Disabled check for ffmpeg.

[dop251]

Some Linux distributions (e.g. Debian) have avconv instead of ffmpeg. youtube-dl can work with either, but podsync insists on having ffmpeg in the $PATH. This PR removes the check which allows it to work in Debian. Also, after applying #121 the lack of ffmpeg becomes immediately obvious in the logs:

INFO[2020-04-16T13:44:21Z] ! downloading episode https://youtube.com/watch?v=7JFhrFAal74  episode_id=7JFhrFAal74 index=1
ERRO[2020-04-16T13:44:25Z] youtube-dl error: /tmp/podsync-957548525/7JFhrFAal74.%(ext)s  error="failed to execute youtube-dl: exit status 1"
ERRO[2020-04-16T13:44:25Z] [youtube] 7JFhrFAal74: Downloading webpage
[download] Destination: /tmp/podsync-957548525/7JFhrFAal74.m4a
[download] 100% of 8.22MiB in 00:0039MiB/s ETA 00:000nown ETA
WARNING: 7JFhrFAal74: writing DASH m4a. Only some players support this container. Install ffmpeg or avconv to fix this automatically.
ERROR: ffprobe/avprobe and ffmpeg/avconv not found. Please install one. 

[mxpv]

Should we check either ffprobe OR avprobe available on a system instead of removing the check entirely ? I'd prefer podsync to fail at start if the environment is wrong

[dop251]

It is definitely an option, however I went for the easiest fix for a blocker. Besides, youtube-dl is not bundled or vendor-locked. Their requirements may change in a future version (for instance, they may decide to drop support for avconv or they may introduce another option). There is no simple and reliable way for podsync to determine whether the environment is sane unless you do version checking... I just don't think it's worth the effort tbh.

[mxpv]

youtube-dl can work independently from ffprobe/avprobe, however podsync can't. So if there is no ffprobe or avprobe, it'll fail. And it'll be frustrating if your feed does checks once a week and it turns out it doesn't work a week later, so it's important to check that the env is sufficient and fail early.

[dop251]

It may fail to work for many other reasons (like the 429 error I mentioned). You should always check the logs and if it's really important set up some kind of alerting mechanism. But that's another story.

podsync never uses ffmpeg directly, so making some checks on behalf of youtube-dl just doesn't feel right to me. Especially considering possible introduction of new Downloaders in the future which may not require youtube-dl at alll.

[mxpv]

Can you please check 4afc477
Will this work for you?

[dop251]

It will fix the blocker for now, yes.

[mxpv]

Thanks. I'm going to close this one then