AC3 file restoration

[canuckerfan]

Okay, I have this AC3 file which I'm considering restoring for a DVD. However, the file is huge, and when outputted to a WAVE file, it is 5 GB (out of the WAVE spec) and no program will take it for editing. So I'm guessing I need to split the AC3, encode both segments to WAV, process both WAVE files as needed, encode back to ac3 and join them back together. Would this method be good in my situation? I have tried some other methods, but they haven't works (ala ac3split), and I apologize if a similar situation of mine has already been posted.

PS: It's an AC3 5.1 channel stream. I would like to preserve all the streams if possible. And the main things I plan on doing during the process are reducing the gain on the rear surround channels and removing hiss.

[tebasuna51]

I recommend you WaveWizard (http://www.rarewares.org/wavewiz/wavewizardv0.54b.zip)

1) Open the 5 GB wav file and Menu Edit -> Preferences:
- Ignore size in header
- Stream Manipulation: Mono Streams
- Convert
Now you have 6 mono wav < 1 GB

2) Maybe you want edit in stereo FL-FR, SL-SR, ...
Open the FL, FR wav files and Menu Edit -> Preferences:
- Stream Manipulation: Merge files
- Convert

3) Edit the wav files

4) To ac3 encode you can use the old SoftEncode or others commercial encoders using mono wav's. If you want a free encoder you can use Aften (WaveWizard can generate a new wav 6 chan > 4 GB accepted by Aften)

[canuckerfan]

Sweet, sounds promising. I'll give it a shot. Thanks:)

Just one more question... I've heard Aften is a good free solution for encoding AC3, can commercial options compete?

One more question... when merging the 6 channels back together, does Wavewizard now how to map which channel where as long as the filenames are kept the same?

[canuckerfan]

Aften is not encoding the outputted wav file from WW. I separated the 6 channels, encoded 5 of them (left out the LFE channel), and merged them back together. However, I can't play the WAV file and naturally, Aften doesn't encode it (it just says encoding successful and the AC3 file has no size).

[tebasuna51]

Just one more question... I've heard Aften is a good free solution for encoding AC3, can commercial options compete?
Now Aften is the best free ac3 encoder but need some improvements before compare with commercial one's (Sony, SurCode, ...?)
One more question... when merging the 6 channels back together, does Wavewizard now how to map which channel where as long as the filenames are kept the same?
You need ADD the mono files in order FL, FR, C, LFE, SL, SR, if you have stereo wav's FL-FR, C-LFE, SL-SR, also work FL-FR, C, LFE, SL-SR.
Aften is not encoding the outputted wav file from WW. I separated the 6 channels, encoded 5 of them (left out the LFE channel), and merged them back together. However, I can't play the WAV file and naturally, Aften doesn't encode it
Maybe you want say "edited" instead "encoded"?

Please specify the wav editor used, kind of edition and size of wav file merged.

[canuckerfan]

I used Goldwave v5.14 to edit the individual mono streams. I then outputted them as mono streams (16bit, 48000 Hz [same as original]).

I was a little off with my estimation about the original AC3 file, it's actually 562 MB, which resulted in an uncompressed 6.59 WAV file. The merged WAV (post-editing) is that big as well. Any ideas? Sorry if I forgot to post more info...

PS: I am able to play the merged WAV with VLC, but MPC w/ffdshow won't play it.

EDIT: corrected for "The merged AC3 is that big as well." confusion. sorry.

[tebasuna51]

Please confirm the data:

You have a original ac3 5.1, 384 Kb/s, 562 MB, 3h 25m.
The decoded wav 6 chan is 6.59 GB
You have 6 edited mono wav's 16 int 48000 Hz, 1.1 GB.

Using WaveWizard with Preferences:
- Stream manipulation: Merge files
- Output format: Wave PCM
- Other options unchecked.
Adding the 6 mono wav's (order: FL,FR,C,LFE,SL,SR)
When you press Convert, do you obtain another 6.59 GB wav file?

Aften can convert this wav to ac3?
What is: "The merged AC3 is that big as well."?

A wav > 4GB have two fields in the header wrong, then some players don't work, but you don't need play the wav, you need play the ac3.

[canuckerfan]

Please confirm the data:

You have a original ac3 5.1, 384 Kb/s, 562 MB, 3h 25m.
The decoded wav 6 chan is 6.59 GB
You have 6 edited mono wav's 16 int 48000 Hz, 1.1 GB.

Using WaveWizard with Preferences:
- Stream manipulation: Merge files
- Output format: Wave PCM
- Other options unchecked.
Adding the 6 mono wav's (order: FL,FR,C,LFE,SL,SR)
When you press Convert, do you obtain another 6.59 GB wav file?

Aften can convert this wav to ac3?
What is: "The merged AC3 is that big as well."?

A wav > 4GB have two fields in the header wrong, then some players don't work, but you don't need play the wav, you need play the ac3.
That is all correct except I never edited the LFE channel, that's the only channel left untouched (shouldn't make a difference, should it?). And Aften can't encode the file.

[tebasuna51]

That is all correct except I never edited the LFE channel, that's the only channel left untouched (shouldn't make a difference, should it?). And Aften can't encode the file.
If LFE is also 16 bit 48000 Hz and same length, can't be a problem (WaveWizard can't merge the channels if have different samplerate or sample depth).

Then the problem is in Aften, maybe you have a bad version without support for wav > 4 GB. Try this aften (http://www.mytempdir.com/952189) version.

[canuckerfan]

the original untouched LFE channel is 16 bit, 48000 Hz as well, just like the rest of the streams. I'll try the version of Aften you attached later on. by the way, how is the sonic ac3 encoder packaged within scenarist?

[tebasuna51]

by the way, how is the sonic ac3 encoder packaged within scenarist?
Is a Dolby Digital certified product ..., I only test free encoders.