Sony time stretch not stretching accurately -Sound Forge - PC

Subject:Sony time stretch not stretching accurately Posted by: Doug_Marshall Date:8/24/2005 8:31:19 AM I've got an issue that has come up with Sony Time Stretch. I'm working on a project where I'm doing MIDI note and timing recognition largely by hand. From an original wave file I've produced two slowed down files as work files. One file is pitch shifted so it plays at half speed. The other is time stretched (200%) to play at half speed while maintaining pitch. Each file is useful for hearing different details in the music, but the length of the time stretched file is off by a small amount, enough to make it useless for A-B purposes. The Sony Time Stretch dialog box says the final output file will be 00:06:12.262 long (which is what I want), but the ACTUAL output file is 00:06:12.037. Obviously, the math is funky somewhere. I realize that my particular application may be a little stringent on timing requirements, but isn't it reasonable to expect the output to match the length indicated in the dialog? Any thoughts on how I might resolve this? Thanks. Doug
Subject:RE: Sony time stretch not stretching accurately Reply by: Iacobus Date:8/30/2005 11:37:39 AM So I take it the original file was 00:03:06.131 long? Just for giggles, I tried this myself using the exact same length and percentage you had. I got different results depending on the "Mode" option (available at the top in the Time Stretch dialog). Using the "A01. Music 1" setting, for example, gave me an actual output of 00:06:12.205. Try the "A17. Drums, unpitched" mode. That seemed to give the most accurate (exact in my case) calculation. Iacobus ------- RodelWorks - Original Music for the Unafraid Buy Instant ACID by JohnnyRoy and mD! mD at ACIDplanet

Subject:Sony time stretch not stretching accurately

Date:8/24/2005 8:31:19 AM

I've got an issue that has come up with Sony Time Stretch. I'm working on a project where I'm doing MIDI note and timing recognition largely by hand. From an original wave file I've produced two slowed down files as work files. One file is pitch shifted so it plays at half speed. The other is time stretched (200%) to play at half speed while maintaining pitch. Each file is useful for hearing different details in the music, but the length of the time stretched file is off by a small amount, enough to make it useless for A-B purposes.

The Sony Time Stretch dialog box says the final output file will be 00:06:12.262 long (which is what I want), but the ACTUAL output file is 00:06:12.037. Obviously, the math is funky somewhere.

I realize that my particular application may be a little stringent on timing requirements, but isn't it reasonable to expect the output to match the length indicated in the dialog? Any thoughts on how I might resolve this? Thanks.

Doug

Subject:RE: Sony time stretch not stretching accurately

Reply by: Iacobus

Date:8/30/2005 11:37:39 AM

So I take it the original file was 00:03:06.131 long?

Just for giggles, I tried this myself using the exact same length and percentage you had. I got different results depending on the "Mode" option (available at the top in the Time Stretch dialog).

Using the "A01. Music 1" setting, for example, gave me an actual output of 00:06:12.205.

Try the "A17. Drums, unpitched" mode. That seemed to give the most accurate (exact in my case) calculation.

Iacobus
-------
RodelWorks - Original Music for the Unafraid
Buy Instant ACID by JohnnyRoy and mD!
mD at ACIDplanet