• Main Page
  • Related Pages
  • Modules
  • Data Structures
  • Files
  • File List
  • Globals

libavformat/oggparseogm.c

Go to the documentation of this file.
00001 
00025 #include <stdlib.h>
00026 #include "libavutil/intreadwrite.h"
00027 #include "libavcodec/bitstream.h"
00028 #include "libavcodec/bytestream.h"
00029 #include "avformat.h"
00030 #include "oggdec.h"
00031 #include "riff.h"
00032 
00033 static int
00034 ogm_header(AVFormatContext *s, int idx)
00035 {
00036     struct ogg *ogg = s->priv_data;
00037     struct ogg_stream *os = ogg->streams + idx;
00038     AVStream *st = s->streams[idx];
00039     const uint8_t *p = os->buf + os->pstart;
00040     uint64_t time_unit;
00041     uint64_t spu;
00042     uint32_t default_len;
00043 
00044     if(!(*p & 1))
00045         return 0;
00046     if(*p != 1)
00047         return 1;
00048 
00049     p++;
00050 
00051     if(*p == 'v'){
00052         int tag;
00053         st->codec->codec_type = CODEC_TYPE_VIDEO;
00054         p += 8;
00055         tag = bytestream_get_le32(&p);
00056         st->codec->codec_id = codec_get_id(codec_bmp_tags, tag);
00057         st->codec->codec_tag = tag;
00058     } else if (*p == 't') {
00059         st->codec->codec_type = CODEC_TYPE_SUBTITLE;
00060         st->codec->codec_id = CODEC_ID_TEXT;
00061         p += 12;
00062     } else {
00063         uint8_t acid[5];
00064         int cid;
00065         st->codec->codec_type = CODEC_TYPE_AUDIO;
00066         p += 8;
00067         bytestream_get_buffer(&p, acid, 4);
00068         acid[4] = 0;
00069         cid = strtol(acid, NULL, 16);
00070         st->codec->codec_id = codec_get_id(codec_wav_tags, cid);
00071         st->need_parsing = AVSTREAM_PARSE_FULL;
00072     }
00073 
00074     p += 4;                     /* useless size field */
00075 
00076     time_unit   = bytestream_get_le64(&p);
00077     spu         = bytestream_get_le64(&p);
00078     default_len = bytestream_get_le32(&p);
00079 
00080     p += 8;                     /* buffersize + bits_per_sample */
00081 
00082     if(st->codec->codec_type == CODEC_TYPE_VIDEO){
00083         st->codec->width = bytestream_get_le32(&p);
00084         st->codec->height = bytestream_get_le32(&p);
00085         st->codec->time_base.den = spu * 10000000;
00086         st->codec->time_base.num = time_unit;
00087         st->time_base = st->codec->time_base;
00088     } else {
00089         st->codec->channels = bytestream_get_le16(&p);
00090         p += 2;                 /* block_align */
00091         st->codec->bit_rate = bytestream_get_le32(&p) * 8;
00092         st->codec->sample_rate = spu * 10000000 / time_unit;
00093         st->time_base.num = 1;
00094         st->time_base.den = st->codec->sample_rate;
00095     }
00096 
00097     return 1;
00098 }
00099 
00100 static int
00101 ogm_dshow_header(AVFormatContext *s, int idx)
00102 {
00103     struct ogg *ogg = s->priv_data;
00104     struct ogg_stream *os = ogg->streams + idx;
00105     AVStream *st = s->streams[idx];
00106     uint8_t *p = os->buf + os->pstart;
00107     uint32_t t;
00108 
00109     if(!(*p & 1))
00110         return 0;
00111     if(*p != 1)
00112         return 1;
00113 
00114     t = AV_RL32(p + 96);
00115 
00116     if(t == 0x05589f80){
00117         st->codec->codec_type = CODEC_TYPE_VIDEO;
00118         st->codec->codec_id = codec_get_id(codec_bmp_tags, AV_RL32(p + 68));
00119         st->codec->time_base.den = 10000000;
00120         st->codec->time_base.num = AV_RL64(p + 164);
00121         st->codec->width = AV_RL32(p + 176);
00122         st->codec->height = AV_RL32(p + 180);
00123     } else if(t == 0x05589f81){
00124         st->codec->codec_type = CODEC_TYPE_AUDIO;
00125         st->codec->codec_id = codec_get_id(codec_wav_tags, AV_RL16(p + 124));
00126         st->codec->channels = AV_RL16(p + 126);
00127         st->codec->sample_rate = AV_RL32(p + 128);
00128         st->codec->bit_rate = AV_RL32(p + 132) * 8;
00129     }
00130 
00131     return 1;
00132 }
00133 
00134 static int
00135 ogm_packet(AVFormatContext *s, int idx)
00136 {
00137     struct ogg *ogg = s->priv_data;
00138     struct ogg_stream *os = ogg->streams + idx;
00139     uint8_t *p = os->buf + os->pstart;
00140     int lb;
00141 
00142     if(*p & 8)
00143         os->pflags |= PKT_FLAG_KEY;
00144 
00145     lb = ((*p & 2) << 1) | ((*p >> 6) & 3);
00146     os->pstart += lb + 1;
00147     os->psize -= lb + 1;
00148 
00149     return 0;
00150 }
00151 
00152 const struct ogg_codec ff_ogm_video_codec = {
00153     .magic = "\001video",
00154     .magicsize = 6,
00155     .header = ogm_header,
00156     .packet = ogm_packet
00157 };
00158 
00159 const struct ogg_codec ff_ogm_audio_codec = {
00160     .magic = "\001audio",
00161     .magicsize = 6,
00162     .header = ogm_header,
00163     .packet = ogm_packet
00164 };
00165 
00166 const struct ogg_codec ff_ogm_text_codec = {
00167     .magic = "\001text",
00168     .magicsize = 5,
00169     .header = ogm_header,
00170     .packet = ogm_packet
00171 };
00172 
00173 const struct ogg_codec ff_ogm_old_codec = {
00174     .magic = "\001Direct Show Samples embedded in Ogg",
00175     .magicsize = 35,
00176     .header = ogm_dshow_header,
00177     .packet = ogm_packet
00178 };

Generated on Sat Feb 16 2013 09:23:15 for ffmpeg by  doxygen 1.7.1