Feature parity for windows builds

[hmaarrfk]

Things already compiled for windows upstream:

• libopenvino: Added OpenVINO 2.0 support for FFMPEG (avfilter) #223

Things that seem to support windows upstream:

• libvpx: https://github.com/conda-forge/libvpx-feedstock
• lame: https://github.com/conda-forge/lame-feedstock

Things that don't obviously support windows upstream

• gmp support: https://github.com/conda-forge/gmp-feedstock
• libva support: https://github.com/conda-forge/libva-feedstock

Recently added feature parity

• openh264: https://github.com/conda-forge/openh264-feedstock
• svt-av1: https://github.com/conda-forge/svt-av1-feedstock
• ffnvcodec-headers: https://github.com/conda-forge/ffnvcodec-headers-feedstock

[marc-wien]

@hmaarrfk Hi, would you say that once this issue is resolved in conda-forge/lame-feedstock, then LAME in FFMPEG on Windows should be able to be supported? Or am I missing something?
conda-forge/lame-feedstock#7

Thanks!

[hmaarrfk]

This is correct. But honestly, i don't use audio. So i have little incentive to complete the PR you pointed to. You can try to copy over the progress and complete it.

[marc-wien]

Understood. Thanks for the tip!

[hmaarrfk]

Libass was recently added to Unix builds. Unsure how easy it is to add it to windows builds.