[Operandi]

Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif While some applications choose to buffer a song in ram before playback, this really has no effect in terms of jitter (timing irregularities between data sent/received and/or clocking irregularities). Data is read quickly enough from hard disks and sent across enough interfaces that it realistically doesn't matter how much you buffer. Remember, there's still the southbridge, audio interface (sound card or USB controller) and digital receiver that all do a small amount of buffering (usually just enough that bits aren't lost).

Amen.

 

[khaos974]

Quote:

Originally Posted by UncleFestive /img/forum/go_quote.gif Khaos974, Ihave to respectfully disagree with you. I think you'll find most if not all other players function by constantly emptying and refilling the buffers, accompanied by a series of Hard Drive seeks. You can verify this by observing the HDD access light while playing a song in MM or Foobar, you'll find an almost constant stream of small accesses. This process, along with all the other processes going on in your comp is a source of jitter.

I perfectly understand how cMP works but what any other media play does is the following:
FLAC or Wav on HDD => Player decoding => raw audio data i.e. PCM in buffer.

Of course, due to memory consumption, only 1 seconds (Foobar allows 16s) is in the RAM. The interesting thing is that the buffer is NEVER emptied. As such all the audio data that arrives to to USB port/soundcard comes from the memory buffer. So the fact that the HDD is read does not matter since the audio data as seen by the DAC comes from the RAM.

cMP does exactly the same thing except that it loads the whole album is buffered instead of a few seconds removing the need of "refilling the buffer".

One last thing, read and write locations in RAM is random (hence the acronym), so loading the whole album is basically writes the file in random empty spaces. So, unless you memory isn't fast enough to support simultaneous read/write operations (unlikely, a modern computer's RAM averages at 10 GB/s), there should be no difference because cMP plays from memory.

As for any jitter issues, it is of my opinion that the output stream from the computer should be buffered in the DAC and slaved to the DAC's own clock which would solve sooo many problems.

 

[jaycalgary]

Does AIMP2 modify the sound?

 

[Nirvana1000]

Technically?No.The DSP plug-ins enhance the frequency output and add some cool surround sound effects,reverb and stuff like that.You can simply equalize the sound output to have a perceived change in sound.I highly recommend to try out the DEE DSP V1.20 plug-in which comes with the plug-in packs.

The audio stream may sound different with equalization and enhancements.And of course your set up.But no audio player really modifies or changes the "sound" or original music file.Editing is the only way to do that.

 

[Ham Sandwich]

Quote:

Originally Posted by khaos974 /img/forum/go_quote.gif As for any jitter issues, it is of my opinion that the output stream from the computer should be buffered in the DAC and slaved to the DAC's own clock which would solve sooo many problems.

That would/could create latency problems by creating a delay between when the computer sends the audio to when it actually gets played. Could cause problems when you need to keep audio in sync with video. You can't delay the audio too much or the audio will no longer be in sync with the movie. Words won't happen at the same time the actors lips move. Digital effects like the visuals some people like to play while music plays would no longer happen right in sync with the music. You hit pause or stop in your media player and the music will continue untll the buffer in the DAC is emptied. Lots of potential difficulties with having the DAC buffer more than just a small number of samples.

 

[khaos974]

I honestly did not think about video playback. As for audio playback, jitter issues are in the ns or the ps range if it is really really bad, that's 10^-9 s, a sample at 96kHz is roughly 10^-5 s, so I think that even 100 stored samples are completely invisible as far as delay is concerned.

 

[oohms]

Pretty much all media players read ahead and buffer the pcm output into ram. If this buffer were to run out, you would hear it clearly as gaps in the music. And DSP just adds distortion, no matter how you look at it.

 

[Ham Sandwich]

Quote:

Originally Posted by khaos974 /img/forum/go_quote.gif I honestly did not think about video playback. As for audio playback, jitter issues are in the ns or the ps range if it is really really bad, that's 10^-9 s, a sample at 96kHz is roughly 10^-5 s, so I think that even 100 stored samples are completely invisible as far as delay is concerned.

