From patchwork Fri Jan 27 17:20:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tim Angus X-Patchwork-Id: 40148 Delivered-To: ffmpegpatchwork2@gmail.com Received: by 2002:a05:6a20:3ca3:b0:b9:1511:ac2c with SMTP id b35csp1526586pzj; Fri, 27 Jan 2023 09:21:25 -0800 (PST) X-Google-Smtp-Source: AK7set98LcwXIJqkSl68/WPQ07qwoIzixBT4tkGqhd6RenEVZYGev/ktmmXetCT760MTNnzCscJ2 X-Received: by 2002:a17:907:9625:b0:879:6abc:3bfc with SMTP id gb37-20020a170907962500b008796abc3bfcmr5605295ejc.19.1674840085060; Fri, 27 Jan 2023 09:21:25 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1674840085; cv=none; d=google.com; s=arc-20160816; b=S2Ks8brNt0NfCYKXqtzorefrJRs8Kqy26nbkiGFDJphevlHY212Uot2fGI3iaUDMwR 0EEb5w917rDyB+oDseELOps9sxm6dzx1Z6ejMXBafBABZ2RT889XdJ9/S2mbY/SdVU9F 6LfQFEK31t0zDZg81Gsp61fcBClXg+oT9Sj79oHEOkxcC4Qh4bBb8DFIA4j8voHY7rAs GYMhlJ3h1td5zhp0IwSqJJ5W+pO2RabQs0L8zL8g8iwtR/XQh6OplKH5sHfRKhC7rrx6 y/cWGj/GW1DZmLE0JipUDpgmQg2r0E7schDzFxdjVtd6qkedpVwSfMrGm6IrbJNztNNv hg1w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:content-transfer-encoding:cc:reply-to :list-subscribe:list-help:list-post:list-archive:list-unsubscribe :list-id:precedence:subject:mime-version:references:in-reply-to :message-id:date:to:from:delivered-to; bh=5R9QAiMxOgPJJKwInZICNqUVe4wbuS/LYmJ6AZZnjBE=; b=09dH71DKmjsCdtW4xtwZs7lhU/mTU3OrN2/uVIJ2m95eoTVUlQRPpRVV1sFcLLCunS TfMgRLdHjMkySgZxmBPha+72kSvASaoSJgSyIbf7Rd18eItRA24qMM+dBKAnsOGvKotJ 60Xl2DhvZuKZkLjAJ8fwm07/fcaBsPYPjzilp89d7Dhz1+5s/zkkmXlNwgWBzEtCYKhW 1MEMnBgkK7vqJx8EIOtxD6XwdTrfTGcPIxzrXCB8775EXdGvJ2uW1U0lVrRW8zZpFop5 bBxWAm/QIUR9p4xS+6bGDLWo7sEpMhAuz5GG+TVs8dzk0AzE/TL6TChsO22qXCZ9/r78 KXjQ== ARC-Authentication-Results: i=1; mx.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 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org. [79.124.17.100]) by mx.google.com with ESMTP id 23-20020a170906021700b00870f0d7edd3si5702522ejd.831.2023.01.27.09.21.15; Fri, 27 Jan 2023 09:21:25 -0800 (PST) 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; 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 0F80E68BE77; Fri, 27 Jan 2023 19:21:06 +0200 (EET) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from mailrelay.ngus.net (mailrelay.ngus.net [109.237.26.52]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id B54DC68BE67 for ; Fri, 27 Jan 2023 19:20:59 +0200 (EET) Received: from cpc102338-sgyl38-2-0-cust655.18-2.cable.virginm.net ([77.102.34.144] helo=zebop) by mailrelay.ngus.net with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1pLSPL-00BuUk-1g for ffmpeg-devel@ffmpeg.org; Fri, 27 Jan 2023 17:20:59 +0000 Received: from [192.168.101.3] (helo=localhost.localdomain) by zebop with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1pLSPJ-004QtN-FG; Fri, 27 Jan 2023 17:20:58 +0000 From: Tim Angus To: ffmpeg-devel@ffmpeg.org Date: Fri, 27 Jan 2023 17:20:47 +0000 Message-Id: <20230127172047.1024276-2-tim@ngus.net> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230127172047.1024276-1-tim@ngus.net> References: <20230127172047.1024276-1-tim@ngus.net> MIME-Version: 1.0 X-Spam-Score: -2.9 (--) Subject: [FFmpeg-devel] [PATCH 1/1] avformat/assenc: avoid incorrect copy of null terminator 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: Tim Angus Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" X-TUID: 6DQZRirEezMx When writing a subtitle SSA/ASS subtitle file, the AVCodecParameters::extradata buffer is written directly to the output. In the case where the buffer is filled from a matroska source file produced by some older versions of Handbrake, this buffer ends with a null terminating character, which is then erroneously copied into the middle of the output file. The refactoring here avoids this problem by copying the source buffer, manually null terminating it, then treating it as a string rather than a raw buffer. This way it is agnostic as to whether the source buffer was null terminated or not. Signed-off-by: Tim Angus --- libavformat/assenc.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/libavformat/assenc.c b/libavformat/assenc.c index 1600f0a02b..4c9ea6f982 100644 --- a/libavformat/assenc.c +++ b/libavformat/assenc.c @@ -24,6 +24,7 @@ #include "internal.h" #include "libavutil/opt.h" +#include "libavutil/mem.h" typedef struct DialogueLine { int readorder; @@ -55,6 +56,7 @@ static int write_header(AVFormatContext *s) avpriv_set_pts_info(s->streams[0], 64, 1, 100); if (par->extradata_size > 0) { size_t header_size = par->extradata_size; + char *header_string = NULL; uint8_t *trailer = strstr(par->extradata, "\n[Events]"); if (trailer) @@ -69,9 +71,20 @@ static int write_header(AVFormatContext *s) ass->trailer = trailer; } - avio_write(s->pb, par->extradata, header_size); - if (par->extradata[header_size - 1] != '\n') - avio_write(s->pb, "\r\n", 2); + header_string = av_malloc(header_size + 1); + if (!header_string) + return AVERROR(ENOMEM); + + memcpy(header_string, par->extradata, header_size); + header_string[header_size] = 0; + + avio_printf(s->pb, "%s", header_string); + + if (header_string[strlen(header_string) - 1] != '\n') + avio_printf(s->pb, "\r\n"); + + av_free(header_string); + ass->ssa_mode = !strstr(par->extradata, "\n[V4+ Styles]"); if (!strstr(par->extradata, "\n[Events]")) avio_printf(s->pb, "[Events]\r\nFormat: %s, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text\r\n",