int ff_mp4_read_dec_config_descr(AVFormatContext *fc, AVStream *st, AVIOContext *pb) { int len, tag; int object_type_id = avio_r8(pb); avio_r8(pb); /* stream type */ avio_rb24(pb); /* buffer size db */ avio_rb32(pb); /* max bitrate */ avio_rb32(pb); /* avg bitrate */ if(avcodec_is_open(st->codec)) { av_log(fc, AV_LOG_DEBUG, "codec open in read_dec_config_descr\n"); return -1; } st->codec->codec_id= ff_codec_get_id(ff_mp4_obj_type, object_type_id); av_dlog(fc, "esds object type id 0x%02x\n", object_type_id); len = ff_mp4_read_descr(fc, pb, &tag); if (tag == MP4DecSpecificDescrTag) { av_dlog(fc, "Specific MPEG4 header len=%d\n", len); if (!len || (uint64_t)len > (1<<30)) return -1; av_free(st->codec->extradata); if (ff_alloc_extradata(st->codec, len)) return AVERROR(ENOMEM); avio_read(pb, st->codec->extradata, len); if (st->codec->codec_id == AV_CODEC_ID_AAC) { MPEG4AudioConfig cfg = {0}; avpriv_mpeg4audio_get_config(&cfg, st->codec->extradata, st->codec->extradata_size * 8, 1); st->codec->channels = cfg.channels; if (cfg.object_type == 29 && cfg.sampling_index < 3) // old mp3on4 st->codec->sample_rate = avpriv_mpa_freq_tab[cfg.sampling_index]; else if (cfg.ext_sample_rate) st->codec->sample_rate = cfg.ext_sample_rate; else st->codec->sample_rate = cfg.sample_rate; av_dlog(fc, "mp4a config channels %d obj %d ext obj %d " "sample rate %d ext sample rate %d\n", st->codec->channels, cfg.object_type, cfg.ext_object_type, cfg.sample_rate, cfg.ext_sample_rate); if (!(st->codec->codec_id = ff_codec_get_id(mp4_audio_types, cfg.object_type))) st->codec->codec_id = AV_CODEC_ID_AAC; } } return 0; }