FS#4742 - Hybrid Wavpack .WV Skips (interrupts) every 15sec

Attached to Project: Rockbox
Opened by Anonymous Submitter - Monday, 27 February 2006, 21:33 GMT
Task Type Bugs
Category Codecs
Status Closed
Assigned To No-one
Operating System Iriver H100 series
Severity Medium
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 0
Private No


Hybrid Wavpack .WV made from a 24-bit/96khz file with -b320 -c (yielding a 432kbps WV)
interrupts every 15 sec.
Wavpack -f (fast) mode produced a file that skips less.
Wavpack -hx (maximum compression) mode skipped more.
This task depends upon

Closed by  Christi Scarborough (christi-s)
Sunday, 19 March 2006, 12:24 GMT
Reason for closing:  Invalid
Additional comments about closing:  Hybrid mode playback is unsupported. Please submit a feature request.
Comment by jbthiel (jbthiel) - Monday, 27 February 2006, 22:26 GMT
Note: in the details, the -f and -hx modes were also both using hybrid mode at -b320.

On iriver h120:
from 24/96 source:
hybrid .wv + .wvc SKIPS. (and plays as 432kbps, even when .wvc is present; see also other wavpack .wvc bug filed)
non-hybrid lossless .wv plays OK, no skips. (2908kbps vbr)

from 16/44 source:
hybrid .wv+.wvc OK (except doesn't see .wvc if present)
non-hybrid, lossless .wv OK

It would be great to get the hybrid mode non-skipping from 24/96 source, I would guess the iRiver H120 has enough cpu, since the pure .wv file from 24/96 plays ok.

Comment by Paul Louden (darkkone) - Tuesday, 28 February 2006, 21:23 GMT
Lossless .wv uses a *lot* less processing power to decompress than lossy, which is why the lossless one doesn't skip even though it's a significantly higher bitrate.

It seems unlikely that a lossy 24/96 at 432kbps will decompress easily at full speed. There's a fairly large difference in how lossless and lossy files work, and lossless once, even though they're much higher bitrate, *tend* to require much less effort to decompress.

As for the hybrid, if my understanding of comments made by someone (I think it was Mr. Bryant) realtime playback in hybrid mode requires too much to be feasible. I could be misremembering the statement I read though. It may just be "difficult."