Bugzilla – Bug 1820
24/48 audio files (WAV or FLAC) not playing on SB2
Last modified: 2008-12-18 11:37:19 UTC
Hi, Running Slimserver 6.1B2 on XP SP2, Squeezebox2 FW14. I have ripped the content of some DVD-A. The resulting files are 24bits at 48khz PCM WAV files. I can play them directly on the computer (with Media Player or Adobe Audition). I also converted them in FLAC (please find below the result of Metaflac on one of them, at least the beginning, it confirms 24/48). When I try to play these files on the SB2, I get some kind of loud statis with some low level music in the background. I get the same result with both WAV and FLAC and both on analog (headphone) or digital outputs. In slimserver->File types, both WAV and FLAC are set to play natively on the SB2 (i.e. no conversion on the server). The files are quite big. If needed I can email them or let me know if I can upload one of them somewhere. Let me know. Michel _______________________ METADATA block #0 type: 0 (STREAMINFO) is last: false length: 34 minumum blocksize: 4608 samples maximum blocksize: 4608 samples minimum framesize: 16 bytes maximum framesize: 27660 bytes sample_rate: 48000 Hz channels: 2 bits-per-sample: 24 total samples: 13017200 MD5 signature: 55f3e288a4fd14210e5253e2055ea097 METADATA block #1 type: 3 (SEEKTABLE) is last: false length: 486 seek points: 27 point 0: sample_number=0, stream_offset=0, frame_samples=4608 point 1: sample_number=479232, stream_offset=1685213, frame_samples=4608 point 2: sample_number=963072, stream_offset=3845903, frame_samples=4608 __________________________
Created attachment 636 [details] -d_source log file I've played first the .wav file and then the .flac file.
Michel, the wav->flc conversion seems to be disabled. Can you playback the WAV files with that reenabled?
Also, try attaching the FLAC file to this bug. If it's too large, I'll see about finding a place to upload it.
Yes, I play WAV natively and FLAC natively. I'll enable the WAV to FLAC conversion and try again later today. I'll keep you informed. I already tried to attach the files (both WAV and FLAC) but they are too big... Michel
Hmm...a flac -a of the file you sent me results in: flac 1.1.1, Copyright (C) 2000,2001,2002,2003,2004 Josh Coalson flac comes with ABSOLUTELY NO WARRANTY. This is free software, and you are welcome to redistribute it under certain conditions. Type `flac' for details. bug1820.flac: analyzing, 16% complete bug1820.flac: ERROR while decoding data state = FLAC__STREAM_DECODER_END_OF_STREAM What do you get if you do a flac -a (analyze) on the file? I wonder if there are any compatibility issues between flac 1.1.1 and 1.1.2 (which was used to encode the file, I believe).
I just only managed to upload the file successfuly a few minutes ago after several interrupted transfers. I guess the file you tried was not complete. Could you try again. On the file that is now in the FTP site. I did flac -a and got: D:\Music Storage\R.E.M\Automatic For The People>flac -a "01 Drive.flac" flac 1.1.2, Copyright (C) 2000,2001,2002,2003,2004,2005 Josh Coalson flac comes with ABSOLUTELY NO WARRANTY. This is free software, and you are welcome to redistribute it under certain conditions. Type `flac' for details. 01 Drive.flac: done Note that the WAV file is transfering at the moment, still more than 1 hour to go. Michel
You're probably right - I grabbed the file too early. I'll have to wait for Dan to come back (it's his FTP server) to grab the complete file. In the meantime, could you attach the flac -a output to the bug? Thanks.
Created attachment 645 [details] Flac analysis file - 01 drive.ana Analysis file generated by Flac 1.1.2 (-a) on "01 drive.flac"
Looking at the analysis, I wonder if this is related to bug 1508.
