[FFmpeg-user] Burning DVD subtitles into video using overlay filter not working

[Paul B Mahol]

On 8/29/13, Nicolas George <nicolas.george at normalesup.org> wrote:
> Le duodi 12 fructidor, an CCXXI, Thierry Lelegard a ecrit :
>> It seems the simplest possible command to do. Please don't comment on
>> video
>> quality, it is just a test to see if the subtitles are burnt into the
>> video.
>> The resulting video does not contain subtitles.
>
> It should be working. I suggest three steps to understand how it fails:
>
> First, use -loglevel debug and look at the "palette:" lines: maybe the
> subtitles are completely transparent.
>
> Second, add a showinfo filter after the subtitles input, something like
> that:
>
>   [0:s]ashowinfo[s];[0:v][s]overlay
>
> That way, you can see if subtitles packets arrive.
>
> Third, extract the subtitles track with mkvextract, and look at the index,
> especially the size, the palette, etc.
>
> Please ignore Paul's comment, he is mistaken.

Its first time I heard that bitmap subtitles are supported.