BRRip's with Onkyo/HK

[NetFreak]

What does AVR (say onkyo 6200) display when movie has AAC 5.1 audio?
If AVR is connected with HDMI, Do we get real 5.1 surround sound for these movies?

Movie will never have AAC audio in DVD or Blu Ray. However a RIP might be created with audio.

AVR will not accept AAC audio and media player will have to decode it. AVR would show "PCM". PCM is decoded Audio.

If media player handles AAC properly, you will get 5.1 sound.

I want to know whether it is really needed to convert AAC 5.1 audio to AC3 (DD).

 

[alokbharti]

Movie will never have AAC audio in DVD or Blu Ray. However a RIP might be created with audio.

AVR will not accept AAC audio and media player will have to decode it. AVR would show "PCM". PCM is decoded Audio.

If media player handles AAC properly, you will get 5.1 sound.

Thanks NetFreak.
Your explanation looks reasonable.
That means there is no need to convert your rips from AAC to AC3 (or anything else)..
If media player handles AAC correctly and decodes it to 5.1 PCM, then AVR will display "PCM" while playing these rips and we will get 5.1 sound.

I think you need to understand the difference between codec, container and the compression ........ To ans your question straight, if a movie originally on a Bluray had DTS, and was ripped with AAC audio codec, the AVR would show DTS, similarly if the movie originally had DTS and was ripped using AC3 codec, the AVR still would show DTS. Again to summerise, AVR does not display the codec or container, just the Audio technology (compression) the movie was originally encoded with ......

And finally yes we do get proper 5.1 surround sound if the avr is connected with a source via HDMI that can read multichannel AAC

sam9s,

quite contradicting with NetFreak's comments..
are you sure if movie originally had DTS audio and is ripped with AAC codec, AVR will show 'DTS'?

 

[NetFreak]

That means there is no need to convert your rips from AAC to AC3 (or anything else)..
If media player handles AAC correctly and decodes it to 5.1 PCM, then AVR will display "PCM" while playing these rips and we will get 5.1 sound.

Though its not "required", AC3 is preferable to AAC because AC3 is a "mandatory" codec for a Blu Ray/DVD player to be certified.

Because of this requirement, AC3 would usually be better implemented and supported in AVR and media players.

If AC3 is used, AVR should display "Dolby Digital" which is trade name for AC3.

 

[alokbharti]

Though its not "required", AC3 is preferable to AAC because AC3 is a "mandatory" codec for a Blu Ray/DVD player to be certified.

Because of this requirement, AC3 would usually be better implemented and supported in AVR and media players.

If AC3 is used, AVR should display "Dolby Digital" which is trade name for AC3.

Thanks again.
I also had similar understanding that AC3 is widely supported and not even need to be decoded at media player.
Also that it is call "Dolby Digital" (DD is short)

please correct me if I am wrong.

Following comment from sam9s is confusing.

if the movie originally had DTS and was ripped using AC3 codec, the AVR still would show DTS.

 

[vaibhavyagnik]

I think you have a Laptop right, Install the latest XBMC on your laptop. Scan your rips to library, In the settings menu, Select Audio output, Select HDMI/SPDIF as source, select speaker configuration (5.1, 7.1, 2.1 etc.) check DD compatible reciever, check DTS compatible reciever. Now XBMC will bitstream DD/DTS irrespective of the codec used in the movie. you get multichannel with the minimum of fuss. Tell me if you get stuck. I am playing multichannel AAC rips on pc using XBMC and my Philips home theatre which is connected through co-ax shows DD.

 

[NetFreak]

I also had similar understanding that AC3 is widely supported and not even need to be decoded at media player.
Also that it is call "Dolby Digital" (DD is short)

Thats correct. If you have short sample files that used to be DTS but have been converted to AC3, I can test those with my AVR.

 

[sam9s]

Movie will never have AAC audio in DVD or Blu Ray. However a RIP might be created with audio.

AVR will not accept AAC audio and media player will have to decode it. AVR would show "PCM". PCM is decoded Audio.

If media player handles AAC properly, you will get 5.1 sound.

Yes that is correct, apologies for the confusing statement, its for AC3, AVR shows DD, and for AAC it would be PCM, but as I said if the source is capable of reading multichannel AAC, the out put would be 5.1 ........ apologies again for the confusion ...... and thanks to Netfreak for straightening this up .....

And to add it is not required as such to convert AAC to AC3 if your source is able to decode multichannel AAC, however if it does not (as is the case with WDTV Live) then the conversion is necessary .....

However what I dont understand is AAC is a lossy compression and PCM lossless, why does then AVR shows PCM when receiving AAC decoded audio .....??

 

[NetFreak]

However what I dont understand is AAC is a lossy compression and PCM lossless, why does then AVR shows PCM when receiving AAC decoded audio .....??

AAC is not understood by AVRs, so Media player has to decode it and send raw audio (PCM) to AVR.

And since PCM is sent to AVR, AVR will report PCM on it panel.

 

[sam9s]

^^ No what I mean is once the audio is compressed by the ripper with AAC, it becomes lossy, and if lossy audio is sent to AVR, AVR should not show PCM,
(a lossy audio cannot be raw technically) as that is confusing, since PCM is lossless. A casual viewer would be under the impression that the movie had PCM audio (uncompressed) and ripper has not touched it ..... where as this is not the case ....

 

[alokbharti]

(a lossy audio cannot be raw technically) as that is confusing, since PCM is lossless. A casual viewer would be under the impression that the movie had PCM audio (uncompressed) and ripper has not touched it ..... where as this is not the case ....

does PCM mean lossless audio?

