[FFmpeg-cvslog] doc: Remove libav-merge.txt

Mon Jun 30 17:01:22 EEST 2025

ffmpeg | branch: master | Derek Buitenhuis <derek.buitenhuis at gmail.com> | Mon Jun 23 21:15:18 2025 +0100| [5bcff199d9f47991772cf82133fb51c7ce7c1832] | committer: Derek Buitenhuis

doc: Remove libav-merge.txt

It not longer exists.

Signed-off-by: Derek Buitenhuis <derek.buitenhuis at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5bcff199d9f47991772cf82133fb51c7ce7c1832
---

 doc/libav-merge.txt | 115 ----------------------------------------------------
 1 file changed, 115 deletions(-)

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)

