AyreWave- A New OSX Audio Player Released AT RMAF

[Lars]

audiozorro,

 

As you obviously know, the cMP/cPlay memory player is based on a different operating system. For OSX, I feel that more memory yields improved sonics especially for memory players like AyreWave and Pure Music. Pure Music does take things a bit farther by loading all the tracks of a selection for gapless playback into memory at once. The number of tracks loaded is limited by the memory available.

 

[milehi]

I occasionally see the artwork, but not always? What is the criteria? I have a cover.jpg file in every folder with the FLAC files, all of a small modest size, some show up, some do not?

 

[sbooth]

I'm not a technician though and after burning my cd's to flac files I have a gap between all tracks. This is not an issue with most recordings but with live stuff it's a bit off putting. I converted with EAC on a windows laptop and play on a Mac mini.

Is gapless play something that should have originated in the ripping and conversion stage or is there something I can manipulate in AW? If so how?

 

Gapless is something that is inherent to the files themselves. FLACs, for example, contain a certain number of audio samples that were present when the files were first encoded. If the CD was ripped properly, queuing the tracks in AyreWave should result in the same playback experience- the last sample of one file should be immediately followed by the first sample of the next file. There are a lot of options for CD ripping and pregap handling- depending on where the pregaps were saved that could affect gapless sound.

 

As I mentioned previously, using memory play may affect gapless performance. The explanation is slightly technical, but here it is:

 

When AyreWave decodes a file, the audio data is converted from the file's format (FLAC, MP3, etc) to a linear PCM format and saved to a ring buffer. The ring buffer is of a fixed size and right now is set to 16384 frames. As one file finishes decoding, the next file is opened, parsed, and decoding starts. The process of opening and parsing a file takes some unbounded amount of time (the OS may have to mount a volume, allocate a huge amount of memory, or perform page-ins/outs depending on the system state).

 

IO in AyreWave is performed on a realtime, high-priority thread. This means that AW has to provide audio right now to the OS when it is requested. To allow this, files are decoded in one thread, saved to a shared ring buffer, and rendered (sent to the device) on another thread (the realtime thread).

 

So back to gapless- if the process of opening, parsing, and decoding the start of a file takes longer than the amount of data available in the buffer, glitching will occur. In AW this is silence perceived as an unwanted gap between tracks. Typically the process doesn't take too long- I chose the value 16384 after some trial and error. 16384 samples of audio at 44.1 is about 0.37 seconds. But, if you are listening to tracks at 88.2 the buffer duration is halved.

 

The typical process of opening a file is quick, because not much reading from the disk is performed. When memory play is enabled, though, the entire file has to be read from disk before anything else can happen. Depending on the file's size and the disk speed, this can easily take more than 0.17 seconds for a large 88.2 file.

 

There are workarounds for this, but no real solution.

 

For example, the buffer size can be increased. This will fix some problems for some people, but since there is no time limit on how long it takes to open files and allocate memory, it would not be a guarantee.

 

Reading the entire playlist in memory is not an option- many users have several thousand tracks in their playlist, and it is not possible to allocate enough memory to hold them all at once.

 

Try listening to your gapless files with memory play off- if that fixes the issue then the problem is not with the files themselves.

 

[sbooth]

I occasionally see the artwork, but not always? What is the criteria? I have a cover.jpg file in every folder with the FLAC files, all of a small modest size, some show up, some do no

 

AyreWave only reads album art that is embedded in files. Right now it won't see art in external files like cover.jpg.

 

[CG]

sidho:

 

Where do you store your audio files? Is it on an external drive of some kind? If so, what type of connection is used between your playback machine and the storage? (USB 1.0, Firewire 800, network, wireless, etc...)

 

[dizziness]

Sbooth: Thanks for the lengthy explanation on gapless playback. Perhaps it would be possible to only load complete albums into memory but not entire playlists?

 

I tested one of my examples. It played gapless in iTunes and in AyreWave with memory play turned off.

 

[SidHo]

My music is pretty much all flac files stored in an external WD 1tb Hard drive which is connected with the USB cable that came with it to a 2010 mini. I believe that means it's USB 2.0?

Thanks CG for the reply and sbooth for all the detail. I finally understand what causes gapless playback. I'm thinking I should re-burn the live CD's.

 

Edit: I thought I should mention that the gaps between tracks range from less than a second to over 5 seconds preceding large files. I have AW set to memory play which I'm sure doesn't help the gap issue I'll turn that option off I guess.

I should mention again for the umpteenth time I love the sound coming from AW which in the end over rides all other considerations.

 

[CG]

"I believe that means it's USB 2.0?"

 

This could be the problem.

 

If the files are taking a while to load from the WD into the Mini, you can and will get exactly this problem. The files have to load before playing when you're using memory mode.

 

You might try copying a couple of the problem files onto your Mini internal hard drive and play them through AyreWave from the internal HD. See if the problem goes away.

 

If the problem disappears, it means that either your WD drive is running as USB 1.0 for some reason, there's some kind of conflict because the USB is being shared with some other peripheral that is in the way, the drive setting is wrong (maybe it's set to go to sleep quickly), or the drive just is plain slow.

