[FFmpeg-devel] [PATCH] grayalpha pixfmt + support in pngdec

[Baptiste Coudurier]

On 6/3/10 2:25 PM, Michael Niedermayer wrote:
> On Thu, Jun 03, 2010 at 02:22:48PM -0700, Baptiste Coudurier wrote:
>> On 06/03/2010 02:16 PM, Michael Niedermayer wrote:
>>> On Thu, Jun 03, 2010 at 12:14:58PM -0700, Baptiste Coudurier wrote:
>>>> On 06/03/2010 03:45 AM, Michael Niedermayer wrote:
>>>>> On Wed, Jun 02, 2010 at 05:37:36PM -0700, Baptiste Coudurier wrote:
>>>>>> On 04/18/2010 03:57 PM, Michael Niedermayer wrote:
>>>>>>> On Sun, Apr 18, 2010 at 09:36:22PM +0200, Stefano Sabatini wrote:
>>>>>>>> On date Tuesday 2010-04-13 12:21:47 +0200, Michael Niedermayer
>>>>>>>> encoded:
>>>>>>>>> On Tue, Apr 13, 2010 at 10:34:48AM +0200, Andreas ?man wrote:
>>>>>>>>>> Kostya wrote:
>>>>>>>>>>> On Tue, Apr 13, 2010 at 09:33:51AM +0200, Andreas ?man wrote:
>>>>>>>>>>>> Michael Niedermayer wrote:
>>>>>>>>>>>>> On Mon, Apr 12, 2010 at 09:40:03PM +0200, Andreas ?man wrote:
>>>>>>>>>>>>>> Michael Niedermayer wrote:
>>>>>>>>>>>>>>> On Mon, Apr 12, 2010 at 10:43:02AM +0200, Andreas ?man wrote:
>>>>>>>>>>>>>>>> Hi
>>>>>>>>>>>>>>>> +    [PIX_FMT_GRAYALPHA] = {
>>>>>>>>>>>>>>>> +        .name = "grayalpha",
>>>>>>>>>>>>>>> where does the name grayalpha come from?
>>>>>>>>>>>>>> I just didn't come up with anything better.
>>>>>>>>>>>>>> Ideas are most welcome.
>>>>>>>>>>>>> something that is consistent with existing formats would
>>>>>>>>>>>>> be better also what is it calld in the png docs?
>>>>>>>>>>>> PNG docs seems to call it "Grayscale with alpha" or "ya".
>>>>>>>>>>>> Perhaps "ya" would be a good name then?
>>>>>>>>>>> Nej, it obviously stands for "Y(aka luma) + A(alpha)"
>>>>>>>>>>> i.e. not so good acronym.
>>>>>>>>>>
>>>>>>>>>> Kostya suggested "Y400A" on IRC.
>>>>>>>>
>>>>>>>> I'm not very happy with this name, "4XX" notation only makes sense
>>>>>>>> when we have three components, in this case I would have preferred
>>>>>>>> something of the kind GRAY8ALPHA8 or GRAYALPHA8 (consistent with
>>>>>>>> GRAY8), even YA was not that bad.
>>>>>>>
>>>>>>> GRAY*ALPHA* is inconsistent with the existing naming and gray8 is
>>>>>>> quite
>>>>>>> alone and the exception, not a good example to copy.
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>> Not that I consider this a big issue, we will eventually fix the
>>>>>>>> names
>>>>>>>> at the next major bump.
>>>>>>>
>>>>>>> The naming is good and reasonable consistent. To change it at the next
>>>>>>> maj
>>>>>>> ver
>>>>>>> bump there needs to be a problem in the existing naming and a better
>>>>>>> naming and
>>>>>>> consensus amongth the devels that the new is better and not just the
>>>>>>> yearly
>>>>>>> bikeshed style. Because every such change means everyone will have to
>>>>>>> update
>>>>>>> their applications and this is a lot of work when one considers how
>>>>>>> many
>>>>>>> applications there are. Not to mention the ones that try to support
>>>>>>> differnent
>>>>>>> lav* versions
>>>>>>>
>>>>>>
>>>>>> I need to revive this thread since I've come up with a file that I want
>>>>>> supported.
>>>>>>
>>>>>> I disagree, Y400A is a very bad name since the gray plane is coded
>>>>>> using
>>>>>> 0-255 and IMHO is not really similar to a Y plane IMHO in the YUV
>>>>>> sense,
>>>>>> if
>>>>>> you want to call it Y then YJ400A at least.
>>>>>
>>>>> the luma range, really is indicated by AVCodecContext.color_range
>>>>> the J pixel formats are deprecated.
>>>>
>>>> Then mark them as so,
>>>
>>> done
>>>
>>>
>>>> and start changing the code, because I would
>>>> personally not remove something that has been in the code so long ;)
>>>
>>> changing lavc is not hard but applications need to be changed too
>>> and i just now marked it as deprecated ...
>>> maybe we can add YJ400A as an intermediate workaround because the other
>>> formats where not correctly marked as deprecated as i thought they where
>>
>> Whatever, I'm against this name, stefano as well.
>> Shall we start a vote ?
>
> yes of course ;)
> but first we should wait 48h for people to propose options
>
> currently we have
> YJ400A
> GRAY8A
> GRAY8ALPHA8
> GRAYALPHA8

GRAY8A input support in libswscale :)

-- 
Baptiste COUDURIER
Key fingerprint                 8D77134D20CC9220201FC5DB0AC9325C5C1ABAAA
FFmpeg maintainer                                  http://www.ffmpeg.org
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