xiph / theora

Reference implementation of the Theora video compression format.
https://theora.org/
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Add cmake support #14

Open mcmtroffaes opened 3 years ago

mcmtroffaes commented 3 years ago

This patch adds cmake support. This is currently used by vcpkg to build theora on windows under msvc (since msvc has excellent cmake support these days). The cmake script builds the theora, theoraenc, and theoradec libraries, as well as the test suite, which it can run via ctest as usual.

In principle it can also be used to build theora under linux, macos, and other systems. I've tested the build on linux and it passes regression testing (even though it uses the windows source files from the x86_vc folder; it would be possible to change this with some configuration switches). It would not be too hard to fully support these systems properly.

An issue I ran into: msvc does not support inline assembler in 64 bit mode (see https://docs.microsoft.com/en-us/cpp/assembler/inline/inline-assembler?view=vs-2019: "Inline assembly is not supported on the ARM and x64 processors."). However the theora x86 optimisations for msvc are written in inline assembler. Therefore, these optimisations are currently only enabled for the 32 bit builds. To fix this, the assembler code would have to be moved to separate files. I'm not sure if it's worth the effort given most folks have likely moved on to more modern codecs, but I thought it was worth pointing out since you might wonder why the configuration is set up in this way.

MrSapps commented 3 years ago

Is this every likely to be merged?

mcmtroffaes commented 3 years ago

Looks like upstream is maintained here: https://gitlab.xiph.org/xiph/theora/ Will repost there when I get some time, as it seems that the devs don't consider github PRs.

mcmtroffaes commented 3 years ago

https://gitlab.xiph.org/xiph/theora/-/issues/2316

MrSapps commented 3 years ago

Hardly any activity over there? Is this project dead? I've been thinking about libvpx to use VP8/9 instead...