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 9FF50453B8 for ; Fri, 27 Jan 2023 17:21:13 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id C9A4368BE75; Fri, 27 Jan 2023 19:21:05 +0200 (EET) 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 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: 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", -- 2.25.1 _______________________________________________ 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".