dt>&lsquo;<samp>LFE</samp>&rsquo;</dt>
    882. 

  882. <dd><p>low frequency
    883. 

  883. </p></dd>
    884. 

  884. <dt>&lsquo;<samp>BL</samp>&rsquo;</dt>
    885. 

  885. <dd><p>back left
    886. 

  886. </p></dd>
    887. 

  887. <dt>&lsquo;<samp>BR</samp>&rsquo;</dt>
    888. 

  888. <dd><p>back right
    889. 

  889. </p></dd>
    890. 

  890. <dt>&lsquo;<samp>FLC</samp>&rsquo;</dt>
    891. 

  891. <dd><p>front left-of-center
    892. 

  892. </p></dd>
    893. 

  893. <dt>&lsquo;<samp>FRC</samp>&rsquo;</dt>
    894. 

  894. <dd><p>front right-of-center
    895. 

  895. </p></dd>
    896. 

  896. <dt>&lsquo;<samp>BC</samp>&rsquo;</dt>
    897. 

  897. <dd><p>back center
    898. 

  898. </p></dd>
    899. 

  899. <dt>&lsquo;<samp>SL</samp>&rsquo;</dt>
    900. 

  900. <dd><p>side left
    901. 

  901. </p></dd>
    902. 

  902. <dt>&lsquo;<samp>SR</samp>&rsquo;</dt>
    903. 

  903. <dd><p>side right
    904. 

  904. </p></dd>
    905. 

  905. <dt>&lsquo;<samp>TC</samp>&rsquo;</dt>
    906. 

  906. <dd><p>top center
    907. 

  907. </p></dd>
    908. 

  908. <dt>&lsquo;<samp>TFL</samp>&rsquo;</dt>
    909. 

  909. <dd><p>top front left
    910. 

  910. </p></dd>
    911. 

  911. <dt>&lsquo;<samp>TFC</samp>&rsquo;</dt>
    912. 

  912. <dd><p>top front center
    913. 

  913. </p></dd>
    914. 

  914. <dt>&lsquo;<samp>TFR</samp>&rsquo;</dt>
    915. 

  915. <dd><p>top front right
    916. 

  916. </p></dd>
    917. 

  917. <dt>&lsquo;<samp>TBL</samp>&rsquo;</dt>
    918. 

  918. <dd><p>top back left
    919. 

  919. </p></dd>
    920. 

  920. <dt>&lsquo;<samp>TBC</samp>&rsquo;</dt>
    921. 

  921. <dd><p>top back center
    922. 

  922. </p></dd>
    923. 

  923. <dt>&lsquo;<samp>TBR</samp>&rsquo;</dt>
    924. 

  924. <dd><p>top back right
    925. 

  925. </p></dd>
    926. 

  926. <dt>&lsquo;<samp>DL</samp>&rsquo;</dt>
    927. 

  927. <dd><p>downmix left
    928. 

  928. </p></dd>
    929. 

  929. <dt>&lsquo;<samp>DR</samp>&rsquo;</dt>
    930. 

  930. <dd><p>downmix right
    931. 

  931. </p></dd>
    932. 

  932. <dt>&lsquo;<samp>WL</samp>&rsquo;</dt>
    933. 

  933. <dd><p>wide left
    934. 

  934. </p></dd>
    935. 

  935. <dt>&lsquo;<samp>WR</samp>&rsquo;</dt>
    936. 

  936. <dd><p>wide right
    937. 

  937. </p></dd>
    938. 

  938. <dt>&lsquo;<samp>SDL</samp>&rsquo;</dt>
    939. 

  939. <dd><p>surround direct left
    940. 

  940. </p></dd>
    941. 

  941. <dt>&lsquo;<samp>SDR</samp>&rsquo;</dt>
    942. 

  942. <dd><p>surround direct right
    943. 

  943. </p></dd>
    944. 

  944. <dt>&lsquo;<samp>LFE2</samp>&rsquo;</dt>
    945. 

  945. <dd><p>low frequency 2
    946. 

  946. </p></dd>
    947. 

  947. </dl>
    948. 

  948. 

  949. <p>Standard channel layout compositions can be specified by using the
    950. 

  950. following identifiers:
    951. 

  951. </p><dl compact="compact">
    952. 

  952. <dt>&lsquo;<samp>mono</samp>&rsquo;</dt>
    953. 

  953. <dd><p>FC
    954. 

  954. </p></dd>
    955. 

  955. <dt>&lsquo;<samp>stereo</samp>&rsquo;</dt>
    956. 

  956. <dd><p>FL+FR
    957. 

  957. </p></dd>
    958. 

  958. <dt>&lsquo;<samp>2.1</samp>&rsquo;</dt>
    959. 

  959. <dd><p>FL+FR+LFE
    960. 

  960. </p></dd>
    961. 

  961. <dt>&lsquo;<samp>3.0</samp>&rsquo;</dt>
    962. 

  962. <dd><p>FL+FR+FC
    963. 

  963. </p></dd>
    964. 

  964. <dt>&lsquo;<samp>3.0(back)</samp>&rsquo;</dt>
    965. 

