Films with 5.1 and 6.1 sound for PC

Villager1971

Hi all

As I’ve been unable to retrieve my password due to old email address I’ve had to become a ‘new’ member.

Anyway, I’ve downloaded a couple of movies recently which carry either a 5.1 or 6.1 soundtrack.  This is saved as an mkv file. The problem I have is that I’m unable to get any programs on my media pc to output this in 5.1 (Dolby Digital).

Ordinarily, Windows Media Player, VLC or Power DVD will play them with surround sound like all my dvds I have ripped to a large drive. The amp automatically switches to DD 5.1. On the downloaded files this doesn’t happen. I can force VLC to output in 5.1 sound for the files but isn’t true 5.1 Dolby Digital.  I also have to manually change the amp from stereo which is the normal setting for the pc as I play a lot of music and music videos from it.

Do I need to burn these files to a dvd rom to get the 5.1 sound ?

I’ve had a similar thing downloading 5.1 music files and they won’t play in 5.1 either even though the size of the files are much larger than your big standard mp3 files.

Any help would be really appreciated.

EndlessWaves

The first thing I'd check is whether the sound track is encoded in Dolby Digital. It's an old lossy audio compression designed for squeeze surround sound down a limited bandwidth S/PDIF link and while the big studios and discs maintain it for backwards compatibility, many other videos these days have switched to more modern audio formats such as AAC.

VLC's codec information function will show you which audio and video formats the MKV file contains. Dolby Digital may also be known as A/52 and AC3.

How is your amp connected (HDMI, USB, S/PDIF etc.) and what audio formats does it accept?

What do you mean when you say the amp is set to stereo? Are you having it upmix stereo into surround?

If you do need to output dolby digital from files that aren't encoded that way then there are utilities that'll encode on the fly, but as it's a lossy compression I'd consider that a last resort.

Trollslayer

The downloaded files have probably been compressed and the way to do that is to reduce the quality of video and audio.
What does VLC say the audio is?

next010

As the others have mentioned bandwidth limits of SPDIF do not allow anything more than compressed Dolby 5.1 (AC3) and DTS 5.1

Things like TrueHD (EAC3), DTS-MA will not play over SPDIF, a direct HDMI connection to sound system is required.

If you are limited to SPDIF/optical, download MPC-BE
* click view->options
* select internal filters
* select audio decoders->audio decoder configuration
* under pass-through select only AC-3, DTS (if supported by audio system) and Encode to AC-3
* select audio section->audio renderer and change system default to your SPDIF output.

That will make MPC-BE always transcode any non AC3/DTS audio source into AC3.