Topic: [SOLVED] Audio cuts in and out only on STEREO Tv channels (Read 13481 times)

tzr916 · « **on:** January 12, 2016, 03:22:31 pm »

Audio plays for 5-10 seconds then cuts out for 5-10 seconds, then comes back for 5-10 seconds, etc, etc. Picture is not affected. MC version 21.0.35. Front panel of AVR "DD" led goes on/off when audio drop comes/goes.

Affects ALL stereo channels, like Music Choice.

Affects Server machine (nvidia hdmi) AND Client machine (AMD hdmi). Each machine using their own hdmi connections to the same AVR/Tv.

Tried all combinations of MC audio/video settings.

No problems at all with 5.1 DD Tv channels.

No problems with stereo channels in WMC.

SOVLED: Via latest version update

RoderickGI · « **Reply #1 on:** January 12, 2016, 06:38:53 pm »

Hmmm. If the DD LED is going on and off, then your AVR thinks it is getting DD encoded in a stereo package, such as you would with an S/PDIF connection, and then it thinks it isn't.

My first thought was a weak signal from the broadcaster. These are OTA channels aren't they? But if WMC plays them okay, then that seems less likely.

What is the Audio Path showing when this is happening? Does it keep changing, or is it stable, and what is it saying?

tzr916 · « **Reply #2 on:** January 12, 2016, 06:55:40 pm »

Not OTA. Comcast cable card. Not weak signal.

Yes, 2 channel stereo in DD package.

Not sure how to check "Audio Path" during play back?

tzr916 · « **Reply #3 on:** January 12, 2016, 07:03:40 pm »

When played in WMC the DD is lit solid on the AVR.

RoderickGI · « **Reply #4 on:** January 12, 2016, 07:40:12 pm »

Play one of the TV programs and leave it playing, then switch to Standard View (Ctrl-1 is easiest if you have a keyboard connected), then hover your mouse over the Audio Path icon, as shown in the Audio Path Wiki Article.

tzr916 · « **Reply #5 on:** January 12, 2016, 09:11:58 pm »

Theater View - Drop outs constantly
Display View - Drop outs constantly
Mini View - No Drop outs
Standard View - No Drop outs

In Display View (while the drop outs are happening), the Audio Path, Input, and Output are all staying the same:
Audio Path: Direct
Input: 48k 16bit 2 channel from source format ac3
Changes: No changes being made
Output: 48k 16bit 2 channel using WASAPI (bitstreaming)

CountryBumkin · « **Reply #6 on:** January 13, 2016, 10:47:34 am »

If I read your original post correctly, you are sending to audio to AVR. In JRiver audio settings do Not use bit streaming, use/try WASAPI (not Direct), and then check in Windows Sound properties check the Properties>Advanced tab to be sure it is set for correct/max bits and Hz (like 24bit, 192000Hz).

tzr916 · « **Reply #7 on:** January 13, 2016, 01:40:15 pm »

Magically the problem is gone today

I did not do anything to either machine and did not power off the AVR. Only closed JRiver on both machines and used WMC overnight. When I restarted JRiver, both machines playing the stereo channels just fine.

CountryBumkin · « **Reply #8 on:** January 13, 2016, 01:47:15 pm »

That's because your a few days away from purchasing - MC knows this and is on its best behavior. Once you purchase, the problem will be back.

RoderickGI · « **Reply #9 on:** January 13, 2016, 04:53:03 pm »

Quote from: CountryBumkin on January 13, 2016, 10:47:34 am

If I read your original post correctly, you are sending to audio to AVR. In JRiver audio settings do Not use bit streaming, use/try WASAPI (not Direct), and then check in Windows Sound properties check the Properties>Advanced tab to be sure it is set for correct/max bits and Hz (like 24bit, 192000Hz).

This, although the Windows Sound properties only matter if you are using Direct Sound somewhere in the audio chain. For example from a source external to MC. Best to set them high like that though.

I am no longer a fan of Bitstreaming. MC does all the audio processing I need, and I just send the result to my old AVR in a format it understands. Bitstreaming was all about sending exactly the audio bits in a file on a computer out to some external audio processor, such as an AVR/DAC.

As the problem has gone, for now (cheeky CountryBumkin!), it probably doesn't matter, but what settings do you have in Options/Audio/Settings/Bitstreaming?

tzr916 · « **Reply #10 on:** January 13, 2016, 06:01:21 pm »

Quote from: RoderickGI on January 13, 2016, 04:53:03 pm

... As the problem has gone, for now (cheeky CountryBumkin!), it probably doesn't matter, but what settings do you have in Options/Audio/Settings/Bitstreaming?

Yep the problem is back already, although not as bad... yet.

Even though the Audio Path details I posted say "Direct", I am NOT using Direct Sound, I am using WASAPI and Bitstreaming (Yes).

