I've recently ripped a load of my CDs to the losseless format Flac. However when i play them back via my PC soundcard and headphones I experience dropout. I.e. the there is a split second up to one seconds worth of silence every now and again whilst I am listening to a track.
Does anyone else get this and know why it happens?
I'm using Flac 1.7.1 to encode files and listening back via Winamp and SlimServer.

MC

is it a short silence like you'd get with a buffer underflow, or an actual period of silence in the decoded data?

either the CPU isn't giving enough time to decoding flac, or something hideously wrong is going on

possibly something to do with a decoder that isn't compatible with the version of flac you're using... i've never used slimserver before so i can't comment on that

Well, a logical quick test would be to decode one of the FLACs producing dropouts, and see whether the dropouts are actually present in the decoded WAV. My hunch is that your network is not feeding data fast enough to keep up with the decoding process, and that your SlimServer/Winamp combination is buffering during the silence.

- M.

Have you set a value for "Buffer-ahead on track change" on the DirectSound output plugin?

You mean flac 1.1.0 , right ?

Yup, I mean Flac 1.1.0.
And no, it's not a problem wih the flac file as decoding it produces a perfect wave.
and...
"is it a short silence like you'd get with a buffer underflow, or an actual period of silence in the decoded data?"
Dunno. How can I tell? I'm trying to see if i can keep the beat when it drops out, i.e. does the music just drop or does it carry on and have a little silent period, but haven't figured it out yet as the dropout is quite intermittent and I have not had the patience to tap along for long enough yet.
and
"Have you set a value for "Buffer-ahead on track change" on the DirectSound output plugin?"
Output of what plugin? Where do i find this parameter?
I experience these drop outs with both players I use (Winamp 2, and now 5, and Foobar2000)

Thanks for all your all help...

MC

Winamp 2.x and 5.xx
You can find it Options > Preferences > Plug-ins > Output > DirectSound Output vx.xx > Buffering

Thanks,
Unfortunately the Squeezebox (www.slimp3.com) uses the free Slimserver software to stream the flacs to my hifi, so I don't think winamp settings don't enter into it. I think the problem may a bit more fundamental the player issues.. perhaps... but then... I know sweet fa.

I've changed Winamp setting tho... and will see if it makes a difference... so thanks!

BTW. I have also just re-installed my sound card drivers (Terratec DMX 6Fire) incase this helps.

MC

From what I read in the Slim Devices website, it seems the Slimserver is transcoding your FLACs to MP3 on the fly, so perhaps this could be solved with more RAM.

It doesn't transcode them to mp3s (I think the web site may not have been updated)., it decompresses them to wavs - thus getting better than CD quality, (due to lack of CD transport) to my Squeezebox digital out... This is the reason I so desperately want to get Flac streaming to work correctly with my Squeezebox.

BTW. MP3s play fine thru Squeezebox and on my PC. It's just Flacs that seem to have the problem... even when the resource use on my PC is very low indeed.

sorry, I don't understand what you are saying...

I was being provocative, but here's my explanation.

A CD holds the music information lots of 1's and 0's. The CD transport reads this information quite imperfectly and uses error correction as it has to read it quite quickly for you to hrear the music in real time. The second component that affects the quality of the output it the CD player's DAC (Digital to Audio Covertor).

I burn my CDs to Flac using Exact Audio Copy in secure mode, thereby ensuring I have a bit for bit perfect copy of the CD. The Flaccs are held on my hard drive and streamed across my wireless network to my Squueezebox. The information on the hardrive reads my Flac 1's and 0's perfectly and the stream to the Squeezebox is just a pipe and reassembles the information to be an exact replica of the information that went in. The information that exits from the Squeezebox digital-out is not changed by the Squeezebox. Therefore the digital information sent from the Squeezebox's digital out is exactly, bit by bit, that which is on the CD itself.
The only change made to the information entering my hifi in the lounge is by the DAC I choose. Second hand DACS are very cheap on eBay right now and it is possible to pick up a DAC for £100 that is at least on a par with that in a £500.

Have you posted on the Squeezebox mailing list? They might be able to help you more than the folks here.

If you're having dropouts when playing the files back through Winamp and foobar, as well as through the Squeezebox, then there's something wrong with either the files themselves or your PC. I play FLAC files back through foobar and never get any dropouts whatsoever, so I'm not sure where your problem lies.

