libavformat/isom.c

   1 /*
   2  * ISO Media common code
   3  * Copyright (c) 2001 Fabrice Bellard
   4  * Copyright (c) 2002 Francois Revol <revol@free.fr>
   5  * Copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@free.fr>
   6  *
   7  * This file is part of FFmpeg.
   8  *
   9  * FFmpeg is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * FFmpeg is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with FFmpeg; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 #include "avformat.h"
  25 #include "riff.h"
  26 #include "isom.h"
  27
  28 /* http://www.mp4ra.org */
  29 /* ordered by muxing preference */
  30 const AVCodecTag ff_mp4_obj_type[] = {
  31     { CODEC_ID_MOV_TEXT  , 0x08 },
  32     { CODEC_ID_MPEG4     , 0x20 },
  33     { CODEC_ID_H264      , 0x21 },
  34     { CODEC_ID_AAC       , 0x40 },
  35     { CODEC_ID_MPEG2VIDEO, 0x61 }, /* MPEG2 Main */
  36     { CODEC_ID_MPEG2VIDEO, 0x60 }, /* MPEG2 Simple */
  37     { CODEC_ID_MPEG2VIDEO, 0x62 }, /* MPEG2 SNR */
  38     { CODEC_ID_MPEG2VIDEO, 0x63 }, /* MPEG2 Spatial */
  39     { CODEC_ID_MPEG2VIDEO, 0x64 }, /* MPEG2 High */
  40     { CODEC_ID_MPEG2VIDEO, 0x65 }, /* MPEG2 422 */
  41     { CODEC_ID_AAC       , 0x66 }, /* MPEG2 AAC Main */
  42     { CODEC_ID_AAC       , 0x67 }, /* MPEG2 AAC Low */
  43     { CODEC_ID_AAC       , 0x68 }, /* MPEG2 AAC SSR */
  44     { CODEC_ID_MP3       , 0x69 }, /* 13818-3 */
  45     { CODEC_ID_MP2       , 0x69 }, /* 11172-3 */
  46     { CODEC_ID_MPEG1VIDEO, 0x6A }, /* 11172-2 */
  47     { CODEC_ID_MP3       , 0x6B }, /* 11172-3 */
  48     { CODEC_ID_MJPEG     , 0x6C }, /* 10918-1 */
  49     { CODEC_ID_PNG       , 0x6D },
  50     { CODEC_ID_JPEG2000  , 0x6E }, /* 15444-1 */
  51     { CODEC_ID_VC1       , 0xA3 },
  52     { CODEC_ID_DIRAC     , 0xA4 },
  53     { CODEC_ID_AC3       , 0xA5 },
  54     { CODEC_ID_VORBIS    , 0xDD }, /* non standard, gpac uses it */
  55     { CODEC_ID_DVD_SUBTITLE, 0xE0 }, /* non standard, see unsupported-embedded-subs-2.mp4 */
  56     { CODEC_ID_QCELP     , 0xE1 },
  57     { 0, 0 },
  58 };
  59
  60 const AVCodecTag codec_movvideo_tags[] = {
  61 /*  { CODEC_ID_, MKTAG('I', 'V', '5', '0') }, *//* Indeo 5.0 */
  62
  63     { CODEC_ID_RAWVIDEO, MKTAG('r', 'a', 'w', ' ') }, /* Uncompressed RGB */
  64     { CODEC_ID_RAWVIDEO, MKTAG('y', 'u', 'v', '2') }, /* Uncompressed YUV422 */
  65     { CODEC_ID_RAWVIDEO, MKTAG('A', 'V', 'U', 'I') }, /* YUV with alpha-channel (AVID Uncompressed) */
  66     { CODEC_ID_RAWVIDEO, MKTAG('2', 'v', 'u', 'y') }, /* UNCOMPRESSED 8BIT 4:2:2 */
  67
  68     { CODEC_ID_MJPEG,  MKTAG('j', 'p', 'e', 'g') }, /* PhotoJPEG */
  69     { CODEC_ID_MJPEG,  MKTAG('m', 'j', 'p', 'a') }, /* Motion-JPEG (format A) */