 

[barrows]

"Sbooth: Thanks for the lengthy explanation on gapless playback. Perhaps it would be possible to only load complete albums into memory but not entire playlists?"

 

Is how Pure Music deals with gapless memory playback; if an album is tagged as gapless in iTunes, PM will load the entire album into memory (this requires a lot of RAM-typically 4 Gb will handle all 16/44.1 albums, and some 24/96 albums, but 8 Gb is required for a lot of 24/96, and for everything above 24/96).

 

 

 

[CG]

Has anybody with the AyreWave clicking problem found out anything more through their experiments?

 

How many folks are having this problem?

 

If you are having this problem, would you please list what kinds of software you might have loaded on the machine in addition to the usual Apple software? Especially Windows virtual machines like VM and Parallels...

 

 

[earther]

Looks like the clicking is caused by a usb/bluetooth conflict. If your dac is plugged in via USB and you experience clicking in HOG mode, try using a different USB port. When i checked my system info, i noticed that my USB port was being shared with the Bluetooth USB Host Controller. When i plugged into a different port with nothing else on the bus, the clicking went away.

 

[CG]

Great! All problems should be so easy to fix.

 

Thanks for the update.

 

[dizziness]

Brilliant. Tried my M2Tech on a sole USB bus instead of through a hub and preliminary test indicates gapless.

 

[findog3103]

I still get clicking in both USB ports but I am using a iBook. Thoughts? How can I check to see which port is the Bluetooth USB Host Controller shared one?

 

 

 

[AB835]

The clicking in AW is still occurring in exclusive mode. I experienced the clicking sound coming from having multiple devices on the same USB bus early on when setting up my IMAC. I have not experienced this type of problem in a long time, long before the introduction of PM when I started using PV. As best I can explain this is not the same type of clicking. What I hear is faint, in the background and random. I have tried AW with two different DACs, QB-9 and BM DAC1 USB, with multiple sampling rates with the same results, turn on exclusive mode clicking starts, turn it off and it goes away. Last evening I had a case where the clicking did not begin until over 30 seconds into the track. I have watched the Activity Monitor to see if anything would change when I went turned exclusive mode on and off and I cannot detect any differences. Hope this info is helpful.

 

[CG]

An iBook? As far as I know, iBooks only came with PPC processors.

 

AyreWave requires a 64 bit Intel processor (like a Core 2) to work.

 

As far as checking what your USB ports are assigned to, run System Profiler from your Utilities folder. Look under Hardware > USB. This is discussed in much greater detail in one of the other threads here on CA, but I forget just where.

 

[findog3103]

Sorry, it's a MacBook with an Intel Core 2 Duo.

 

[SidHo]

I think I figured out why there is such a long gap between tracks in my system. I should have figured it out before but this evening when it took so long (at least 1/2 minute) to start the next track after a 20 minute piece. When earlier in the day the gap was far less than a second after shorter pieces.

The hard drive is going into sleep or standby mode so I'll go into settings and I feel confident it will solve the issue.

 

[I. G.]

One could keep two tracks in the memory, the currently played and the next one. A couple of secs before the end of the current one, the next would be read into the memory.

 

[damien78]

I concur for this technique: having two files loaded at a time.

A playing buffer, and a non-playing one.

The next file has plenty of time (playing time of previous track) to be loaded in the non-playing buffer.

This ensures gapless playback each time, even for slow network load, though it doubles the memory needed for memory play.

That's the method I use in a player I'm coding for my own tests. I can upload it on sourceforge if you're interested.

 

[CG]

So... A 384 KHz 24 bit version of Thick As A Brick would only consume about 6 Gb for its two tracks.

 

[Charles Hansen]

Where can I buy the 384/24 version??? I'll pay $500 for it!!!

 

Sorry, CG, I'm just teasing you!

 

I know that you were trying to make a point, but I think your example was a bit over the top. 99.9% of everything we all listen to (excepting Fred at AA) is just 44/16. But let's give them the benefit of the doubt and say that they are going to load a 96/24 album. Then they would only need 1.5 GB instead of 6 GB.

 

My opinion is that a player should try to load either:

 

a) A full album, or;

 

b) Two tracks in alternate buffers as suggested a couple of posts down.

 

I think most machines could do well with either approach. But then again, I'm not a programmer. I'm just a dumb analog hardware guy...

 

[cfmsp]

 

 

what about 32-bit? ;0

 

clay

 

[CG]

Well, you see, I think the big problem with modern DACs is that they do too much. They do all sorts of digital filtering (filtering in technical sense) on the fly. It might be far better to do all this off line and save the newly filtered files on hard disks, which are cheap. Then just stream this pre-filtered file to a DAC that only needs to perform the digital to analog conversion. No problem with async USB 2.0.

 

Nevertheless, I'm also on the lookout for even a 96 KHz 24 bit version of Gerald Bostock's composition.

 

[wgscott]

Yes, please.