Audio Signal Processing with Digital Media for HT

[Nikhil]

Last week I had visited a friend to have a listen of his setup and it brought up an issue of audio on HT which I realize I need to get some more info. Many folks these days use a media server (NAS, WDTV etc)) to store and play movies eliminating the DVD player from the chain. My question is when you feed a AVR these digital sources, do they get resolved into 5.1 like its done with a proper DVD player in place?

My understanding of this was that this should not be the case. If a media server feeds the movie sound to the AVR, then all channels are fed the same signal. This is opposed to the true multi-channel HT sound where a DVD would process the signal and dish out the appropriate sound signal to the appropriate channels. So in effect using a media server doesn't give you true HT sound unless there is a way to store multi-channel sound in the media file.

Am I wrong on this or is it possible to correctly decode a digital file when using a media server only to feed an AVR?

 

[cmsajith]

you missed the media player (can be a PC based / media players like wd live). The NAS is only a HDD container which holds your files. The media player plays and process the files and the digital out from the player can be processed by the AVR.

 

[NetFreak]

Am I wrong on this or is it possible to correctly decode a digital file when using a media server only to feed an AVR?

Is this a network AVR that directly reads files from NAS?

If that is the case, then AVR would have proper 5.1 if it supports the codec used in digital file.

 

[Nikhil]

you missed the media player (can be a PC based / media players like wd live). The NAS is only a HDD container which holds your files. The media player plays and process the files and the digital out from the player can be processed by the AVR.

The question I have is if the processing of the signal is 5.1 if there is no PC - just a network storage or say a USB memory stick.

 

[Masoodarif]

Optical output to 5.1 channel speaker system

The question I have is if the processing of the signal is 5.1 if there is no PC - just a network storage or say a USB memory stick.

Dear all,
I am having samsung d8000 led 3d tv with an optical output but I don't have optical input in my speakers how did I get 5.1 surround sound through my normal speakers using any kind of converter or cable please help

 

[manoj.p]

The question I have is if the processing of the signal is 5.1 if there is no PC - just a network storage or say a USB memory stick.

If the AVR has the Dolby Digital/DTS decoder, then yes, it will be able to do 5.1 decoding. almost all the current avr's do DD, DTS, Dolby True HD, DTS HD, DTS-HDMA. So its totally covered.

Main thing though, the source should have the 5.1 tracks. Don't assume that all the sources have 5.1. I have seen lots of Indian movies (especially old movies) encoded Dolby Digital 5.1 but only have 2 front channel data. They never bothered to re-master the mono/2 channel audio from film to 5.1 on DVD.

 

[cmsajith]

The question I have is if the processing of the signal is 5.1 if there is no PC - just a network storage or say a USB memory stick.

Still your question is unclear. If you are connecting the NAS/pendrive to a n/w enabled AVR (plays audio files only, correct me if I am wrong), how will you process the file / play it, AVR cannot read / play a video file directly. Assuming if you play it using some device and gives the AVR a digital in (source file should be multichannel encoded) any normal AVR can process the audio as per the encoding.

 

[GeorgeO]

If I have understood your question correctly, if the signal is encoded in 5.1 or 7.1, the AVR will decode all of these channels irrespective of whether it is from a disk or from a Hard disk. A lot of my content is in my HDD, I have no problem playing 5.1

 

[cmsajith]

If I have understood your question correctly, if the signal is encoded in 5.1 or 7.1, the AVR will decode all of these channels irrespective of whether it is from a disk or from a Hard disk. A lot of my content is in my HDD, I have no problem playing 5.1

Initially I thought the same (asking about the mediaplayer), but later I got confused.

 

[silkograph]

5.1 / 7.1 Dolby Digital or DTS signal resides in a file. It is decoders look out to handle particular encoding. Decoder is sound processor in TV, PC, Receiver or Media player / server.

I have Samsung 51E550 + Yamaha HTiB where I get real 5.1 Dolby Digital sound when I play MKV, AVI , MP4 etc files from TV's USB port. So far I have connected optical cable from TV to Yamaha receiver.

 

[rud3dawg]

5.1 / 7.1 Dolby Digital or DTS signal resides in a file. It is decoders look out to handle particular encoding. Decoder is sound processor in TV, PC, Receiver or Media player / server.

I have Samsung 51E550 + Yamaha HTiB where I get real 5.1 Dolby Digital sound when I play MKV, AVI , MP4 etc files from TV's USB port. So far I have connected optical cable from TV to Yamaha receiver.

Sorry dragging the discussion off the topic Nikhil, but just wanted to know something...

