On Tue, Nov 21, 2017 at 03:19:38PM -0800, Dale Curtis wrote: > 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 > >
> utils.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
> 37722f8edea291bc79742519d06fbea906031074 wrap_bits_v4.patch
> 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 &&
I dont think wrap_bits can/should be > 64 or do i miss something ?
maybe a av_assert* for that would be better.
Static analyzers like coverity love to assume that a check implies
the possibility of a field having some value. That could lead to
strange things and false positves if its not actually possible
[...]
--
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
Democracy is the form of government in which you can choose your dictator
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