Do you mean something to automatically split your files at 'silent'areas, to save disk space ?

Presumably this would need a threshold adjustment, to decide what parts are silent, a la noise gate ....

I guess this would need a custom track file format (existing) to accomodate the fragments in one seamless file, or it would end up with an incredible mess on your drive.

geoff


geoff

The functions in Logic and the 2480 are similar. The regions are sized by threshold, pre and post lengths.
This would be a great feature in Vegas. Once the silence was removed, the edited project could be saved as a trimmed one, thus saving disk space.
Thanks for the responses.
Regards,
Rich

If it's disk space you want to save (and who doesn't!) and you have the patience, this should work:

1) Right click on the audio on the timeline and choose 'Apply Non-Real Time Event FX'
2) Choose noise gate and add it to the FX chain
3) Set up the noise gate appropriately
4) Render the new take using the SoFo PCA audio format
5) Delete the original audio take

The PCA format uses lossless compression; the areas of silence effectively take up ZERO disk space. The sound quality will remain identical, but the file size will shrink alot. It will take a slight hit on CPU performance (playing back the compressed files), but I'm sure you know if this will cause problems on your system.

I always convert audio files to PCA before archiving them to CD-R - batch converter is v.useful for this.

Mike K

Are you sure the file shrinks? I thought that even if there was silence and you rendered a file, you still had silence (which took up disk space).
Trimming is a different function all together, it actually removes the silence, because the silence has been edited out (no regions) so the file shrinks.
Regards,
Rich

Trust me - the file size will be quite a bit smaller using the PCA format. Even files with no apparent areas of silence will benefit. I can't give a full and detailed description of how the PCA compression works, but:

Pretend that a section of silence is represented as 'AAAAAAAA'

Basically, uncompressed you would represent this as AAAAAAAA taking up 8 'blocks' of info, the same as the original file.
Compressed, you could instead say A8, taking up only 2 blocks of info.

The more complex sections of audio (FJIELSIHEOTDJJLSKE etc!) won't benifit from lossless compression so much, becase the the smallest way to store the above is 'FJIELSIHEOTDJJLSKE' - ie the same size.

This is why in the Render dialogue box the description of PCA says "The compression ratio of this lossless format depends on the audio source."

The WAV format doesn't use any form of file compression, so it will always represent AAAAAAAA as AAAAAAAA. A minute of silence will take up exactly the same amount of space as a minute of random noise.

10 minutes of silence in the PCA formate creates a file only 940Kb in size

I've just picked a song at random, 6:25 in length, 16bit stereo; rendered file sizes were as follows:
WAV = 64.9MB
PCA = 37.5MB

Mike K

The real worth in this feature is not disc-space savings...That's not the point. The real point is threshold-based, non-destructive editing in *automated* fashion!!!

I use this feature ALL THE TIME on my Neve AudioFile editor at work. SADiE has had this for years...It saves tons of time by automating a lot of manual edits in voiceover/vocals. With a default crossfade setting, a lot of edits are done at the end of the strip silence pass. Those that aren't are close and ready for a final tweak.

This should be an easy thing to implement and darn worth it!!!

Please SF...Take note.

It wouldn't save any disk space, as the split regions would still require the silence in their events to separate them. Unless the program removed the audio, respliced the regions with audio so that they sat next to each other in the actual file, but that would be wierd.

Neat...kind of like a JPEG file. As long as you could set the thresholds for that reduction to take place, and preserve everything else, it sounds like a good idea.

Yeah, I've been asking for this since Vegas 1. Great for long voice over sessions.

>Yeah, I've been asking for this since Vegas 1. Great for long voice over sessions.

Same here!

George Ware

...a SONG gets reduced in file size? Is there silence in the song?

If not, it's processing the material with audio, which is a definite NO-NO for my uses.

If you are refering to this from my earlier post:

"I've just picked a song at random, 6:25 in length, 16bit stereo; rendered file sizes were as follows:
WAV = 64.9MB
PCA = 37.5MB"

There may have been a couple of seconds of silence at the start and end of the file, but the rest was pure music. The compression is LOSSLESS. For obvious reasons it is more effective on ares of silence, but it will reduce the file size of any audio file you use it on. Covert a WAV to PCA and the PCA back to WAV. Compare the new WAV to the original - identical.

Magic, ain't it? Don't know how it's done.

If you could split and trim the areas of silence out of an event (based on threshhold and an time overlap) imagine what a mess these tracks would look like on reloading - spewing fragmented events all over the place !

Or can this be achieved while falsifying the displayed events as still being continuous ...?

geoff

The strip silence function can be used for cleaning up a region, and if you want, then removing the silenced materials (a new wave is made).Or not (non-destructive) and you can use the wave in a different program.
I've used this function in Logic and Saw Studio to clean up a mix. It really made the process quick and easy. With the state of Sonic Foundry, who knows if this will be implemented. I hope there is a Vegas 4.0, I really like working in Vegas (mostly editing).
Regards,
Rich

Oh, there's a Vegas 4 alright!

(taken from www.creativecow.net)

"V.A.S.S.T Day with Douglas Spotted Eagle: Tues. Feb. 18
Sonic Foundry and V.A.S.S.T. present an exclusive all-day training event focused on Sonic Foundry’s new version of its Professional Video, Audio and DVD Production Studio, Vegas+DVD 4.0. Join Grammy and Emmy winner and Cow host extraordinaire, Douglas Spotted Eagle, as he guides attendees through the powerful new features of Vegas 4.0, DVD Architect and Surround Encoding. Learn about audio editing and surround encoding, chromakeying and advanced compositing, primary and secondary color correction, advanced streaming tools plus insider tips and tricks for getting the most out of Vegas and how it seamlessly works with all of Sonic Foundry’s other award-winning software tools. "

Exciting, ain't it?

yeah now let those of us who need it use it

I suppose you think 192 KHz MP3 is "identical", but it ain't. Compression on audio is never lossless.

Before I thought you were talking about areas that fell below a certain threshold and thus were reduced to zero. Otherwise you're throwing out data.

No you're not. Trust me, I can hear MP3 compression. The PCA format is LOSSLESS as in when you convert it back to WAV, it is bit-for-bit identical to the original.

When a PCA file is played back it is 'decoded' in real time, producing an identical sonic output to playing the original WAV file. This results in a tiny CPU overhead.

Based on your argument that compression must lose data, I'm guess you've never used Winzip to archive data files for fear that your Word documents will come back with half the vowels missing or something.

To quote the manual:

"Perfect Clarity Audio is the Sonic Foundry Perfect Clarity Audio (PCA) format, a compressed format that is completely lossless. Unlike MP3 and other highly compressed formats which are lossy, 100% of the quality of your audio is maintained by using the PCA format."