[FFmpeg-devel] [PATCH 1/2] avcodec/lcldec: Make PNG filter addressing match the code afterwards

[James Almer]

On 5/31/2023 9:26 PM, Michael Niedermayer wrote:
> Also update check accordingly
> 
> Fixes: tickets/10237/mszh_306_306_yuv422_nocompress.avi
> Fixes: tickets/10237/mszh_306_306_yuv411_nocompress.avi
> 
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>   libavcodec/lcldec.c | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/libavcodec/lcldec.c b/libavcodec/lcldec.c
> index ed78d9d570..1c93378c4c 100644
> --- a/libavcodec/lcldec.c
> +++ b/libavcodec/lcldec.c
> @@ -231,16 +231,19 @@ static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
>               break;
>           case COMP_MSZH_NOCOMP: {
>               int bppx2;
> +            int widtha = width;

nit: aligned_width is clearer, imo.

>               switch (c->imgtype) {
>               case IMGTYPE_YUV111:
>               case IMGTYPE_RGB24:
>                   bppx2 = 6;
>                   break;
>               case IMGTYPE_YUV422:
> +                widtha &= ~3;
>               case IMGTYPE_YUV211:
>                   bppx2 = 4;
>                   break;
>               case IMGTYPE_YUV411:
> +                widtha &= ~3;
>               case IMGTYPE_YUV420:
>                   bppx2 = 3;
>                   break;
> @@ -248,7 +251,7 @@ static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
>                   bppx2 = 0; // will error out below
>                   break;
>               }
> -            if (len < ((width * height * bppx2) >> 1))
> +            if (len < ((widtha * height * bppx2) >> 1))
>                   return AVERROR_INVALIDDATA;
>               break;
>           }
> @@ -314,8 +317,8 @@ static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
>               }
>               break;
>           case IMGTYPE_YUV422:
> +            pixel_ptr = 0;
>               for (row = 0; row < height; row++) {
> -                pixel_ptr = row * width * 2;
>                   yq = uq = vq =0;
>                   for (col = 0; col < width/4; col++) {
>                       encoded[pixel_ptr] = yq -= encoded[pixel_ptr];
> @@ -331,8 +334,8 @@ static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
>               }
>               break;
>           case IMGTYPE_YUV411:
> +            pixel_ptr = 0;
>               for (row = 0; row < height; row++) {
> -                pixel_ptr = row * width / 2 * 3;
>                   yq = uq = vq =0;
>                   for (col = 0; col < width/4; col++) {
>                       encoded[pixel_ptr] = yq -= encoded[pixel_ptr];