[FFmpeg-devel] [PATCH] avformat/riffenc: fix handling monowhite when pix_fmt is not set

Mats Peterson matsp888 at yahoo.com
Tue Feb 23 16:14:09 CET 2016

On 02/23/2016 03:54 PM, Michael Niedermayer wrote:
> On Tue, Feb 23, 2016 at 01:41:54PM +0100, Mats Peterson wrote:
>> On 02/23/2016 01:11 PM, Michael Niedermayer wrote:
>>> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
>> When is pix_fmt AV_PIX_FMT_NONE in this context? Sorry if I sound
>> uninitiated.
> the pix_fmt describes the decoder output and encoder input
> demuxers may set it but do not have to (especially if theres nothing
> in their headers that contains that information)
> AV_PIX_FMT_NONE is the default if it has not been set
> this is documented in the header defining the field (avcodec.h)
> [...]
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel

That sounds overly paranoid. I haven't been able to produce a case where 
pix_fmt is AV_PIX_FMT_NONE here.

Please answer the following questions:

1. What about "enum AVPixelFormat pix_fmt = enc->pix_fmt"? What good 
does it do? enc->pix_fmt is already a proper AVPixelFormat enum.

2. You say that demuxers might not set the pixel format. This is on the 
muxing side though. Isn't the pixel format always set when muxing?

Mats Peterson

More information about the ffmpeg-devel mailing list