From: Derek Buitenhuis <derek.buitenhuis-at-gmail.com@ffmpeg.org> To: ffmpeg-devel@ffmpeg.org Subject: [FFmpeg-devel] [PATCH] doc: Remove libav-merge.txt Date: Mon, 23 Jun 2025 21:15:18 +0100 Message-ID: <20250623201518.45827-1-derek.buitenhuis@gmail.com> (raw) He's dead, Jim. Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com> --- doc/libav-merge.txt | 115 -------------------------------------------- 1 file changed, 115 deletions(-) delete mode 100644 doc/libav-merge.txt diff --git a/doc/libav-merge.txt b/doc/libav-merge.txt deleted file mode 100644 index bcd0aacba5..0000000000 --- a/doc/libav-merge.txt +++ /dev/null @@ -1,115 +0,0 @@ -CONTEXT -======= - -The FFmpeg project merges all the changes from the Libav project -(https://libav.org) since the origin of the fork (around 2011). - -With the exceptions of some commits due to technical/political disagreements or -issues, the changes are merged on a more or less regular schedule (daily for -years thanks to Michael, but more sparse nowadays). - -WHY -=== - -The majority of the active developers believe the project needs to keep this -policy for various reasons. - -The most important one is that we don't want our users to have to choose -between two distributors of libraries of the exact same name in order to have a -different set of features and bugfixes. By taking the responsibility of -unifying the two codebases, we allow users to benefit from the changes from the -two teams. - -Today, FFmpeg has a much larger user database (we are distributed by every -major distribution), so we consider this mission a priority. - -A different approach to the merge could have been to pick the changes we are -interested in and drop most of the cosmetics and other less important changes. -Unfortunately, this makes the following picks much harder, especially since the -Libav project is involved in various deep API changes. As a result, we decide -to virtually take everything done there. - -Any Libav developer is of course welcome anytime to contribute directly to the -FFmpeg tree. Of course, we fully understand and are forced to accept that very -few Libav developers are interested in doing so, but we still want to recognize -their work. This leads us to create merge commits for every single one from -Libav. The original commit appears totally unchanged with full authorship in -our history (and the conflict are solved in the merge one). That way, not a -single thing from Libav will be lost in the future in case some reunification -happens, or that project disappears one way or another. - -DOWNSIDES -========= - -Of course, there are many downsides to this approach. - -- It causes a non negligible merge commits pollution. We make sure there are - not several level of merges entangled (we do a 1:1 merge/commit), but it's - still a non-linear history. - -- Many duplicated work. For instance, we added libavresample in our tree to - keep compatibility with Libav when our libswresample was already covering the - exact same purpose. The same thing happened for various elements such as the - ProRes support (but differences in features, bugs, licenses, ...). There are - many work to do to unify them, and any help is very much welcome. - -- So much manpower from both FFmpeg and Libav is lost because of this mess. We - know it, and we don't know how to fix it. It takes incredible time to do - these merges, so we have even less time to work on things we personally care - about. The bad vibes also do not help with keeping our developers motivated. - -- There is a growing technical risk factor with the merges due to the codebase - differing more and more. - -MERGE GUIDELINES -================ - -The following gives developer guidelines on how to proceed when merging Libav commits. - -Before starting, you can reduce the risk of errors on merge conflicts by using -a different merge conflict style: - - $ git config --global merge.conflictstyle diff3 - -tools/libav-merge-next-commit is a script to help merging the next commit in -the queue. It assumes a remote named libav. It has two modes: merge, and noop. -The noop mode creates a merge with no change to the HEAD. You can pass a hash -as extra argument to reference a justification (it is common that we already -have the change done in FFmpeg). - -Also see tools/murge, you can copy and paste a 3 way conflict into its stdin -and it will display colored diffs. Any arguments to murge (like ones to suppress -whitespace differences) are passed into colordiff. - -TODO/FIXME/UNMERGED -=================== - -Stuff that didn't reach the codebase: -------------------------------------- - -- HEVC DSP and x86 MC SIMD improvements from Libav (see https://ffmpeg.org/pipermail/ffmpeg-devel/2015-December/184777.html) - - 1f821750f hevcdsp: split the qpel functions by width instead of by the subpixel fraction - - 818bfe7f0 hevcdsp: split the epel functions by width - - 688417399 hevcdsp: split the pred functions by width - - a853388d2 hevc: change the stride of the MC buffer to be in bytes instead of elements - - 0cef06df0 checkasm: add HEVC MC tests - - e7078e842 hevcdsp: add x86 SIMD for MC - - 7993ec19a hevc: Add hevc_get_pixel_4/8/12/16/24/32/48/64 -- use av_cpu_max_align() instead of hardcoding alignment requirements (see https://ffmpeg.org/pipermail/ffmpeg-devel/2017-September/215834.html) - - f44ec22e0 lavc: use av_cpu_max_align() instead of hardcoding alignment requirements - - 4de220d2e frame: allow align=0 (meaning automatic) for av_frame_get_buffer() -- Support recovery from an already present HLS playlist (see 16cb06bb30) -- Remove all output devices (see 8e7e042d41, 8d3db95f20, 6ce13070bd, d46cd24986 and https://ffmpeg.org/pipermail/ffmpeg-devel/2017-September/216904.html) -- avcodec/libaomenc: export the Sequence Header OBU as extradata (See a024c3ce9a) - -Collateral damage that needs work locally: ------------------------------------------- - -- Merge proresenc_anatoliy.c and proresenc_kostya.c -- Fix MIPS AC3 downmix - -Extra changes needed to be aligned with Libav: ----------------------------------------------- - -- Switching our examples to the new encode/decode API (see 67d28f4a0f) -- HEVC IDCT bit depth 12-bit support (Libav added 8 and 10 but doesn't have 12) -- 2.49.0 _______________________________________________ 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".
reply other threads:[~2025-06-23 20:15 UTC|newest] Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20250623201518.45827-1-derek.buitenhuis@gmail.com \ --to=derek.buitenhuis-at-gmail.com@ffmpeg.org \ --cc=ffmpeg-devel@ffmpeg.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
Git Inbox Mirror of the ffmpeg-devel mailing list - see https://ffmpeg.org/mailman/listinfo/ffmpeg-devel This inbox may be cloned and mirrored by anyone: git clone --mirror https://master.gitmailbox.com/ffmpegdev/0 ffmpegdev/git/0.git # If you have public-inbox 1.1+ installed, you may # initialize and index your mirror using the following commands: public-inbox-init -V2 ffmpegdev ffmpegdev/ https://master.gitmailbox.com/ffmpegdev \ ffmpegdev@gitmailbox.com public-inbox-index ffmpegdev Example config snippet for mirrors. AGPL code for this site: git clone https://public-inbox.org/public-inbox.git