  70     { CODEC_ID_MJPEG,  MKTAG('A', 'V', 'D', 'J') }, /* MJPEG with alpha-channel (AVID JFIF meridien compressed) */
  71 /*  { CODEC_ID_MJPEG,  MKTAG('A', 'V', 'R', 'n') }, *//* MJPEG with alpha-channel (AVID ABVB/Truevision NuVista) */
  72     { CODEC_ID_MJPEG,  MKTAG('d', 'm', 'b', '1') }, /* Motion JPEG OpenDML */
  73     { CODEC_ID_MJPEGB, MKTAG('m', 'j', 'p', 'b') }, /* Motion-JPEG (format B) */
  74
  75     { CODEC_ID_SVQ1, MKTAG('S', 'V', 'Q', '1') }, /* Sorenson Video v1 */
  76     { CODEC_ID_SVQ1, MKTAG('s', 'v', 'q', '1') }, /* Sorenson Video v1 */
  77     { CODEC_ID_SVQ1, MKTAG('s', 'v', 'q', 'i') }, /* Sorenson Video v1 (from QT specs)*/
  78     { CODEC_ID_SVQ3, MKTAG('S', 'V', 'Q', '3') }, /* Sorenson Video v3 */
  79
  80     { CODEC_ID_MPEG4, MKTAG('m', 'p', '4', 'v') },
  81     { CODEC_ID_MPEG4, MKTAG('D', 'I', 'V', 'X') }, /* OpenDiVX *//* sample files at http://heroinewarrior.com/xmovie.php3 use this tag */
  82     { CODEC_ID_MPEG4, MKTAG('X', 'V', 'I', 'D') },
  83     { CODEC_ID_MPEG4, MKTAG('3', 'I', 'V', '2') }, /* experimental: 3IVX files before ivx D4 4.5.1 */
  84
  85     { CODEC_ID_H263, MKTAG('h', '2', '6', '3') }, /* H263 */
  86     { CODEC_ID_H263, MKTAG('s', '2', '6', '3') }, /* H263 ?? works */
  87
  88     { CODEC_ID_DVVIDEO, MKTAG('d', 'v', 'c', 'p') }, /* DV PAL */
  89     { CODEC_ID_DVVIDEO, MKTAG('d', 'v', 'c', ' ') }, /* DV NTSC */
  90     { CODEC_ID_DVVIDEO, MKTAG('d', 'v', 'p', 'p') }, /* DVCPRO PAL produced by FCP */
  91     { CODEC_ID_DVVIDEO, MKTAG('d', 'v', '5', 'p') }, /* DVCPRO50 PAL produced by FCP */
  92     { CODEC_ID_DVVIDEO, MKTAG('d', 'v', '5', 'n') }, /* DVCPRO50 NTSC produced by FCP */
  93     { CODEC_ID_DVVIDEO, MKTAG('A', 'V', 'd', 'v') }, /* AVID DV */
  94     { CODEC_ID_DVVIDEO, MKTAG('A', 'V', 'd', '1') }, /* AVID DV100 */
  95     { CODEC_ID_DVVIDEO, MKTAG('d', 'v', 'h', 'q') }, /* DVCPRO HD 720p50 */
  96     { CODEC_ID_DVVIDEO, MKTAG('d', 'v', 'h', 'p') }, /* DVCPRO HD 720p60 */
  97     { CODEC_ID_DVVIDEO, MKTAG('d', 'v', 'h', '1') },
  98     { CODEC_ID_DVVIDEO, MKTAG('d', 'v', 'h', '2') },
  99     { CODEC_ID_DVVIDEO, MKTAG('d', 'v', 'h', '4') },
 100     { CODEC_ID_DVVIDEO, MKTAG('d', 'v', 'h', '5') }, /* DVCPRO HD 50i produced by FCP */
 101     { CODEC_ID_DVVIDEO, MKTAG('d', 'v', 'h', '6') }, /* DVCPRO HD 60i produced by FCP */
 102     { CODEC_ID_DVVIDEO, MKTAG('d', 'v', 'h', '3') }, /* DVCPRO HD 30p produced by FCP */
 103
 104     { CODEC_ID_VP3,     MKTAG('V', 'P', '3', '1') }, /* On2 VP3 */
 105     { CODEC_ID_RPZA,    MKTAG('r', 'p', 'z', 'a') }, /* Apple Video (RPZA) */
 106     { CODEC_ID_CINEPAK, MKTAG('c', 'v', 'i', 'd') }, /* Cinepak */
