| Message ID | 20240904080652.3486-1-jon@jonb.org |
|---|---|
| State | New |
| Headers | show |
| Series | [FFmpeg-devel] avformat/rtpdec: fix integer overflow in start_time_realtime calculation | expand |
| Context | Check | Description |
|---|---|---|
| yinshiyou/make_loongarch64 | success | Make finished |
| yinshiyou/make_fate_loongarch64 | success | Make fate finished |
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
diff --git a/libavformat/rtsp.c b/libavformat/rtsp.c index d8f45cf8d5..c48fa26d90 100644 --- a/libavformat/rtsp.c +++ b/libavformat/rtsp.c @@ -2320,7 +2320,7 @@ redo: } // Make real NTP start time available in AVFormatContext if (s->start_time_realtime == AV_NOPTS_VALUE) { - s->start_time_realtime = av_rescale (rtpctx->first_rtcp_ntp_time - (NTP_OFFSET << 32), 1000000, 1LL << 32); + s->start_time_realtime = av_rescale (rtpctx->first_rtcp_ntp_time, 1000000, 1LL << 32) - NTP_OFFSET_US; if (rtpctx->st) { s->start_time_realtime -= av_rescale_q (rtpctx->rtcp_ts_offset, rtpctx->st->time_base, AV_TIME_BASE_Q);
From: Jonathan Baudanza <jon@jonb.org> I encountered this problem with NTP timestamps that are extremely old, like from January, 1990. Although RFC3550 suggests that the timestamps in the RTCP packets use the actual wallclock, some implementations use other clocks, such as the CLOCK_MONOTONIC on linux. I'm my case, I'm dealing with packets from mediasoup. Without this patch, start_time_realtime shows up in the distance future instead of around Jan 1900. --- libavformat/rtsp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)