Ah, realized this approach can work for wrap_bits == 64 too. Updated the
patch.
On Mon, Nov 20, 2017 at 5:42 PM, Dale Curtis <dalecur...@chromium.org>
wrote:
> On Mon, Nov 20, 2017 at 2:24 PM, Michael Niedermayer <
> mich...@niedermayer.cc> wrote:
>
>>
>> I think that could end with the correct result
>>
>>
> Thanks for the review. Done.
>
> - dale
>
From 6f087bbdb6499dc21a53fcb838348ea271d4ca5a Mon Sep 17 00:00:00 2001
From: Dale Curtis <dalecur...@chromium.org>
Date: Fri, 17 Nov 2017 13:35:56 -0800
Subject: [PATCH] [avformat] Prevent undefined shift with wrap_bits > 64.
2LL << (wrap_bits=64 - 1) does not fit in int64_t; change the
code to use a uint64_t (2ULL) and apply the check used in other
places to ensure wrap_bits <= 64.
Signed-off-by: Dale Curtis <dalecur...@chromium.org>
---
libavformat/utils.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/libavformat/utils.c b/libavformat/utils.c
index ff5e14df6c..2cf8d61e82 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -1738,9 +1738,9 @@ int av_read_frame(AVFormatContext *s, AVPacket *pkt)
// current one had no dts, we will set this to AV_NOPTS_VALUE.
int64_t last_dts = next_pkt->dts;
while (pktl && next_pkt->pts == AV_NOPTS_VALUE) {
- if (pktl->pkt.stream_index == next_pkt->stream_index &&
- (av_compare_mod(next_pkt->dts, pktl->pkt.dts, 2LL << (wrap_bits - 1)) < 0)) {
- if (av_compare_mod(pktl->pkt.pts, pktl->pkt.dts, 2LL << (wrap_bits - 1))) {
+ if (pktl->pkt.stream_index == next_pkt->stream_index && wrap_bits <= 64 &&
+ av_compare_mod(next_pkt->dts, pktl->pkt.dts, 2ULL << (wrap_bits - 1)) < 0) {
+ if (av_compare_mod(pktl->pkt.pts, pktl->pkt.dts, 2ULL << (wrap_bits - 1))) {
// not B-frame
next_pkt->pts = pktl->pkt.dts;
}
--
2.15.0.448.gf294e3d99a-goog
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