  965. <dd><p>FL+FR+BC
    966. 

  966. </p></dd>
    967. 

  967. <dt>&lsquo;<samp>4.0</samp>&rsquo;</dt>
    968. 

  968. <dd><p>FL+FR+FC+BC
    969. 

  969. </p></dd>
    970. 

  970. <dt>&lsquo;<samp>quad</samp>&rsquo;</dt>
    971. 

  971. <dd><p>FL+FR+BL+BR
    972. 

  972. </p></dd>
    973. 

  973. <dt>&lsquo;<samp>quad(side)</samp>&rsquo;</dt>
    974. 

  974. <dd><p>FL+FR+SL+SR
    975. 

  975. </p></dd>
    976. 

  976. <dt>&lsquo;<samp>3.1</samp>&rsquo;</dt>
    977. 

  977. <dd><p>FL+FR+FC+LFE
    978. 

  978. </p></dd>
    979. 

  979. <dt>&lsquo;<samp>5.0</samp>&rsquo;</dt>
    980. 

  980. <dd><p>FL+FR+FC+BL+BR
    981. 

  981. </p></dd>
    982. 

  982. <dt>&lsquo;<samp>5.0(side)</samp>&rsquo;</dt>
    983. 

  983. <dd><p>FL+FR+FC+SL+SR
    984. 

  984. </p></dd>
    985. 

  985. <dt>&lsquo;<samp>4.1</samp>&rsquo;</dt>
    986. 

  986. <dd><p>FL+FR+FC+LFE+BC
    987. 

  987. </p></dd>
    988. 

  988. <dt>&lsquo;<samp>5.1</samp>&rsquo;</dt>
    989. 

  989. <dd><p>FL+FR+FC+LFE+BL+BR
    990. 

  990. </p></dd>
    991. 

  991. <dt>&lsquo;<samp>5.1(side)</samp>&rsquo;</dt>
    992. 

  992. <dd><p>FL+FR+FC+LFE+SL+SR
    993. 

  993. </p></dd>
    994. 

  994. <dt>&lsquo;<samp>6.0</samp>&rsquo;</dt>
    995. 

  995. <dd><p>FL+FR+FC+BC+SL+SR
    996. 

  996. </p></dd>
    997. 

  997. <dt>&lsquo;<samp>6.0(front)</samp>&rsquo;</dt>
    998. 

  998. <dd><p>FL+FR+FLC+FRC+SL+SR
    999. 

  999. </p></dd>
    1000. 

  1000. <dt>&lsquo;<samp>hexagonal</samp>&rsquo;</dt>
    1001. 

  1001. <dd><p>FL+FR+FC+BL+BR+BC
    1002. 

  1002. </p></dd>
    1003. 

  1003. <dt>&lsquo;<samp>6.1</samp>&rsquo;</dt>
    1004. 

  1004. <dd><p>FL+FR+FC+LFE+BC+SL+SR
    1005. 

  1005. </p></dd>
    1006. 

  1006. <dt>&lsquo;<samp>6.1</samp>&rsquo;</dt>
    1007. 

  1007. <dd><p>FL+FR+FC+LFE+BL+BR+BC
    1008. 

  1008. </p></dd>
    1009. 

  1009. <dt>&lsquo;<samp>6.1(front)</samp>&rsquo;</dt>
    1010. 

  1010. <dd><p>FL+FR+LFE+FLC+FRC+SL+SR
    1011. 

  1011. </p></dd>
    1012. 

  1012. <dt>&lsquo;<samp>7.0</samp>&rsquo;</dt>
    1013. 

  1013. <dd><p>FL+FR+FC+BL+BR+SL+SR
    1014. 

  1014. </p></dd>
    1015. 

  1015. <dt>&lsquo;<samp>7.0(front)</samp>&rsquo;</dt>
    1016. 

  1016. <dd><p>FL+FR+FC+FLC+FRC+SL+SR
    1017. 

  1017. </p></dd>
    1018. 

  1018. <dt>&lsquo;<samp>7.1</samp>&rsquo;</dt>
    1019. 

  1019. <dd><p>FL+FR+FC+LFE+BL+BR+SL+SR
    1020. 

  1020. </p></dd>
    1021. 

  1021. <dt>&lsquo;<samp>7.1(wide)</samp>&rsquo;</dt>
    1022. 

  1022. <dd><p>FL+FR+FC+LFE+BL+BR+FLC+FRC
    1023. 

  1023. </p></dd>
    1024. 

  1024. <dt>&lsquo;<samp>7.1(wide-side)</samp>&rsquo;</dt>
    1025. 

  1025. <dd><p>FL+FR+FC+LFE+FLC+FRC+SL+SR
    1026. 

  1026. </p></dd>
    1027. 

  1027. <dt>&lsquo;<samp>octagonal</samp>&rsquo;</dt>
    1028. 

  1028. <dd><p>FL+FR+FC+BL+BR+BC+SL+SR
    1029. 

  1029. </p></dd>
    1030. 

  1030. <dt>&lsquo;<samp>hexadecagonal</samp>&rsquo;</dt>
    1031. 