Quote from: tzr916 on January 12, 2016, 09:11:58 pm

... the Audio Path, Input, and Output are all staying the same:
Audio Path: Direct
Input: 48k 16bit 2 channel from source format ac3
Changes: No changes being made
Output: 48k 16bit 2 channel using WASAPI (bitstreaming)

RoderickGI · « **Reply #11 on:** January 13, 2016, 07:36:39 pm »

The "Direct" mentioned against your Audio Path is not referring to using Direct Sound. I think it refers to the internal audio path in MC. i.e. Whether the input to MC can be directly output from MC. Some further searching around here may clarify that.

I see this problem is on your Server PC and your cheap extender PC.

Also you are using HDMI connections. I would suggest turning off Bitstreaming and see if the problem goes away, since HDMI can handle the stereo PCM data no problem.

If you really want to use Bitstreaming, or turning it off doesn't fix the problem, you will need to detail all the settings you have in Audio Options and in particular the DSP Studio.

tzr916 · « **Reply #12 on:** January 13, 2016, 08:24:56 pm »

Recap:
Bitstreaming AC3 Stereo tv channels has worked perfectly in WMC on the Server for more than two years and still works.
Drop outs affect MC Server and MC Client.
MC "View" affects the problem:

Quote

Theater View - Drop outs constantly
Display View - Drop outs constantly
Mini View - No Drop outs
Standard View - No Drop outs

Tools > Options > Audio:
HDMI Ouput (High Definition Audio Device) [WASAPI]
Bitstreaming = Yes
Exclusive = Yes
DSP = NONE / NOTHING
Disable Display from Turning Off (useful for HDMI audio) = Yes

Tools > Options > Video:
Hardware Acceleration = Yes
VideoClock = Yes

Strange that bitstreaming AC3 2.0 seems harder for MC to do than AC3 5.1 ?

RoderickGI · « **Reply #13 on:** January 13, 2016, 09:13:31 pm »

Quote from: tzr916 on January 13, 2016, 08:24:56 pm

Strange that bitstreaming AC3 2.0 seems harder for MC to do than AC3 5.1 ?

I agree! Especially the different result with different views. That sort of sounds like a processing issue, and as you are using HDMI out, from your graphics cards I assume, that could be related to graphics power or drivers. But I know you are using nVidia on one PC and AMD on the other, so drivers are unlikely. You might need someone who knows more about the internals of MC processing to comment on this issue.

Did you try turning Bitstreaming off? Or are you committed to Bitstreaming and doing all your audio manipulation in your AVR? (Room Correction, Volume Levelling, and so on.)

If you turn Bitstreaming off, and your DSP currently has "Output Encoding" set to "None", then MC should be decoding the DD AC-3 2.0 stream to a Stereo PCM stream, I would have thought. Try that, and also with "Output Encoding" set to "Dolby Digital".

tzr916 · « **Reply #14 on:** January 13, 2016, 09:34:26 pm »

Quote from: RoderickGI on January 13, 2016, 09:13:31 pm

I agree! Especially the different result with different views. That sort of sounds like a processing issue, and as you are using HDMI out, from your graphics cards I assume, that could be related to graphics power or drivers. But I know you are using nVidia on one PC and AMD on the other, so drivers are unlikely...

But the whole point of bitstreaming is that there is no processing done at all. The tv channel broadcasts an AC3 audio stream, tuner passes it to the software which sends it out the spdif/hdmi connection un-touched. Converting it to PCM and using DSP would introduce processing.

Bitstream - send the raw digital audio without processing.
PCM - the player will convert the raw audio.

RoderickGI · « **Reply #15 on:** January 13, 2016, 09:52:18 pm »

Yes, yes. Which means any Room Correction, Volume Levelling, Equalisation, etc. that you do want to do, you have to do in your AVR. Which means that you miss out on using a lot of the nice functionality in MC. Also, a lot of people on this forum think MC can do a better job of audio processing than many (most?) AVRs.

As I said above, I am no longer a fan of Bitstreaming. It used to be the way to get the best sound. It no longer is.
Bitstream - send the raw digital audio without processing (decoding or further DSP) - which is then sent to a Digital to Analogue Converter, either a stand alone unit or one built into an AVR, as in your case. When using an AVR, any DSP processing is applied before converting to analogue using the internal DAC.
PCM - the player (MC) will convert the raw audio - to a digital audio stream, and do it as well if not better than the decoder in your AVR, then apply any DSP required, and then send it to a Digital to Analogue Converter, either a stand alone unit or one built into an AVR, as in your case.

If you don't think you need to do any processing on audio, how have you done Room Correction for your speakers? Do you do any Volume Levelling between or within tracks or video? But I'm not going to evangelise MC processing versus Bitstreaming to an external device to process audio, but I suggest you search for some threads on Bitstreaming around here.

