From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id 217DE49D8D for ; Wed, 10 Apr 2024 07:07:08 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 2346F68D06F; Wed, 10 Apr 2024 10:07:06 +0300 (EEST) Received: from mail0.khirnov.net (red.khirnov.net [176.97.15.12]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id A49B768CFB7 for ; Wed, 10 Apr 2024 10:06:59 +0300 (EEST) Authentication-Results: mail0.khirnov.net; dkim=pass (2048-bit key; unprotected) header.d=khirnov.net header.i=@khirnov.net header.a=rsa-sha256 header.s=mail header.b=Nsq8UKOy; dkim-atps=neutral Received: from localhost (localhost [IPv6:::1]) by mail0.khirnov.net (Postfix) with ESMTP id 6C59E240DAC; Wed, 10 Apr 2024 09:06:59 +0200 (CEST) Received: from mail0.khirnov.net ([IPv6:::1]) by localhost (mail0.khirnov.net [IPv6:::1]) (amavis, port 10024) with ESMTP id W2n0NLe3EGIQ; Wed, 10 Apr 2024 09:06:58 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=khirnov.net; s=mail; t=1712732818; bh=OlhTx7dSvKgBcrq+Wz51NjMKoshYlPYozeUWDU7cvGU=; h=Subject:From:To:Cc:In-Reply-To:References:Date:From; b=Nsq8UKOy9ZK6OOuSIPfzUp9K5PTNKWTyUnj4NiYAqXshMSHsooxLtU6Jx0IJACKj9 4Zdc7AClyjEjaMnhs5ZONqoqlBHX3YizphGudlfz9+cZg238fpIfie69/yewybDLLz 8e/KtQ1hY7Uy4d1DaoHYBXpM59mDyl1pAdwwfe6g56H02X6FMCjXcSNiLyHE+ZYjxl QWADOpyMKJ3HtEFX7hlbCrmazMiTDvwQksqEH5v503Ug+0o4vOMtNQthxH0iXUXExu 0Lwbq1ojfIqWdDpC7X6Xna7hac3tNWWhIG6b/1jMyr+Z4w8JQILQfRYQx4m/CYGlL+ zNk5eb9v0QXqQ== Received: from lain.khirnov.net (lain.khirnov.net [IPv6:2001:67c:1138:4306::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "lain.khirnov.net", Issuer "smtp.khirnov.net SMTP CA" (verified OK)) by mail0.khirnov.net (Postfix) with ESMTPS id B8A7F2404E5; Wed, 10 Apr 2024 09:06:58 +0200 (CEST) Received: by lain.khirnov.net (Postfix, from userid 1000) id 901EA1601B9; Wed, 10 Apr 2024 09:06:58 +0200 (CEST) From: Anton Khirnov To: FFmpeg development discussions and patches In-Reply-To: References: Mail-Followup-To: FFmpeg development discussions and patches , Andreas Rheinhardt Date: Wed, 10 Apr 2024 09:06:58 +0200 Message-ID: <171273281857.22242.15680967665971235982@lain.khirnov.net> User-Agent: alot/0.8.1 MIME-Version: 1.0 Subject: Re: [FFmpeg-devel] [PATCH v2 06/27] avcodec/vp9: Fix race when attaching side-data for show-existing frame 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 Cc: Andreas Rheinhardt Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: Quoting Andreas Rheinhardt (2024-04-08 22:13:44) > When outputting a show-existing frame, the VP9 decoder simply > created a reference to said frame and returned it immediately to > the caller, without waiting for it to have finished decoding. > In case of frame-threading it is possible for the frame to > only be decoded while it was waiting to be output. > This is normally benign. > > But there is one case where it is not: If the user wants > video encoding parameters to be exported, said side data > will only be attached to the src AVFrame at the end of > decoding the frame that is actually being shown. Without > synchronisation adding said side data in the decoder thread > and the reads in av_frame_ref() in the output thread > constitute a data race. This happens e.g. when using the > venc_data_dump tool with vp90-2-10-show-existing-frame.webm > from the FATE-suite. > > Fix this by actually waiting for the frame to be output. > > Signed-off-by: Andreas Rheinhardt > --- > libavcodec/vp9.c | 18 +++++++++++------- > 1 file changed, 11 insertions(+), 7 deletions(-) LGTM, though it'd be nice of someone more familiar with this decoder looked at it. -- Anton Khirnov _______________________________________________ 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".