[FFmpeg-user] Creating ffv1 full-range and broadcast-range files

[Robert Krüger]

On Tue, May 13, 2014 at 5:30 PM, Andy Furniss <adf.lists at gmail.com> wrote:
> Robert Krüger wrote:
>
>>> I also am not qualified in any way, but one thing to consider is
>>> sub-sampling positions.
>>>
>>> I don't know what ffmpeg does, so it may make no difference, but
>>> AIUI jpeg/mpeg1 420 is slightly different from >= mpeg2. Maybe it
>>> makes no difference, but I suppose there's a chance that it could
>>> if conversions are involved.
>>
>>
>> I compared the decoded frames' md5 hashes from the original mjpeg
>> stream and the ffv1 video (see earlier in this thread), so I would
>> assume that this does not seem to be a problem in this case.
>
>
> Yea - but the test was already yuvj, so no conversion from something
> else involving subsampling.
>

If my understanding is correct the subsampling part is not the
encoder's job, so it should not matter here. The encoder encodes an
already subsampled raw signal, so if something is wrong regarding
subsampling, it happened before the encoding step.