[FFmpeg-devel] [PATCH] lavu/hwcontext_vaapi: cope with race map for YUV420P

[Fu, Linjie]

> -----Original Message-----
> From: Fu, Linjie
> Sent: Thursday, August 1, 2019 12:45
> To: ffmpeg-devel at ffmpeg.org
> Cc: Fu, Linjie <linjie.fu at intel.com>
> Subject: [PATCH] lavu/hwcontext_vaapi: cope with race map for YUV420P
> 
> There is a race condition for AV_PIX_FMT_YUV420P when mapping from
> pix_fmt
> to fourcc, both VA_FOURCC_I420 and VA_FOURCC_YV12 could be find by
> pix_fmt.
> 
> Currently, vaapi_get_image_format will go through the query results of
> pix_fmt and returned the first matched result according to the declared
> order in driver.This may leads to a wrong image_format.
> 
> Modify to find image_format via fourcc.
> 
> Fix vaapi CSC to I420:
> ffmpeg -hwaccel vaapi -vaapi_device /dev/dri/renderD128 -f rawvideo
> -pix_fmt nv12 -s:v 1280x720 -i NV12.yuv -vf
> 'format=nv12,hwupload,scale_vaapi=format=yuv420p,hwdownload,format=
> yuv420p'
> -f rawvideo -vsync passthrough -vframes 10 -y aa.yuv
> 
> Signed-off-by: Linjie Fu <linjie.fu at intel.com>
> ---
>  libavutil/hwcontext_vaapi.c | 14 +++++++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)
> 
> diff --git a/libavutil/hwcontext_vaapi.c b/libavutil/hwcontext_vaapi.c
> index cf11764..64f14de 100644
> --- a/libavutil/hwcontext_vaapi.c
> +++ b/libavutil/hwcontext_vaapi.c
> @@ -63,6 +63,7 @@ typedef struct VAAPIDevicePriv {
>  typedef struct VAAPISurfaceFormat {
>      enum AVPixelFormat pix_fmt;
>      VAImageFormat image_format;
> +    unsigned int fourcc;
>  } VAAPISurfaceFormat;
> 
>  typedef struct VAAPIDeviceContext {
> @@ -171,15 +172,21 @@ static int
> vaapi_get_image_format(AVHWDeviceContext *hwdev,
>                                    VAImageFormat **image_format)
>  {
>      VAAPIDeviceContext *ctx = hwdev->internal->priv;
> +    VAAPIFormatDescriptor *desc;
>      int i;
> 
> +    desc = vaapi_format_from_pix_fmt(pix_fmt);
> +    if (!desc || !image_format)
> +        goto fail;
> +
>      for (i = 0; i < ctx->nb_formats; i++) {
> -        if (ctx->formats[i].pix_fmt == pix_fmt) {
> -            if (image_format)
> -                *image_format = &ctx->formats[i].image_format;
> +        if (ctx->formats[i].fourcc == desc->fourcc) {
> +            *image_format = &ctx->formats[i].image_format;
>              return 0;
>          }
>      }
> +
> +fail:
>      return AVERROR(EINVAL);
>  }
> 
> @@ -368,6 +375,7 @@ static int vaapi_device_init(AVHWDeviceContext
> *hwdev)
>              av_log(hwdev, AV_LOG_DEBUG, "Format %#x -> %s.\n",
>                     fourcc, av_get_pix_fmt_name(pix_fmt));
>              ctx->formats[ctx->nb_formats].pix_fmt      = pix_fmt;
> +            ctx->formats[ctx->nb_formats].fourcc       = fourcc;
>              ctx->formats[ctx->nb_formats].image_format = image_list[i];
>              ++ctx->nb_formats;
>          }
> --
> 2.7.4
A gentle ping.