Extract Individual Audio Channels from BD?

[EmpireStrikesBack198]

Hi, everyone. I've been looking over the forums to find an answer to my question, but I can't seem to find it. I was wondering how you can rip individual audio channels (namely, rear speakers) from a 5.1 (or 7.1) channel mix on a Blu-ray disc. I know with DVDs you need the .ac3 file to get the individual channels, but how does it work for Blu-ray? With DVDs, I would rip the .ac3 file with DVD Decrypter and I would get the audio channels I wanted with with HeadAC3. The process similar with Blu-ray? I would appreciate any insight or help. Thank you.

[poisondeathray]

Rip the audio, convert to wav, open in an audio editor to isolate channels. You could use anydvd + eac3to for example

The main audio is usually HD variety e.g lpcm, true hd, dts-ma instead of AC3

[EmpireStrikesBack198]

Thank you for the information. How do you extract only the audio from a BD?

[poisondeathray]

eac3to , hdbrstreamextractor, tsmuxer, a few others. eac3to can extract and convert to wav in 1 step, then input into audio editor. The others would need conversion to wav as a 2nd setp

[EmpireStrikesBack198]

Thanks again. I'm extracting the audio with hdbrstreamextractor and I plan to open it with Adobe Audition with the ac3/DTS filter. Do you know if each channel will be separate as a mono track? How would I know which is the left channel and which is the right channel? With HeadAC3 I was able to create a stereo WAV file with either the rear channels or front channels. Is there is a program like that for DTS files? Thank you.

[poisondeathray]

If this is the main audio track, I don't think audition will be able to handle it ; it would likely be DTS-MA, not the garden variety DTS 1536 (I don't think audition has a decoder for the hd audio types commonly found on blu-ray)

You can export mono wavs out of eac3to , and they are labelled eg. FR, FL, C, LFE, etc..

Are you trying to downmix to stereo? What is your goal?

[EmpireStrikesBack198]

I am trying to get the rear channels (left and right) as a stereo file. I tried using eac3to, but I can't figure it out and I can't find any tutorials on how to use it correctly. What I am really looking for is a software program that will be able to extract the audio from a BD (in dtshd for example) and then be able to extract the left and right rear channels into a stereo WAV file from that dtshd file. I am willing to learn a new method on how to do all this with BDs. It seems to be a lot more challenging with BDs than it is with DVDs.

[poisondeathray]

Did you rip/extract the audio yet? Was it dtshd or something else?

I would just export mono wavs, and you can take the 2 channels that you want and make your stereo file in any audio program, audition, audacity etc...

the gui for eac3to is harder to use than the commandline. You have to setup all the program paths in the 1st tab configuration (but the only one you need is eac3to.exe and tsmuxer.exe, the others aren't required for what you are doing), then select the audio track in the audio tab (2nd tab) input file drop down menu

for mono wavs using commandline, it's just 1 line and way easier:

eac3to input.dtshd output.wavs

http://en.wikibooks.org/wiki/Eac3to/How_to_Use

Can I ask why are you using only 2 channels? A proper stereo downmix will use weighted coefficients using all the channels

[EmpireStrikesBack198]

It's ripping right now and since it's ripping the audio from the whole movie it is taking a long time. I'm used to ripping audio by the chapters instead of the whole movie. The file is dtshd.

I will try out ec3to when it's done exporting and let you know.

I am trying to extract only the music from the 5.1 mix (or 7.1 if supported by eac3to) and usually the rear channels have the least amount of sound effects, if any at all. That's why I want to get a stereo mix and usually the rear channels is sufficient enough for that.

[EmpireStrikesBack198]

I just converted the dtshd file to a wav file, but the file is over 4GB and Adobe Audition can't handle that. It will only import about 20 minutes of each channel. Also, the files specify which channels are which and which is the left and which is on the right. Is there any way to extract the audio file by selecting chapters so a little can be done at a time?

[EmpireStrikesBack198]

I'm running into another problem. When I import the the WAV files into Adobe Audition, both rear left and right channels are the same and both front left and right channels are the same as well. When I put the the left and right rear channels together, it is a "stereo" mono track. I'm not sure why the left and right are the same mono track when they shouldn't be.

[poisondeathray]

Can you use wave64 or flac in audition ? They don't have the filesize limitation that WAV has. If not, I think you can do it in audacity

It's possible that the channel mapping was incorrect with that decoder. You can specify different decoders e.g. if you have arcsoft installed instead of libav. Or you can force libav by adding -libav to the end of the commandline, go through that link above and you will see the options

You can also ask at doom9 where the author "lives"
http://forum.doom9.org/showthread.php?t=125966

If you wanted to process only a segment, you would need to cut the corresponding .m2ts segment e.g. with tsmuxer

You could also do your mixing with an avisynth script and soundout() , but you probably want to decode and identify the correct channels first. This is the way I would do it. So first try an switch the decoder, and see if the mono wav channel is correct.

a=WavSource("leftchannel.wav")
b=WavSource("rightchannel.wav")
MergeChannels(a,b)
Soundout()

[EmpireStrikesBack198]

Audition accepts flac, but it would only allow 50 minutes to be imported. I haven't tried Audacity yet. I also tried a different decoder, but I still get the same result with the mono channels, even when I convert it to flac. I may have to ask in doom9 and find out what is going on. Thank you for all your help. I appreciate it greatly.