I tried the work-around suggested in bug 1508 (disable the built-in flac decoding and use the server) but it doesn't help. Note that once the wav file will be uploaded (45 minutes to go) you should be able to check that it also doesn't work. So I am not sure the problem relates to flac decoding. Note that this wav file plays fine with other players like Media-player or inside Adobe Audition.
Well...the WAV issue is known (surprisingly, this is the first time it's made the bug database). The hardware can play back 24-bit audio, but the server has a bug that doesn't correctly send it the right parameters (it's interpreting the input as 16-bit). FWIW, the WAV->FLAC conversion should fix this problem. The FLAC issue is separate and my speculation is still that the problem is similar to the one mentioned in bug 1508.
OK, I didn't know about the Wav issue. I've set the WAV->FLAC conversion and guess what... it works. So yes, it looks like it is related. But then I am not sure I understand what's happening: the WAV file is converted to FLAC on the server, FLAC is streamed to the SB2 and then the SB2 use the built-in FLAC decoder... so what's the difference between that and sending the FLAC file directly from the server? In any case the wav file is now also uploaded to the FTP site! Cheers, Michel
The difference probably relates to the encoding parameters. The 24-bit FLAC that you've encoded seems to have FLAC frames that we're having problems with in the hardware. I'm guessing that the encoding parameters for the on-the-fly result in files that we're more comfortable with. The quality is the same, of course, but the compression factor may be different.
Another test... I have another DVD-A with 24/96 source (Donald Fagen- Karmakiriad). Now that I have set Wav to Flac conversion on the server, playing these 24/96 wav files works as well... except that they are too slow, the files are just playing at half speed. Should be easy to fix, no?
Heh, no. If they are getting transcoded to 96KHz FLAC files, we're not currently able to play them on the SB2. 48KHz is the highest sample rate we support. I'm not sure if this is possible, but you may be able to get flac to downsample to 48KHz. If you can figure out the parameters that allow you to do this, you should be able to modify the wav->flc in your convert.conf file to get these to work.
Downsampling is not an audiophile word ;-) I'll wait you support higher frequencies then (96 and 192). I hope it will be doable, you would then cover the whole range. Is there already a request for enhancement about that, should I file one? So if I summarize this bug report, we see 2 issues. 1) 24/48 WAV files don't work if streamed directly (not recognised as 24bits), they have first to be transcoded to FLAC on the server side. 2) some 24/48 FLAC files are not interpreted correctly by the SB2 (appears similar to bug 1508).
I found another issue... although some 24/48 WAV files are playing just fine with the server side transcoding to FLAC as mentioned above (for example like the file I sent you), I found several tracks on the same album that are causing problems. These tracks usually start playing correctly but then at some stage the music obviously slows down and artifacts are added (it sounds as if samples are skipped). It affects both the SB2 digital and analog outputs. Pausing, unpausing doesn't help, but sometime the artifacts comes and go during the song. It seems systematic on some tracks and always happens at the same location on these tracks. I've played these tracks on the PC with Adobe Audition and they play fine, so it looks like a SB2 specific issue. Let me know if you want one of these track to the same location.
Still tracking this down. Hoping to get it in for 6.1.
Fixed with firmware 15 (just checked in). Michel, this will probably also fix the WAV files your having problems transcoding to FLAC.
I just installed the new version with FW 15 but unfortunately I still have problems with most of these 24/48 files. Here is a summary of a few tests done with different 24/48 WAV and FLAC files and various settings (tracks extracted from 2 different disks): 1) WAV->WAV->built in: gives kind of white noise, doesn't work at all. 2) WAV->FLAC->FLAC: plays OK but at some stage, on most tracks, the music slows down and the music becomes very jerky (like skipping samples). 3) FLAC->FLAC->built in: plays OK but at some stage, on most tracks, the music is jerky (sounds very similar to 2). Hope this helps, if you need some of these files let me know.
This bug was marked resolved in Slimserver 6.1, which is several versions ago. If you're still seeing this bug, please re-open it. Thanks!