Quick answers:
- Yes, they are used during the analysis phase
- I don’t think avconv is more fragile than ffmpeg. Most of the code is the same between the two–avconv is a fork of ffmpeg.
- Running them externally isn’t an apples-to-apples test because Roon still handles all of the demuxing internally–so a lot of file-handling details still happen on our end.
- There is a known bug where “long” (meaning 10-20minute+) MP3/AAC files cause the decoder to hang during analysis, playback, etc. Only on Linux. This will be fixed in our next release (soon).
- If when you get stuck, you have an avconv process hanging around forever using 0% of the CPU, that’s probably the bug.
- If you submit logs to us, in a situation like this, we generally look towards the end for trace that says stuff like “analyzing (file)” or “extracting (file)” to see if there’s a pattern. If we see a pattern, we grab the file and debug here.