[Ffmpeg-devel] [PATCH] GIF encoder

[Baptiste Coudurier]

Baptiste Coudurier wrote:
> Michael Niedermayer wrote:
>> Hi
>>
>> On Wed, Nov 01, 2006 at 11:12:07PM +0100, Baptiste Coudurier wrote:
>>> Michael Niedermayer wrote:
>>>> Hi
>>>>
>>>> On Wed, Nov 01, 2006 at 09:11:27PM +0100, Baptiste Coudurier wrote:
>>>>> Hi
>>>>>
>>>>> GIF encoder ported from lavf to lavc.
>>>>> Very simple encoder (no compression), if someone is motivated to code
>>>>> LZW compression it would be nice.
>>>>>
>>>>> Now we can remove AVImageFormat from lavf without regression.
>>>> what about animated gifs, do they work too with your encoder?
>>>>
>>>> and do the regression tests pass if the new encoder is used instead
>>>> of the old? if not why not?
>>> In fact, goal is to remove AVImageFormat, old gif muxer/demuxer in lavf
>>> are still present and they provide animated gif support.
>>> Now with encoder, image format can be dropped in favor of image2.
>> yes but what is missing for animated gif support? it cant be much ...
>>
>> the idea that we would have a libavformat/gif.c which could do animated
>> gif while libavcodec/gif.c wouldnt be able to is a lttle strange ...
>>
>> but if you dont want to support it its still better to be able to finally
>> kill AVImageFormat at least even if we have to keep libavformat/gif.c ...
> 
> Encoder as is will encode each picture as a standalone gif image.
> 
> I see animated gif more as muxing feature (adding gce extension with
> correct delay based on timebase).
> 
> And yes, for now I want to kill AVImageFormat.
> 
>>>> if yes to both then apply it
>>>>
>>>> [...]
>>>>> -    put_byte(pb, 0x00); /* end of image block */
>>>>> -
>>>>> +    bytestream_put_byte(bytestream, 0x00); /* end of image block */
>>>>> +    bytestream_put_byte(bytestream, 0x3b);
>>>>>      return 0;
>>>>>  }
>>>> this looks different?
>>>>
>>> In fact line was moved from gif_write to gif_image_write_image, but I
>>> can let it in encode_frame if you want.
>> doesnt help, libavformat/gif.c wrote it only at the end of the movie
>> IIRC
> 
> At the end of image writing also, see gif_write function.
> 
>> note you can easily detect the end of the movie by missusing CODEC_CAP_DELAY
>> and writing the 0x3b if theres no input pic
>>
> 
> Thanks for the tip.
> 

Applied.

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Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
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