A few hundred samples buffered on the DAC probably wouldn't be a problem for consumer playback. Could be a problem for studios where they actually need very low latency to be able to mix and keep tracks in sync during editing.

The ASIO/WDM driver for my audio interface has a setting for buffer size going up to 4096 samples. The buffer that is inside the driver. More buffer means the driver isn't as time critical. Makes it more resilient to dropouts that can happen if the OS doesn't keep up. More buffer means more reliable sound at the expense of added latency.

There are many places where audio data gets buffered. All of those buffers are necessary. All of those buffers add up to increase the overall latency.

A problem for computer based audio is that Windows (also Linux and OSX) is not a real time OS and never was intended to be. Audio playback is real time. There will always be problems when trying to get a non real time OS to behave like a real time OS. You can try these specialized audio players that try to buffer audio in unique ways and/or strip the system down to only needed essentials, but you will never get around the fact that Windows (or Liniux or OSX) is not a real time OS and will always be doing funky things with interrupt delays, context switching, and other things. The OS is always busy doing things even when nothing is happening.

 

[koshui]

Quote:

Originally Posted by khaos974 /img/forum/go_quote.gif One last thing, read and write locations in RAM is random (hence the acronym), so loading the whole album is basically writes the file in random empty spaces.

Wrong.
Random Access Memory means that you can access any address of the memory within equal amount of time O(1). There is no implication that data stored into it will be at random address, it will be exactly on the address you wrote it to*.

*In operating systems where you have process model you are working on virtual address space, the actual physical address is controlled by MMU.

 

[Nirvana1000]

I find it's best to leave the ASIO buffer at default,or whatever program that's controlling it.I was using Virtual DJ one time and messed around with the buffers,and some other configurations.And i started to get a very annoying interrupted sound stream,with blank breaks every few seconds.Mentioned this in a earlier post by "oohms".Anyways i did some PC clean up maintenance and rebooted.Also deleted some programs and codecs that could be also problematic and it cleared the problem.But i believe the buffer had some kind of conflict preventing it from properly functioning or simply ran out.Anyways my three favourite audio players are Aimp2,Winamp(especially for internet radio) and Jet Cowon for my S9.Monkey is also pretty good.But I don't really get why people like Foobar so much here."To each his own"

 

[Mphile]

Just got J River Jukebox

Link Here

Seems to be a great player, supports ASIO too, and has a great interface. so far so good

 

[neergan1216]

Up to now, I have settled on Foobar 2000 w/Wasapi as the best sounding player in my Toshiba (Vista) laptop/Sennheiser HD600 system. I attempted to install Aimp2 a while back, with no success in getting the zip file to run. But, your endorsement made me determined to make another attempt. This time it worked. I agree it is the best sounding player. I do not know what it does, but it must somehow bypass Vista audio to sound better than Wasapi. I do not see any ASIO option. BTW, I have uninstalled Foobar.

 

[Nirvana1000]

Quote:

Originally Posted by neergan1216 /img/forum/go_quote.gif Up to now, I have settled on Foobar 2000 w/Wasapi as the best sounding player in my Toshiba (Vista) laptop/Sennheiser HD600 system. I attempted to install Aimp2 a while back, with no success in getting the zip file to run. But, your endorsement made me determined to make another attempt. This time it worked. I agree it is the best sounding player. I do not know what it does, but it must somehow bypass Vista audio to sound better than Wasapi. I do not see any ASIO option. BTW, I have uninstalled Foobar.

Yes ASIO is compatible with Aimp2.Here is a screenshot with the Dee DSP controls open.A lot of great skins available.

 

[t1337Dude]

Sounds the same as Foobar to me.

 

[neergan1216]

Hi Nirvana:
I have installed ASIO into the Plugin folder. But, my Winamp DSP Plug-In is disabled, not allowing options. Any solution?