Bugzilla – Bug 13865
lame transcoding yields incorrect progress/timing information
Last modified: 2011-01-13 22:44:01 UTC
My player is an older squeezebox v1. I've always used lame with a 320kbps rate limit to handle my AAC files. In recent versions of squeezecenter (incl. 7.3.4) the music plays fine, but the progress bar and time remaining indicator does not update correctly. 10 seconds of progress reported on my squeezebox corresponds to 25 seconds of music, so it is off by ~2.5X. Since encountering this problem I have now disabled lame on 7.3.4 and don't see this problem, but I believe this means I've lost the ability to rate limit AAC streams from my server.
Alan: your thoughts on this one?
I'll look at it.
Update hours
The problem is that the server does not know the bitrate of the lame-encoded stream and the player does not report time played. The server guesses at the bitrate based on any bit-rate limit but lame may actually use a lower bitrate resulting in the problem that you see. One solution would be to add "-b 320" to the lame command line in convert.conf. This would force lame to use 320kb/s
That would, of course, have the effect of defeating lame's VBR (variable bit-rate) capability and would also require that you specify the desired bitrate for the player under Settings / Player/ Audio / Bitrate Limiting, rather than leaving it at "No Limit". Because of these issues I do not propose to apply an actual patch to the product. I will attach a patch to this bug that users could apply themselves if they so wish. I would note that, in a previous release of SqueezeboxServer, lame was configured to use CBR (constant bit-rate) and so the server did know the actual bitrate to use in time-played calculations. But VBR has so many advantages over CBR that I do not propose to revert that change.
Created attachment 7080 [details] Patch to force lame to use CBR when transcoding