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libavformat/oggparseogm.c

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00001 
00025 #include <stdlib.h>
00026 #include "libavutil/intreadwrite.h"
00027 #include "libavcodec/get_bits.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 
00047     if(*p == 1) {
00048         p++;
00049 
00050         if(*p == 'v'){
00051             int tag;
00052             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00053             p += 8;
00054             tag = bytestream_get_le32(&p);
00055             st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, tag);
00056             st->codec->codec_tag = tag;
00057         } else if (*p == 't') {
00058             st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
00059             st->codec->codec_id = CODEC_ID_TEXT;
00060             p += 12;
00061         } else {
00062             uint8_t acid[5];
00063             int cid;
00064             st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00065             p += 8;
00066             bytestream_get_buffer(&p, acid, 4);
00067             acid[4] = 0;
00068             cid = strtol(acid, NULL, 16);
00069             st->codec->codec_id = ff_codec_get_id(ff_codec_wav_tags, cid);
00070             st->need_parsing = AVSTREAM_PARSE_FULL;
00071         }
00072 
00073         p += 4;                     /* useless size field */
00074 
00075         time_unit   = bytestream_get_le64(&p);
00076         spu         = bytestream_get_le64(&p);
00077         default_len = bytestream_get_le32(&p);
00078 
00079         p += 8;                     /* buffersize + bits_per_sample */
00080 
00081         if(st->codec->codec_type == AVMEDIA_TYPE_VIDEO){
00082             st->codec->width = bytestream_get_le32(&p);
00083             st->codec->height = bytestream_get_le32(&p);
00084             st->codec->time_base.den = spu * 10000000;
00085             st->codec->time_base.num = time_unit;
00086             st->time_base = st->codec->time_base;
00087         } else {
00088             st->codec->channels = bytestream_get_le16(&p);
00089             p += 2;                 /* block_align */
00090             st->codec->bit_rate = bytestream_get_le32(&p) * 8;
00091             st->codec->sample_rate = spu * 10000000 / time_unit;
00092             st->time_base.num = 1;
00093             st->time_base.den = st->codec->sample_rate;
00094         }
00095     } else if (*p == 3) {
00096         if (os->psize > 8)
00097             ff_vorbis_comment(s, &st->metadata, p+7, os->psize-8);
00098     }
00099 
00100     return 1;
00101 }
00102 
00103 static int
00104 ogm_dshow_header(AVFormatContext *s, int idx)
00105 {
00106     struct ogg *ogg = s->priv_data;
00107     struct ogg_stream *os = ogg->streams + idx;
00108     AVStream *st = s->streams[idx];
00109     uint8_t *p = os->buf + os->pstart;
00110     uint32_t t;
00111 
00112     if(!(*p & 1))
00113         return 0;
00114     if(*p != 1)
00115         return 1;
00116 
00117     t = AV_RL32(p + 96);
00118 
00119     if(t == 0x05589f80){
00120         st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00121         st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, AV_RL32(p + 68));
00122         st->codec->time_base.den = 10000000;
00123         st->codec->time_base.num = AV_RL64(p + 164);
00124         st->codec->width = AV_RL32(p + 176);
00125         st->codec->height = AV_RL32(p + 180);
00126     } else if(t == 0x05589f81){
00127         st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00128         st->codec->codec_id = ff_codec_get_id(ff_codec_wav_tags, AV_RL16(p + 124));
00129         st->codec->channels = AV_RL16(p + 126);
00130         st->codec->sample_rate = AV_RL32(p + 128);
00131         st->codec->bit_rate = AV_RL32(p + 132) * 8;
00132     }
00133 
00134     return 1;
00135 }
00136 
00137 static int
00138 ogm_packet(AVFormatContext *s, int idx)
00139 {
00140     struct ogg *ogg = s->priv_data;
00141     struct ogg_stream *os = ogg->streams + idx;
00142     uint8_t *p = os->buf + os->pstart;
00143     int lb;
00144 
00145     if(*p & 8)
00146         os->pflags |= AV_PKT_FLAG_KEY;
00147 
00148     lb = ((*p & 2) << 1) | ((*p >> 6) & 3);
00149     os->pstart += lb + 1;
00150     os->psize -= lb + 1;
00151 
00152     while (lb--)
00153         os->pduration += p[lb+1] << (lb*8);
00154 
00155     return 0;
00156 }
00157 
00158 const struct ogg_codec ff_ogm_video_codec = {
00159     .magic = "\001video",
00160     .magicsize = 6,
00161     .header = ogm_header,
00162     .packet = ogm_packet,
00163     .granule_is_start = 1,
00164 };
00165 
00166 const struct ogg_codec ff_ogm_audio_codec = {
00167     .magic = "\001audio",
00168     .magicsize = 6,
00169     .header = ogm_header,
00170     .packet = ogm_packet,
00171     .granule_is_start = 1,
00172 };
00173 
00174 const struct ogg_codec ff_ogm_text_codec = {
00175     .magic = "\001text",
00176     .magicsize = 5,
00177     .header = ogm_header,
00178     .packet = ogm_packet,
00179     .granule_is_start = 1,
00180 };
00181 
00182 const struct ogg_codec ff_ogm_old_codec = {
00183     .magic = "\001Direct Show Samples embedded in Ogg",
00184     .magicsize = 35,
00185     .header = ogm_dshow_header,
00186     .packet = ogm_packet,
00187     .granule_is_start = 1,
00188 };

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