Can't get 5.1 from aac format in mpc-hc only stereo

Go down

Can't get 5.1 from aac format in mpc-hc only stereo

Post by someguy on Mon Mar 26, 2018 11:42 pm

Hi guys,

I'm struggling with this problem for more than a year now. I posted on several french forums and never got a solution. It's driving me nuts and that's why I decided to ask on an english forum. I saw a topic below with someone having a similar problem but the answer wasn't detailed enough and it didn't help me. That's why I'm creating a new one.

My problem is : I have a PC connected to a 5.1 receiver via spdif. I use MPC-HC to play video, with k-lite codec pack (and lav filters) installed. I can play most 5.1 audio format in video just fine, except when it's aac, he-aac (is it the same?), flac and ogg.

From what I understood, it seems that aac format is encoded in pcm 5.1 which is not compatible with spdif (only stereo). So I need to encode this to AC3, by using ffdshow for exemple. In the k-lite codec pack, there's only "ffdshow VFW interface" and it seems it has nothing to do with audio. So, I installed ffdshow separately, only checking things related to audio during install. Now I have ffdshow audio decoder configuration.

But I can't get this thing to work. If someone could just tell me a step by step way of configuring this, that would be nice.

What I did :
- In mpc-hc, options, extern filters, I added "ffsdhow audio processor" and I checked "prefered".
- In mpc-hc, options, intern filters, I have "source filter" and "decoding filter" I don't know what that is. I checked "aac" in "decoding filter".
- In ffdshow audio decoder configuration, codecs, every format is disabled, except aac which is set to "libavcodec"
- In ffdshow audio decoder configuration, output, I checked "ac3 (spdif encode mode)"

This doesn't work. when I play a video with aac 5.1 audio, it seems lav audio convert it to PCM 5.1 then ffdshow has : input PCM 5.1 output PCM 5.1. I tried fiddling with all that : checking/unchecking things in mpc filters options, trying different aac decoder in ffdshow. Nothing works  Evil or Very Mad

I'm going insane. Please help.

someguy

Posts : 3
Join date : 2018-03-26

View user profile

Back to top Go down

Re: Can't get 5.1 from aac format in mpc-hc only stereo

Post by Admin on Tue Mar 27, 2018 12:49 am

ffdshow is also included in the codec pack, but not used by default.

1) Run the codec pack installer again. If it asks to remove ffdshow, click YES.
2) Uncheck "Perform quick upgrade" at the beginning of the installer. Then it will show all settings.
3) On the "Select Components" page, additionally select:
DirectShow Audio Decoding Filters -> Process uncompressed audio (PCM) -> Use ffdshow (only in MPC-HC)
4) On the "Audio Configuration" page, select "Same as input" and enable bitstreaming
5) Continue with the installation

6) Access the settings of ffdshow audio processor (not to be confused with the decoder). There is a shortcut in the Start menu. Or you can access it through its system tray icon during playback. Change these settings in ffdshow:
6a) Enable "Resample" and set it to 48000 Hz
6b) Enable "Mixer" and select "3/0/2 - 5 channels". Also enable "LFE" and (optionally) "Expand Stereo to surround".
6c) On the "Output" page, enable "AC3 (S/PDIF encode mode)" and "Dolby Digital (AC3)" pass-through

With these settings the audio is first handled by LAV Audio decoder. That will bitstream AC3 and DTS to your receiver. Other formats are decoded to uncompressed audio (= PCM). Ffdshow will then process that audio and convert it to AC3 and bitstream it.


Admin
Admin

Posts : 4194
Join date : 2011-06-17

View user profile http://codecs.forumotion.net

Back to top Go down

Re: Can't get 5.1 from aac format in mpc-hc only stereo

Post by Admin on Tue Mar 27, 2018 12:50 am

There will probably be some kind of option in the codec pack in the future that does all of this with a single click.

Admin
Admin

Posts : 4194
Join date : 2011-06-17

View user profile http://codecs.forumotion.net

Back to top Go down

Re: Can't get 5.1 from aac format in mpc-hc only stereo

Post by someguy on Tue Mar 27, 2018 4:06 pm

Hi,
Thanks for reply.

I did exactly what you wrote. Except for 6b), I selected 6 channels (3/2/1) because I have 2 back speakers, 2 front, 1 center and 1 subwoofer (thus 6 channels if i'm correct, not 5). The result is the same :
it seems lav audio convert it to PCM 5.1 then ffdshow has : input PCM 5.1 output PCM 5.1.

I checked MPC-HC configuration, and it seems like nothing changed. I still have ffdshow in extern filter, I don't know if I should keep that or not. Maybe there's still a few tweaks to do in MPC config ?

someguy

Posts : 3
Join date : 2018-03-26

View user profile

Back to top Go down

Re: Can't get 5.1 from aac format in mpc-hc only stereo

Post by Admin on Tue Mar 27, 2018 4:42 pm

You should only have "ffdshow audio processor" in the external filter list, not the decoder.

The LFE checkbox is for the subwoofer. 3/0/2 is for the normal speakers. Your current selection is 6.1 instead of 5.1. The AC3 encoder only works with 5.1 and less.

Admin
Admin

Posts : 4194
Join date : 2011-06-17

View user profile http://codecs.forumotion.net

Back to top Go down

Re: Can't get 5.1 from aac format in mpc-hc only stereo

Post by someguy on Tue Mar 27, 2018 6:29 pm

Indeed, I picked 5 channels +lfe and it works. Finally !

Thank you so much. I will definitely keep this installation guide.

someguy

Posts : 3
Join date : 2018-03-26

View user profile

Back to top Go down

Re: Can't get 5.1 from aac format in mpc-hc only stereo

Post by Sponsored content


Sponsored content


Back to top Go down

Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum