[FFmpeg-devel] [PATCH] libavfilter/vf_overlay_qsv: Use format of first input to set output format for overlay_qsv

[Soft Works]

> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of Wenbin Chen
> Sent: Friday, December 10, 2021 3:22 AM
> To: ffmpeg-devel at ffmpeg.org
> Cc: Wenbin Chen <wenbin.chen at intel.com>
> Subject: [FFmpeg-devel] [PATCH] libavfilter/vf_overlay_qsv: Use format of
> first input to set output format for overlay_qsv
> 
> overlay_qsv hard coded to use nv12 as output format. Now use the format
> of the first input to set output format. Now the following command
> works:
> 
> ffmpeg -hwaccel qsv -c:v hevc_qsv -i input_p010.265 -hwaccel qsv -c:v
> hevc_qsv \
> -i input2_p010.265 -filter_complex "[0:v][1:v]overlay_qsv=x=0:y=0:alpha=255,
> \
> hwdownload,format=p010le" -f rawvideo -y output_p010.yuv
> 
> Signed-off-by: Wenbin Chen <wenbin.chen at intel.com>
> ---
>  libavfilter/vf_overlay_qsv.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/libavfilter/vf_overlay_qsv.c b/libavfilter/vf_overlay_qsv.c
> index 7e76b39aa9..d947a1faa1 100644
> --- a/libavfilter/vf_overlay_qsv.c
> +++ b/libavfilter/vf_overlay_qsv.c
> @@ -276,6 +276,7 @@ static int config_output(AVFilterLink *outlink)
>      int ret;
> 
>      av_log(ctx, AV_LOG_DEBUG, "Output is of %s.\n",
> av_get_pix_fmt_name(outlink->format));
> +    vpp->qsv_param.out_sw_format = in0->format;
>      if ((in0->format == AV_PIX_FMT_QSV && in1->format != AV_PIX_FMT_QSV) ||
>          (in0->format != AV_PIX_FMT_QSV && in1->format == AV_PIX_FMT_QSV)) {
>          av_log(ctx, AV_LOG_ERROR, "Mixing hardware and software pixel
> formats is not supported.\n");
> @@ -288,6 +289,7 @@ static int config_output(AVFilterLink *outlink)
>              av_log(ctx, AV_LOG_ERROR, "Inputs with different underlying QSV
> devices are forbidden.\n");
>              return AVERROR(EINVAL);
>          }
> +        vpp->qsv_param.out_sw_format = hw_frame0->sw_format;
>      }
> 
>      outlink->w          = vpp->var_values[VAR_MW];
> --

When you're already looking at that area:

Do you have any idea why it sets the output time_base to the reciprocal
input0 framerate? 
I think it should rather set it to the same as the input0 time_base.

https://github.com/FFmpeg/FFmpeg/blob/4f44a218e53cd92e64ba10a935bc1e7583c3e218/libavfilter/vf_overlay_qsv.c#L293-L296

What do you think? (also @Haihao)

Thanks,
softworkz