On 26/03/18 22:44, Michael Niedermayer wrote:
> On Mon, Mar 26, 2018 at 08:34:06AM +0200, Paul B Mahol wrote:
>> On 3/26/18, Michael Niedermayer <mich...@niedermayer.cc> wrote:
>>> On Wed, Mar 21, 2018 at 09:18:21AM +0100, Paul B Mahol wrote:
>>>> On 3/20/18, Michael Niedermayer <mich...@niedermayer.cc> wrote:
>>>>> Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc>
>>>>> ---
>>>>> libavfilter/vf_scale.c | 7 ++++++-
>>>>> 1 file changed, 6 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/libavfilter/vf_scale.c b/libavfilter/vf_scale.c
>>>>> index 9f45032e85..2f6fa4791d 100644
>>>>> --- a/libavfilter/vf_scale.c
>>>>> +++ b/libavfilter/vf_scale.c
>>>>> @@ -407,6 +407,7 @@ static int filter_frame(AVFilterLink *link, AVFrame
>>>>> *in)
>>>>> AVFilterLink *outlink = link->dst->outputs[0];
>>>>> AVFrame *out;
>>>>> const AVPixFmtDescriptor *desc =
>>>>> av_pix_fmt_desc_get(link->format);
>>>>> + const AVPixFmtDescriptor *out_desc =
>>>>> av_pix_fmt_desc_get(outlink->format);
>>>>> char buf[32];
>>>>> int in_range;
>>>>>
>>>>> @@ -497,7 +498,11 @@ static int filter_frame(AVFilterLink *link,
>>>>> AVFrame
>>>>> *in)
>>>>> table, out_full,
>>>>> brightness, contrast,
>>>>> saturation);
>>>>>
>>>>> - out->color_range = out_full ? AVCOL_RANGE_JPEG :
>>>>> AVCOL_RANGE_MPEG;
>>>>> + // color_range describes YUV, it is undefined for RGB
>>>>> + if ((out_desc->flags & AV_PIX_FMT_FLAG_RGB) &&
>>>>> out_desc->nb_components != 1) {
>>>>> + out->color_range = AVCOL_RANGE_UNSPECIFIED;
>>>>> + } else
>>>>> + out->color_range = out_full ? AVCOL_RANGE_JPEG :
>>>>> AVCOL_RANGE_MPEG;
>>>>> }
>>>>>
>>>>> av_reduce(&out->sample_aspect_ratio.num,
>>>>> &out->sample_aspect_ratio.den,
>>>>> --
>>>>> 2.16.2
>>>>>
>>>>
>>>> This is not optimal, as full color_range should remain full when not
>>>> changed.
>>>
>>> there is no range for rgb formats. The range is specific to YUV based
>>> formats.
>>> Thats, if iam guessing correctly what you meant. You did not really say
>>> which case you meant here. So maybe there is an issue and i misunderstand
>>> what you refer to
>>
>> Maybe not for swscale here but does exist otherwise.
>
> It has no meaning for RGB. There is no limited range RGB
> also, the API defines it only for YUV. So if it had meaning for RGB its not
> defined
> what meaning that would be. The ranges for luma and chroma differ so its not
> natural or obvious how to extend it to RGB.
> Iam also not aware of any specification that defines limited range RGB
See HDMI, HD-SDI, CEA-861, pretty much anything related to sending RGB over
wires in a non-PC context.
(No comment on whether it is useful to include it, but dismissing limited range
RGB as not a thing is probably not a good idea. I would kindof expect things
like DeckLink to be using limited-range RGB everywhere, but I'm not familiar
with the details there.)
- Mark
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
