IPB

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
DTS 5.1 to AAC/M4A 5.1?
Gornot
post Dec 25 2009, 13:33
Post #1





Group: Members
Posts: 6
Joined: 25-December 09
Member No.: 76334



I have been searching around the internet for days and found many solutions that in the end didn't actually work.

The title says it all. I have a few DTS 5.1 files which I'd like to convert to 5.1 AAC. Now, my first problem is that most solutions I found on the internet don't mention HE-AAC, which is exactly what I want. I do not wish to use LC-AAC because the HE encoder I use in Winamp gives me acceptable results at only 64kb/s (that's actually the bitrate I use for all my music CD rips) and it works perfect for my taste. I will not accept to raise the bitrate because I am using these conversions as backups to DVDs, so I can't play around with the filesizes.

BeSweet was the first thing I tried and it seems it just doesn't work in Windows 7. Then I installed the DTS decoder plugin for Winamp, but i can't use that for encoding into AAC. Then I tried foobar2000 to produce the AAC file directly, again, it seems that it isn't the HE encoder. Then i tried XviD4PSP in Audio only mode and, again, the AAC encoder isn't HE, so I produced a 6ch WAV file, 16bit, 48000kHz. I have already used these kind of WAV files in Winamp and I know I can convert them into AAC, but when I started conversion, I encountered an error "Cannot start encoder" or something similar.

So what am I supposed to do? I encode my video files with Handbrake which can't produce the 5.1 AAC audio file no matter what I do, BeSweet just stops responding after a couple of seconds (tried compatibility mode, run as admin, still nothing), and even if I manage to get a 6ch WAV file, Winamp can't use the HE-AAC encoder to give me the appropriate result.
I would really appreciate any help. I know that this has probably been discussed many times, even here at Hydrogenaudio, but some of the threads I have read through are pretty old.

This post has been edited by Gornot: Dec 25 2009, 13:34
Go to the top of the page
+Quote Post
kurtnoise
post Dec 25 2009, 18:23
Post #2





Group: Members
Posts: 326
Joined: 26-June 02
From: Aix-en-Provence
Member No.: 2400



you should try eac3to within the Nero AAC encoder...


--------------------
http://www.unite-video.com/phpbb/viewtopic.php?t=5412 :: An overview of all lossless Audio Formats (in french language ;-)
Go to the top of the page
+Quote Post
Gornot
post Dec 25 2009, 21:09
Post #3





Group: Members
Posts: 6
Joined: 25-December 09
Member No.: 76334



Thanks for the reply, I already tried it (just forgot to mention it) but it's just too complicated, no guides help on setting it up and after much sc***ing around I just had to give up. Besides, I don't see the option to output the file in acc/m4a/mp4 or anything that has to do with aac except to set the filepath to the encoder.
Go to the top of the page
+Quote Post
Gornot
post Dec 25 2009, 23:05
Post #4





Group: Members
Posts: 6
Joined: 25-December 09
Member No.: 76334



QUOTE (Gornot @ Dec 25 2009, 21:09) *
Thanks for the reply, I already tried it (just forgot to mention it) but it's just too complicated, no guides help on setting it up and after much sc***ing around I just had to give up. Besides, I don't see the option to output the file in acc/m4a/mp4 or anything that has to do with aac except to set the filepath to the encoder.

Ummm,, no edit button?

Anyway, in the end I used eac3to to create a 6ch signed wav file and then found enc_aacPlus.exe on the internet. I copied the two required .dll files from the Winamp folder so okay, now it seems I can do it (I had to use --rawpcm command, though, that was a few more minutes of confusion XD). But now it seems that no matter what I do, I can't change the bitrate from 128000 to 64000 bps. The second thing I see is that MediaInfo still displays the file as LC-AAC and stereo, even though the encoder was properly set. Here's the command line I used:

enc_aacPlus C:\Users\Gornot\Desktop\wav.wav C:\Users\Gornot\Desktop\audio.aac --rawpcm 48000 6 16 --he --br=64000 --mpeg4aac

Now, this --br part confuses me still. Is it --br=64000 or --br64000 or --br 64000 or something else. No matter what I set, the encoder seems to randomly set either 128000 or 96000 bps as the bitrate...
Go to the top of the page
+Quote Post
Skelsgard
post Dec 26 2009, 00:12
Post #5





Group: Members
Posts: 126
Joined: 4-December 05
From: A bubble
Member No.: 26214



QUOTE (Gornot @ Dec 25 2009, 19:05) *
Now, this --br part confuses me still. Is it --br=64000 or --br64000 or --br 64000 or something else. No matter what I set, the encoder seems to randomly set either 128000 or 96000 bps as the bitrate...

