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 3EE514054E for ; Sat, 21 Jan 2023 19:50:36 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 1F4A368BA48; Sat, 21 Jan 2023 21:50:33 +0200 (EET) Received: from mailrelay.ngus.net (mailrelay.ngus.net [109.237.26.52]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id DCCE56808C9 for ; Sat, 21 Jan 2023 21:50:26 +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 1pJJsf-00BR3i-3P for ffmpeg-devel@ffmpeg.org; Sat, 21 Jan 2023 19:50:25 +0000 Received: from [192.168.101.3] by zebop with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.95) (envelope-from ) id 1pJJsa-00HEql-IG for ffmpeg-devel@ffmpeg.org; Sat, 21 Jan 2023 19:50:24 +0000 Message-ID: <639cde55-b550-3323-f6da-3580237834c7@ngus.net> Date: Sat, 21 Jan 2023 19:50:20 +0000 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.2 Content-Language: en-US To: ffmpeg-devel@ffmpeg.org References: <20230118143113.324703-1-tim@ngus.net> From: Tim Angus In-Reply-To: <20230118143113.324703-1-tim@ngus.net> X-Spam-Score: -3.0 (---) Subject: Re: [FFmpeg-devel] [PATCH 0/1] Handle ASS format subtitle encoding ambiguity 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 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: On 18/01/2023 14:31, Tim Angus wrote: > Some matroska files embed ASS format subtitles. The header for said subtitles > include the header for the subtitle stream in the "codec private data" section. > It appears to be optional whether or not the last byte of this data is 0, i.e. > a null terminator for the string data. Using ffmpeg to extract subtitles for > such a file, this header is copied directly to the output file, including the > null terminator, if it was present. This results in a file in which there is a > null terminator after the header, but preceeding the actual content of the > subtitle file. Obviously this is not correct. > > As a data point, of the ~600 mkvs I have locally, 22 of them have ASS > subtitles, and of them 20 include the null terminator, so it doesn't appear to > be a rare phenomenon. > > As another data point, the tool mkvextract from mkvtoolnix avoids the ambiguity > by first assuming that the source buffer is *not* null terminated, and then > manually adding a (possibly second) null terminator. The buffer is then > interpreted as a null terminated string and processed that way. > (https://gitlab.com/mbunkus/mkvtoolnix/-/blob/main/src/extract/xtr_textsubs.cpp#L117) > > My change here simply avoids copying the trailing null terminator(s) present. > FATE succeeds as there are no mkvs in the suite that have ASS subtitles > embedded. > > Tim Angus (1): > avformat/assenc: fix incorrect copy of null terminator > > libavformat/assenc.c | 6 ++++++ > 1 file changed, 6 insertions(+) Why is there a gap of submitted patches on patchwork? Have I missed something? https://patchwork.ffmpeg.org/project/ffmpeg/list/ _______________________________________________ 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".