Ensure CBR for audio #18
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…nc as my understanding is that will let ffmpeg drop packets it couldn't process fast enough instead of forcing them to be queued and processed in order, regardless of timing. Issue rfht#5
…512', plus only on the video & audio input when encoding, not on the raw audio inputs being merged). Also introduces the use of the filter on the individual audio streams being merged/mixed-down _and_ when merging the video and audio. The latter required moving the audio encoding to the ffmpeg process which is encoding the video. By using the 'async=1' option, the 'aresample' filter will fill and/or trim audio to keep it synced, but will not perform the more advanced stretch and/or sqeezing (I think this makes sense for our uses and _should_ be more efficient). Issue rfht#5
…; if line is too long, break with additional indentation) and tabs for indentation
…ched '*_bufsize' & 'gop' calculations from using 'expr' to arithmetic expansion expressions. Sets '-minrate', '-maxrate', and '-bufsize' for the audio track, in addition to '-b:a', when assembling AUDIO_CONV. Issue rfht#11
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NOTE: This is applied ontop of PR #13, which fixes audio/video desync. I'll rebase this as that PR is updated and merged (hopefully.)
As noted in issue #11, I had found that while my now-merged implementation of CBR (constant bit rate) in issue #6 has been working well, I was seeing fluctuations in the audio bit rate.
While our use of the AAC encoder implies it should be generating CBR, I found that
ffmpegsupports the-minrate,-maxrate, and-bufsizeoptions for all encoders. So, this splits our buffer size variables into audio & video versions and sets-minrate,-maxrate, and-bufsizeappropriately to produce a CBR for both audio & video.It has been working correctly in my testing, but I'll want to re-test after #13 is merged.