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Tasklist

FS#6479 - Compressed audio watermark calculation is wrong for high bitrate formats.

Attached to Project: Rockbox
Opened by Nils Wallménius (nls) - Wednesday, 27 December 2006, 21:09 GMT+1
Task Type Bugs
Category Music playback
Status New
Assigned To No-one
Player type All players
Severity Low
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 0%
Private No

Details

The compressed audio buffer watermark calculation does not take the bitrate of the audio into account. This makes the watermark too low for high bitrate formats such as flac and therefore can cause a skip in music playback when the buffer has to be refilled, especially if the disk is powered down wich makes the spin up time slightly longer.
This task depends upon

Comment by Mark Arigo (lowlight) - Tuesday, 02 January 2007, 18:33 GMT+1
Try increasing the "Anti-Skip Buffer" which increases the default watermark.

In reviewing the code, it appears that the watermark calculation does use the current track's bitrate. However, the watermark does not appear to be updated for each track. It looks like it gets set when the codec is loaded and when new tracks are loaded, but the calculation is based on the current track. I guess a solution would be to have the codec update the watermark for each new track and take that calculation out of the playback code.
Comment by Steve Bavin (pondlife) - Wednesday, 03 January 2007, 14:00 GMT+1
Could this perhaps explain the reported cases where buffering never seems to stop with low bitrate files? Or is that a seperate problem where the audio buffer still isn't full after buffering the allowed 32 tracks..?
Comment by Brandon Low (lostlogic) - Wednesday, 24 October 2007, 20:31 GMT+1
It definitely seems reasonable, since we set the anti-skip buffer in seconds, to have some kind of average bitrate for all files currently buffered which lets us update the watermark setting.

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