Flac to MP3 transcodiing results in "choppy" sound
Posted: Sun Apr 01, 2012 11:33 amHi
Running Serviio 6.2 on Windows 7 64 bit, or indeed on Centos 6 64 bit on another machine, playback of audio transcoded from FLAC to MP3 is choppy and I can't fathom out why.
My transcode statement is simple:
<Transcoding>
<Audio targetContainer="mp3" aBitrate="192">
<Matches container="flac" />
</Audio>
</Transcoding>
The resultant MP3 is perfectly playable if I copy it from the transcoded file temp directory to another folder so I can play it back through Serviio as an MP3 without transcoding, so the transcoding output itself appears to be fine. The problem occurs whether I run the renderer on the same machine as Serviio or on a remote machine, which suggest it isn't a network problem (as does the fact that the transcoded MP3 can be played ok). None of the CPU cores are ever more than 40% utilized and there is plenty of free memory even if I double the maximum available to Serviio's VM to 768MB. With Log4J set to TRACE nothing untoward is revealed; the transcoding command used is shown as "C:\appls\java\serviio\bin\\..\lib/ffmpeg.exe -i C:\Music\Test\Flacs\dilvie_-_the_dragonfly.flac -y -ab 192k -ac 2 -f mp3 C:\Windows\TEMP\Serviio\dilvie_-_the_dragonfly-MP3.stf"
All in all, I'm perplexed, especially as I cannot find a report of a similar problem in these forums. What am I missing?
Steve
Running Serviio 6.2 on Windows 7 64 bit, or indeed on Centos 6 64 bit on another machine, playback of audio transcoded from FLAC to MP3 is choppy and I can't fathom out why.
My transcode statement is simple:
<Transcoding>
<Audio targetContainer="mp3" aBitrate="192">
<Matches container="flac" />
</Audio>
</Transcoding>
The resultant MP3 is perfectly playable if I copy it from the transcoded file temp directory to another folder so I can play it back through Serviio as an MP3 without transcoding, so the transcoding output itself appears to be fine. The problem occurs whether I run the renderer on the same machine as Serviio or on a remote machine, which suggest it isn't a network problem (as does the fact that the transcoded MP3 can be played ok). None of the CPU cores are ever more than 40% utilized and there is plenty of free memory even if I double the maximum available to Serviio's VM to 768MB. With Log4J set to TRACE nothing untoward is revealed; the transcoding command used is shown as "C:\appls\java\serviio\bin\\..\lib/ffmpeg.exe -i C:\Music\Test\Flacs\dilvie_-_the_dragonfly.flac -y -ab 192k -ac 2 -f mp3 C:\Windows\TEMP\Serviio\dilvie_-_the_dragonfly-MP3.stf"
All in all, I'm perplexed, especially as I cannot find a report of a similar problem in these forums. What am I missing?
Steve
I would not necessarily use the samples from ffmpeg as they are possibly corner case examples or broken files people upload for the ffmpeg team to fix.