Sending to ffmpeg-devel because I do not know if my workaround makes any sense? For some reason hevc alpha decoding was not working for us. I picked up https://source.ffmpeg.org/gitweb/ffmpeg.git/commit/eedf8f0165fe6523be692c5a9... avcodec/hevc: workaround hevc-alpha videos generated by VideoToolbox but videos were still not showing their alpha channel. So I added this to libavcodec/hevc/hevcdec.c: --- ./libavcodec/hevc/hevcdec.c 2026-03-16 18:13:04.000000000 +0000 +++ ./libavcodec/hevc/hevcdec.c.new 2026-05-09 05:22:45.098799320 +0000 @@ -712,9 +712,11 @@ break; } + if (alpha_fmt != AV_PIX_FMT_NONE) *fmt++ = alpha_fmt; - *fmt++ = sps->pix_fmt; + if(alpha_fmt == AV_PIX_FMT_NONE) + *fmt++ = sps->pix_fmt; *fmt = AV_PIX_FMT_NONE; // export multilayer information from active VPS to the caller, ==== basically only adding main layer (?) formats if there was no alpha) It seems to work with two hevc-alpha files and one normal hevc file May be this is only cingg specific problem - due to way we pick pixel formats on decoding? ffmpeg itself works ok without this workaround Even with this patch ffmpeg cli still picks correct format, on encoding to png: thirdparty/ffmpeg-8.1/ffmpeg -i /dev/shm/av1--test.mp4 -vframes 1 1.png 1.png contain transparency test files from https://developer.apple.com/documentation/avfoundation/using-hevc-video-with... more test files: https://lf-tk-sg.ibytedtos.com/obj/tcs-client-sg/resources/video_demo_hevc.h... possibly related https://trac.ffmpeg.org/ticket/10901 HEVC with alpha to PNG does not maintain alpha
When I try to compile with the x265 patches using alpha, I get a crash. Here's the link to the cinlog: https://limewire.com/d/rw9zl#dr8Khyi0r0
Andrea/Andrew: Another early ARCH warning in Andrea's cin5.log due to cmake 4.3.2 running there. See indents below. But could this suggestion fix it for CinGG?* Or, add -DCMAKE_POLICY_VERSION_MINIMUM=3.5 to try configuring anyway.* CMake Deprecation Warning at CMakeLists.txt:10 (cmake_minimum_required):
Compatibility with CMake < 3.10 will be removed from a future version of CMake. Update the VERSION argument <min> value. Or, use the <min>...<max> syntax to tell CMake that the project requires at least <min> but has been updated to work with policies introduced by <max> or earlier. -- cmake version 4.3.2 CMake Error at CMakeLists.txt:10 (cmake_policy): Policy CMP0025 may not be set to OLD behavior because this version of CMake no longer supports it. The policy was introduced in CMake version 3.0.0, and use of NEW behavior is now required.
Please either update your CMakeLists.txt files to conform to the new
behavior or use an older version of CMake that still supports the old behavior. Run cmake --help-policy CMP0025 for more information. CMake Error at CMakeLists.txt:16 (cmake_policy): Policy CMP0054 may not be set to OLD behavior because this version of CMake no longer supports it. The policy was introduced in CMake version 3.1.0, and use of NEW behavior is now required.
Please either update your CMakeLists.txt files to conform to the new
behavior or use an older version of CMake that still supports the old behavior. Run cmake --help-policy CMP0054 for more information.
CMake Error at CMakeLists.txt:20 (cmake_minimum_required):
Compatibility with CMake < 3.5 has been removed from CMake.
Update the VERSION argument <min> value. Or, use the <min>...<max> syntax to tell CMake that the project requires at least <min> but has been updated to work with policies introduced by <max> or earlier.
* Or, add -DCMAKE_POLICY_VERSION_MINIMUM=3.5 to try configuring anyway. *
On Sun, May 10, 2026 at 4:09 AM Andrea paz <gamberucci.andrea@gmail.com> wrote:
When I try to compile with the x265 patches using alpha, I get a crash. Here's the link to the cinlog:
participants (3)
-
Andrea paz -
Andrew Randrianasulu -
Phyllis Smith