Transcoded FLACs don't start playing

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Transcoded FLACs don't start playing

Postby bobobo » Thu Aug 21, 2014 3:14 am

Hi,

I'm running Subsonic 5.0.beta1 on Ubuntu 14.04 on an ARM-based machine (Odroid U3). Subsonic worked fine on Ubuntu 13.10 with ffmpeg but has had the following problem since the upgrade to 14.04 and avconv.

The problem is that FLAC files, which are set to transcode to MP3 using Ubuntu's avconv, don't start playing in either the web player or DSub on my Android phone and tablet. Oddly, if I drag the play position in the web player to the right (from the start of the track to somewhere in the middle) it plays from that position. So it's just when I first tell it to play the track. I can see on the server that avconv's CPU usage goes up when I hit play and then drops down again later, presumably when the transcoding is complete. But the track doesn't start playing. Only if I drag the slider does the track start playing.

MP3 tracks seem to play OK, which leads me to think the issue is with starting to stream a track after transcoding.

This was happening with Subsonic 4.9 too before I upgraded to 5.0 beta1.

In DSub for transcoded FLACs it says "Downloading - 360KB" (or some number of KB) when I hit play, then says "Buffering", but then the player just goes back to its idle state - the track never starts playing. Dragging the slider in DSub doesn't start the track playing. MP3 tracks seem to play back OK in DSub.

My avconv settings are taken from this thread: viewtopic.php?f=2&t=10655

Any ideas about what's going wrong? Is this a known issue with avconv or have other people got avconv working OK?

Thanks!
bobobo
 
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Re: Transcoded FLACs don't start playing

Postby chiviak » Thu Aug 21, 2014 10:30 am

I recently had the same issue, but with ffmpeg. I discovered that it was due to the cover art being transcoded as a "video" along with the audio stream. I assume the two streams confused the flash player and caused it to not play the music. After looking at the ffmpeg docs I discovered that you can disable video streams using the '-vn' option with the command. So now my full audio transcoding command looks like:

Code: Select all
ffmpeg -i %s -vn -ab %bk -v 0 -f mp3 -


So I'm not sure about avconv but the arguments seem similar, so perhaps adding that command will work for you too.
chiviak
 
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Re: Transcoded FLACs don't start playing

Postby _jorb » Sat Aug 30, 2014 9:02 pm

I've recently run into this issue as well, and I consider it a bug in FFMPEG. I am trying to troubleshoot when this was introduced, or if there is any way a newer release of ffmpeg or avconv solves ths issue. Either way the root cause is not just FLAC files but also pretty much any non-id3 tagged audio container.

I agree with chiviak's workaround too and have this setting for my server. That being said I'm not a big fan of just disabling the video stream, because if you play these files raw they will properly display the album art. I could also be very wrong on that considering I don't have a lot of files to test with...

Was asking for some help over on this site too --> http://superuser.com/questions/804508/some-transcoded-streams-delayed-or-not-playable-from-ffmpeg
_jorb
 
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Re: Transcoded FLACs don't start playing

Postby Ratel001 » Wed Sep 17, 2014 3:03 am

I have what must be a very similar problem: I note that some Flac files are transcoded, others are not, and as said above, I can start the file by nudging the slider. My transcoding command looks like this:

Code: Select all
ffmpeg -i %s -ab %bk -v 0 -f mp3 -


However, if I change it to this (add the 'n'):

Code: Select all
ffmpeg -i %s -ab %bk -vn 0 -f mp3 -


Then it doesn't play, even if I do move the slider. I also tried changing Downsample and HTTP Live Streaming (adding the 'n') with no success.
Ratel001
 
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Re: Transcoded FLACs don't start playing

Postby bonnettenotbunny » Wed Jun 26, 2019 9:04 am

_jorb wrote:I've recently run into this issue as well, and I consider it a bug in FFMPEG. I am trying to troubleshoot when this was introduced, or if there is any way a newer release of ffmpeg or avconv solves ths issue. Either way the root cause is not just FLAC files but also pretty much any non-id3 tagged audio container.

I agree with chiviak's workaround too and have this setting for my server. That being said I'm not a big fan of just disabling the video stream, because if you play these files raw they will properly display the album art. I could also be very wrong on that considering I don't have a lot of files to test with...

Was asking for some help over on this site too --> http://superuser.com/questions/804508/some-transcoded-streams-delayed-or-not-playable-from-writemyessaytoday-ffmpeg



Hi,

I had issues with my Plex server (Version 7.0.0 for Android app). My transcoding command didn't work. The superuser discussion is no longer available. Is it possible to convert FLAC files to AAC?
Sorry for bumping, just noticed it's an old thread.
bonnettenotbunny
 
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