Subject:Why does sound forge create massive files from a small AVI!?

Posted by: secretsam007

Date:11/20/2004 2:42:29 AM

Ive recorded a day's worth of screen presentation + audio at 2pfs (using Camtasia Studio - a fab little product that Ive just just bought!) but Ive got a whole day's worth of poor audio recording in my AVI files (blame a poor radio mic) that I need to touch up - before turning into a flash presentation.

One hour was about 20-30Mb - which was a reasonable size with the products special low-bw video codec, and GSM 6.10.

I then did some editing on Sound Forge 7, produced an excellent audio-track, and went to save it (in the same format, 2fps video-using the same special video codec, audio: GSM 6.1, etc) and instead it becomes over 30Gb in size...!!!!
Any suggestions why such a massive growth in file-size!?
The strange thing is that the AVI is still understood my my application file - but the performance and storage problems with 30++Gb/hr files is truly terrible!

I tried the same thing with Vegas - but the rendering process seemed to mess up the file so that Camtasia lost all of its event markers (and going through 8 hours of video and adding in slide transitions isnt alot of fun!)

Yours - rapidly running out of disk space and patience!
Sam

Subject:RE: Why does sound forge create massive files from a small AVI!?

Reply by: Sonic

Date:11/20/2004 8:23:35 AM

Sounds like it is not really re-compressing. In many AVI cases, Sound Forge and Vegas should just leave the video stream alone, but that may be codec dependent.

One thing you might try is to save the custom avi template before saving the file. Otherwise, provide as much detail as possible on the codec and on how you save. Also, aside from the marker thing, was the file size correct in Vegas?

J.

Subject:RE: Why does sound forge create massive files from a small AVI!?

Reply by: secretsam007

Date:11/20/2004 4:05:48 PM

Vegas actually had a smaller file than the original strangely enough..!

I took your advice and it seemed to work fine with SoundForge!
I had to change absolutely everything, then save it as a template before it seemed to "keep" my settings...

Now Ive got a nicely touched up AVI file that I can use, with all of the same markers as before

many thanks - your a life-saver!

All the best!
Mark

Subject:RE: Why does sound forge create massive files from a small AVI!?

Reply by: mpd

Date:11/21/2004 2:24:49 PM

In Camtasia, save out the audio track as a WAV and edit the file in SF. When you are done with the edits, open the AVI in Camtasia Producer, mute out the AVII's audio track, and add in the edited one. Then produce the file as an AVI or SWF. I know Camtaia Producer can do all of this, but I forget the exact sequence.

Subject:RE: Why does sound forge create massive files from a small AVI!?

Reply by: secretsam007

Date:11/21/2004 4:30:12 PM

I found a much better way of doing this with Camtasia, but it took alot of experimentation, so I thought Id include it (as well as what _didnt_ work!).
I now understand the importance of work-flow!!!

WORKFLOW SHEET FOR TOUCHING UP SPEECH AUDIO IN A TYPICA VoD PRESENTATION WITH AUDIO MIC NOISE (or other redular noise) WITH CAMTASIA.

1. Cleaning up the audio quality
This took ALOT of trial and error to get right...
- Use SoundForge 7 (not Vegas, for reasons that will become obvious later)

Part A - Normalisation
Processes --> Normalise
Select Speech, but be sure to select "If clipping occurs: Normalise Peak Value to 0 dB" then OK.

Part B - Noise reduction

Select the required audio plug-in chainers
- Go to the audio chainer: View-->Plug in Chainer (or can be selected from the graphic)
Add in (in this order)
1. Noise reduction
2. Clipped peak restoration
3. Smooth/Enhance

Setting the Chainers
1. Noise reduction
* Find a suitable part of the presentation where there is no talking, so you can only hear the background noise, select this section
* Select Capture Noiseprint
* Play (the option in the Plug in Chainer
* Look at the fingerprint in the Noiseprint tab
* Press Play and experiment with the mode (typcicall 3) and the "Reduce Noise by" (typically 16-22) and "Noise Bias" settings (typically 1 to 6)
Check the documentation on this, which is very instructive.

