DTS -gt; AAC for headphones 5.1 quot;souroundquot;???

andy

Is there a way to encode a AC3 or DTS track (like a concert) that is in 5.1 with quot;psuedoquot; HFRT so the headphones quot;soundquot; like 5.1???

Does it have anything to do with quot;MPEG-4 Encoder GUIsquot;?


Originally Posted by sjchmuraIs there a way to encode a AC3 or DTS track (like a concert) that is in 5.1 with quot;psuedoquot; HFRT so the headphones quot;soundquot; like 5.1???

Recent FFDShow versions have the HRTF mixer DSP.
Use the graphedit or the avisynth environment to transcode through the FFDShow dsfilter.
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Hi sjchmura,

Did you mean to mention quot;AACquot; in your thread title?Cheers


Originally Posted by sjchmuraDTS -gt; AAC for headphones 5.1 quot;souroundquot;???

It has indeed nothing to do with the MPEG-4 Encoder GUIs, thus moved in from the other section.
I understood he made his point very clear that he wants to transcode 6ch sources to aac 2ch containing the HRTF signal for his headphone use to feel 5.1ch effect??

I wonder what your point is SeeMoreDigital?


Originally Posted by RockariaI wonder what your point is SeeMoreDigital?

I was under the impression that HRTF (Head Related Transfer Function) is not specific to an AAC audio signal!

Surely it can be applied to any audio signal, can't it. So why transcode to AAC?


Originally Posted by SeeMoreDigitalSurely it can be applied to any audio signal, can't it. So why transcode to AAC?

That's true. The HRTF is said designed to reduce(by adding the natural spatial feeling) the discomfort after long use of the headphone in normal mode(regardless of the channels).
The mode actually has some spatial feeling which I believe can be enhanced by 5.1 sources.

The portable formats would be mp3gt;wmagt;ogg/aac... and the player devices would be mostly portable players which asks 2ch clips.
Of course, in pc environment(with a headphone), we can just use the ffdshow's HRTF mixer dsp dynamically.

wiki/HRTF
[edit] clarification, added a reference.

What you are after is called BINAURAL processing.
A google search will point you in the right direction.


Originally Posted by specise_8472A google search will point you in the right direction.

wiki/Binaural_recording
A typical binaural recording unit has two high-fidelity microphones mounted in a dummy head, inset in ear-shaped molds to fully capture all of the audio frequency adjustments (known as head-related transfer functions (HRTFs) in the psychoacoustic research community) that happen naturally as sound wraps around the human head and is quot;shapedquot; by the form of the outer and inner ear. The Neumann KU-81, and KU-100 are the most commonly used binaural packages. The KEMAR system is another alternative.
SOrry for the wrong section - but I thought since this was AAC/MP4 section and I am NOT programming savy if there was  GUI way to do this.

The graphedit way - so do I setup a custom command line and PROCESS through MeGUI or StatRX?????

I ahve the U2 Live Chicaog concert ( I was actually there) and would LOVe to get the deep 5.1 soudn to 2 channel AAC in some simple GUI way

Sorry again

Steve

but unfortunately the HRTFs cannot reproduce the feeling of binaural recordings (in German it is called quot;Kunstkopf-Stereoquot;).

.

Try both methods from the easier one. Anyway, the Avisynth's DirectShowSource() can also read from the dsfilters or grf graphedit files.
Both are very flexible and worth to be familiar with.

THanks  I should have done Audio  I never thought of doing this but to be honest why don't we all do this for our DVD rips, HDTV conversion etc?

Rockaria, thanks!!!!

BUt I thought AVISynth had NO DTS filer - just AC3 - that is why Megui quot;script creatorquot; only works with AC3 - correct? If so which AVIsyny 2.55 plugin should I use?

Anny suggstions on the HFRT settings for headphones? Do I measure my head

Steve

@sjchmura: if you want to convert DTS sources with AVISynth, you may use directshowsource(quot;source.dtsquot;) with AC3Filter set as preferred decoder.

@rockaria: it was just meant to be a comment on HRTFs. For sure they are an improvement over plain stereo on headphones. Also I don't have an idea how to implement binaural codings...


Originally Posted by scharfis_brain@sjchmura: if you want to convert DTS sources with AVISynth, you may use directshowsource(quot;source.dtsquot;) with AC3Filter set as preferred decoder.
This is good, it has practical suggestions.

But I already included

Code:
#NicDTSSource(quot;1.dtsquot;)for the dts decoding.(# is for remarks)
The directshowsource() method requires the accurate dsfilter merit control when there are more than one candidates to perform the same functions, not recommended for normal uses.

@sjchmura, I believe you need to get down to it and take your time.
The linked page amp; here contains all the related informations and links to the related files you need.(get the latest versions)

There has been this efforts since some while ago, but recently reintroduced and is being implemented in MeGui also.
It's very flexible and powerful...

THanks Rock!!!

I will get it down well - and post my results

Thanks again.

Steve

I  know how to implement the HRTF based filtering.
In fact, I have implemented something like this in Matlab,
and was planing to produce a converter from 5.1 to stereo
with HRTF-based downmix.
But the results were dissapointing and I found it not very practical.
I.e. I exptected good results, but honestly they were far
below my expectations.
Please check this out, and you will see how strongly the result depends on the head and shoulders shape:
equipes/sa...en/sounds.html

Just to mention.
AAC may not very good for storing the HRTF stereo downmix,
because upper subband does not contain exact phase properties of the encoded sounds, while the phase characteristics is of importance in the filtering.

Why the supposedly front sounds are playing behind..

What was your impression with the FFDSHow's generic HRTF approach?
Dolby headphone amp; virtual speaker technology also provide some surround media flash samples on their site.

The HRTF  stream, directed to any 2ch headphone, is not reconstructed anywhere, unlike DPL II.
So I believe there is no possibility of the aac he's SBR band area being broken(or mixed reconstructed).