avi with 16 bit AND 12 bit audio

[weshuang]

I have a bizarre problem that is entirely of my own doing (coming from screwing around with options without reading the owner's manual).

I had a tape that consists of footage with two types of audio track, the first portion in 16 bit audio, the remainder in 12 bit. Unfortunately, I loaded the entire thing at once into my computer, and don't have the original anymore.

When I try to do any splicing of the avi file, or any encoding for DVD, the 12 bit portion gets completely screwed up. I assume that's because the software is expecting the audio to be in 16 bit the whole way through, and the change is messing it up.

Is there a way to take the portion in 12 bit and change it to 16 bit?

[troyvcd1]

I think that your problem may be more related to 16 bit being 48kbit and 12 bit being 32kbit. You can capture the 12 bit at 32k, split the audio from video, resample the audio to 48k and recombine them.

[troyvcd1]

Oh sorry you already go it captured. I dont really know what you should do then. Maybe you could try to just separate and resample your audio and see if that works.

[weshuang]

Oh sorry you already go it captured. I dont really know what you should do then. Maybe you could try to just separate and resample your audio and see if that works.

OK, thanks for responding. Any suggestions as to software that I can use to resample the audio?

[proxyx99]

check your other thread

this is a double post!!!

https://www.videohelp.com/forum/viewtopic.php?t=216645

[weshuang]

I think that your problem may be more related to 16 bit being 48kbit and 12 bit being 32kbit. You can capture the 12 bit at 32k, split the audio from video, resample the audio to 48k and recombine them.

I think you just helped me figure something out. I didn't realize that 16 bit =48khz and 12 bit =32khz. I think now I may have what I need to screw around with the audio settings and export pieces of wav files that work. Late night ahead of me to see....

Thanks!

[weshuang]

check your other thread

this is a double post!!!

https://www.videohelp.com/forum/viewtopic.php?t=216645

It is a double post, I was worried that since it had become clear it was an audio problem, that I wasn't in the right forum any longer. Hope I didn't vioate forum policy...

[proxyx99]

You almost did. Keep one thread alive and you'll be fine

[daamon]

It is a double post, I was worried that since it had become clear it was an audio problem, that I wasn't in the right forum any longer. Hope I didn't vioate forum policy...

You almost did. Keep one thread alive and you'll be fine

Even better still, you could put a link in one thread to the second thread and ask the moderators to close the first one by posting in the "Please report problem posts / threads / members here!" thread in the "Feedback" forum, or by clicking on the "Report this post" link in the bottom right of each person's post. Nice 'n' tidy then...

Anyway, to your problem...

Any suggestions as to software that I can use to resample the audio?

VirtualDub - it's free and does the job on WAV files. You can also use it for basic video editing (cutting, joining etc. of AVIs).

Here's an idea that I think may work:

1. Capture the bit of the tape that you know has 16-bit / 48KHz audio. Use VirtualDub to trim off bits that you don't want (i.e. if you capture some of the 12-bit audio).

2. Capture the bit of the tape that you know has 12-bit / 32KHz audio. Use VirtualDub to trim off bits that you don't want (i.e. if you capture some of the 16-bit audio).

3. Then use VirtualDub to extract the 12-bit 32KHz audio to 16-bit 48KHz. There are options (can't recall the exact menu selections) under the "Audio" menu where you can set it to 48,000 Hz. You also need to set it to "Full Processing Mode".

4. In VirtualDub, File -> Save WAV will save the audio to a WAV file in "Full Processing Mode" (i.e. not "Direct Stream Copy" - a direct copy with no processing), and hence picking up the 48,000Hz setting.

5. Mux (short for "multiplex", or "join") the new WAV with the original AVI. I'm not sure if VirtualDub can do this (anyone?), or what other tools can. Check out "Audio Editors" in the "Tools" section if no-one suggests anything.

6. Join your good AVI and your was-bad-now-good AVI in VirtualDub.

7. Cross your fingers...

Hope that helps. Good luck...

[weshuang]

Daamon, thanks for the detailed response!

I need to learn yet another piece of software like I need a hole in the head, but I may have no choice...

I will give it a shot, thanks!

[daamon]

No problem - I can't guarantee it will work, but I think the logic's sound.

VirtualDub is a pretty intuitive tool, so it's not as daunting as the steps I describe would suggest.

On reflection, I think VirtualDub can do what I describe in step 5 - I'll have a look tonight and post back either how to do it or "No, it can't".

Catch ya later...

[daamon]

Hi weshuang,

Step 3 revised: "Audio" -> "Full Processing Mode". This will activate the "Compression" option under "Audio". When selecting "Compression", you'll see that you can set the "Sampling Rate" to 48000Hz. There's no need to extract the audio, as I had said originally. Only adjust the sampling rate.

Step 5 revised: As it's DV AVI, you'll need to save using a DV compression codec, otherwise VirtualDub will save to uncompressed AVI (much bigger file size, no benefit). Use the codec that's already installed on your system - you can tell by using AVICodec on your AVI file.

Note - You can use the "Panasonic DV Codec" that's free and works well. But beware of very minor framerate differences (like 24.99969 vs 24.99963) when joining. Best thing is to capture and then re-save your amended AVIs using the same codec.

Then, "Video" -> "Full Processing Mode". This will activate the "Compression" option under "Video". When selecting "Compression", you'll see that you can set the compression to use the "INSERT YOUR DV CODEC NAME HERE" codec identified by AVICodec.

Then, "File" -> "Save as AVI..." will pick up your audio and video settings and give you a spangly new DV AVI file. A good check is to see that the file sizes are identical, or very close. (If the latter, you may get framerate differences when trying to join them).

Step 6 additional: Check out this guide for joining AVI's:

https://www.videohelp.com/guides.php?guideid=374#374

Don't forget to rate it when you're done...

Good luck.

[weshuang]

Daamon, what can I say? You are a scholar and a gentleman...

Looks like another late night for me!

Thanks again,
Wes

[daamon]

Hi Wes,

No problem. Like I say, I think the logic's sound but I'd recommend trying out the whole process on a few short clips first to tease out any problems.

I'm concerned: I've tried the guide I referred you to and don't get two AVI's joining together. Other guides say pretty much the same, just in a slightly different order - shouldn't make a difference.

I'm gonna look into it...

EDIT: Hmmm... Weird. I've currently got v1.5.6 of VirtualDub installed and followed several guides - no luck. I've downloaded v1.5.10 and all's OK. I'm wondering if it was my install rather than a bug in v1.5.6 - I'd be surprised that something so simple was faulty in a well established app.

P.S. The only thing the guide's missing is to do a "File" -> "Save as AVI..." when you're done appending.