static int rtcp_parse_packet(RTPDemuxContext *s, const unsigned char *buf, int len) { int payload_len; while (len >= 2) { switch (buf[1]) { case RTCP_SR: if (len < 16) { av_log(NULL, AV_LOG_ERROR, "Invalid length for RTCP SR packet\n"); return AVERROR_INVALIDDATA; } payload_len = (AV_RB16(buf + 2) + 1) * 4; s->last_rtcp_ntp_time = AV_RB64(buf + 8); s->last_rtcp_timestamp = AV_RB32(buf + 16); if (s->first_rtcp_ntp_time == AV_NOPTS_VALUE) { s->first_rtcp_ntp_time = s->last_rtcp_ntp_time; if (!s->base_timestamp) s->base_timestamp = s->last_rtcp_timestamp; s->rtcp_ts_offset = s->last_rtcp_timestamp - s->base_timestamp; } buf += payload_len; len -= payload_len; break; case RTCP_BYE: return -RTCP_BYE; default: return -1; } } return -1; }