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 7E9384B3F7 for ; Wed, 5 Jun 2024 10:00:12 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 790B068D6E8; Wed, 5 Jun 2024 13:00:09 +0300 (EEST) Received: from haasn.dev (haasn.dev [78.46.187.166]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 7C13C68D50D for ; Wed, 5 Jun 2024 13:00:02 +0300 (EEST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=haasn.xyz; s=mail; t=1717581601; bh=2QbDte8zuF4QVAIS2adVIq+QS34pTSMMFqcpgc6t7pc=; h=From:To:Cc:Subject:Date:From; b=M4nXegBG9SnjBHsXMTRd8nKdXUPPIRfCrcXqDzEGmphlz7/Kk4mrPCkT/Fry8FWmq pI980CodSZbJCOIS1VbfLRtMkKPydpSwQ0ulkhewsTOjjA460pqSjntY5ASngFi2x7 yVKgY/eRxSB4xnu7VdVX8U6xp1xoJNsj1gSTz568= Received: from haasn.dev (unknown [10.30.0.2]) by haasn.dev (Postfix) with ESMTP id B326140C0A; Wed, 5 Jun 2024 12:00:01 +0200 (CEST) From: Niklas Haas To: ffmpeg-devel@ffmpeg.org Date: Wed, 5 Jun 2024 11:59:59 +0200 Message-ID: <20240605095959.17135-1-ffmpeg@haasn.xyz> X-Mailer: git-send-email 2.45.1 MIME-Version: 1.0 Subject: [FFmpeg-devel] [PATCH] avcodec/dovi_rpudec: replace brittle struct copying code 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: Niklas Haas 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: From: Niklas Haas This code was unnecessarily trying to be robust against downgrades of libavutil (relative to the version libavcodec was compiled against), but in the process, ended up with very brittle code that is easy to accidentally forget to update when adding new fields. Instead, do the obvious thing and just directly copy the parts of the struct known at compile time. Since it is not generally supported to link against a version of libavutil older than the version libavcodec was compiled against, the struct shrinking externally is not a case we need to be worrying about. --- libavcodec/dovi_rpudec.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/libavcodec/dovi_rpudec.c b/libavcodec/dovi_rpudec.c index 7c7eda9d09..adf2c00cf5 100644 --- a/libavcodec/dovi_rpudec.c +++ b/libavcodec/dovi_rpudec.c @@ -56,14 +56,12 @@ int ff_dovi_attach_side_data(DOVIContext *s, AVFrame *frame) return AVERROR(ENOMEM); } - /* Copy only the parts of these structs known to us at compiler-time. */ -#define COPY(t, a, b, last) memcpy(a, b, offsetof(t, last) + sizeof((b)->last)) - COPY(AVDOVIRpuDataHeader, av_dovi_get_header(dovi), &s->header, disable_residual_flag); - COPY(AVDOVIDataMapping, av_dovi_get_mapping(dovi), s->mapping, nlq_pivots); - COPY(AVDOVIColorMetadata, av_dovi_get_color(dovi), s->color, source_diagonal); - ext_sz = FFMIN(sizeof(AVDOVIDmData), dovi->ext_block_size); + *av_dovi_get_header(dovi) = s->header; + *av_dovi_get_mapping(dovi) = *s->mapping; + *av_dovi_get_color(dovi) = *s->color; + av_assert0(dovi->ext_block_size >= sizeof(AVDOVIDmData)); for (int i = 0; i < s->num_ext_blocks; i++) - memcpy(av_dovi_get_ext(dovi, i), &s->ext_blocks[i], ext_sz); + *av_dovi_get_ext(dovi, i) = s->ext_blocks[i]; dovi->num_ext_blocks = s->num_ext_blocks; return 0; } -- 2.45.1 _______________________________________________ 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".