From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.ffmpeg.org (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTPS id 3B88B4CA92 for ; Thu, 7 Aug 2025 15:12:20 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTP id 5CE6168CC4F; Thu, 7 Aug 2025 18:12:16 +0300 (EEST) Received: from 0f9ae49ae7c8 (code.ffmpeg.org [188.245.149.3]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTPS id D93C768B277 for ; Thu, 7 Aug 2025 18:12:13 +0300 (EEST) MIME-Version: 1.0 From: nyanmisaka To: ffmpeg-devel@ffmpeg.org Subject: [FFmpeg-devel] =?utf-8?q?=5BPATCH=5D_lavu/hwcontext=5Fvaapi=3A_f?= =?utf-8?q?ix_a_race_mapping_to_allow_CSC_to_YUV420P_=28PR_=2320158=29?= X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Message-Id: <20250807151216.5CE6168CC4F@ffbox0-bg.ffmpeg.org> Date: Thu, 7 Aug 2025 18:12:16 +0300 (EEST) Archived-At: List-Archive: List-Post: PR #20158 opened by nyanmisaka URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20158 Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20158.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 This was discovered because some NVR software's object recognition requires fully-planar YUV420P instead of NV12. >From 4b69c844b03da78cd12205e7f8865cc8f16c1a67 Mon Sep 17 00:00:00 2001 From: nyanmisaka Date: Thu, 7 Aug 2025 22:32:20 +0800 Subject: [PATCH 1/2] 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; } -- 2.49.1 >From fcceafc72c1c6116011a1a34911a5b9cb1026de5 Mon Sep 17 00:00:00 2001 From: nyanmisaka Date: Thu, 7 Aug 2025 22:48:04 +0800 Subject: [PATCH 2/2] lavu/hwcontext_vaapi: drop a redundant check vaapi_get_image_format() will be called in vaapi_map_frame(). So it's a double check, drop it to avoid redundancy. Signed-off-by: nyanmisaka --- libavutil/hwcontext_vaapi.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/libavutil/hwcontext_vaapi.c b/libavutil/hwcontext_vaapi.c index 7c243ec1ef..51af22a607 100644 --- a/libavutil/hwcontext_vaapi.c +++ b/libavutil/hwcontext_vaapi.c @@ -1019,12 +1019,6 @@ static int vaapi_map_to_memory(AVHWFramesContext *hwfc, AVFrame *dst, { int err; - if (dst->format != AV_PIX_FMT_NONE) { - err = vaapi_get_image_format(hwfc->device_ctx, dst->format, NULL); - if (err < 0) - return err; - } - err = vaapi_map_frame(hwfc, dst, src, flags); if (err) return err; -- 2.49.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".