Regardless, there seems to be some issue in MC with Bitstreaming 2 channel AC-3 audio. That should be addressed.

tzr916 · « **Reply #16 on:** January 13, 2016, 10:19:36 pm »

Hmm maybe later. Right now I am not really interested in testing whether PC software can do a better job on my speakers than a 2015 gen Denon AVR running Audyssey MultEQ XT, room calibrated with eight microphone positions, including Dynamic Volume, and Dynamic EQ. I just expect simple AC3 2.0 bitstreaming to work 100% out of the box without any tinkering.

CountryBumkin · « **Reply #17 on:** January 14, 2016, 06:54:42 am »

Quote from: tzr916 on January 13, 2016, 08:24:56 pm

Tools > Options > Audio:
HDMI Ouput (High Definition Audio Device) [WASAPI]
Bitstreaming = Yes
Exclusive = Yes
DSP = NONE / NOTHING
Disable Display from Turning Off (useful for HDMI audio) = Yes

Tools > Options > Video:
Hardware Acceleration = Yes
VideoClock = Yes

Also, note that with Bit steaming On, the VideoClock feature doesn't work.

tzr916 · « **Reply #18 on:** January 14, 2016, 08:59:20 am »

It's ok with me that VideoClock feature doesn't work when bitstreaming.

As long as I have this bug logged with JRiver and they take a look at it on their end. I'll provide any system information they need.

Quote from: RoderickGI on January 13, 2016, 09:52:18 pm

...Regardless, there seems to be some issue in MC with Bitstreaming 2 channel AC-3 audio. That should be addressed.

tzr916 · « **Reply #19 on:** January 14, 2016, 11:55:39 am »

New information:

Problem seems to be related to LIVE viewing of an AC3 Stereo tv channel. I recorded a few minutes from one of these channels and playing back the recording does not have audio dropping out. Time shifting at least a minute or two back also seems to help eliminate the audio dropping out. Yet FF back to LIVE and the audio drops out. I also watched a full 30 minute AC3 Stereo show (Cops on Spike) without any drop outs at all.

Not sure if a sample AC3 2.0 file would help since it seems to be a LIVE issue but here is a sample (4MB 2 minutes ts video):

https://drive.google.com/file/d/0B82GqdDf8HSyR1pFakFzQ2FYZDA/view?usp=sharing

Yaobing · « **Reply #20 on:** January 14, 2016, 02:35:06 pm »

Thanks for the sample. It does not have any problem when played as a recording.

This sample was recorded from a Comcast Music Choice channel. Do you get the problem only such channels? No problem with regular video, such as a TV show or a movie?

If so, I think I have an idea. I will look into it.

RoderickGI · « **Reply #21 on:** January 14, 2016, 03:53:00 pm »

Quote from: tzr916 on January 14, 2016, 11:55:39 am

New information:

Ah. That makes a big difference. Even more so if it was on specific channels (which you did say in the first post), as Yaobing is asking.

I assumed it was all AC3 2.0 TV, live or recorded, as you didn't say any different. I should have asked...

tzr916 · « **Reply #22 on:** January 14, 2016, 04:05:25 pm »

Quote from: Yaobing on January 14, 2016, 02:35:06 pm

Thanks for the sample. It does not have any problem when played as a recording.

This sample was recorded from a Comcast Music Choice channel. Do you get the problem only such channels? No problem with regular video, such as a TV show or a movie?

If so, I think I have an idea. I will look into it.

Correct no problems playing file back. Only on LIVE 2.0 channels.
Happens on all Comcast Music Choice that are 2.0
Only way to test on another channel might be tune in LIVE to "Cops" on Spike which seems to be 2.0 Stereo (next chance appears to be tomorrow at 4pm local).

There is workaround that I have confirmed:
-tune to tv channel
-let it play for at least one minute
-rewind to beginning of time shift

OR:
-tune to tv channel
-wait for playback to start and press PAUSE
-wait at least one minute
-rewind to beginning of time shift

As long as it is time shifted back a minute or two, there are no drop outs at all.

Yaobing · « **Reply #23 on:** January 14, 2016, 04:51:41 pm »

It probably has nothing to do with 2 channel or 5.1 channel. It has to do with the video. Since it is a music channel, the video/image is just slide shows that get updated every few seconds. It will be fixed in an upcoming build.

tzr916 · « **Reply #24 on:** January 22, 2016, 11:53:07 am »

Quote from: Matt on January 22, 2016, 07:49:30 am

...21.0.38 (1/18/2016)

2. Fixed: Some music channels from some cable providers played intermittently when played near live position.

Thanks! So far seems to be a big improvement.

Before the update, besides the audio drop outs, music channels were virtually impossible to pause/rewind and changing channels to/from a music channel would cause problems like black screen or the channel would not change at all... would have to press stop in order to change channels to/from a music channel.

All of those issues are gone and audio drop outs are rare.

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Author Topic: [SOLVED] Audio cuts in and out only on STEREO Tv channels (Read 13481 times)