[FFmpeg-devel] [PATCH]Add a 4444 profile to a prores encoder

[Robert Krüger]

On Thu, Sep 13, 2012 at 4:35 PM, Derek Buitenhuis
<derek.buitenhuis at gmail.com> wrote:
> On 13/09/2012 9:11 AM, Robert Krüger wrote:
>> creating a frame with thin colored lines, that make the chroma
>> subsampling obvious would certainly reveal if it's correctly decoded
>> as 444. If you want I could do that.
>
> It's supposed to be 4:4:4:4, not 4:4:4.
>
Of course but since we know ffmpeg doesn't write the alpha information
into the file (at least that's my understanding but that could be
verified by directly transcoding a PNG with alpha to prores, which I
haven't done yet), the only remaining thing to check is whether chroma
subsampling looks ok when Quicktime decodes the file. At least that is
how I understood Carl.