2. Clipped peak restoration
- Go to the clipped peak option
- Attenuation: 1dB
- Enable post-limiter
- Crossfade edges

3. Smooth/Enhance
- Play with this for enhancing the sound quality.
Note: Deep voice dont seem to sound right with this, as they probably dont have much high-frequency in the first palce, best left off.
For higher voices this does restore some of the high frequencies.

Save: These settings can be saved for later use on that day's presentation - although best to check for each presentaiton.

Testing: As before, hit the preview button in the Plug-in-chainer, and you can turn the chainers on/off and adjust their properties.
Applying: Once happy Process the Selection.

Part C - Saving into the original AVI file - CRITICAL
- Save the AVI file, ensuring you use the same audio codec and more importantly Video Codec (these are NOT the defaults) - otherwise your file will be huge!

i.e.
---> Save as --> Custom --> Audio Tab --> GSM 6.10 11kHz 16 Bit Mono 4kb/s OR MP3 11kHz 20kbps OR PCM
--> Video Tab Custom Frame Size: (whatever it was captured in) 1024 x 768
Frame Rate: 2 (or whatever you used before)
Field Order: None
Pixel Aspect: 1.00
Video Format: Techsmiths Screen Capture Codec --> Configure: Better Compression
Interleave every: 1 seconds
Keyframe every: 300 frames
Note: Do NOT change the length/clip the AVI file at all, and save with Metadata - otherwise Camtasia will get VERYconfused later on...and you will have to manually do everything..

Part D- Opening in Camstasia
- Note: Save the AVI (above) with a new name, and then rename the old file.
- Open the the Camtasia project file
- Camtasia will then not find the AVI and prompt you for the new AVI name.

Part E - Clipping the Presentation
Clip the start and the end using Camtasia
Note : Do NOT use Soundforge, Vegas or any external utility to do this- see above, as Camtasia's project files are linked into time/frame markers inside the AVI file.

Part F - Adding call-outs at the start and end with the presenters name, etc
Adding in a callouts, etc

Part G - Produce the Flash media
--> Produce video as --> Macromedia Flash --> Next
Video: All automatic
Audio: MP3 11 KHz Mono 16 kbits/sec
Advanced: (All defaults) No pause at start, No Allow resizing, End Action: Stop
Options: (All defaults)
--> Next
Preset video size: 640x480
Stretch to fit: off
Disable callout fade effects: Off
Use instant pan and zoom: Off
--> Next
Include Watermark: If required
--> Next
Preset Video Sizes

APPENDIX - Other Methods tried for audio editing!
b) Blanking track-1 & adding a naration track into track-2
- Save in SoundForge as a suitable MP3 file (22kHz 16 Bit Mono)
- Remove Track-1: In castasia Adjust Audio -> Track-1 --> Select the entire presentation --> replace with silience
- Add naration: Play from soundforge while recording naration in Camtasia
-Summary: Difficult to get the start times synchronised, makes it impossible to later clip/edit/delete-slide from your presentation, as Camtasia uses an external MP3 file
(and has'nt thought to use index markers for editing the file, as they appear to do in AVI files)

c) Blanking track-1 & simply adding in a new sound-track
-Summary: While sychronising start times is no longer an issue, the same problems with later editing your file remain.

d) Editing the audio with Vegas and rendering...
Re-rendering seems to mess up Camtasia's marker-points in the file...
- Summary: Same problem as before

Conclusion: The only workable option if you want the flexability of later editing your file (and who doesnt!) is to use Soundforge and re-create a new AVI file, as Camtasia's ability to use MP3 files is very basic (at best).

I hope this helps others - as it took quite a few calls with Camtasia tech support, and some experimentation to get this procedure down pat!