[FFmpeg-devel] [PATCH] lavc/qsvdec: respect AVCodecContext->{width, height}

["zhilizhao(赵志立)"]

> On Jun 8, 2023, at 13:47, Xiang, Haihao <haihao.xiang-at-intel.com at ffmpeg.org> wrote:
> 
> From: Haihao Xiang <haihao.xiang at intel.com>
> 
> width and height may be known from the container
> 
> Signed-off-by: Haihao Xiang <haihao.xiang at intel.com>
> ---
> libavcodec/qsvdec.c | 6 ++++++
> 1 file changed, 6 insertions(+)
> 
> diff --git a/libavcodec/qsvdec.c b/libavcodec/qsvdec.c
> index da700f25e9..5325030ea1 100644
> --- a/libavcodec/qsvdec.c
> +++ b/libavcodec/qsvdec.c
> @@ -910,6 +910,7 @@ static int qsv_process_data(AVCodecContext *avctx, QSVContext *q,
>     }
> 
>     if (q->reinit_flag || !q->session || !q->initialized) {
> +        int reset_crop = !q->session;
>         mfxFrameAllocRequest request;
>         memset(&request, 0, sizeof(request));
> 
> @@ -929,6 +930,11 @@ static int qsv_process_data(AVCodecContext *avctx, QSVContext *q,
>         avctx->coded_width  = param.mfx.FrameInfo.Width;
>         avctx->coded_height = param.mfx.FrameInfo.Height;
> 
> +        if (reset_crop && avctx->width && avctx->height) {
> +            param.mfx.FrameInfo.CropW = avctx->width;
> +            param.mfx.FrameInfo.CropH = avctx->height;
> +        }
> +

I can see two issues here:

1. Reset CropW/CropH from container without reset CropX/CropY might create some
mismatch.

2. Width/Height from container can be larger than coded_width/coded_height. For
example, mp4 container can apply a scaling after decoding. So decoder should only
care about ES, while user can apply the info from container after decoding, like 
rotation, scaling and cropping. But it’s complex in practice.

I don’t have idea for these issues.

>         ret = MFXVideoDECODE_QueryIOSurf(q->session, &param, &request);
>         if (ret < 0)
>             return ff_qsv_print_error(avctx, ret, "Error querying IO surface");
> -- 
> 2.34.1
> 
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".