Windows 10 long path support

[stax76]

I would like to request long path support in Windows 10. Currently, long paths work only with long path prefix
?\ or 8.3 names. I would like to request native long path support that don't need a prefix or 8.3 (short) name.

​https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file#maximum-path-length-limitation

​https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file#short-vs-long-names

​https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file#enable-long-paths-in-windows-10-version-1607-and-later

This is frequently requested by staxrip users.

​https://github.com/staxrip/staxrip/issues/226#issuecomment-687586840

[Carl Eugen Hoyos]

Please reopen this ticket if you can explain how the issue you see can be reproduced, either show the command line you tested together with the complete, uncut console output or provide source code.

[stax76]

Samples> ffmpeg -i 'C:\Users\frank\long path\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\fitness.mkv' -hide_banner
C:\Users\frank\long path\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\fitness.mkv: No such file or directory

The file exists, it works when the file is prefixed, so it's likely sufficient to modify the manifest info to make it work.

​https://github.com/staxrip/staxrip/blob/master/My%20Project/app.manifest#L25

​https://gitlab.com/mbunkus/mkvtoolnix/-/blob/9cdae214ae5055aa2b0c218fccff96b862d3746f/src/extract/manifest.xml.erb#L14

Desktop> ffmpeg -i '\\?\C:\Users\frank\long path\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\fitness.mkv' -hide_banner
Input #0, matroska,webm, from '\\?\C:\Users\frank\long path\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\iiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\fitness.mkv':
  Metadata:
    encoder         : libebml v1.3.4 + libmatroska v1.4.5
    creation_time   : 2017-05-18T11:30:45.000000Z
    Writing frontend: StaxRip 1.4.4.5
  Duration: 00:00:21.58, start: 0.000000, bitrate: 1117 kb/s
    Stream #0:0: Video: h264 (Main), yuv420p(tv, bt709, progressive), 1280x720 [SAR 1:1 DAR 16:9], 29.59 fps, 29.59 tbr, 1k tbn, 59.18 tbc (default)

[Carl Eugen Hoyos]

The unavoidable question is now: What on earth is a manifest when discussing FFmpeg source code?

Please understand that -hide_banner makes every bug report invalid unless you want to report an issue with the option.

[Marton Balint]

Replying to cehoyos:

The unavoidable question is now: What on earth is a manifest when discussing FFmpeg source code?

​https://www.samlogic.net/articles/manifest.htm

So this ticket is about the inclusion of a long path aware manifest in ffmpeg.exe executable.

[stax76]

I've looked at a ffmpeg build made by Patman (media-autobuild_suite based I think) using Resource Hacker and it contains a manifest without long path support enabled.

My question is where is this manifest added? I've searched the ffmpeg and media-autobuild_suite source code and didn't find any manifest file.

[stax76]

Technical details from projects that have solved the issue:

​https://github.com/staxrip/staxrip/issues/338

[stax76]

More info:

​https://github.com/staxrip/staxrip/wiki/Windows-10-long-path-support

[Carl Eugen Hoyos]

Apparently not as unrealistic as I thought.

[Blacklands]

Any chance that this gets addressed?

From my understanding, the only thing that needs to change in the source code is that any hard-coded checks for the old maximum path length (260) are removed.
The MAX_LENGTH Windows macro always expands to 260, so that cannot be used, I believe.

Apart from that, only the manifest needs to be added during the build process, for Windows builds. (See e.g. here in the Microsoft docs: ​https://docs.microsoft.com/en-us/cpp/build/how-to-embed-a-manifest-inside-a-c-cpp-application)

[Elad Karako]

f.y.i.
you should be able to seamlessly patch up most of exe/dll/ocx (etc..) by using mt.exe (available in visual studio build tools you probably already have) and a generic manifest file like this one:
​https://github.com/eladkarako/manifest/blob/master/example_manifests/generic.manifest#L13

(you can add assemblyIdentity and description blocks if you want)

the commands are: (for exe use 1, for dll use 2, this is just an example, repeat as needed for any of your files).

