[FFmpeg-devel] [PATCH 1/2] libwebpenc_animencoder: zero initialize the WebPAnimEncoderOptions struct

[Michael Niedermayer]

On Thu, Mar 17, 2016 at 09:47:10PM -0300, James Almer wrote:
> On 3/17/2016 3:33 PM, Michael Niedermayer wrote:
> > On Thu, Mar 17, 2016 at 01:15:23PM -0300, James Almer wrote:
> >> On 3/17/2016 1:02 PM, Michael Niedermayer wrote:
> >>> On Thu, Mar 17, 2016 at 11:06:29AM -0300, James Almer wrote:
> >>>> On 3/17/2016 4:32 AM, wm4 wrote:
> >>>>> On Thu, 17 Mar 2016 01:03:49 -0300
> >>>>> James Almer <jamrial at gmail.com> wrote:
> >>>>>
> >>>>>> This zeroes the WebPAnimEncoderOptions.verbose field, silencing library info messages
> >>>>>> printed to stderr.
> >>>>>>
> >>>>>> Signed-off-by: James Almer <jamrial at gmail.com>
> >>>>>> ---
> >>>>>>  libavcodec/libwebpenc_animencoder.c | 2 +-
> >>>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>>>>>
> >>>>>> diff --git a/libavcodec/libwebpenc_animencoder.c b/libavcodec/libwebpenc_animencoder.c
> >>>>>> index d7437a9..35c456a 100644
> >>>>>> --- a/libavcodec/libwebpenc_animencoder.c
> >>>>>> +++ b/libavcodec/libwebpenc_animencoder.c
> >>>>>> @@ -41,7 +41,7 @@ static av_cold int libwebp_anim_encode_init(AVCodecContext *avctx)
> >>>>>>      int ret = ff_libwebp_encode_init_common(avctx);
> >>>>>>      if (!ret) {
> >>>>>>          LibWebPAnimContext *s = avctx->priv_data;
> >>>>>> -        WebPAnimEncoderOptions enc_options;
> >>>>>> +        WebPAnimEncoderOptions enc_options = { 0 };
> >>>>>>          WebPAnimEncoderOptionsInit(&enc_options);
> >>>>>>          // TODO(urvang): Expose some options on command-line perhaps.
> >>>>>>          s->enc = WebPAnimEncoderNew(avctx->width, avctx->height, &enc_options);
> >>>>>
> >>>>> Does this mean it was reading uninitialized values from the stack?
> >>>>
> >>>> Apparently. Should i backport this?
> >>>
> >>> please backport if older releases are affected
> >>
> >> 2.7 and newer, yes.
> >>
> >>>
> >>> also my gcc is not fully happy about this:
> >>> libavcodec/libwebpenc_animencoder.c: In function ‘libwebp_anim_encode_init’:
> >>> libavcodec/libwebpenc_animencoder.c:44:9: warning: missing braces around initializer [-Wmissing-braces]
> >>> libavcodec/libwebpenc_animencoder.c:44:9: warning: (near initialization for ‘enc_options.anim_params’) [-Wmissing-braces]
> >>>
> >>
> >> Odd, GCC 5.3 doesn't complain, at least not when targeting mingw-w64.
> >> anim_params is a WebPMuxAnimParams struct within the WebPAnimEncoderOptions struct,
> >> and WebPAnimEncoderOptionsInit() initializes it to default values anyway, so probably
> >> not an issue.
> >>
> >> In any case, would something like 
> >>
> >> WebPAnimEncoderOptions enc_options = { .anim_params = { 0 }, 0 };
> > 
> > that fixes it, also
> > WebPAnimEncoderOptions enc_options = { { 0 } };
> > Fixes it too
> 
> Pushed that then.

thanks

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

He who knows, does not speak. He who speaks, does not know. -- Lao Tsu
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