Extracting Audio Files

[Len M.]

Using Build 14, we recorded a 54.14 second clip with four tracks of audio. I want to export those four different audio tracks from the clip to four mono WAV files.

These are the filenames of the five files in the clip directory:

A001_C004_080210_001.R3D
A001_C004_080210_F.mov
A001_C004_080210_H.mov
A001_C004_080210_M.mov
A001_C004_080210_P.mov

The R3D file is 1.46 GB long, so I guess that's where the entire clip (video and audio) is stored. Each of the four MOV files are only 19 KB long so it's clear that they don't contain the 24-bit/48 KS/s audio data.

When I play the first MOV file in QuickTime Pro 7.3, I hear an audio track but don't see any video. I exported that audio track to a 32-bit/48 KS/s mono WAV format file.

I did the same for the other three audio tracks.

When I compare the four resulting WAV files in an audio workstation application, they are exactly bit-for-bit identical. They are not the four different tracks that we recorded, but rather four identical tracks.

What am I doing wrong?

How do I export the four individual audio tracks?

[Anders Holck]

- Video and audio is stored in the .R3D file only.
- All the quicktime files reference the data inside the .R3D file.
- The quicktimes are identical but each one triggers a different video decode quality inside the RED quicktime codec.
- the_F file doesnt show the video as this quality trigger is not implemented yet in the codec. 16:9 4k doesnt work yet either.

[jbeale]

Possibly you need FCP to export more than one audio track? I'm guessing the quicktime player by itself does not recognize or extract four separate audio channels.

[Dj Joofa]

How do I export the four individual audio tracks?

I think the Open Source program Audacity may be able to read Quicktime files. I am not fully sure about it. Still, Audacity is a wonderful free program to have for audio manipulation.

[Steve Sherrick]

Possibly you need FCP to export more than one audio track? I'm guessing the quicktime player by itself does not recognize or extract four separate audio channels.

Quicktime can contain 24 audio tracks.

[Len M.]

I think the Open Source program Audacity may be able to read Quicktime files. I am not fully sure about it.

Audacity can read AIFF and WAV files, but not MOV files.

[Len M.]

- Video and audio is stored in the .R3D file only.
- All the quicktime files reference the data inside the .R3D file.
- The quicktimes are identical but each one triggers a different video decode quality inside the RED quicktime codec.
- the_F file doesnt show the video as this quality trigger is not implemented yet in the codec. 16:9 4k doesnt work yet either.

Thanks for this information.

Using QT 7.3.1 on a Windows XP PC, video does not display for any of the four MOV files. When loading the _H, _M and _P files, QT says that a component may be missing and directs me to a QT Web page with a list of plug-ins, but it's not clear which plug-in is required.

In any case, I still don't understand how to extract the four audio tracks. Is Final Cut Pro necessary? Do I need to use RED ALERT! or REDCINE?

I've downloaded the RED QuickTime plugin, but it's not clear how to install it (or even if it can be installed) for QuickTime for Windows.

[Dj Joofa]

Audacity can read AIFF and WAV files, but not MOV files.

Okay, then please use the free program MPEG Stream Clip. Please get the version 1.9 (which I think is currently the latest). MPEG Stream Clip is a very powerful program, not just for audio extraction, but for video extraction, transcoding etc., and in many cases makes the pro version of Quicktime unnecessary, though it is based off Quicktime libraries supplied by Apple.

[Len M.]

Okay, then please use the free program MPEG Stream Clip. Please get the version 1.9 (which I think is currently the latest).

Thanks for the suggestion.

Playback using MPEG Streamclip is garbled; it only allows extraction of a mono or stereo audio file; and it doesn't export to WAV format, only AIFF and a few compressed formats.

It doesn't play back the video at all.

It appears that this application won't do the job.

[Anders Holck]

Thanks for this information.
I've downloaded the RED QuickTime plugin, but it's not clear how to install it (or even if it can be installed) for QuickTime for Windows.

The quicktime codec is currently Mac OS X only so you cant see the video on Windows.

