Support Video & Audio Capture

[AntumDeluge]

💡 Describe your idea

FFmpeg is a powerful command line tool that has the ability to capture & record desktop video & audio. I would like to add support for securely passing parameters to an external app (or FFmpeg executable itself) to allow convenient recording of the client.

Progress has been started with using the web MediaStream Recording API instead.

🔬 Motivation

Gamers love to record their play time.

📝 Alternatives

Using the web MediaStream Recording API. It might be more simple, but I don't know anything about it yet or what types of codecs it supports.

🛠️ Progress

• Video capture support of the viewport using WebAPI has been added in Support Video Capture #741. It requires debugging to be enabled with /debug screencap. Then it can be started/stopped with /screencap chat command or from main menu.

Remaining to do

Video capture:

• support capturing viewport only
• support capturing entire web page
• allow setting custom parameters: (if possible in WebAPI, may be browser dependent)
  • container (WebM, MP4, Ogg, Matroska, etc.)
    • currently only WebM is supported as tested in Firefox on Windows
  • codec/encoder (AVC (H.264), HEVC (H.265), VP8, VP9, AV1, Theora, etc.)
  • bitrate (bps)
  • framerate (fps)

Audio capture:

• rework sound manager to play all sound from single output (AudioContext may be the solution)
• allow setting custom parameters: (if possible in WebAPI, may be browser dependent)
  • codec/encoder (lossy: AAC, Vorbis, Opus, MP3, etc.) (lossless: FLAC, ALAC, PCM (WAV), etc.)
  • bitrate (bps)
  • frequency (audio rate / Hz)
  • channels (mono / stereo)

UI:

• slash action to start/stop
• menu button to start/stop