Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[BryanC]

I've been trying over the last several days to switch to PCM playback for my audio and video files. I've tried the two WASAPI modes and I am unable to playback any files. My HDMI audio output is set to 24/96000 and it shows that it can accept 6-channel sound in the windows device properties.

If I set my output to 24/96000/5.1 in MC, I get unsupported filetype errors if my playback buffer is over 0.50s in WASAPI and over 100ms in WASAPI - Event Style. If I set the buffer below these values, the file will play but no sound is heard (like it's muted). I can see the PCM icon flashing on my receiver (Onkyo HT-R380) like it is trying to connect, but it never plays. I've tried setting the receiver to PCM mode only and it does not help. I've also turned off the TV audio output in case it was causing handshaking issues between the receiver and HTPC.

2-channel PCM playback works fine for my audio files, but I need 5.1 for video in order to enable reclock/videoclock.

I've updated all nVidia drivers to the latest release (6/1/2011).


Ideas?

[Matt]

It's normally good to start at the OS level, and when that's working, get MC working.

If you play Windows test tones (in Control Panel > Sound), do you hear them?

[BryanC]

Yes, I get sounds from the Windows test. I've been able to playback 2 channel PCM audio in MC fine, but now that I need to switch to 5.1 for video, playback fails.

[Matt]

Yes, I get sounds from the Windows test. I've been able to playback 2 channel PCM audio in MC fine, but now that I need to switch to 5.1 for video, playback fails.

Next try audio at 5.1 using DSP Studio > Output Format.

Try different sample rates to see if that makes a difference.

You already saw this, but WASAPI is sensitive to buffer sizes.  I would pick a small buffer size, like WASAPI - Event Style @ 10ms or 25ms.

You can watch DSP Studio > Analyzer to see if Media Center is actually piping audio data through the chain.

Once 5.1 audio works, hopefully video will fall into place.

[BryanC]

On the advice of SamuriHL, I dropped down to 24-bit/48khz and it works! I don't know why 96khz is not compatible even though it's accepted by the receiver?

I have not been able to use reclock since making the switch to PCM but VideoClock seems to be doing an alright job. From the madVR OSD:

1. Nothing (bitstream): 1 frame drop every 35 seconds
2. VideoClock (PCM): 1 frame drop every 2 minutes and 45 seconds
3. ReClock (bitstream): 1 frame drop every 4.8 hours (see note below)

Any reason why ReClock seems to perform better than VideoClock?

At this point I'm going to stick to bitstreaming and use ReClock until I can get some issues worked out.

Note: I don't know if it is an experimental feature or not, but it works great. In the Reclock settings you have to select "Accept bitstream formats (not recommended)" and uncheck "Disable media speed connection with bitstream audio (recommended)" to get it to work. So basically bypassing two of their safety features, yikes.