 107     { CODEC_ID_8BPS,    MKTAG('8', 'B', 'P', 'S') }, /* Planar RGB (8BPS) */
 108     { CODEC_ID_SMC,     MKTAG('s', 'm', 'c', ' ') }, /* Apple Graphics (SMC) */
 109     { CODEC_ID_QTRLE,   MKTAG('r', 'l', 'e', ' ') }, /* Apple Animation (RLE) */
 110     { CODEC_ID_MSRLE,   MKTAG('W', 'R', 'L', 'E') },
 111     { CODEC_ID_QDRAW,   MKTAG('q', 'd', 'r', 'w') }, /* QuickDraw */
 112
 113     { CODEC_ID_RAWVIDEO, MKTAG('W', 'R', 'A', 'W') },
 114
 115     { CODEC_ID_H264, MKTAG('a', 'v', 'c', '1') }, /* AVC-1/H.264 */
 116
 117     { CODEC_ID_MPEG1VIDEO, MKTAG('m', 'p', 'e', 'g') }, /* MPEG */
 118     { CODEC_ID_MPEG2VIDEO, MKTAG('h', 'd', 'v', '1') }, /* MPEG2 HDV 720p30 */
 119     { CODEC_ID_MPEG2VIDEO, MKTAG('h', 'd', 'v', '2') }, /* MPEG2 HDV 1080i60 */
 120     { CODEC_ID_MPEG2VIDEO, MKTAG('h', 'd', 'v', '3') }, /* MPEG2 HDV 1080i50 */
 121     { CODEC_ID_MPEG2VIDEO, MKTAG('h', 'd', 'v', '5') }, /* MPEG2 HDV 720p25 */
 122     { CODEC_ID_MPEG2VIDEO, MKTAG('h', 'd', 'v', '6') }, /* MPEG2 HDV 1080p24 */
 123     { CODEC_ID_MPEG2VIDEO, MKTAG('h', 'd', 'v', '7') }, /* MPEG2 HDV 1080p25 */
 124     { CODEC_ID_MPEG2VIDEO, MKTAG('h', 'd', 'v', '8') }, /* MPEG2 HDV 1080p30 */
 125     { CODEC_ID_MPEG2VIDEO, MKTAG('m', 'x', '5', 'n') }, /* MPEG2 IMX NTSC 525/60 50mb/s produced by FCP */
 126     { CODEC_ID_MPEG2VIDEO, MKTAG('m', 'x', '5', 'p') }, /* MPEG2 IMX PAL 625/50 50mb/s produced by FCP */
 127     { CODEC_ID_MPEG2VIDEO, MKTAG('m', 'x', '4', 'n') }, /* MPEG2 IMX NTSC 525/60 40mb/s produced by FCP */
 128     { CODEC_ID_MPEG2VIDEO, MKTAG('m', 'x', '4', 'p') }, /* MPEG2 IMX PAL 625/50 40mb/s produced by FCP */
 129     { CODEC_ID_MPEG2VIDEO, MKTAG('m', 'x', '3', 'n') }, /* MPEG2 IMX NTSC 525/60 30mb/s produced by FCP */
 130     { CODEC_ID_MPEG2VIDEO, MKTAG('m', 'x', '3', 'p') }, /* MPEG2 IMX PAL 625/50 30mb/s produced by FCP */
 131     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', '5', '9') }, /* XDCAM HD422 720p60 CBR */
 132     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', '5', 'a') }, /* XDCAM HD422 720p50 CBR */
 133     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', '5', 'b') }, /* XDCAM HD422 1080i60 CBR */
 134     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', '5', 'c') }, /* XDCAM HD422 1080i50 CBR */
 135     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', '5', 'd') }, /* XDCAM HD422 1080p24 CBR */
 136     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', '5', 'e') }, /* XDCAM HD422 1080p25 CBR */
 137     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', '5', 'f') }, /* XDCAM HD422 1080p30 CBR */
 138     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', 'v', '1') }, /* XDCAM EX 720p30 VBR */
