static int rtp_parse_packet_internal(RTPDemuxContext *s, AVPacket *pkt, const uint8_t *buf, int len) { unsigned int ssrc, h; int payload_type, seq, ret, flags = 0; int ext; AVStream *st; uint32_t timestamp; int rv= 0; ext = buf[0] & 0x10; payload_type = buf[1] & 0x7f; if (buf[1] & 0x80) flags |= RTP_FLAG_MARKER; seq = AV_RB16(buf + 2); timestamp = AV_RB32(buf + 4); ssrc = AV_RB32(buf + 8); /* store the ssrc in the RTPDemuxContext */ s->ssrc = ssrc; /* NOTE: we can handle only one payload type */ if (s->payload_type != payload_type) return -1; st = s->st; // only do something with this if all the rtp checks pass... if(!rtp_valid_packet_in_sequence(&s->statistics, seq)) { av_log(st?st->codec:NULL, AV_LOG_ERROR, "RTP: PT=%02x: bad cseq %04x expected=%04x\n", payload_type, seq, ((s->seq + 1) & 0xffff)); return -1; } if (buf[0] & 0x20) { int padding = buf[len - 1]; if (len >= 12 + padding) len -= padding; } s->seq = seq; len -= 12; buf += 12; /* RFC 3550 Section 5.3.1 RTP Header Extension handling */ if (ext) { if (len < 4) return -1; /* calculate the header extension length (stored as number * of 32-bit words) */ ext = (AV_RB16(buf + 2) + 1) << 2; if (len < ext) return -1; // skip past RTP header extension len -= ext; buf += ext; } if (!st) { /* specific MPEG2TS demux support */ ret = ff_mpegts_parse_packet(s->ts, pkt, buf, len); /* The only error that can be returned from ff_mpegts_parse_packet * is "no more data to return from the provided buffer", so return * AVERROR(EAGAIN) for all errors */ if (ret < 0) return AVERROR(EAGAIN); if (ret < len) { s->read_buf_size = len - ret; memcpy(s->buf, buf + ret, s->read_buf_size); s->read_buf_index = 0; return 1; } return 0; } else if (s->parse_packet) { rv = s->parse_packet(s->ic, s->dynamic_protocol_context, s->st, pkt, &timestamp, buf, len, flags); } else { // at this point, the RTP header has been stripped; This is ASSUMING that there is only 1 CSRC, which in't wise. switch(st->codec->codec_id) { case AV_CODEC_ID_MP2: case AV_CODEC_ID_MP3: /* better than nothing: skip mpeg audio RTP header */ if (len <= 4) return -1; h = AV_RB32(buf); len -= 4; buf += 4; av_new_packet(pkt, len); memcpy(pkt->data, buf, len); break; case AV_CODEC_ID_MPEG1VIDEO: case AV_CODEC_ID_MPEG2VIDEO: /* better than nothing: skip mpeg video RTP header */ if (len <= 4) return -1; h = AV_RB32(buf); buf += 4; len -= 4; if (h & (1 << 26)) { /* mpeg2 */ if (len <= 4) return -1; buf += 4; len -= 4; } av_new_packet(pkt, len); memcpy(pkt->data, buf, len); break; default: av_new_packet(pkt, len); memcpy(pkt->data, buf, len); break; } pkt->stream_index = st->index; } // now perform timestamp things.... finalize_packet(s, pkt, timestamp); return rv; }