Some things you might try to do. If you manually decode your flacs to wave files, do the wave files play back correctly, or are there dropouts there as well? You say you're using a wireless network to stream the data to your Squeezebox - try using a cat5 cable instead of wireless to see if that helps.

C

Thanks for you explanation.

Although it's true that FLAC-decoding usually is 100% error free while cd-reading is not it is questionable if it's possible to hear the difference...

Have you tried using your Squeezebox with aac files, from nero or iTunes? Does it read the tags correctly? Do you recommend this product?

The code is there to read tags from aac files, but I don't have any aac files so I can't test it. Songs purchases from the ITMS cannot be played on the Squeezebox without hackery.

Without knowing your requirements, I can't make a recommendation either way.

--jth

ModelCitizen: Do the FLAC drop-out problems persist when you have the Squeezebox connected via wired (not wireless) ethernet?

I built myself a media server winxp box over the weekend to feed my squeezebox. I was having terrible problems with drop-outs that I eventually traced down to the gigabit lan built onto the motherboard of the server machine. Once I disabled the on-board lan and added a cheap d-link 10/100 ethernet card, all the drop-outs disappeared. I find that I can now stream flac flawlessly over my wireless network, even with 128b WEP enabled.

Do you have an opinion about the quality of the DACs in the Squeezebox? I'm using the analog outputs since I currently don't have a pre-amp with a digital in.

This reminds me - people have reported various problems with some Intel network cards .

See: http://www.slimdevices.com/su_faq.html#tro...ooting-intelpro

--jth

To answer as many posts as i can:

I believe that the Squeezebox does play AAC files but i do not know much about it as my lossy file format of choice is MP3. The Squeezebox developers are ex-Apple employees so i think so they may well have paid particular attention to the AAC file format.

The Squeezebox analogue-out is of a good quality and quite acceptable for most home audio systems. However it is possible to improve the music quality for medium and higher end systems by adding a dedicated DAC to the digital outs. The major problem with the analogue-outs is the low volume. You should join the SlimDevices mailing list, it's fun... :-(.

I'll try using Cat5 and a different network card when i have the time to move all my hardware around. Thanks for the suggestion.

Wierdly I thnk it is quite easy to hear the difference betwen music played from a CD and from Flac files ripped from the same CD. I'm suspicious about this.

I have stopped the dropouts when playing Flac files on my PC by reinstaling my sound drivers. However i still get drop outs when playing flac files on my Squeezebox via my wireless network... :-(

Just to finish off my own thread.
The Squeezebox is really a killer bit of kit. No-one should think twice about buying one. None of the competition comes even close.

My drop out problem cured itself when I replaced Win98 with 2000 on one of the PCs on my network. However, at the same time I reinstalled XP on my main PC, increased my wireless signal strength from 35% to 65% and updated the Squeezebox firmware and Slimserver software... so really it could have been any one of these things that cured the problem!

The next version of the Squeezebox firmware will have support for decoding flac files which means it will be the flac files that are streamed rather than as happens at the moment where the uncompressed PCM information is streamed. This should considerably improve the situation for users who connot obtain a reasonable wireless signal and want to listen to lossless music on their hifi.

In addition, the Squeezeboxes have just been reduced in price. They are now under $200. And... a Shoutcast plugin has been included with the Slimserver software so immediately after install you can listen to any Shoutcast radio stations (as well as music encoded in a multitude of file types!).

It raawwks...

http://www.slimp3.com

No, I don't work for them (but wish i did!)

There's a good chance that the updated Squeezebox firmware cured your problem. The network stack was reworked to better handle retransmissions which are common on wifi.

Slim Devices has not committed to native FLAC support in the hardware. They did say they were investigating the possibility but there hasn't been a firm annoucement. That said, I've rarely been let down by the developers...

--jth

The Squeezebox like the original Slimp3 has to transcode AAC to MP3
on the server. There is no AAC or WMA support in either of the Slim devices.

This is not correct. The Squeezebox will decode AAC or WMA to WAV or transcode to MP3.

--jth

edit: remove ad hom.

Thanks for the correction. I own an original Slimp3 which requires lame
on the server side to play AAC. It looks like the hardware in the squeezebox
has improved support.

Sean