  1031. <dd><p>FL+FR+FC+BL+BR+BC+SL+SR+WL+WR+TBL+TBR+TBC+TFC+TFL+TFR
    1032. 

  1032. </p></dd>
    1033. 

  1033. <dt>&lsquo;<samp>downmix</samp>&rsquo;</dt>
    1034. 

  1034. <dd><p>DL+DR
    1035. 

  1035. </p></dd>
    1036. 

  1036. </dl>
    1037. 

  1037. 

  1038. <p>A custom channel layout can be specified as a sequence of terms, separated by
    1039. 

  1039. &rsquo;+&rsquo; or &rsquo;|&rsquo;. Each term can be:
    1040. 

  1040. </p><ul>
    1041. 

  1041. <li> the name of a standard channel layout (e.g. &lsquo;<samp>mono</samp>&rsquo;,
    1042. 

  1042. &lsquo;<samp>stereo</samp>&rsquo;, &lsquo;<samp>4.0</samp>&rsquo;, &lsquo;<samp>quad</samp>&rsquo;, &lsquo;<samp>5.0</samp>&rsquo;, etc.)
    1043. 

  1043. 

  1044. </li><li> the name of a single channel (e.g. &lsquo;<samp>FL</samp>&rsquo;, &lsquo;<samp>FR</samp>&rsquo;, &lsquo;<samp>FC</samp>&rsquo;, &lsquo;<samp>LFE</samp>&rsquo;, etc.)
    1045. 

  1045. 

  1046. </li><li> a number of channels, in decimal, followed by &rsquo;c&rsquo;, yielding the default channel
    1047. 

  1047. layout for that number of channels (see the function
    1048. 

  1048. <code>av_get_default_channel_layout</code>). Note that not all channel counts have a
    1049. 

  1049. default layout.
    1050. 

  1050. 

  1051. </li><li> a number of channels, in decimal, followed by &rsquo;C&rsquo;, yielding an unknown channel
    1052. 

  1052. layout with the specified number of channels. Note that not all channel layout
    1053. 

  1053. specification strings support unknown channel layouts.
    1054. 

  1054. 

  1055. </li><li> a channel layout mask, in hexadecimal starting with &quot;0x&quot; (see the
    1056. 

  1056. <code>AV_CH_*</code> macros in <samp>libavutil/channel_layout.h</samp>.
    1057. 

  1057. </li></ul>
    1058. 

  1058. 

  1059. <p>Before libavutil version 53 the trailing character &quot;c&quot; to specify a number of
    1060. 

  1060. channels was optional, but now it is required, while a channel layout mask can
    1061. 

  1061. also be specified as a decimal number (if and only if not followed by &quot;c&quot; or &quot;C&quot;).
    1062. 

  1062. </p>
    1063. 

  1063. <p>See also the function <code>av_get_channel_layout</code> defined in
    1064. 

  1064. <samp>libavutil/channel_layout.h</samp>.
    1065. 

  1065. </p>
    1066. 

  1066. <a name="Expression-Evaluation"></a>
    1067. 

  1067. <h2 class="chapter">3 Expression Evaluation<span class="pull-right"><a class="anchor hidden-xs" href="#Expression-Evaluation" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Expression-Evaluation" aria-hidden="true">TOC</a></span></h2>
    1068. 

  1068. 

  1069. <p>When evaluating an arithmetic expression, FFmpeg uses an internal
    1070. 

  1070. formula evaluator, implemented through the <samp>libavutil/eval.h</samp>
    1071. 

  1071. interface.
    1072. 

  1072. </p>
    1073. 

  1073. <p>An expression may contain unary, binary operators, constants, and
    1074. 

  1074. functions.
    1075. 

  1075. </p>
    1076. 

  1076. <p>Two expressions <var>expr1</var> and <var>expr2</var> can be combined to form
    1077. 

  1077. another expression &quot;<var>expr1</var>;<var>expr2</var>&quot;.
    1078. 

  1078. <var>expr1</var> and <var>expr2</var> are evaluated in turn, and the new
    1079. 

  1079. expression evaluates to the value of <var>expr2</var>.
    1080. 

  1080. </p>
    1081. 

  1081. <p>The following binary operators are available: <code>+</code>, <code>-</code>,
    1082. 

  1082. <code>*</code>, <code>/</code>, <code>^</code>.
    1083. 

  1083. </p>
    1084. 

  1084. <p>The following unary operators are available: <code>+</code>, <code>-</code>.
    1085. 

  1085. </p>
    1086. 

  1086. <p>The following functions are available:
    1087. 

  1087. </p><dl compact="compact">
    1088. 

  1088. <dt><samp>abs(x)</samp></dt>
    1089. 

  1089. <dd><p>Compute absolute value of <var>x</var>.
    1090. 

  1090. </p>
    1091. 

  1091. </dd>
    1092. 

  1092. <dt><samp>acos(x)</samp></dt>
    1093. 

  1093. <dd><p>Compute arccosine of <var>x</var>.
    1094. 

  1094. </p>
    1095. 

  1095. </dd>
    1096. 

