Geekzone: technology news, blogs, forums
Guest
Welcome Guest.
You haven't logged in yet. If you don't have an account you can register now.


Glurp
8271 posts

Uber Geek
+1 received by user: 3798

Subscriber

Topic # 198569 14-Jul-2016 12:50
Send private message

This is a subject I posted on before, and I received a lot of valuable help from several people. At the time, I understood nothing about how audio playback works under Windows and thanks to the tips I was given, I was eventually able to fix this. I was using an old pc for testing, with DVD drive and HDMI card, and I could only get two-channel stereo from 5.1 DVD sources. Following advice, I added a separate sound card with digital output and finally got Dolby 5.1 working by running the spdif cable directly from the sound card to the receiver, though I was still never able to get 5.1 audio through HDMI. That would only play as two-channel stereo.

 

Now I am running up against the same problem again and I hope someone can help me further with this. Dolby Surround still works as it is supposed to if I use a DVD in the computer as the source, but I can’t get this to work from a video file and I don’t understand why. I have gone through everything and eliminated the obvious. The test file I am using is a Harry Potter recording, which was broadcast on TV2 in HD 5.1. If I play the recording on either of my two HD STBs, which double as media players, I get 5.1 sound. This is confirmed by the display on my receiver, which pops up 5 speaker symbols and DD 5.1, but I can also clearly hear it.

 

Yet if I play the same file on either of two computers running Windows 7, both with sound cards with optical digital outputs, I get only two channels. This happens with both MPC and VLC. If I look at the audio data in either player, it says 5.1 but I still only get stereo. I have checked the settings in Playback Devices and I am using the correct device, but I only get two channels as an option. Yet if I run the Dolby 5.1 test, all 5 speakers suddenly come up on my receiver display and I get the test tones from all five. But as soon as I play the source file, the display falls back to 2-channel stereo and that is also clearly what I am hearing.

 

So what am I missing here? If someone can explain to me why this is happening, and even better, how to fix it, I would be very grateful.

 

 

 

  





I reject your reality and substitute my own. - Adam Savage
 


Create new topic
27076 posts

Uber Geek
+1 received by user: 6522

Moderator
Trusted
Biddle Corp
Lifetime subscriber

  Reply # 1592462 14-Jul-2016 13:07
One person supports this post
Send private message

My pick would be you're not selecting the 5.1 stream. Freeview broadcasts two audio streams, 2ch AAC and AC3 5.1 and if you don't select the AC3 stream you'll only find it defaulting to the 2ch AAC

 

 




Glurp
8271 posts

Uber Geek
+1 received by user: 3798

Subscriber

  Reply # 1592486 14-Jul-2016 13:18
Send private message

Thanks but I don't think that is it. When I checked the stream there was only one, marked 5.1. The PVR I used lets me choose the stream before recording and then only records the stream chosen. I will check again but I'm pretty sure there was only the one.

 

 





I reject your reality and substitute my own. - Adam Savage
 


444 posts

Ultimate Geek
+1 received by user: 83


  Reply # 1592489 14-Jul-2016 13:24
One person supports this post
Send private message

Possible codec problem, the DVD playback software will include a licence for a Dolby decoder. Other players that you use may not have access to a suitable codec. What are you using for playback?


27076 posts

Uber Geek
+1 received by user: 6522

Moderator
Trusted
Biddle Corp
Lifetime subscriber

  Reply # 1592503 14-Jul-2016 13:54
Send private message

Rikkitic:

 

Thanks but I don't think that is it. When I checked the stream there was only one, marked 5.1. The PVR I used lets me choose the stream before recording and then only records the stream chosen. I will check again but I'm pretty sure there was only the one.

 

 

 

 

Sounds like it's possibly your software then. What are you using? All good TV software like NextPVR, MediaPortal etc all dump the H.264 stream straight to a file straight from the MUX, so contain all audio streams present in the container.

 

 


22 posts

Geek
+1 received by user: 2


  Reply # 1592506 14-Jul-2016 13:57
One person supports this post
Send private message

Have you enabled audio bit-streaming on the playback software?



Glurp
8271 posts

Uber Geek
+1 received by user: 3798

Subscriber

  Reply # 1592593 14-Jul-2016 14:54
Send private message

A lot of this is still over my head but it looks like the media player I normally use for files, Media Player Classic, may need to have bit-streaming enabled. I will have to check into this further. I am working my way through some information I have downloaded, but like I say, a lot of it is over my head. We have guests at the moment, so I cannot immediately access the computer I need to test this on. I will report back when I know more.

 

 





I reject your reality and substitute my own. - Adam Savage
 




Glurp
8271 posts

Uber Geek
+1 received by user: 3798

Subscriber

  Reply # 1593040 15-Jul-2016 11:47
Send private message

OK, I got it working. The problem was entirely due to my own ignorance. When I installed the codec pack, I missed the bitstream setting.

 

I now get surround sound on file playback. But I still can't get it to work with SVOD. When I stream a 5.1 test file on YouTube, it still will only come out as stereo. Can anyone help me with that?

 

Thanks everyone for the great support and the useful tips. It really helps.

 

 





I reject your reality and substitute my own. - Adam Savage
 


Create new topic

Twitter »

Follow us to receive Twitter updates when new discussions are posted in our forums:



Follow us to receive Twitter updates when news items and blogs are posted in our frontpage:



Follow us to receive Twitter updates when tech item prices are listed in our price comparison site:



Geekzone Live »

Try automatic live updates from Geekzone directly in your browser, without refreshing the page, with Geekzone Live now.



Are you subscribed to our RSS feed? You can download the latest headlines and summaries from our stories directly to your computer or smartphone by using a feed reader.

Alternatively, you can receive a daily email with Geekzone updates.