[FFmpeg-devel] [PATCH 1/2] avcodec: add photocd decoder

Paul B Mahol onemda at gmail.com
Tue Apr 7 14:57:52 EEST 2020


On 4/7/20, Vittorio Giovara <vittorio.giovara at gmail.com> wrote:
> On Sat, Dec 22, 2018 at 3:18 PM Paul B Mahol <onemda at gmail.com> wrote:
>
>> On 12/22/18, Steinar H. Gunderson <steinar+ffmpeg at gunderson.no> wrote:
>> > On Sat, Dec 22, 2018 at 09:04:26PM +0100, Paul B Mahol wrote:
>> >> I can not accept internal conversion to RGB. This is subsampled format
>> >> after all.
>> >
>> > Well, it's not Y'CbCr, so if so, you'd need to add a new AVPixelFormat
>> value
>> > (e.g. AV_PIX_FMT_YCC420P). I'm not sure what applications would do with
>> it
>> > except convert it to RGB, though. (You can't convert subsampled YCC to
>> > subsampled Y'CbCr without upsampling, converting and then subsampling
>> again,
>> > which is obviously lossy.)
>>
>> Unacceptable, I'm not adding another yuv420p variant.
>>
>
> Agreed, no need for another pixel format variant, but maybe you could just
> leave the buffer as is and tag the color transfer with
> AVCOL_TRC_IEC61966_2_1?

Hmm, you sure that thing is exactly same what photocd uses?
Is there a way to check it, in way that there is tool that converts
that one to 709?

> --
> Vittorio
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".


More information about the ffmpeg-devel mailing list