[FFmpeg-devel] [PATCH]ffplay 2/2: Fix subtitle rendering for special cases

Björn Axelsson gecko
Mon Feb 9 00:18:32 CET 2009


>On Sun, 8 Feb 2009, Robert Swain wrote:
>
>> 2009/2/6 Bj?rn Axelsson <gecko at acc.umu.se>:
>> On Thu, 5 Feb 2009, Michael Niedermayer wrote:
>>> > blend_subrect_2.diff:
>>> > Fix blend_subrect for even-width subrects positioned on odd columns.
>>> >
>>> > When a subrect starts on an odd column, the first column is rendered
>>> > separately and the chroma pointers are increased by one as if two
>>> > columns
>>> > were rendered. If the subrect had an even width to start width, the
>>> > rest
>>> > of the subrect has now an odd width and the final column is rendered
>>> > separately, also increasing the chroma pointers as if two columns
>>> > were
>>> > rendered. This results in the chroma part of the subtitle getting
>>> > offset
>>> > one additional sample to the right for each row.
>>> > The effect can be seen in the first, the sixth and the seventh
>>> > subtitles
>>> > of the sample[1].
>>>
>>> this change looks wrong
>>
>> Here's a cleaner approach...
>
>I'm not sure if I'm doing something wrong but I don't see any
>subtitles when playing that sample using ffplay. What is required to
>test this patch?

Press t when playing to select the first subtitle stream.

-- 
Bj?rn Axelsson




More information about the ffmpeg-devel mailing list