 139     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', 'v', '2') }, /* XDCAM HD 1080i60 */
 140     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', 'v', '3') }, /* XDCAM HD 1080i50 VBR */
 141     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', 'v', '4') }, /* XDCAM EX 720p24 VBR */
 142     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', 'v', '5') }, /* XDCAM EX 720p25 VBR */
 143     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', 'v', '6') }, /* XDCAM HD 1080p24 VBR */
 144     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', 'v', '7') }, /* XDCAM HD 1080p25 VBR */
 145     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', 'v', '8') }, /* XDCAM HD 1080p30 VBR */
 146     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', 'v', '9') }, /* XDCAM EX 720p60 VBR */
 147     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', 'v', 'a') }, /* XDCAM EX 720p50 VBR */
 148     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', 'v', 'b') }, /* XDCAM EX 1080i60 VBR */
 149     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', 'v', 'c') }, /* XDCAM EX 1080i50 VBR */
 150     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', 'v', 'd') }, /* XDCAM EX 1080p24 VBR */
 151     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', 'v', 'e') }, /* XDCAM EX 1080p25 VBR */
 152     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', 'v', 'f') }, /* XDCAM EX 1080p30 VBR */
 153     { CODEC_ID_MPEG2VIDEO, MKTAG('A', 'V', 'm', 'p') }, /* AVID IMX PAL */
 154
 155     { CODEC_ID_JPEG2000, MKTAG('m', 'j', 'p', '2') }, /* JPEG 2000 produced by FCP */
 156
 157     { CODEC_ID_TARGA, MKTAG('t', 'g', 'a', ' ') }, /* Truevision Targa */
 158     { CODEC_ID_TIFF,  MKTAG('t', 'i', 'f', 'f') }, /* TIFF embedded in MOV */
 159     { CODEC_ID_GIF,   MKTAG('g', 'i', 'f', ' ') }, /* embedded gif files as frames (usually one "click to play movie" frame) */
 160     { CODEC_ID_PNG,   MKTAG('p', 'n', 'g', ' ') },
 161
 162     { CODEC_ID_VC1, MKTAG('v', 'c', '-', '1') }, /* SMPTE RP 2025 */
 163     { CODEC_ID_CAVS, MKTAG('a', 'v', 's', '2') },
 164
 165     { CODEC_ID_DIRAC, MKTAG('d', 'r', 'a', 'c') },
 166     { CODEC_ID_DNXHD, MKTAG('A', 'V', 'd', 'n') }, /* AVID DNxHD */
 167     { CODEC_ID_SGI,   MKTAG('s', 'g', 'i', ' ') }, /* SGI  */
 168
 169     { CODEC_ID_NONE, 0 },
 170 };
 171
 172 const AVCodecTag codec_movaudio_tags[] = {
 173     { CODEC_ID_PCM_S32BE, MKTAG('i', 'n', '3', '2') },
 174     { CODEC_ID_PCM_S32LE, MKTAG('i', 'n', '3', '2') },
 175     { CODEC_ID_PCM_S24BE, MKTAG('i', 'n', '2', '4') },
 176     { CODEC_ID_PCM_S24LE, MKTAG('i', 'n', '2', '4') },
 177     { CODEC_ID_PCM_S16BE, MKTAG('t', 'w', 'o', 's') }, /* 16 bits */