  1096. <dt><samp>asin(x)</samp></dt>
    1097. 

  1097. <dd><p>Compute arcsine of <var>x</var>.
    1098. 

  1098. </p>
    1099. 

  1099. </dd>
    1100. 

  1100. <dt><samp>atan(x)</samp></dt>
    1101. 

  1101. <dd><p>Compute arctangent of <var>x</var>.
    1102. 

  1102. </p>
    1103. 

  1103. </dd>
    1104. 

  1104. <dt><samp>atan2(x, y)</samp></dt>
    1105. 

  1105. <dd><p>Compute principal value of the arc tangent of <var>y</var>/<var>x</var>.
    1106. 

  1106. </p>
    1107. 

  1107. </dd>
    1108. 

  1108. <dt><samp>between(x, min, max)</samp></dt>
    1109. 

  1109. <dd><p>Return 1 if <var>x</var> is greater than or equal to <var>min</var> and lesser than or
    1110. 

  1110. equal to <var>max</var>, 0 otherwise.
    1111. 

  1111. </p>
    1112. 

  1112. </dd>
    1113. 

  1113. <dt><samp>bitand(x, y)</samp></dt>
    1114. 

  1114. <dt><samp>bitor(x, y)</samp></dt>
    1115. 

  1115. <dd><p>Compute bitwise and/or operation on <var>x</var> and <var>y</var>.
    1116. 

  1116. </p>
    1117. 

  1117. <p>The results of the evaluation of <var>x</var> and <var>y</var> are converted to
    1118. 

  1118. integers before executing the bitwise operation.
    1119. 

  1119. </p>
    1120. 

  1120. <p>Note that both the conversion to integer and the conversion back to
    1121. 

  1121. floating point can lose precision. Beware of unexpected results for
    1122. 

  1122. large numbers (usually 2^53 and larger).
    1123. 

  1123. </p>
    1124. 

  1124. </dd>
    1125. 

  1125. <dt><samp>ceil(expr)</samp></dt>
    1126. 

  1126. <dd><p>Round the value of expression <var>expr</var> upwards to the nearest
    1127. 

  1127. integer. For example, &quot;ceil(1.5)&quot; is &quot;2.0&quot;.
    1128. 

  1128. </p>
    1129. 

  1129. </dd>
    1130. 

  1130. <dt><samp>clip(x, min, max)</samp></dt>
    1131. 

  1131. <dd><p>Return the value of <var>x</var> clipped between <var>min</var> and <var>max</var>.
    1132. 

  1132. </p>
    1133. 

  1133. </dd>
    1134. 

  1134. <dt><samp>cos(x)</samp></dt>
    1135. 

  1135. <dd><p>Compute cosine of <var>x</var>.
    1136. 

  1136. </p>
    1137. 

  1137. </dd>
    1138. 

  1138. <dt><samp>cosh(x)</samp></dt>
    1139. 

  1139. <dd><p>Compute hyperbolic cosine of <var>x</var>.
    1140. 

  1140. </p>
    1141. 

  1141. </dd>
    1142. 

  1142. <dt><samp>eq(x, y)</samp></dt>
    1143. 

  1143. <dd><p>Return 1 if <var>x</var> and <var>y</var> are equivalent, 0 otherwise.
    1144. 

  1144. </p>
    1145. 

  1145. </dd>
    1146. 

  1146. <dt><samp>exp(x)</samp></dt>
    1147. 

  1147. <dd><p>Compute exponential of <var>x</var> (with base <code>e</code>, the Euler&rsquo;s number).
    1148. 

  1148. </p>
    1149. 

  1149. </dd>
    1150. 

  1150. <dt><samp>floor(expr)</samp></dt>
    1151. 

  1151. <dd><p>Round the value of expression <var>expr</var> downwards to the nearest
    1152. 

  1152. integer. For example, &quot;floor(-1.5)&quot; is &quot;-2.0&quot;.
    1153. 

  1153. </p>
    1154. 

  1154. </dd>
    1155. 

  1155. <dt><samp>gauss(x)</samp></dt>
    1156. 

  1156. <dd><p>Compute Gauss function of <var>x</var>, corresponding to
    1157. 

  1157. <code>exp(-x*x/2) / sqrt(2*PI)</code>.
    1158. 

  1158. </p>
    1159. 

  1159. </dd>
    1160. 

  1160. <dt><samp>gcd(x, y)</samp></dt>
    1161. 

  1161. <dd><p>Return the greatest common divisor of <var>x</var> and <var>y</var>. If both <var>x</var> and
    1162. 

  1162. <var>y</var> are 0 or either or both are less than zero then behavior is undefined.
    1163. 

  1163. </p>
    1164. 

  1164. </dd>
    1165. 

  1165. <dt><samp>gt(x, y)</samp></dt>
    1166. 

  1166. <dd><p>Return 1 if <var>x</var> is greater than <var>y</var>, 0 otherwise.
    1167. 

  1167. </p>
    1168. 

  1168. </dd>
    1169. 

  1169. <dt><samp>gte(x, y)</samp></dt>
    1170. 

