Transcoding fails, intermittently

[hakko]

Brief description:

I have a song in Apple Lossless format. When I played it from the iSub client, the transcoding to mp3 using ffmpeg failed half way through and the song skipped. When I played the same song just afterwards from the Subsonic web interface, the transcoding worked as expected and the whole song played.

Another scenario:

A friend of mine tried listening to transcoded lossless files from my library using the web interface, and the transcoding failed for her. When I tried listening to the same songs from the web interface (although surfing via localhost, not remotely), it worked.

I'm using Subsonic 4.6.

I'd just like to hear if this is the known issue that's been up in the forum lately? GJ51 has written that this was introduced in 4.6 and didn't happen in 4.5. I need to dive into it and fix it, but if someone can point out some more details, I'd be interested as I'm a bit baffled of what's happening here. It's hard to tell if Subsonic has some bug or if I should try another ffmpeg build (or similar).

Here's the subsonic log:

Code: Select all

[2012-05-05 23:16:05,539] DEBUG TranscodeInputStream - Starting transcoder: [/Library/Application Support/Subsonic/transcode/ffmpeg] [-i] [/Volumes/NO NAME 1/iTunes/Music/King Geedorah/Take Me to Your Leader/13 The Fine Print.m4a] [-aq] [2] [-v] [0] [-f] [mp3] [-]
[2012-05-05 23:16:05,791] DEBUG InputStreamReaderThread - (/Library/Application Support/Subsonic/transcode/ffmpeg) FFmpeg version UNKNOWN, Copyright (c) 2000-2011 the FFmpeg developers
[2012-05-05 23:16:05,792] DEBUG InputStreamReaderThread - (/Library/Application Support/Subsonic/transcode/ffmpeg)   built on Mar 13 2011 21:02:55 with gcc 4.0.1 (Apple Inc. build 5494)
[2012-05-05 23:16:05,792] DEBUG InputStreamReaderThread - (/Library/Application Support/Subsonic/transcode/ffmpeg)   configuration: --cc=gcc-4.0 --enable-gpl --enable-shared --enable-pthreads --enable-libmp3lame --mandir=/usr/local/share/man
[2012-05-05 23:16:05,792] DEBUG InputStreamReaderThread - (/Library/Application Support/Subsonic/transcode/ffmpeg)   libavutil    50. 39. 0 / 50. 39. 0
[2012-05-05 23:16:05,792] DEBUG InputStreamReaderThread - (/Library/Application Support/Subsonic/transcode/ffmpeg)   libavcodec   52.114. 0 / 52.114. 0
[2012-05-05 23:16:05,792] DEBUG InputStreamReaderThread - (/Library/Application Support/Subsonic/transcode/ffmpeg)   libavformat  52.103. 0 / 52.103. 0
[2012-05-05 23:16:05,792] DEBUG InputStreamReaderThread - (/Library/Application Support/Subsonic/transcode/ffmpeg)   libavdevice  52.  3. 0 / 52.  3. 0
[2012-05-05 23:16:05,792] DEBUG InputStreamReaderThread - (/Library/Application Support/Subsonic/transcode/ffmpeg)   libavfilter   1. 76. 0 /  1. 76. 0
[2012-05-05 23:16:05,792] DEBUG InputStreamReaderThread - (/Library/Application Support/Subsonic/transcode/ffmpeg)   libswscale    0. 12. 0 /  0. 12. 0
[2012-05-05 23:16:05,866] DEBUG InputStreamReaderThread - (/Library/Application Support/Subsonic/transcode/ffmpeg) Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/Volumes/NO NAME 1/iTunes/Music/King Geedorah/Take Me to Your Leader/13 The Fine Print.m4a':

[...]

2012-05-05 23:16:05,895] DEBUG InputStreamReaderThread - (/Library/Application Support/Subsonic/transcode/ffmpeg) Press [q] to stop encoding

[...]

[2012-05-05 23:18:30,332] DEBUG InputStreamReaderThread - (/Library/Application Support/Subsonic/transcode/ffmpeg) av_interleaved_write_frame(): Operation not permitted


The last line, av_interleaved_write_frame(): Operation not permitted, is the only indication of something going wrong, no more detailed error messages that I can find.

[GJ51]

I don't get to into the details of what's going on under the hood, but I do recall that Sindre changed the method used to estimate the length of tracks in ver 4.6 that adversely affected mobile playback. I think it had something to do with changing a REST method, but as I said, I'm not really int the code. The only REST methods I'm familiar with are the ones I learned after I retired; those I know VERY well. It wasn't discovered that there was a problem until after the final release of 4.6. It is supposed to be addressed in 4.7

At this point, it may be less time consuming to either just wait for 4.7, which should be ready for a beta release soon, or just drop back to 4.5.

As always, your welcome to test your phone on my 4.5 site to see if the problem goes away, just drop me a pm. I'll be happy to drop a known "bad" track in a folder for you if you like.

[hakko]

Thanks for that generous offer! I think just to nail it down, I need to install 4.5 and the 4.7 beta1 that's available, to make sure the same ffmpeg is being used, having the same OS etc. I'm building my own music player on top of Subsonic so I really need to find the exact cause.