Bugzilla – Bug 1859
Jerky sound with some 24/48 FLAC files
Last modified: 2009-09-08 09:22:01 UTC
Follow up to bug 1820... I installed the new 6.1 version with FW 15 but unfortunately I still have problems with many 24/48 files (I have both WAV and FLAC files extracted from 2 DVD-A). Note that some tracks are just playing fine and others are always giving intermittent issues at the same locations. I tested with different 24/48 WAV and FLAC files and various settings: 1) WAV->FLAC->FLAC (server converts WAV to FLAC): the track starts playing OK but at some stage, on many of these tracks, the music becomes very jerky (like skipping samples). In most of the case the problems goes away after a few seconds and the music plays fine again. This problem can appear several time on one track. 2) FLAC->FLAC->built in (WAV files were first manually converted to FLAC version 1.1.2): this gives exactly the same result, same tracks are causing the same issue. On the two albums that I ripped, I only have a couple a tracks that play fine from end to end. Note that I tried with wired and wireless SB2 and with 2 different DAC's and the issue is reproduceable. Hope this helps, if you need some of these files let me know. Unfortunatelly they are all quite big (around 50MB for the smallest) and I cannot upload them to the bug report. I can email them or upload them to some FTP site. PS: note that streaming directly 24/48 WAV files (WAV->WAV->built in) gives some kind of white noise, doesn't work at all. Vidur mentioned that this is a known issue that the files are still interpreted as 16 bits. I understand that this is a different and known bug.
I've uploaded the files to an FTP server. Email me and I'll give you the link. Michel
vidur: could this be a player cpu loading problem?
It's possible, I suppose, though I don't remember us getting anywhere near stressing the CPU with FLAC decoding.
Test files have been uploaded. Michel
Test files can be found at http://ftp.electricrain.com/daniel/vidur. Dean to try to recreate. Michel says: I uploaded some FLAC files: 02.FLAC doesn't play fine 05.FLAC plays fine 07.FLAC doesn't play fine 12.FLAC doesn't play fine they are all extracted from the same disc. I've added a readme.txt that shows the results per track for the whole disc. I could not upload all of them... takes too long. I also had similar results with a second disc.
Michel: One thing to confirm... When you tested these files were you using the final version of firmware that shipped with 6.1.1? There was a day or two where firmware version 15 did not have vidur's FLAC fixes. If you have 6.1.1 installed, try forcing a firmware upgrade (press and hold BRIGHTNESS) and verify that they still do not work. Thanks!
Sorry for the late reply (I was abroad for a few days). Yes I was using the latest FW15 but to be sure I just reinstalled the official 6.1.1 and forced a new upgrade of firmware 15, I can confirm that I still have the issue with the same files.
vidur will be looking at this when he has time.
Alas, this is going to have to wait until after the 6.2 release.
I have jerky sound with some FLAC files which contain DTS data (see this forum thread for background): http://forums.slimdevices.com/showthread.php?t=15271&page=5&pp=10 My guess was that the decoder was somehow having difficulty because of the low compression ratio: the FLAC files are approximately the same size as the original WAV files, and FLAC reports a ratio of about 1.000 (somtimes more!). I notice that at least one of the example FLAC files posted above also has poor compression; I tried 02.flac and, recompressing the extracted WAV, saw a ratio of 0.958. I wonder if the poor compression is a factor here.
(In reply to comment #9) > Alas, this is going to have to wait until after the 6.2 release. FYI: Since I upgraded to firmware 29 all the FLAC files I mentionned earlier are now jerky (even the few that were working fine with previous firmware). Michel
Are you using a wireless or wired connection? If wireless, can you try connecting via ethernet temporarily and add information about your access point model if there is any difference?
(In reply to comment #12) I have two SB2: one wired and one wireless: same behaviour with both. FWIW, I am using a Netgear router (WGT634U). Michel
Hi guys, I can confirm that the new FW35 fixed my problem. My 24/48 FLAC files are now playing fine. Well done! Thanks. Michel
Great, I'll close this. (If you are still having problems with 24/48 FLAC PCM files, please reopen. If you are having issues with dolby/ac3 files, see bug 2990).