[FFmpeg-devel] [PATCH] AVFoundation: Add -pixel_format option

Thilo Borgmann thilo.borgmann at mail.de
Tue May 20 22:59:18 CEST 2014

Am 20.05.14 21:40, schrieb sfan5:
> Am 19.05.2014 11:16, schrieb Thilo Borgmann:
>> Am 17.05.14 18:19, schrieb sfan5:
>>> ON 11.05.2014 19:34, Carl Eugen Hoyos wrote:
>>>> sfan5 <sfan5 <at> live.de> writes:
>>>>>>> +    { AV_PIX_FMT_BGRA, kCVPixelFormatType_32BGRA },
>>>>>> This should be AV_PIX_FMT_BGR0: The camera cannot
>>>>>> record an alpha channel, the fourth channel is (or at
>>>>>> least can be) 0, so it should be ignored.
>>>>>> Same for the other 32 bit rgb formats.
>>>>> Isn't AVFoundation a generic API for video sources?
>>>>> (not only cameras)
>>>>> There might be other devices that can record RGBA.
>>>> I can't really answer this but since AVFoundation
>>>> provides transparent images for 32 bit RGB it has
>>>> to be mapped to RGB0 to work at all.
>>>> (If a user ever protests that his alpha channel
>>>> disappears, we will have to find a solution.)
>>> I've changed the mapping as suggested.
>> Have you also tried querying for device capabilities like I suggested?
>> http://article.gmane.org/gmane.comp.video.ffmpeg.devel/177722
>> -Thilo
> I haven't tried this yet but I will look into it when I have time and send a
> seperate patch if it works.
> By the way: The -pixel_format patch should be ready for merge now.

The code looks good enough. However the current behaviour in case of specifying
an unsupported pixel format is not.

I would try to fix that but these days my spare time for working on it is rare.
Whoever fixes it first, it should be adressed before merging.


More information about the ffmpeg-devel mailing list