  1170. <dd><p>Return 1 if <var>x</var> is greater than or equal to <var>y</var>, 0 otherwise.
    1171. 

  1171. </p>
    1172. 

  1172. </dd>
    1173. 

  1173. <dt><samp>hypot(x, y)</samp></dt>
    1174. 

  1174. <dd><p>This function is similar to the C function with the same name; it returns
    1175. 

  1175. &quot;sqrt(<var>x</var>*<var>x</var> + <var>y</var>*<var>y</var>)&quot;, the length of the hypotenuse of a
    1176. 

  1176. right triangle with sides of length <var>x</var> and <var>y</var>, or the distance of the
    1177. 

  1177. point (<var>x</var>, <var>y</var>) from the origin.
    1178. 

  1178. </p>
    1179. 

  1179. </dd>
    1180. 

  1180. <dt><samp>if(x, y)</samp></dt>
    1181. 

  1181. <dd><p>Evaluate <var>x</var>, and if the result is non-zero return the result of
    1182. 

  1182. the evaluation of <var>y</var>, return 0 otherwise.
    1183. 

  1183. </p>
    1184. 

  1184. </dd>
    1185. 

  1185. <dt><samp>if(x, y, z)</samp></dt>
    1186. 

  1186. <dd><p>Evaluate <var>x</var>, and if the result is non-zero return the evaluation
    1187. 

  1187. result of <var>y</var>, otherwise the evaluation result of <var>z</var>.
    1188. 

  1188. </p>
    1189. 

  1189. </dd>
    1190. 

  1190. <dt><samp>ifnot(x, y)</samp></dt>
    1191. 

  1191. <dd><p>Evaluate <var>x</var>, and if the result is zero return the result of the
    1192. 

  1192. evaluation of <var>y</var>, return 0 otherwise.
    1193. 

  1193. </p>
    1194. 

  1194. </dd>
    1195. 

  1195. <dt><samp>ifnot(x, y, z)</samp></dt>
    1196. 

  1196. <dd><p>Evaluate <var>x</var>, and if the result is zero return the evaluation
    1197. 

  1197. result of <var>y</var>, otherwise the evaluation result of <var>z</var>.
    1198. 

  1198. </p>
    1199. 

  1199. </dd>
    1200. 

  1200. <dt><samp>isinf(x)</samp></dt>
    1201. 

  1201. <dd><p>Return 1.0 if <var>x</var> is +/-INFINITY, 0.0 otherwise.
    1202. 

  1202. </p>
    1203. 

  1203. </dd>
    1204. 

  1204. <dt><samp>isnan(x)</samp></dt>
    1205. 

  1205. <dd><p>Return 1.0 if <var>x</var> is NAN, 0.0 otherwise.
    1206. 

  1206. </p>
    1207. 

  1207. </dd>
    1208. 

  1208. <dt><samp>ld(var)</samp></dt>
    1209. 

  1209. <dd><p>Load the value of the internal variable with number
    1210. 

  1210. <var>var</var>, which was previously stored with st(<var>var</var>, <var>expr</var>).
    1211. 

  1211. The function returns the loaded value.
    1212. 

  1212. </p>
    1213. 

  1213. </dd>
    1214. 

  1214. <dt><samp>lerp(x, y, z)</samp></dt>
    1215. 

  1215. <dd><p>Return linear interpolation between <var>x</var> and <var>y</var> by amount of <var>z</var>.
    1216. 

  1216. </p>
    1217. 

  1217. </dd>
    1218. 

  1218. <dt><samp>log(x)</samp></dt>
    1219. 

  1219. <dd><p>Compute natural logarithm of <var>x</var>.
    1220. 

  1220. </p>
    1221. 

  1221. </dd>
    1222. 

  1222. <dt><samp>lt(x, y)</samp></dt>
    1223. 

  1223. <dd><p>Return 1 if <var>x</var> is lesser than <var>y</var>, 0 otherwise.
    1224. 

  1224. </p>
    1225. 

  1225. </dd>
    1226. 

  1226. <dt><samp>lte(x, y)</samp></dt>
    1227. 

  1227. <dd><p>Return 1 if <var>x</var> is lesser than or equal to <var>y</var>, 0 otherwise.
    1228. 

  1228. </p>
    1229. 

  1229. </dd>
    1230. 

  1230. <dt><samp>max(x, y)</samp></dt>
    1231. 

  1231. <dd><p>Return the maximum between <var>x</var> and <var>y</var>.
    1232. 

  1232. </p>
    1233. 

  1233. </dd>
    1234. 

  1234. <dt><samp>min(x, y)</samp></dt>
    1235. 

  1235. <dd><p>Return the minimum between <var>x</var> and <var>y</var>.
    1236. 

  1236. </p>
    1237. 

  1237. </dd>
    1238. 

  1238. <dt><samp>mod(x, y)</samp></dt>
    1239. 

  1239. <dd><p>Compute the remainder of division of <var>x</var> by <var>y</var>.
    1240. 

  1240. </p>
    1241. 

  1241. </dd>
    1242. 

  1242. <dt><samp>not(expr)</samp></dt>
    1243. 

