How to convert .ac3->ac3wav & .dts->dtswav?

[ontherocks]

How to convert .ac3->ac3wav & .dts->dtswav? (I wish to burn a DTS/DD AudioCD with the .ac3 & .dts files)

AC3Filter tools -> spdifer http://ac3filter.net/projects/tools says that it can do it, but I am not having any success.
I tried the following commands

spdifer filename.ac3 filename.wav -wav

spdifer filename.dts filename.wav -wav

Pls help. Any other ideas?

[Midzuki]

but I am not having any success.

HOW You run the command-line, and then happens what ?
Any error messages? Do you get 0-byte files? Something else?
Need more info!

[ontherocks]

Nevermind, figured it out myself.

The problem was that the converted dtswav or ac3wav had the frequency 48kHz (same as that of the parent .dts & .ac3 files).
This was giving static noise while trying to play them through my HT system via SPDIF, and was also giving input file read errors when the CD burner software was trying to write them as AudioCD.
I used a hex editor to change the frequency to 44.1kHz in the wav header and everything was perfect.

[ontherocks]

Well, it turns out everything is not perfect

The problem is they play a little longer because they play @44.1kHz.
The question is, why would they play @44.1kHz, since inherently they are .dts/.ac3 files @48kHz in the wav container. Is it just because the wav header tells it is @44.1kHz??

[guns1inger]

AC3 or DTS in a WAV container needs to be re-sampled down to 44.1, not just a header change. Do the job properly and you don't have these problems.

[Alex_ander]

Any other ideas?

To avoid resampling etc, you can make a mini-DVD (DVD Video folder on CDR) of original ac3+(or)dts files by authoring in DVDLab (current version even supports individual image for each chapter if you want). Unlike mini-DVDs with video content, audio+stills should play in almost any DVD player due to low bitrate. Nero has an option for burning mini-DVD. Do a simple test project for your player first.

[ontherocks]

AC3 or DTS in a WAV container needs to be re-sampled down to 44.1, not just a header change. Do the job properly and you don't have these problems.

You mean
.ac3->decode to wav->downsample to 44.1kHz->Re-encode (free, ok)
.dts->decode to wav->downsample to 44.1kHz->Re-encode (not free, not ok)

@Alex_ander
Will try it out.

[Bladergroen]

Hi,

Registered a few days ago to this forum, because i'm trying to do something with my music/movie files, but can't get it done...

What am i trying then ? Well, to begin with, I was trying to stream the AC3 surround part of my AVI file over an airport express to my home cinema system (Sony HTR-6100). Just to try if this would work. It doesn't.
Now I would like to stream surround music the same way.
Problem: my files are 48kHz and as described above, i found out that this has to be 44.1kHz.
At this point I'm able to:

a) extract sound from a movie in ac3 format using Handbrake
b) convert this to a multichannel .wav format using spdifconvert (a python script - see www.slimdevices.com)

At this point "c)" should come, but here I get stuck.
After that point d) would be: convert back to AC3.
Main question: how can i downsample a AC3/DTS-Wav file to 44.1kHz and convert this back to ac3? I'm using a Mac and do not have any windows machine near me ;p.

I hope anybody can help me. Thanks in advance,

Reno
Belgium

[guns1inger]

I don't believe it can be done unless the airport express can pass the wav file as a digital stream via optical or coax to the amplifier. How is the airport express connected to the amp ? If it is by stereo RCA connectors or mini-jack then you cannot do what you are trying to do.

[Bladergroen]

My Airport is connected to my home system via optical cable. It can be done, i already have AC3-Wav files with 44.1kHz, which can be streamed and played correctly in Dolby Digital over my amplifier. So what I need to know is how to downsample a AC3(-Wav) file from 48kHz to 44.1kHz.

Greets, Reno

[guns1inger]

You have to demux the channels back to mono wav files, resample, then re-encode as a 5.1 AC3 inside a WAV container. Easy enough in theory.

As to what software is available to the MAC . . . ProTools ?

The main issue that there is only a small audience for AC3 in a wav container, and therefore few programs that do it. DTS is even rarer.

However you should only need to do this if you intend to burn the wav files to CD for playback in a DVD player or digitally connected CD player. For streaming the amplifier really wont care if the file is sampled at 441. or 48 kHz. Unless this is a restriction of AirPort itself, in which case AirPort isn't really streaming.