[vlc-devel] [PATCH] logo: output in RGBA

[Steve Lhomme]

On 2019-05-29 16:26, Alexandre Janniaux wrote:
> Hi,
> 
> I agree with the use case, but now that we're starting to have hw
> accelerated SPU scaling, it gets more sense to also support the
> video output case. However, I also agree that forcing RGBA instead
> of YUV might not be the ideal solution.
> 
> Shouldn't the conversion be handled by the SPU system from the
> original chroma of the file?

I agree it's rather weird to force a conversion when it may not be 
needed or counter intuitive.

> About premultiplied, VLC doesn't really support premultiplied in any
> case and the biggest clients are still d3d11/9 and opengl, so I think
> it can be forgotten for now.

I can't find a display module that accepts YUVA a subpicture chroma.

It may be useful when blending is necessary, when transcoding for 
example. But in that rare case there's a conversion if necessary.

> Greats,
> 
> --
> Alexandre Janniaux
> VideoLabs
> 
> On Wed, May 29, 2019 at 04:57:00PM +0300, Rémi Denis-Courmont wrote:
>> Hi,
>>
>> Logo was designed, and is primarily intended for use with encoding. It uses YUVA because that's easy to blend into video.
>>
>> And while it is true that vout display expect RGBA, they don't seem to agree on whether it should be premultipled or not.
>>
>> Le 29 mai 2019 14:23:55 GMT+03:00, Steve Lhomme <robux4 at ycbcr.xyz> a écrit :
>>> That's what most display module will prefer anyway
>>> ---
>>> modules/spu/logo.c | 4 ++--
>>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/modules/spu/logo.c b/modules/spu/logo.c
>>> index c120b503e1..0b2ddd3ca8 100644
>>> --- a/modules/spu/logo.c
>>> +++ b/modules/spu/logo.c
>>> @@ -380,7 +380,7 @@ static subpicture_t *FilterSub( filter_t *p_filter,
>>> vlc_tick_t date )
>>>          goto exit;
>>>
>>>      /* Create new SPU region */
>>> -    video_format_Init( &fmt, VLC_CODEC_YUVA );
>>> +    video_format_Init( &fmt, VLC_CODEC_RGBA );
>>>      fmt.i_sar_num = fmt.i_sar_den = 1;
>>> fmt.i_width = fmt.i_visible_width = p_pic->p[Y_PLANE].i_visible_pitch;
>>> fmt.i_height = fmt.i_visible_height =
>>> p_pic->p[Y_PLANE].i_visible_lines;
>>> @@ -612,7 +612,7 @@ static picture_t *LoadImage( vlc_object_t *p_this,
>>> const char *psz_filename )
>>>          return NULL;
>>>
>>>      video_format_t fmt_out;
>>> -    video_format_Init( &fmt_out, VLC_CODEC_YUVA );
>>> +    video_format_Init( &fmt_out, VLC_CODEC_RGBA );
>>>
>>>      char *psz_url = vlc_path2uri( psz_filename, NULL );
>>>      picture_t *p_pic = image_ReadUrl( p_image, psz_url, &fmt_out );
>>> --
>>> 2.17.1
>>>
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>>
>> --
>> Envoyé de mon appareil Android avec Courriel K-9 Mail. Veuillez excuser ma brièveté.
> 
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