static int read_part_of_packet(AVFormatContext *s, int64_t *pts, int *len, int *strid, int read_packet) { AVIOContext *pb = s->pb; PVAContext *pvactx = s->priv_data; int syncword, streamid, reserved, flags, length, pts_flag; int64_t pva_pts = AV_NOPTS_VALUE, startpos; int ret; recover: startpos = avio_tell(pb); syncword = avio_rb16(pb); streamid = avio_r8(pb); avio_r8(pb); /* counter not used */ reserved = avio_r8(pb); flags = avio_r8(pb); length = avio_rb16(pb); pts_flag = flags & 0x10; if (syncword != PVA_MAGIC) { pva_log(s, AV_LOG_ERROR, "invalid syncword\n"); return AVERROR(EIO); } if (streamid != PVA_VIDEO_PAYLOAD && streamid != PVA_AUDIO_PAYLOAD) { pva_log(s, AV_LOG_ERROR, "invalid streamid\n"); return AVERROR(EIO); } if (reserved != 0x55) { pva_log(s, AV_LOG_WARNING, "expected reserved byte to be 0x55\n"); } if (length > PVA_MAX_PAYLOAD_LENGTH) { pva_log(s, AV_LOG_ERROR, "invalid payload length %u\n", length); return AVERROR(EIO); } if (streamid == PVA_VIDEO_PAYLOAD && pts_flag) { pva_pts = avio_rb32(pb); length -= 4; } else if (streamid == PVA_AUDIO_PAYLOAD) { /* PVA Audio Packets either start with a signaled PES packet or * are a continuation of the previous PES packet. New PES packets * always start at the beginning of a PVA Packet, never somewhere in * the middle. */ if (!pvactx->continue_pes) { int pes_signal, pes_header_data_length, pes_packet_length, pes_flags; unsigned char pes_header_data[256]; pes_signal = avio_rb24(pb); avio_r8(pb); pes_packet_length = avio_rb16(pb); pes_flags = avio_rb16(pb); pes_header_data_length = avio_r8(pb); if (pes_signal != 1 || pes_header_data_length == 0) { pva_log(s, AV_LOG_WARNING, "expected non empty signaled PES packet, " "trying to recover\n"); avio_skip(pb, length - 9); if (!read_packet) return AVERROR(EIO); goto recover; } ret = avio_read(pb, pes_header_data, pes_header_data_length); if (ret != pes_header_data_length) return ret < 0 ? ret : AVERROR_INVALIDDATA; length -= 9 + pes_header_data_length; pes_packet_length -= 3 + pes_header_data_length; pvactx->continue_pes = pes_packet_length; if (pes_flags & 0x80 && (pes_header_data[0] & 0xf0) == 0x20) pva_pts = ff_parse_pes_pts(pes_header_data); } pvactx->continue_pes -= length; if (pvactx->continue_pes < 0) { pva_log(s, AV_LOG_WARNING, "audio data corruption\n"); pvactx->continue_pes = 0; } } if (pva_pts != AV_NOPTS_VALUE) av_add_index_entry(s->streams[streamid-1], startpos, pva_pts, 0, 0, AVINDEX_KEYFRAME); *pts = pva_pts; *len = length; *strid = streamid; return 0; }