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avformat/rtpdec: int overflow in start_time_realtime

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This was previously adjusted by me in 6b3f9c2e92.
Unfortunately, I traded one integer overflow bug for
another.

Currently, NTP timestamps that exceed INT64_MAX
(~Jan 20, 1968) will cause an overflow when passed
to av_rescale.

This patch replaces av_rescale, which operates on
int64_t, with ff_parse_ntp_time, which operates on
uint64_t. This will give the correct values for
timestamps back around the NTP epoch and present day
timestamps.

Fixes ticket #11388.

Signed-off-by: Martin Storsjö <martin@martin.st>
This commit is contained in:
Jonathan Baudanza 2025-01-08 09:22:13 +09:00 • committed by Martin Storsjö
parent 251de1791e
commit c0fbb6d5b7
1 changed files with 1 additions and 1 deletions
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2
libavformat/rtsp.c
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@ -2320,7 +2320,7 @@ redo:
} }
// Make real NTP start time available in AVFormatContext // Make real NTP start time available in AVFormatContext
if (s->start_time_realtime == AV_NOPTS_VALUE) { if (s->start_time_realtime == AV_NOPTS_VALUE) {
s->start_time_realtime = av_rescale (rtpctx->first_rtcp_ntp_time, 1000000, 1LL << 32) - NTP_OFFSET_US; s->start_time_realtime = ff_parse_ntp_time(rtpctx->first_rtcp_ntp_time) - NTP_OFFSET_US;
if (rtpctx->st) { if (rtpctx->st) {
s->start_time_realtime -= s->start_time_realtime -=
av_rescale_q (rtpctx->rtcp_ts_offset, rtpctx->st->time_base, AV_TIME_BASE_Q); av_rescale_q (rtpctx->rtcp_ts_offset, rtpctx->st->time_base, AV_TIME_BASE_Q);