From eb9070aba4fa20fc9b4929a40182675d1d458844 Mon Sep 17 00:00:00 2001 From: nyanmisaka Date: Thu, 7 Aug 2025 22:32:20 +0800 Subject: [PATCH] lavu/hwcontext_vaapi: fix a race mapping to allow CSC to YUV420P There's a race condition for YUV420P when mapping from pix_fmt to VA fourcc, both I420 and YV12 could be found by pix_fmt. Currently, vaapi_get_image_format() iterates over the query results of pix_fmt and returns the first matching result in the order declared in the driver. This may result in an incorrect image_format. Now use fourcc to find the image_format. Fixes: ffmpeg -hwaccel vaapi -hwaccel_output_format vaapi -i INPUT \ -vf scale_vaapi=format=yuv420p,hwmap,format=yuv420p \ -vframes 1 -f rawvideo -y yuv420p.yuv Signed-off-by: nyanmisaka --- 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 95aa38d9d2..7c243ec1ef 100644 --- a/libavutil/hwcontext_vaapi.c +++ b/libavutil/hwcontext_vaapi.c @@ -72,6 +72,7 @@ typedef struct VAAPIDevicePriv { typedef struct VAAPISurfaceFormat { enum AVPixelFormat pix_fmt; VAImageFormat image_format; + unsigned int fourcc; } VAAPISurfaceFormat; typedef struct VAAPIDeviceContext { @@ -218,15 +219,21 @@ static int vaapi_get_image_format(AVHWDeviceContext *hwdev, VAImageFormat **image_format) { VAAPIDeviceContext *ctx = hwdev->hwctx; + const 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(ENOSYS); } @@ -435,6 +442,7 @@ 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; }