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More => Old Versions => Media Center 17 => Topic started by: msnider44 on January 27, 2012, 08:48:29 pm

Title: WASAPI - Music Static and Stuttering at 192,000 Hz Output
Post by: msnider44 on January 27, 2012, 08:48:29 pm
Hello all.  I'm having an audio problem with the latest version of MC17.  With the settings I have listed below, the sound is superb.  I have messed around with so many audio settings but what I have below sounds the best.  However - something strange happens when playing music with below settings:  If I surf the web or use other computer applications heavily while playing music at 192,000 Hz sample rate......stuttering, skipping, and static starts to happen about a minute into the song(s) and I have to stop and restart. 

But when I switch to 48,000 Hz sample rate, I can surf and use applications just as heavily, but the static, skipping, stuttering does not happen.  But I can tell that the overall sound quality isn't as good as 192,000 Hz, and specifically the bass coming out of the sub is not as clean and has more of a distorted thump.

Here is what and how I have MC 17 set up to play music where it sounds superb:

Sony Vaio VPCEB390X
HDMI output to 7.1 receiver (using all 8 speakers with an extended stereo setting on my Pioneer receiver)

AUDIO SETTINGS:
WASAPI (open device for exclusive access is checked, the rest are not, buffering is set to max; MORE SKIP RESISTANT)
Prebuffering at 20 secs
Play silence for hardware synch at 1/4 secs
Play files from memory is checked
Disable display from turning off for HDMI is checked

DSP STUDIO OUTPUT FORMAT SETTINGS :
All sample rates converted to 192,000 Hz
24 bit bit-depth
7.1 channels
JRSS surround sound is on
JRSS subwoofer is at 60 Hz
Source is correctly mastered for +10 dB calibration

Again, sampling at 192,000 Hz produces the best sound, but music starts to stutter and static.  Leaving all of the settings above the same, but sampling to 48,000 Hz stops the stutter and static, but overall sound quality is diminished.

Hopefully someone can help or has suggestions.  Apologies if I'm not explaining clearly enough.

Thanks in advance.
Title: Re: WASAPI - Music Static and Stuttering at 192,000 Hz Output
Post by: jimmy neutron on January 27, 2012, 09:03:51 pm
Looks like you're having MC upsample all your music for you. Since this is processor intensive I'm guessing you're just taxing the PC by doing additional tasks like surfing, etc. Personally, I want all my music played back in it's native source rate with with absolutely no processing by MC - what goes in is what goes out. What you describe as sounding better when upsampled is your opinion, and that's all that matters in the end - what sounds good to you. But you are not getting a true representation of the music once you stray away from it's native format.

I would suggest you have a PC for just music playback, and do your surfing, work, etc from a different PC.

Jimmy
Title: Re: WASAPI - Music Static and Stuttering at 192,000 Hz Output
Post by: audioriver on January 28, 2012, 06:09:39 am
You'll probably need a more powerful computer for this. What's your laptop's CPU? You could try make your browsing lighter - change browser, less or no add-ons/extensions etc.
Title: Re: WASAPI - Music Static and Stuttering at 192,000 Hz Output
Post by: Vincent Kars on January 28, 2012, 06:24:21 am
A simple test is to run the DPC Latency checker, it will tell you if the latency of your PC is to high
http://www.thesycon.com/deu/latency_check.shtml

WASAPI can be very sensitive to buffer size. Switch to DS and check if this makes a difference.
Title: Re: WASAPI - Music Static and Stuttering at 192,000 Hz Output
Post by: JimH on January 28, 2012, 08:04:09 am
I don't think upsampling should take a lot of CPU power.
Title: Re: WASAPI - Music Static and Stuttering at 192,000 Hz Output
Post by: BryanC on January 28, 2012, 08:13:23 am
Try switching to WASAPI event-style and mess with the buffer--sometimes lower is actually more skip-resistant (counter-intuitive right?).
Title: Re: WASAPI - Music Static and Stuttering at 192,000 Hz Output
Post by: Vincent Kars on January 28, 2012, 08:55:07 am
Had the same, lowering the hardware buffer size in MC often cures the problem.
Title: Re: WASAPI - Music Static and Stuttering at 192,000 Hz Output
Post by: Listener on January 28, 2012, 06:29:59 pm
A few comments.

1. The static and stuttering may be caused by the DAC chip(s) in the receiver running out of digital data. This can be caused by a holdup in data flow anywhere in the path from the music file on a hard drive through the Windows file system, in JRiver MC in the Windows WASAPI code, in the drive for the HDMI output device or in the receiver.  Vincent's suggestion to use DPClat provides a way to look at one stage in the process to see if something is interfering with the flow of audio data (the driver and the interface between the drive rand MC.)   Task manager (It is in Windows.) provides a way to look at the earlier stages involving the file system and MC.

2. Earlier posts focused on the overhead to upsample your data to 24/192 KHz.  You appear to be sending 7 (or 8 ) channels of 24/192 KHz audio over the HMDI connection.  That means that the CPU load from upsampling is higher than for 2 channels.  It also means that you are sending far more data through the WASAPI interface, the HDMI driver into the receiver.

3. Like many other things in life, computer audio is simpler if you stay on the beaten path.  Sending 7 or 8 channels of 24/192 KHz audio through the WASAPI exclusive mode interface over an HDMI connection to a home theater receiver is very far off the beaten path.  You might be the first human to have tried this combination.  Congratulations!  

Things that may not have been tested for this combination include:

- MC's operation
- Microsoft's WASAPI exclusive mode code
- The HDMI driver
- the HDMI cable you use
- Your receiver itself

Right now 2 channel 24/192 KHz audio is not yet on the beaten path.  It is starting to be used by some audiophiles.  I'd set MC to output at the native sample rate (16/44.1 for CD derived audio and 16/48 for video material.)

Bill