A simple google search landed me to wikipedia link:

Pulse-code modulation - Wikipedia, the free encyclopedia

"PCM streams have two basic properties that determine their fidelity to the original analog signal: the sampling rate, which is the number of times per second that samples are taken; and the bit depth, which determines the number of possible digital values that each sample can take."


I could not comprehend PCM means lossless.
It is just digital representation of analog audio signal.
the 'sampling rate' and 'bit depth' decide the quality.

 

[NetFreak]

PCM is lossless. Once digitized, audio would not lose and information in PCM codec.

This is in comparison to MP3/Dolyby Digital/DTS. All these formats lose some information and hence take less space.

With same bit-rate and bit-depth, PCM would take Maximum space to store.

Wave files and Audio CD are examples of PCM.

 

[sam9s]

does PCM mean lossless audio?

A simple google search landed me to wikipedia link:

Pulse-code modulation - Wikipedia, the free encyclopedia

"PCM streams have two basic properties that determine their fidelity to the original analog signal: the sampling rate, which is the number of times per second that samples are taken; and the bit depth, which determines the number of possible digital values that each sample can take."

Your simple google search just landed you with the technical definition of PCM, a bit more exclusive search will let you know PCM is lossless, as also confirmed by Netfreak. DD, DTS are all lossy, but if you search hard you can find blurays with PCM 5.1 audio as well, which means the audio is lossless. Liked for example "Black Hawk Down" has PCM audio uncompressed

 

[nadroJ]

Hi all. Came across this topic via a google search.

I also download BRRIP movies from the HDLiTE group. They use AAC-LC. Swayam posted a image of it on the first page.

A few days ago I finally hooked up my Onkyo TX-SR308 with the Canton 120 MX 5.1 speakerset. It's working properly. Great sound for movies.

I use my MacBookPro (mid 2007 model) with an optical cable to my Onkyo receiver. For the video I use a DVI->HDMI cable directly to my Panasonic Plasma. I can connect it directly to the Onkyo receiver and put 1 HDMI between the receiver and the tv, but I still have to do that.

I use either VLC or Plex for playing the BRRIPs (i have alot of them with AAC-LC).

During playing I see on the receiver PCM. Ofcoure I can change the listening mode on the receiver to Dolby Digital, Neo:6 and so forth, but to my understanding it is not true 5.1. All these extra listening modes modify the sound to make it 5.1. For example when listening to music (mp3) i can set the receiver to listening mode Dolby Music (or something like that) so the sound comes out all the 5 speakers and the subwoofer.

What I want is the same as Swayam; true 5.1 experience from the downloaded BRRIPs. Is that possible in my situation?

I'm having a look at the settings of Plex and I see I had the audio output set to Autodetect. I can also set it to Force Digital, which gives me two options: Dolby Digital (AC3) Capable Receiver and DTS Capable Receiver. I still have to test that.

-edit-
I have the movie Four Lions on my laptop which has AC3 audio. I will get another version of Four Lions with AAC-LC audio and test them both to see if the receiver displays Dolby Digital or PCM.

Another question, what listening mode should I set if i want the audio untouched or does that goes automatically? The manual isnt really clear on that (or I must read better )

 

[NetFreak]

nadroJ,

PCM can carry true 5.1 audio to Onkyo system. And on onkyo, there would be some setting as "Straight", "Direct" that would send unprocessed audio to speakers.

However, its not straightforward to get VLC + Mac to send proper PCM (or Bitstresm Doldy/DTS) on Optical.

Search net for how to do that, I.e. send proper 5.1 audio from VLC over Optical cable.

 

[nadroJ]

Thanks for your answer, I will do a search on Google. I prefer to use Plex, which looks more neat is a total media app. I will test the two Four Lions movies which I said in the edit. I will look into VLC to and see if there are more options for audio output.

On the Onkyo you have the Direct option. It doesn't sound great actualy. Dolby Digital sounds much better (there are more listening modes which sounds better than Direct).

-edit after testing-

So I tested some movies, including the two Four Lions which supposedly have AAC-LC and AC3 audio.

In Plex:
with the optical audio connected it automatically set the audio output to Force Digital. I now have checked on the two options: Dolby Digital (AC3) Capable Receiver and DTS Capable Receiver. Now when I play movies it doesn't show the PCM icon in the receiver but the red Dolby Digital icon. Listening mode Direct sounds actually pretty good now. Comparable to Dolby Digital. Playing the two different Four Lions movies doesn't give a difference.

In VLC with optical cable connected:
It shows PCM and listening mode Direct sounds awful. When I change the listening mode to PLII Movie it shows the PLII icon and the PCM. When I change it for example to listening mode Neo6:Cinema it shows the dts icon, the Neo:6 icon and the PCM icon. Playing the two different Four Lions movies doesn't give a difference.

-edit 2-
I played one scene with explovies of Prince of Persia in both VLC (listening mode PLII Movie) and in Plex (listening mode Direct with the red dolby icon) and the same scene sounds much much better in Plex. The red dolby digital does seem to make a difference.

Conclusion: I will watch movies in Plex.

 

[NetFreak]

In Plex:
with the optical audio connected it automatically set the audio output to Force Digital. I now have checked on the two options: Dolby Digital (AC3) Capable Receiver and DTS Capable Receiver. Now when I play movies it doesn't show the PCM icon in the receiver but the red Dolby Digital icon. Listening mode Direct sounds actually pretty good now.

This is the Key part.

1. PC needs to Send Dolby or DTS (*) to Onkyo
2. Mode on Onkyo should be "Direct"

(*) It is also fine if PC sends 5.1 PCM Audio, but it take bit more fiddling to see PCM audio is 2 channel (Stereo) of 5.1.

If PC is sending Stereo, Onkyo has some Logic to make 5.1 out of it in Dolby mode. But sound would not be as good as in above configuration (Dolby/DTS + Direct).