  1243. <dd><p>Return 1.0 if <var>expr</var> is zero, 0.0 otherwise.
    1244. 

  1244. </p>
    1245. 

  1245. </dd>
    1246. 

  1246. <dt><samp>pow(x, y)</samp></dt>
    1247. 

  1247. <dd><p>Compute the power of <var>x</var> elevated <var>y</var>, it is equivalent to
    1248. 

  1248. &quot;(<var>x</var>)^(<var>y</var>)&quot;.
    1249. 

  1249. </p>
    1250. 

  1250. </dd>
    1251. 

  1251. <dt><samp>print(t)</samp></dt>
    1252. 

  1252. <dt><samp>print(t, l)</samp></dt>
    1253. 

  1253. <dd><p>Print the value of expression <var>t</var> with loglevel <var>l</var>. If
    1254. 

  1254. <var>l</var> is not specified then a default log level is used.
    1255. 

  1255. Returns the value of the expression printed.
    1256. 

  1256. </p>
    1257. 

  1257. <p>Prints t with loglevel l
    1258. 

  1258. </p>
    1259. 

  1259. </dd>
    1260. 

  1260. <dt><samp>random(x)</samp></dt>
    1261. 

  1261. <dd><p>Return a pseudo random value between 0.0 and 1.0. <var>x</var> is the index of the
    1262. 

  1262. internal variable which will be used to save the seed/state.
    1263. 

  1263. </p>
    1264. 

  1264. </dd>
    1265. 

  1265. <dt><samp>root(expr, max)</samp></dt>
    1266. 

  1266. <dd><p>Find an input value for which the function represented by <var>expr</var>
    1267. 

  1267. with argument <var>ld(0)</var> is 0 in the interval 0..<var>max</var>.
    1268. 

  1268. </p>
    1269. 

  1269. <p>The expression in <var>expr</var> must denote a continuous function or the
    1270. 

  1270. result is undefined.
    1271. 

  1271. </p>
    1272. 

  1272. <p><var>ld(0)</var> is used to represent the function input value, which means
    1273. 

  1273. that the given expression will be evaluated multiple times with
    1274. 

  1274. various input values that the expression can access through
    1275. 

  1275. <code>ld(0)</code>. When the expression evaluates to 0 then the
    1276. 

  1276. corresponding input value will be returned.
    1277. 

  1277. </p>
    1278. 

  1278. </dd>
    1279. 

  1279. <dt><samp>round(expr)</samp></dt>
    1280. 

  1280. <dd><p>Round the value of expression <var>expr</var> to the nearest integer. For example, &quot;round(1.5)&quot; is &quot;2.0&quot;.
    1281. 

  1281. </p>
    1282. 

  1282. </dd>
    1283. 

  1283. <dt><samp>sgn(x)</samp></dt>
    1284. 

  1284. <dd><p>Compute sign of <var>x</var>.
    1285. 

  1285. </p>
    1286. 

  1286. </dd>
    1287. 

  1287. <dt><samp>sin(x)</samp></dt>
    1288. 

  1288. <dd><p>Compute sine of <var>x</var>.
    1289. 

  1289. </p>
    1290. 

  1290. </dd>
    1291. 

  1291. <dt><samp>sinh(x)</samp></dt>
    1292. 

  1292. <dd><p>Compute hyperbolic sine of <var>x</var>.
    1293. 

  1293. </p>
    1294. 

  1294. </dd>
    1295. 

  1295. <dt><samp>sqrt(expr)</samp></dt>
    1296. 

  1296. <dd><p>Compute the square root of <var>expr</var>. This is equivalent to
    1297. 

  1297. &quot;(<var>expr</var>)^.5&quot;.
    1298. 

  1298. </p>
    1299. 

  1299. </dd>
    1300. 

  1300. <dt><samp>squish(x)</samp></dt>
    1301. 

  1301. <dd><p>Compute expression <code>1/(1 + exp(4*x))</code>.
    1302. 

  1302. </p>
    1303. 

  1303. </dd>
    1304. 

  1304. <dt><samp>st(var, expr)</samp></dt>
    1305. 

  1305. <dd><p>Store the value of the expression <var>expr</var> in an internal
    1306. 

  1306. variable. <var>var</var> specifies the number of the variable where to
    1307. 

  1307. store the value, and it is a value ranging from 0 to 9. The function
    1308. 

  1308. returns the value stored in the internal variable.
    1309. 

  1309. Note, Variables are currently not shared between expressions.
    1310. 

  1310. </p>
    1311. 

  1311. </dd>
    1312. 

  1312. <dt><samp>tan(x)</samp></dt>
    1313. 

  1313. <dd><p>Compute tangent of <var>x</var>.
    1314. 

  1314. </p>
    1315. 

  1315. </dd>
    1316. 

  1316. <dt><samp>tanh(x)</samp></dt>
    1317. 

  1317. <dd><p>Compute hyperbolic tangent of <var>x</var>.
    1318. 

  1318. </p>
    1319. 

  1319. </dd>
    1320. 

  1320. <dt><samp>taylor(expr, x)</samp></dt>
    1321. 