Hey silkograph, Just wanted to know because I have a 51E550D .. Is the volume the same when you play a VDO using the TV's USB port ... I d have to increase about about 7-10 db to get the same volume and I' ve connected using a TOSlink too .. unfortunately this model of plasma does not support ARC

 

[baijuxavior]

Last week I had visited a friend to have a listen of his setup and it brought up an issue of audio on HT which I realize I need to get some more info. Many folks these days use a media server (NAS, WDTV etc)) to store and play movies eliminating the DVD player from the chain. My question is when you feed a AVR these digital sources, do they get resolved into 5.1 like its done with a proper DVD player in place?

My understanding of this was that this should not be the case. If a media server feeds the movie sound to the AVR, then all channels are fed the same signal. This is opposed to the true multi-channel HT sound where a DVD would process the signal and dish out the appropriate sound signal to the appropriate channels. So in effect using a media server doesn't give you true HT sound unless there is a way to store multi-channel sound in the media file.

Am I wrong on this or is it possible to correctly decode a digital file when using a media server only to feed an AVR?

Downloaded movie files usually have audio in 2 channel or 5.1 channel. Some files have both 2 channel and 5.1 channel. Usually the audio is encoded in AC3 (dolby digital), DTS or AAC format. For two channel it is usually in mp3 format. While avrs can decode ac3 and dts audio, most avrs can't decode aac audio so you wll get only pseudo surround sound from aac even if the movie has 5.1 sound. So usually you set in your player to bitstream ac3 and dts so that decoding is done at avr and for aac files you set it as pcm so that the decoding is done by the player. I think the movies you demoed has audio in aac format and thats why you got the impression that the audio is not true surround.

 

[silkograph]

Sorry dragging the discussion off the topic Nikhil, but just wanted to know something...

Hey silkograph, Just wanted to know because I have a 51E550D .. Is the volume the same when you play a VDO using the TV's USB port ... I d have to increase about about 7-10 db to get the same volume and I' ve connected using a TOSlink too .. unfortunately this model of plasma does not support ARC

Hi,
I have selected External Speaker option in TV's configuration Menu.
I can keep both speaker on but I must keep TV's volume to zero when my HT is on otherwise I get sound from both devices. There is no effect on HT's sound level if I adjust TV's sound level. Both sounds are independent.

Is this you want to clarify from me?

 

[rud3dawg]

Hi,
I have selected External Speaker option in TV's configuration Menu.
I can keep both speaker on but I must keep TV's volume to zero when my HT is on otherwise I get sound from both devices. There is no effect on HT's sound level if I adjust TV's sound level. Both sounds are independent.

Is this you want to clarify from me?

.. Oops my bad, guess I was vague in my previous post ..
I was asking.. in comparison to normal music played from your AVR (using lets Say HD radio or USB:MP3s or FLACs)

Taking a scenario:
1. Play an MP3/Flac from the AVR using USB/Radio etc
2. Now with the same volume db settings change play the same song using the TV~USB
3. Ofcourse both the times the TV volume is kept @ Zero (or No audio from TV should be heard)

My Question is in both the cases is the volume pitch the same ??:sad: [Because mine is NOT close to about 10 db has to be increased to get to same pitch !! ]

 

[Nikhil]

Thanks guys for the replies. All have been useful in answering my query.

Since it was not clear I will try to rephrase my question: As is popular these days quite a few of us are eliminating the DVD player from the chain. In such a case, I was wondering if the audio signal for multi-channel movie tracks are correctly decoded. I wanted to know where the multi-channel info is decoded/processed.

If the AVR has the Dolby Digital/DTS decoder, then yes, it will be able to do 5.1 decoding. almost all the current avr's do DD, DTS, Dolby True HD, DTS HD, DTS-HDMA. So its totally covered.

Main thing though, the source should have the 5.1 tracks. Don't assume that all the sources have 5.1. I have seen lots of Indian movies (especially old movies) encoded Dolby Digital 5.1 but only have 2 front channel data. They never bothered to re-master the mono/2 channel audio from film to 5.1 on DVD.

+1 to that.

Thanks again guys. I am not really well versed with HT so this was something that was bothering me a little. Its always never too late to learn.

 

[Nikhil]

Downloaded movie files usually have audio in 2 channel or 5.1 channel. Some files have both 2 channel and 5.1 channel. Usually the audio is encoded in AC3 (dolby digital), DTS or AAC format. For two channel it is usually in mp3 format. While avrs can decode ac3 and dts audio, most avrs can't decode aac audio so you wll get only pseudo surround sound from aac even if the movie has 5.1 sound. So usually you set in your player to bitstream ac3 and dts so that decoding is done at avr and for aac files you set it as pcm so that the decoding is done by the player. I think the movies you demoed has audio in aac format and thats why you got the impression that the audio is not true surround.

Thats very useful to know. Must check on the file format we were listening to.