mt.exe -nologo -manifest generic.manifest -outputresource:"ffmpeg.exe";1

mt.exe -nologo -manifest generic.manifest -outputresource:"avcodec-59.dll";2

it should properly write embed the manifest (resource 24) into the file (overwriting any existing one).

after you'll also apply a registry patch (one time):

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem]
"LongPathsEnabled"=dword:00000001

and reboot, you should be able to test it on your PC.

it should effect those functions (they would also ignore existing MAX_PATH value):
CopyFileW, CopyFile2, CopyFileExW, CreateFileW, CreateFile2, CreateHardLinkW, CreateSymbolicLinkW, DeleteFileW, FindFirstFileW, FindFirstFileExW, FindNextFileW, GetFileAttributesW, GetFileAttributesExW, SetFileAttributesW, GetFullPathNameW, GetLongPathNameW, MoveFileW, MoveFileExW, MoveFileWithProgressW, ReplaceFileW, SearchPathW, FindFirstFileNameW, FindNextFileNameW, FindFirstStreamW, FindNextStreamW, GetCompressedFileSizeW, GetFinalPathNameByHandleW.

no actual code change is needed.

​https://docs.microsoft.com/en-gb/windows/win32/fileio/maximum-file-path-limitation?tabs=cmd#enable-long-paths-in-windows-10-version-1607-and-later

[nil-admirari]

Code changes are actually required: FFmpeg uses MAX_PATH-sized buffers. Necessary patches were submitted to the mailing list:
https://ffmpeg.org/pipermail/ffmpeg-devel/2022-April/295391.html
https://ffmpeg.org/pipermail/ffmpeg-devel/2022-April/295388.html
https://ffmpeg.org/pipermail/ffmpeg-devel/2022-April/295389.html
https://ffmpeg.org/pipermail/ffmpeg-devel/2022-April/295390.html
https://ffmpeg.org/pipermail/ffmpeg-devel/2022-April/295387.html
https://ffmpeg.org/pipermail/ffmpeg-devel/2022-April/295392.html

Binaries with these patches applied can be found at ​https://github.com/yt-dlp/FFmpeg-Builds/releases.

[nil-admirari]

Fixed by the following commits:
​https://github.com/FFmpeg/FFmpeg/commit/3fb924464244bc317a5d19ab25625ae35abde512
​https://github.com/FFmpeg/FFmpeg/commit/4cdc14aa955805931b918d30d9c7349ab924dd52
​https://github.com/FFmpeg/FFmpeg/commit/6076dbcb55d0c9b6693d1acad12a63f7268301aa
​https://github.com/FFmpeg/FFmpeg/commit/f579a1d08b269b6dfc89596af20582c01950adb2
​https://github.com/FFmpeg/FFmpeg/commit/6b32ad59c8fe16fc792ca5a468b95ce5232ff6d1
​https://github.com/FFmpeg/FFmpeg/commit/c5aba39a041fdaac267fc8c6a2ef745a94a2b0da
​https://github.com/FFmpeg/FFmpeg/commit/bc8f1bbe233b435dc474df272dac0b5b6d0ef536
​https://github.com/FFmpeg/FFmpeg/commit/5d5a01419928d0c00bae54f730eede150cd5b268
​https://github.com/FFmpeg/FFmpeg/commit/3b3c567ad3d45a3f5d90668a1dd32f11b89fc4b5
​https://github.com/FFmpeg/FFmpeg/commit/fee765c2078ba03e346e311c86a447a116fe8c5f
​https://github.com/FFmpeg/FFmpeg/commit/cc5844da988fb7ca1051775a3dac43de77bf3881
​https://github.com/FFmpeg/FFmpeg/commit/dfa062ed3cae1d7ae3fdc52c7adda09cfc2e29b9
​https://github.com/FFmpeg/FFmpeg/commit/13350e81fd43cbd1aa3bbb7ed567e7dc7dd2b7f5
​https://github.com/FFmpeg/FFmpeg/commit/c381f5412fe810bd8118123aed9bd4f76b75b59d
​https://github.com/FFmpeg/FFmpeg/commit/69364a06c65d3437e8158cdffd98c2f6d1b84dd2

Implemented with \\?\ prefixes, not with a manifest; therefore should work on Windows versions older than Windows 10 version 1607.