From patchwork Tue Apr 18 22:34:54 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lucas Cooper X-Patchwork-Id: 3447 Delivered-To: ffmpegpatchwork@gmail.com Received: by 10.103.3.129 with SMTP id 123csp52582vsd; Tue, 18 Apr 2017 15:41:34 -0700 (PDT) X-Received: by 10.223.153.9 with SMTP id x9mr26736939wrb.117.1492555294428; Tue, 18 Apr 2017 15:41:34 -0700 (PDT) Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org. [79.124.17.100]) by mx.google.com with ESMTP id y187si1148202wmb.76.2017.04.18.15.41.28; Tue, 18 Apr 2017 15:41:34 -0700 (PDT) Received-SPF: pass (google.com: domain of ffmpeg-devel-bounces@ffmpeg.org designates 79.124.17.100 as permitted sender) client-ip=79.124.17.100; Authentication-Results: mx.google.com; dkim=neutral (body hash did not verify) header.i=@google.com; spf=pass (google.com: domain of ffmpeg-devel-bounces@ffmpeg.org designates 79.124.17.100 as permitted sender) smtp.mailfrom=ffmpeg-devel-bounces@ffmpeg.org Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 26B4D6891FA; Wed, 19 Apr 2017 01:41:18 +0300 (EEST) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from mail-pf0-f174.google.com (mail-pf0-f174.google.com [209.85.192.174]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 5B6DA6882B9 for ; Wed, 19 Apr 2017 01:41:11 +0300 (EEST) Received: by mail-pf0-f174.google.com with SMTP id i5so3066786pfc.2 for ; Tue, 18 Apr 2017 15:41:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=iYsrpV2MM6wBWPXLMML3fh1cmW/YJdXFplj6PguRVgk=; b=KNWlPTvZhfwNShbyigN9MeCCutPyq4JeoRLD3IG4OAtP8zZw7H3ML5kBuTSrMC/W83 y20Vxkmq0IrlFFlv/2DD4hpgQlSOHIvJNugnb0rzIyf6nMFr3LuYh0Pfl8ZMlfjPOC3T lyHm6foA9kKz2CUK/vH4XQWi9XR5fa6BWd5XOu9w28QG/g19A+zdDKNIXxIKDyzjWkEP 5/brNad3/+lzLt4jF8UKmWjghVhuBdjQ9hdFeQFvtXdrorofrfOveUe3bSNZXC5Ej19c rkzJkuoZVUao2kjlT3UiGbSbfRRasrcsRQYKFVVa2sMzx+EsgVYTSi+wiwPZ+Knx4nbz oWFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=iYsrpV2MM6wBWPXLMML3fh1cmW/YJdXFplj6PguRVgk=; b=Z+/nM3W8u/koppjPmgg5DPL529jDnP1R65Xaeq8cKKcL4hSMLhtIiQAgCQkBrngzIn VWXxvz7T0wKHG6v41+jT/ibQciyNz96X5uIamit/EraI30xBjMbo4VYkeRwY9C6+Onx1 MRrZugROozWq2xMqW4kxXLpLDz9yqPF3eac62ZGKL/WXzN6aBJuOJNg5agFTNWaVkjRh iO1KM81gPbW3KTNGnsTDpo54iuEjZYfaCz81hsWAjjSoWhGvgzIw1uC9R/E4YCP6BICz hXRDnKCPAKRDfOIZHvBxMgZKQTVghl+rFc13PvDKylpLNIBHppRKFR6i262RVmR6YN5u WP3w== X-Gm-Message-State: AN3rC/5fOXkgF7AuYunDn1CKWEQV8EOugbxDGs9s/4iE8qbjddeRssBa THXA1k4hw65lBX5y X-Received: by 10.98.149.87 with SMTP id p84mr19965346pfd.260.1492554912454; Tue, 18 Apr 2017 15:35:12 -0700 (PDT) Received: from pinkiepie.mtv.corp.google.com ([172.27.196.67]) by smtp.gmail.com with ESMTPSA id 133sm414658pfy.106.2017.04.18.15.35.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 18 Apr 2017 15:35:11 -0700 (PDT) From: Lucas Cooper To: ffmpeg-devel@ffmpeg.org Date: Tue, 18 Apr 2017 15:34:54 -0700 Message-Id: <20170418223454.10371-1-bobobo@google.com> X-Mailer: git-send-email 2.12.2.816.g2cccc81164-goog Subject: [FFmpeg-devel] [PATCH] avformat/movenc: Explicitly address potential division by zero. X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.20 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: Lucas Cooper MIME-Version: 1.0 Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" find_fps attempts to infer framerate from AVCodec's timebase. When this results in a frame rate that isn't explicitly marked as supported in av_timecode_check_frame_rate, find_fps returns the AVStream's avg_frame_rate, which, per avformat.h, _may_ be set (or not). mov_get_mpeg2_xdcam_codec_tag, mov_get_h264_codec_tag and find_compressor attempt to call av_q2d on the return value of find_fps, which in the above case, may result in division by zero. --- libavformat/movenc.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/libavformat/movenc.c b/libavformat/movenc.c index e6e2313c53..0e337d5258 100644 --- a/libavformat/movenc.c +++ b/libavformat/movenc.c @@ -1326,7 +1326,10 @@ static int mov_get_mpeg2_xdcam_codec_tag(AVFormatContext *s, MOVTrack *track) int tag = track->par->codec_tag; int interlaced = track->par->field_order > AV_FIELD_PROGRESSIVE; AVStream *st = track->st; - int rate = av_q2d(find_fps(s, st)); + AVRational rational_framerate = find_fps(s, st); + int rate = 0; + if (rational_framerate.den != 0) + rate = av_q2d(rational_framerate); if (!tag) tag = MKTAG('m', '2', 'v', '1'); //fallback tag @@ -1388,7 +1391,10 @@ static int mov_get_h264_codec_tag(AVFormatContext *s, MOVTrack *track) int tag = track->par->codec_tag; int interlaced = track->par->field_order > AV_FIELD_PROGRESSIVE; AVStream *st = track->st; - int rate = av_q2d(find_fps(s, st)); + AVRational rational_framerate = find_fps(s, st); + int rate = 0; + if (rational_framerate.den != 0) + rate = av_q2d(rational_framerate); if (!tag) tag = MKTAG('a', 'v', 'c', 'i'); //fallback tag @@ -1850,7 +1856,10 @@ static void find_compressor(char * compressor_name, int len, MOVTrack *track) } else if (track->par->codec_id == AV_CODEC_ID_MPEG2VIDEO && xdcam_res) { int interlaced = track->par->field_order > AV_FIELD_PROGRESSIVE; AVStream *st = track->st; - int rate = av_q2d(find_fps(NULL, st)); + AVRational rational_framerate = find_fps(NULL, st); + int rate = 0; + if (rational_framerate.den != 0) + rate = av_q2d(rational_framerate); av_strlcatf(compressor_name, len, "XDCAM"); if (track->par->format == AV_PIX_FMT_YUV422P) { av_strlcatf(compressor_name, len, " HD422");