  1321. <dt><samp>taylor(expr, x, id)</samp></dt>
    1322. 

  1322. <dd><p>Evaluate a Taylor series at <var>x</var>, given an expression representing
    1323. 

  1323. the <code>ld(id)</code>-th derivative of a function at 0.
    1324. 

  1324. </p>
    1325. 

  1325. <p>When the series does not converge the result is undefined.
    1326. 

  1326. </p>
    1327. 

  1327. <p><var>ld(id)</var> is used to represent the derivative order in <var>expr</var>,
    1328. 

  1328. which means that the given expression will be evaluated multiple times
    1329. 

  1329. with various input values that the expression can access through
    1330. 

  1330. <code>ld(id)</code>. If <var>id</var> is not specified then 0 is assumed.
    1331. 

  1331. </p>
    1332. 

  1332. <p>Note, when you have the derivatives at y instead of 0,
    1333. 

  1333. <code>taylor(expr, x-y)</code> can be used.
    1334. 

  1334. </p>
    1335. 

  1335. </dd>
    1336. 

  1336. <dt><samp>time(0)</samp></dt>
    1337. 

  1337. <dd><p>Return the current (wallclock) time in seconds.
    1338. 

  1338. </p>
    1339. 

  1339. </dd>
    1340. 

  1340. <dt><samp>trunc(expr)</samp></dt>
    1341. 

  1341. <dd><p>Round the value of expression <var>expr</var> towards zero to the nearest
    1342. 

  1342. integer. For example, &quot;trunc(-1.5)&quot; is &quot;-1.0&quot;.
    1343. 

  1343. </p>
    1344. 

  1344. </dd>
    1345. 

  1345. <dt><samp>while(cond, expr)</samp></dt>
    1346. 

  1346. <dd><p>Evaluate expression <var>expr</var> while the expression <var>cond</var> is
    1347. 

  1347. non-zero, and returns the value of the last <var>expr</var> evaluation, or
    1348. 

  1348. NAN if <var>cond</var> was always false.
    1349. 

  1349. </p></dd>
    1350. 

  1350. </dl>
    1351. 

  1351. 

  1352. <p>The following constants are available:
    1353. 

  1353. </p><dl compact="compact">
    1354. 

  1354. <dt><samp>PI</samp></dt>
    1355. 

  1355. <dd><p>area of the unit disc, approximately 3.14
    1356. 

  1356. </p></dd>
    1357. 

  1357. <dt><samp>E</samp></dt>
    1358. 

  1358. <dd><p>exp(1) (Euler&rsquo;s number), approximately 2.718
    1359. 

  1359. </p></dd>
    1360. 

  1360. <dt><samp>PHI</samp></dt>
    1361. 

  1361. <dd><p>golden ratio (1+sqrt(5))/2, approximately 1.618
    1362. 

  1362. </p></dd>
    1363. 

  1363. </dl>
    1364. 

  1364. 

  1365. <p>Assuming that an expression is considered &quot;true&quot; if it has a non-zero
    1366. 

  1366. value, note that:
    1367. 

  1367. </p>
    1368. 

  1368. <p><code>*</code> works like AND
    1369. 

  1369. </p>
    1370. 

  1370. <p><code>+</code> works like OR
    1371. 

  1371. </p>
    1372. 

  1372. <p>For example the construct:
    1373. 

  1373. </p><div class="example">
    1374. 

  1374. <pre class="example">if (A AND B) then C
    1375. 

  1375. </pre></div>
    1376. 

  1376. <p>is equivalent to:
    1377. 

  1377. </p><div class="example">
    1378. 

  1378. <pre class="example">if(A*B, C)
    1379. 

  1379. </pre></div>
    1380. 

  1380. 

  1381. <p>In your C code, you can extend the list of unary and binary functions,
    1382. 

  1382. and define recognized constants, so that they are available for your
    1383. 

  1383. expressions.
    1384. 

  1384. </p>
    1385. 

  1385. <p>The evaluator also recognizes the International System unit prefixes.
    1386. 

  1386. If &rsquo;i&rsquo; is appended after the prefix, binary prefixes are used, which
    1387. 

  1387. are based on powers of 1024 instead of powers of 1000.
    1388. 

  1388. The &rsquo;B&rsquo; postfix multiplies the value by 8, and can be appended after a
    1389. 

  1389. unit prefix or used alone. This allows using for example &rsquo;KB&rsquo;, &rsquo;MiB&rsquo;,
    1390. 

  1390. &rsquo;G&rsquo; and &rsquo;B&rsquo; as number postfix.
    1391. 

  1391. </p>
    1392. 

  1392. <p>The list of available International System prefixes follows, with
    1393. 

  1393. indication of the corresponding powers of 10 and of 2.
    1394. 

  1394. </p><dl compact="compact">
    1395. 

  1395. <dt><samp>y</samp></dt>
    1396. 

  1396. <dd><p>10^-24 / 2^-80
    1397. 

  1397. </p></dd>
    1398. 

  1398. <dt><samp>z</samp></dt>
    1399. 

  1399. <dd><p>10^-21 / 2^-70
    1400. 

