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

[Li, Zhong]

> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On Behalf
> Of Fu, Linjie
> Sent: Wednesday, August 14, 2019 9:59 AM
> To: ffmpeg-devel at ffmpeg.org
> Subject: Re: [FFmpeg-devel] [PATCH] lavu/hwcontext_vaapi: cope with race
> map for YUV420P
> 
> > -----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.

find -> found

> > 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.

Patch LGTM