[FFmpeg-user] Use of "-color_range"

[Tim Nicholson]

On 05/07/11 14:59, Mark Himsley wrote:
> On 05/07/11 07:43, Tim Nicholson wrote:
>> On 04/07/11 22:01, Mark Himsley wrote:
[...]
>>> Hi Tim,
>>>
>>> The source says:
>>>
>>> 0 == unspecified
>>> 1 == "MPEG" range
>>> 2 == "JPEG" range
>>>
>> > Therefore, I'd expect 1 to be "broadcast" 16-235, and 2 to be "full"
>>> 0-255. I haven't tested this, just grepped through the source.
>>>
>>
>>
>> Bother! Missed that in my "find", which file was that in?
>
> ./libavcodec/avcodec.h line 502
>
> enum AVColorRange{
> AVCOL_RANGE_UNSPECIFIED=0,
> AVCOL_RANGE_MPEG =1, ///< the normal 219*2^(n-8) "MPEG" YUV ranges
> AVCOL_RANGE_JPEG =2, ///< the normal 2^n-1 "JPEG" YUV ranges
> AVCOL_RANGE_NB , ///< Not part of ABI
> };
>

Ahh, you see color_range transmogrifying into ColorRange threw me off 
the scent...

>
>> I presume that you are presuming MPEG => yuv=> 16-235 and JPEG => RGB
>> =>0-255, which is a bit woolly for such an important parameter.
>
> No. JPEG does not mandate RGB.
>

That's what I mean by woolley, its presumed in this case when it would 
be far better to use a more rigorous definition. :(

-- 
Tim

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