[FFmpeg-devel] [PATCH 1/3] lavf/riffenc: Improve spec compliance

[Mats Peterson]

Mats Peterson <matsp888-at-yahoo.com at ffmpeg.org> skrev: (12 mars 2016 12:25:30 CET)
>Mats Peterson <matsp888-at-yahoo.com at ffmpeg.org> skrev: (12 mars 2016
>12:14:03 CET)
>>On 03/12/2016 12:08 PM, Mats Peterson wrote:
>>> On 03/12/2016 11:53 AM, Mats Peterson wrote:
>>>> On 03/12/2016 11:48 AM, Mats Peterson wrote:
>>>>> On 03/12/2016 11:43 AM, Mats Peterson wrote:
>>>>>>>>>> why do you think they are written by libavformat ?
>>>>>>>>>>
>>>>>>>>>> i see:
>>>>>>>>>> "C:\PROGRAM FILES\ASUS\ASUS LIVE\ASUSLIVE.EXE -AVICAP32- ASUS
>>Video
>>>>>>>>>> Capture Driver, Version:  3.8.2.2"
>>>>>>>>>>
>>>>>>>>>> in asv2_320x240_3.avi
>>>>>>>>>>
>>>>>>>>>>
>>>>>>
>>>>>> Regarding asv1/asv2, they do use 48 in biSize, but since there is
>>no
>>>>>> official documentation for these codecs that explicitly mentions
>>that
>>>>>> biSize should be 48 (which breaks the specs), it's plain wrong to
>>use
>>>>>> anything else than 40.
>>>>>>
>>>>>
>>>>> Furthermore, any "global headers" in *any* codec have nothing to
>do
>>with
>>>>> the BITMAPINFOHEADER. They aren't connected in any way. The size
>of
>>the
>>>>> BITMAPINFOHEADER is 40, so biSize should always be 40, since it
>>defines
>>>>> the size of the BITMAPINFOHEADER, not the size of the
>>BITMAPINFOHEADER +
>>>>> extra data.
>>>>>
>>>>> Mats
>>>>>
>>>>
>>>> If it wasn't for the braindead specification of HuffYUV with its
>own
>>>> BITMAPINFOHEADER variant, this would be a piece of cake. Always use
>>40
>>>> in biSize.
>>>>
>>>> Mats
>>>>
>>>> _______________________________________________
>>>
>>> I vote for using huffyuv and ffvhuff (since it's a variant of
>>huffyuv)
>>> as the only exceptions to using 40 bytes in biSize, regardless of
>any
>>> non-conformant existing or future stuff.
>>>
>>
>>If the authors of future specs should happen to think that biSize
>>should 
>>be anything else than 40, we'd better tell them the facts.
>>
>>Mats
>>
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>
>Perhaps you can use my latest 2-part patch set that includes asv1 and
>asv2 in the "exception list", but thaf's it. No more entries should
>ever need to be added to this list.
>
>Mats
>-- 
>Mats Peterson
>http://matsp888.no-ip.org/~mats/
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>ffmpeg-devel at ffmpeg.org
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In fact, it's wrong to include asv1 and asv2, since there are no specs available. You decide. I'll stop now.
-- 
Mats Peterson
http://matsp888.no-ip.org/~mats/