[FFmpeg-devel] [PATCH v7] lavc/rawdec: Remove monowhite switching code for 1 bpp AVI without a palette

[Mats Peterson]

On 02/11/2016 01:11 AM, Mats Peterson wrote:
> On 02/11/2016 12:07 AM, Mats Peterson wrote:
>> For black & white AVI or QuickTime files, in order to produce a
>> monochrome nut file, force the pixel format with "-pix_fmt monow" or
>> "-pix_fmt monob".
>>
>> Unfortunately, there is a problem with converting from pal8 to monow,
>> and I know what it is now. There seems to be some weird dithering going
>> on of the white color, so there will be black pixels here and there in
>> the monow output. A better way is to use "ffmpeg -i 1bpp.avi -vcodec
>> copy -vtag B1W0 1bpp.nut". The "-vtag" option is currently needed,
>> otherwise FFmpeg will use a RGB[15] codec tag for some reason.
>>
>
> An alternative is to use "-sws_dither none", it seems to work fine. I
> just don't understand why the fully white color is dithered at all when
> converting from pal8 to monow.
>

Nope, doesn't work. I forgot to use "-pix_fmt monow", and it's the same 
as before.

Mats