 178     { CODEC_ID_PCM_S16LE, MKTAG('s', 'o', 'w', 't') }, /*  */
 179     { CODEC_ID_PCM_S16LE, MKTAG('l', 'p', 'c', 'm') },
 180     { CODEC_ID_PCM_F32BE, MKTAG('f', 'l', '3', '2') },
 181     { CODEC_ID_PCM_F64BE, MKTAG('f', 'l', '6', '4') },
 182     { CODEC_ID_PCM_S8,    MKTAG('s', 'o', 'w', 't') },
 183     { CODEC_ID_PCM_U8,    MKTAG('r', 'a', 'w', ' ') }, /* 8 bits unsigned */
 184     { CODEC_ID_PCM_U8,    MKTAG('N', 'O', 'N', 'E') }, /* uncompressed */
 185     { CODEC_ID_PCM_MULAW, MKTAG('u', 'l', 'a', 'w') }, /*  */
 186     { CODEC_ID_PCM_ALAW,  MKTAG('a', 'l', 'a', 'w') }, /*  */
 187
 188     { CODEC_ID_ADPCM_IMA_QT, MKTAG('i', 'm', 'a', '4') }, /* IMA-4 ADPCM */
 189
 190     { CODEC_ID_MACE3, MKTAG('M', 'A', 'C', '3') }, /* Macintosh Audio Compression and Expansion 3:1 */
 191     { CODEC_ID_MACE6, MKTAG('M', 'A', 'C', '6') }, /* Macintosh Audio Compression and Expansion 6:1 */
 192
 193     { CODEC_ID_MP3, MKTAG('.', 'm', 'p', '3') }, /* MPEG layer 3 */ /* sample files at http://www.3ivx.com/showcase.html use this tag */
 194     { CODEC_ID_MP3, 0x6D730055 }, /* MPEG layer 3 */
 195
 196 /*  { CODEC_ID_OGG_VORBIS, MKTAG('O', 'g', 'g', 'S') }, *//* sample files at http://heroinewarrior.com/xmovie.php3 use this tag */
 197
 198     { CODEC_ID_AAC, MKTAG('m', 'p', '4', 'a') }, /* MPEG-4 AAC */
 199     { CODEC_ID_AC3, MKTAG('a', 'c', '-', '3') }, /* ETSI TS 102 366 Annex F */
 200
 201     { CODEC_ID_AMR_NB, MKTAG('s', 'a', 'm', 'r') }, /* AMR-NB 3gp */
 202     { CODEC_ID_AMR_WB, MKTAG('s', 'a', 'w', 'b') }, /* AMR-WB 3gp */
 203
 204     { CODEC_ID_GSM,  MKTAG('a', 'g', 's', 'm') },
 205     { CODEC_ID_ALAC, MKTAG('a', 'l', 'a', 'c') }, /* Apple Lossless */
 206
 207     { CODEC_ID_QCELP, MKTAG('Q','c','l','p') },
 208     { CODEC_ID_QCELP, MKTAG('s','q','c','p') }, /* ISO Media fourcc */
 209
 210     { CODEC_ID_QDM2, MKTAG('Q', 'D', 'M', '2') }, /* QDM2 */
 211
 212     { CODEC_ID_DVAUDIO, MKTAG('v', 'd', 'v', 'a') },
 213     { CODEC_ID_DVAUDIO, MKTAG('d', 'v', 'c', 'a') },
 214
 215     { CODEC_ID_WMAV2, MKTAG('W', 'M', 'A', '2') },
 216
 217     { CODEC_ID_NONE, 0 },
 218 };
 219
 220 const AVCodecTag ff_codec_movsubtitle_tags[] = {
 221     { CODEC_ID_MOV_TEXT, MKTAG('t', 'e', 'x', 't') },
 222     { CODEC_ID_MOV_TEXT, MKTAG('t', 'x', '3', 'g') },
 223     { CODEC_ID_NONE, 0 },
 224 };
 225
 226 /* map numeric codes from mdhd atom to ISO 639 */
 227 /* cf. QTFileFormat.pdf p253, qtff.pdf p205 */
 228 /* http://developer.apple.com/documentation/mac/Text/Text-368.html */
 229 /* deprecated by putting the code as 3*5bit ascii */
 230 static const char * const mov_mdhd_language_map[] = {
 231     /* 0-9 */
