static int au_read_header(AVFormatContext *s) { int size; unsigned int tag; AVIOContext *pb = s->pb; unsigned int id, channels, rate; enum AVCodecID codec; AVStream *st; /* check ".snd" header */ tag = avio_rl32(pb); if (tag != MKTAG('.', 's', 'n', 'd')) return -1; size = avio_rb32(pb); /* header size */ avio_rb32(pb); /* data size */ id = avio_rb32(pb); rate = avio_rb32(pb); channels = avio_rb32(pb); codec = ff_codec_get_id(codec_au_tags, id); if (!av_get_bits_per_sample(codec)) { av_log_ask_for_sample(s, "could not determine bits per sample\n"); return AVERROR_PATCHWELCOME; } if (channels == 0 || channels > 64) { av_log(s, AV_LOG_ERROR, "Invalid number of channels %d\n", channels); return AVERROR_INVALIDDATA; } if (size >= 24) { /* skip unused data */ avio_skip(pb, size - 24); } /* now we are ready: build format streams */ st = avformat_new_stream(s, NULL); if (!st) return -1; st->codec->codec_type = AVMEDIA_TYPE_AUDIO; st->codec->codec_tag = id; st->codec->codec_id = codec; st->codec->channels = channels; st->codec->sample_rate = rate; avpriv_set_pts_info(st, 64, 1, rate); return 0; }