  1400. </p></dd>
    1401. 

  1401. <dt><samp>a</samp></dt>
    1402. 

  1402. <dd><p>10^-18 / 2^-60
    1403. 

  1403. </p></dd>
    1404. 

  1404. <dt><samp>f</samp></dt>
    1405. 

  1405. <dd><p>10^-15 / 2^-50
    1406. 

  1406. </p></dd>
    1407. 

  1407. <dt><samp>p</samp></dt>
    1408. 

  1408. <dd><p>10^-12 / 2^-40
    1409. 

  1409. </p></dd>
    1410. 

  1410. <dt><samp>n</samp></dt>
    1411. 

  1411. <dd><p>10^-9 / 2^-30
    1412. 

  1412. </p></dd>
    1413. 

  1413. <dt><samp>u</samp></dt>
    1414. 

  1414. <dd><p>10^-6 / 2^-20
    1415. 

  1415. </p></dd>
    1416. 

  1416. <dt><samp>m</samp></dt>
    1417. 

  1417. <dd><p>10^-3 / 2^-10
    1418. 

  1418. </p></dd>
    1419. 

  1419. <dt><samp>c</samp></dt>
    1420. 

  1420. <dd><p>10^-2
    1421. 

  1421. </p></dd>
    1422. 

  1422. <dt><samp>d</samp></dt>
    1423. 

  1423. <dd><p>10^-1
    1424. 

  1424. </p></dd>
    1425. 

  1425. <dt><samp>h</samp></dt>
    1426. 

  1426. <dd><p>10^2
    1427. 

  1427. </p></dd>
    1428. 

  1428. <dt><samp>k</samp></dt>
    1429. 

  1429. <dd><p>10^3 / 2^10
    1430. 

  1430. </p></dd>
    1431. 

  1431. <dt><samp>K</samp></dt>
    1432. 

  1432. <dd><p>10^3 / 2^10
    1433. 

  1433. </p></dd>
    1434. 

  1434. <dt><samp>M</samp></dt>
    1435. 

  1435. <dd><p>10^6 / 2^20
    1436. 

  1436. </p></dd>
    1437. 

  1437. <dt><samp>G</samp></dt>
    1438. 

  1438. <dd><p>10^9 / 2^30
    1439. 

  1439. </p></dd>
    1440. 

  1440. <dt><samp>T</samp></dt>
    1441. 

  1441. <dd><p>10^12 / 2^40
    1442. 

  1442. </p></dd>
    1443. 

  1443. <dt><samp>P</samp></dt>
    1444. 

  1444. <dd><p>10^15 / 2^40
    1445. 

  1445. </p></dd>
    1446. 

  1446. <dt><samp>E</samp></dt>
    1447. 

  1447. <dd><p>10^18 / 2^50
    1448. 

  1448. </p></dd>
    1449. 

  1449. <dt><samp>Z</samp></dt>
    1450. 

  1450. <dd><p>10^21 / 2^60
    1451. 

  1451. </p></dd>
    1452. 

  1452. <dt><samp>Y</samp></dt>
    1453. 

  1453. <dd><p>10^24 / 2^70
    1454. 

  1454. </p></dd>
    1455. 

  1455. </dl>
    1456. 

  1456. 

  1457. 

  1458. <a name="See-Also"></a>
    1459. 

  1459. <h2 class="chapter">4 See Also<span class="pull-right"><a class="anchor hidden-xs" href="#See-Also" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-See-Also" aria-hidden="true">TOC</a></span></h2>
    1460. 

  1460. 

  1461. <p><a href="ffmpeg.html">ffmpeg</a>, <a href="ffplay.html">ffplay</a>, <a href="ffprobe.html">ffprobe</a>,
    1462. 

  1462. <a href="libavutil.html">libavutil</a>
    1463. 

  1463. </p>
    1464. 

  1464. 

  1465. <a name="Authors"></a>
    1466. 

  1466. <h2 class="chapter">5 Authors<span class="pull-right"><a class="anchor hidden-xs" href="#Authors" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Authors" aria-hidden="true">TOC</a></span></h2>
    1467. 

  1467. 

  1468. <p>The FFmpeg developers.
    1469. 

  1469. </p>
    1470. 

  1470. <p>For details about the authorship, see the Git history of the project
    1471. 

  1471. (git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
    1472. 

  1472. <code>git log</code> in the FFmpeg source directory, or browsing the
    1473. 

  1473. online repository at <a href="http://source.ffmpeg.org">http://source.ffmpeg.org</a>.
    1474. 

  1474. </p>
    1475. 

  1475. <p>Maintainers for the specific components are listed in the file
    1476. 

  1476. <samp>MAINTAINERS</samp> in the source code tree.
    1477. 

  1477. </p>
    1478. 

  1478. 

  1479. 

  1480.       <p style="font-size: small;">
    1481. 

  1481.         This document was generated using <a href="http://www.gnu.org/software/texinfo/"><em>makeinfo</em></a>.
    1482. 

  1482.       </p>
    1483. 

  1483.     </div>
    1484. 

  1484.   </body>
    1485. 

  1485. </html>
    1486.