Fix AAC codec support for real. Transcode Main and HE-AAC

[cewert]

#1928 correctly tells the server we can't play profile Main but the server is still sending us the same audio stream. This PR actually fixes the problem by forcing AAC profile Main as well as HE-AACv1 to transcode to MP3 since the server doesn't currently support transcoding from one AAC profile to another.

I also added another global session var video to hold the meta data for the currently playing video

Changes

• Add new global var m.global.session.video
• Use new video var to force AAC profiles we don't support to be transcoded
• Adds HE-AAC to the list of AAC profiles we don't support (comes from roku docs)

Issues

Ref #1928

[cewert]

Testing

• AAC profile Main ffmpeg -i video.mkv -c:a aac -profile:a aac_main aac-main.mkv
• AAC profile HE-AAC ffmpeg -i video.mkv -c:a libfdk_aac -profile:a aac_he -b:a 32k he-aac.mkv
  • Need to compile ffmpeg yourself to use libfdk_aac encoder. Ubuntu docs here

AAC LC and HE-AACv2 are more common and I was able to use examples from my library