use --br 64000

But you can skip all the hassle of intermediate wavs by using eac3to + neroaacenc with this command
CODE
eac3to C:\yourfile.dts stdout.wav | neroAacEnc.exe  -cbr 64000 -hev2 -if - -of C:\yourfile.mp4

Using it this way, you can control the parameters for NeroAACEnc.
Now, keep in mind that 64kbps for 5.1ch audio will suck. Big time. It will trash the sound to the equivalent of making noises by blowing bottles.
Now, if you mean 64kbps per channel pair, then that's about 192 kbps for the whole thing, which is more bearable. Even 128kbps would be more acceptable.
I would actually recommend you to use the vbr -q option. Something like:
CODE
eac3to C:\yourfile.dts stdout.wav | neroAacEnc.exe  -q 0.100 -if - -of C:\yourfile.mp4


--------------------
"Screw u guys, Im going home."
Go to the top of the page
+Quote Post
Gornot
post Dec 26 2009, 10:47
Post #6





Group: Members
Posts: 6
Joined: 25-December 09
Member No.: 76334



I tried --br 64000, sometimes it just uses 128000 and sometimes it changes to 96000...

QUOTE
Now, keep in mind that 64kbps for 5.1ch audio will suck. Big time.


That's exactly why I tried to get the 6chWAV first, so that I could use the Winamp's built in HE-aac encoder to do the job. It never let me down before, although I never actually tried doing 5.1 before. So now I'm actually reconsidering to throw away 5.1 and simply downmix it to stereo, or maybe 2.1 'cause that's my speaker config. I cannot change the bitrate of the audio without decreasing the video bitrate, and furthermore, using vbr will mean that there might be a lot of difference between the video files' quality since the filesize has to be exact, for the purpose of backing up to DVDs.
Well, thanks for all the answers, perhaps in time I'll try again smile.gif
Go to the top of the page
+Quote Post
Skelsgard
post Dec 26 2009, 14:12
Post #7





Group: Members
Posts: 126
Joined: 4-December 05
From: A bubble
Member No.: 26214



QUOTE (Gornot @ Dec 26 2009, 06:47) *
That's exactly why I tried to get the 6chWAV first, so that I could use the Winamp's built in HE-aac encoder to do the job. It never let me down before, although I never actually tried doing 5.1 before. So now I'm actually reconsidering to throw away 5.1 and simply downmix it to stereo, or maybe 2.1 'cause that's my speaker config. I cannot change the bitrate of the audio without decreasing the video bitrate, and furthermore, using vbr will mean that there might be a lot of difference between the video files' quality since the filesize has to be exact, for the purpose of backing up to DVDs.
Well, thanks for all the answers, perhaps in time I'll try again smile.gif


-q 0.100 in NeroAacEnc will yield an aproximated 64kbps encoding. If it doesn't hit the 64kbps mark, you can decrease the value by 0.001 until reaching the desired target. Maybe -q 0.098.
It's still recommended because it will use more bitrate when needed by the audio complexity and less when less complex audio.
I would recommend you to go 2.0ch on this, as 6ch will sound bad so there will be really no benefit from having a surround track.
Don't do 2.1 downmixing, no such thing in the speakers realm, except for very specific systems, but 2.1 PC speakers are not 2.1.
The #.# designation translates as number_of_fullrange_ch . n_of_non_fullrange_ch, meaning that the number BEFORE the dot is the number of discrete full range channels, while the number AFTER the dot is the number of discrete non-full range channels. That's why we can say 5.1ch or 6ch, since there are 6 channels in total, whether they're all full range or not.
The so called 2.1 speaker systems are not so, as none of them are full range speakers but limited-range ones. The smaller ones are high frequencies range speakers while the subwoofer is a low frequencies range one. So the apropiate designation is 0.3 speakers: zero full range speakers/3 limited range speakers. All that 2.1 speakers do is to send all the low frequencies to the subwoofer, so even if you create a properly mixed 2.1 downmix (2 full range channels + 1 limited range channel) and have the hardware to send a 3 channel signal to these speakers, the low frequencies from the 2 full range channels will be sent to the low frequencies speaker, not forgetting that these speaker systems don't even have inputs for all 3 channels.
The same way most home-theaters are 0.6 speaker systems as none of the main speakers can carry the full range of frequencies they should to be full range speakers. They are ALL limited range speaker systems.

To sum it up, do a 2ch downmix, you can with this syntax
CODE
eac3to C:\yourfile.dts stdout.wav -down2 | neroAacEnc.exe  -cbr 64000 -he -if - -of C:\yourfile.mp4

or -q 0.240~0.250
CODE
eac3to C:\yourfile.dts stdout.wav -down2 | neroAacEnc.exe  -q 0.250 -if - -of C:\yourfile.mp4


--------------------
"Screw u guys, Im going home."
Go to the top of the page
+Quote Post

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



RSS Lo-Fi Version Time is now: 21st April 2014 - 08:43