 232     "eng", "fra", "ger", "ita", "dut", "sve", "spa", "dan", "por", "nor",
 233     "heb", "jpn", "ara", "fin", "gre", "ice", "mlt", "tur", "hr "/*scr*/, "chi"/*ace?*/,
 234     "urd", "hin", "tha", "kor", "lit", "pol", "hun", "est", "lav",  NULL,
 235     "fo ",  NULL, "rus", "chi",  NULL, "iri", "alb", "ron", "ces", "slk",
 236     "slv", "yid", "sr ", "mac", "bul", "ukr", "bel", "uzb", "kaz", "aze",
 237     /*?*/
 238     "aze", "arm", "geo", "mol", "kir", "tgk", "tuk", "mon",  NULL, "pus",
 239     "kur", "kas", "snd", "tib", "nep", "san", "mar", "ben", "asm", "guj",
 240     "pa ", "ori", "mal", "kan", "tam", "tel",  NULL, "bur", "khm", "lao",
 241     /*                   roman? arabic? */
 242     "vie", "ind", "tgl", "may", "may", "amh", "tir", "orm", "som", "swa",
 243     /*==rundi?*/
 244     NULL, "run",  NULL, "mlg", "epo",  NULL,  NULL,  NULL,  NULL,  NULL,
 245     /* 100 */
 246     NULL,  NULL,  NULL,  NULL,  NULL,  NULL,  NULL,  NULL,  NULL,  NULL,
 247     NULL,  NULL,  NULL,  NULL,  NULL,  NULL,  NULL,  NULL,  NULL,  NULL,
 248     NULL,  NULL,  NULL,  NULL,  NULL,  NULL,  NULL,  NULL, "wel", "baq",
 249     "cat", "lat", "que", "grn", "aym", "tat", "uig", "dzo", "jav"
 250 };
 251
 252 int ff_mov_iso639_to_lang(const char *lang, int mp4)
 253 {
 254     int i, code = 0;
 255
 256     /* old way, only for QT? */
 257     for (i = 0; !mp4 && i < FF_ARRAY_ELEMS(mov_mdhd_language_map); i++) {
 258         if (mov_mdhd_language_map[i] && !strcmp(lang, mov_mdhd_language_map[i]))
 259             return i;
 260     }
 261     /* XXX:can we do that in mov too? */
 262     if (!mp4)
 263         return -1;
 264     /* handle undefined as such */
 265     if (lang[0] == '\0')
 266         lang = "und";
 267     /* 5bit ascii */
 268     for (i = 0; i < 3; i++) {
 269         unsigned char c = (unsigned char)lang[i];
 270         if (c < 0x60)
 271             return -1;
 272         if (c > 0x60 + 0x1f)
 273             return -1;
 274         code <<= 5;
 275         code |= (c - 0x60);
 276     }
 277     return code;
 278 }
 279
 280 int ff_mov_lang_to_iso639(unsigned code, char *to)
 281 {
 282     int i;
 283     /* is it the mangled iso code? */
 284     /* see http://www.geocities.com/xhelmboyx/quicktime/formats/mp4-layout.txt */
 285     if (code > 138) {
 286         for (i = 2; i >= 0; i--) {
 287             to[i] = 0x60 + (code & 0x1f);
 288             code >>= 5;
 289         }
 290         return 1;
 291     }
 292     /* old fashion apple lang code */
 293     if (code >= FF_ARRAY_ELEMS(mov_mdhd_language_map))
 294         return 0;
 295     if (!mov_mdhd_language_map[code])
 296         return 0;
 297     strncpy(to, mov_mdhd_language_map[code], 4);
 298     return 1;
 299 }