In quicktime pro you should be able to press Ctrl+J, select the sound tracks one by one and use the "extract" button to get them out then use export to get them into Aiff/wave format.
Havent seen an actual multitrack file yet, but they might be configured as two stereo tracks in the quicktime.

[Len M.]

I've made a little progress. I've found that REDCINE (1.0 Beta) will render the shot to a QuickTime movie, and now I can see the video. However, the new MOV file doesn't have an audio track.

I suppose that once I figure out how to get an audio track on the rendered MOV file, I can extract the audio with QuickTime Pro's Export function.

Now to figure out how to get an audio track on that MOV file.

(REDCINE for Windows XP Beta is pretty buggy in that screen re-draws don't always happen, and the control buttons and data displays disappear. You end up moving the cursor around and clicking the mouse at the left side of the screen, hoping to land on one of the four mode buttons (Project, Shot, Color, Output). If you do, then most of the screen re-draws.)

[Anders Holck]

REDCINE doesnt support audio yet so that path is currently a no go.
Did you try and use ctrl+j in your quicktime player on one of the proxi quicktime files to inspect the channels "embedded" in them?

[Len M.]

REDCINE doesnt support audio yet so that path is currently a no go.
Did you try and use ctrl+j in your quicktime player on one of the proxi quicktime files to inspect the channels "embedded" in them?

Thanks for the help, Anders.

Ctl-J shows that the proxi QT file has four tracks of 48 KHz (yes!), and I can assign the four tracks into playback channels (e.g., L, R, center...).

When I play back the proxi file, as I change the playback channel assigments, I can hear the change in the stereo playback image. All four channels are being mixed somewhere into the two fronts -- I'm not getting any sound in the side and rear channels, just the front two.

Also, QT Pro only allows export to mono or stereo WAV files, not multi-channel WAV_Extended format files. So I'll have to write the files either individually or in pairs.

So here's a possible solution:

Use QT Pro to "Export" the "Sound to WAV". Select which audio tracks are in the two front channels. First write a stereo file with tracks 1 and 2 in them with tracks 3 and 4 set to "unused", and then do it again for tracks 3 and 4 with tracks 1 and 2 set to "unused".

Sure enough -- I just tried it and it works!

I've just been able to decode the first ambisonic recording made with a RED camera and a TetraMic. I'll upload it to our Web site and post a link to it on the TetraMic thread.

[Anders Holck]

What I ment was that you could just use the extract function of the properties window: Select one track and click the extract button in the upper left of the window, then export to a mono wav. Then repeat for each track. That way you dont need to mess with the channel mixing, and you get the discreet mono files that you want

[Len M.]

What I ment was that you could just use the extract function of the properties window: Select one track and click the extract button in the upper left of the window, then export to a mono wav. Then repeat for each track. That way you dont need to mess with the channel mixing, and you get the discreet mono files that you want

I don't see how to select only one track of the four without using the track assignments to set three of them to "unused". If I have to do that, I may as well write two stereo files instead of four mono files.

Thanks much for your help!

[Anders Holck]

If the Quicktime has a single track with four channels, you are correct that you need to assign the channels.

If it has four tracks each with a single channel, you can use the extract feature to get them out like so: http://www.holckowen.com/extract.mov

I havent seen a multichannel RED proxi myself so I dont know how the channels are assigned.

Nice demo by the way :-)

[Len M.]

If the Quicktime has a single track with four channels, you are correct that you need to assign the channels.


RED seems to store its audio as a single sound track with four channels.


Nice demo by the way :-)

Thanks!

[David Wilson]

Len,

Very happy to hear you were able to extract the 4 channels from the Red Quicktime - promising combination, Red and Ambisonics! Hope to be following in your footsteps shortly. Thank you for pitching-in to make this work Anders.

[David Battistella]

Anders,

This is awesome.

Now all we need is a script that will look at each QT to the batch extracting and name the file with the original r3d files. Mabe an applescript can be written to do this?

This is the kind of functionality I was alluding to with the other thread.

Thanks for your work. It's really great that you have been so generous here so often.

David