[FFmpeg-devel] [PATCH] lavc/avpacket: fill padding area on side data split.

[Michael Niedermayer]

On Sat, Jun 01, 2013 at 02:38:18PM +0200, Clément Bœsch wrote:
> On Sat, Jun 01, 2013 at 02:09:47PM +0200, Clément Bœsch wrote:
> > The padding data is assumed to be 0 in several places, notably in
> > subtitles. This problem was not detected with fate-sub-srt test because
> > the first element of the side data (x1) is 0 in the test, so the
> > trailing side data present in the packet wasn't read by the decoder. The
> > issue can be observed with a large enough x1.
> > 
> > It is also noted in FF_INPUT_BUFFER_PADDING_SIZE doxy that MPEG
> > bitstreams require that padding with 0, so it might fix other issues.
> > ---
> >  libavcodec/avpacket.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/libavcodec/avpacket.c b/libavcodec/avpacket.c
> > index 198365e..2bfb501 100644
> > --- a/libavcodec/avpacket.c
> > +++ b/libavcodec/avpacket.c
> > @@ -389,6 +389,7 @@ int av_packet_split_side_data(AVPacket *pkt){
> >              p-= size+5;
> >          }
> >          pkt->size -= 8;
> > +        memset(pkt->data + pkt->size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
> >          pkt->side_data_elems = i+1;
> >          return 1;
> >      }
> 
> New version after Michael's comment on IRC.
> 
> -- 
> Clément B.

>  avpacket.c |    9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 6b869eb6c8897a813118b4d75b245be711945ed2  0001-lavc-avpacket-fill-padding-area-on-side-data-split.patch
> From e05a63d6a48f06639e2002a5c615528a7a7fb8b6 Mon Sep 17 00:00:00 2001
> From: =?UTF-8?q?Cl=C3=A9ment=20B=C5=93sch?= <ubitux at gmail.com>
> Date: Sat, 1 Jun 2013 14:07:24 +0200
> Subject: [PATCH] lavc/avpacket: fill padding area on side data split.
> 
> The padding data is assumed to be 0 in several places, notably in
> subtitles. This problem was not detected with fate-sub-srt test because
> the first element of the side data (x1) is 0 in the test, so the
> trailing side data present in the packet wasn't read by the decoder. The
> issue can be observed with a large enough x1.
> 
> It is also noted in FF_INPUT_BUFFER_PADDING_SIZE doxy that MPEG
> bitstreams require that padding with 0, so it might fix other issues.
> ---
>  libavcodec/avpacket.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)

LGTM

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The real ebay dictionary, page 2
"100% positive feedback" - "All either got their money back or didnt complain"
"Best seller ever, very honest" - "Seller refunded buyer after failed scam"
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: Digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20130601/b50982f3/attachment.asc>