[FFmpeg-devel] [PATCH] avformat/srtenc: avoid segmentation fault when transcoding from SSA to SRT

Gilles Chanteperdrix gilles.chanteperdrix at xenomai.org
Sun Mar 8 00:27:49 CET 2015

On Sat, Mar 07, 2015 at 11:46:44PM +0100, Nicolas George wrote:
> Le septidi 17 ventôse, an CCXXIII, Gilles Chanteperdrix a écrit :
> > You need an ASS file that produces a sub-title frame without text. I
> > have been carrying this patch since 2013, I am afraid I no longer
> > have the problematic file.
> I tried an ASS file with an empty text part, and it did not crash
> either.

Is not there some way in the ssa format to declare some graphic
elements which are not text?

> It
> is entirely possible the problem has disappeared due to some of the reworks
> of the text subtitles code since you experienced it.

In my modest experience, bugs do not just disappear if you do not
fix them.

> I am sorry to insist, but I am always suspicious of changes that go "if the
> value is not what we expect, silently ignore it", because they frequently
> should return an error or hide a bug earlier in the code; 

Maybe it is not a perfect patch, but if subtitles can contain
graphic elements mixed with text, it seems better to translate the
text only when the target codec only supports text, than to fail
with a segmentation fault.

> for these reasons,
> I would like either a more detailed analysis or a chance to see for myself
> before this patch is applied.

Just to make things clear: you will not get such an analysis for me.
I am perfectly fine with the patch applied in my local copy of

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