Subject:latency with cut list, SF8b
Posted by: johi
Date:11/10/2005 6:31:35 AM
Hello Forum, - using the "Play as Cutlist" generates a latency (pause) before the playback starts. The play cursor moves but for ~0.5s no sound is output. With the Play Normal Button the sounds starts immediately. - at the beginning of the file it works without the pause but deteriorates to the middle and end of the file - changing the playback buffer seems to have an influence however I couldn't find a setting where this is fixed. - I'm using large voice files of ~45min/~200MB This behaviour is seen on different machines running XP&W2k. I'd appreciate any help since without the fix SF is pretty useless for us. Thanks and regards, Jochen |
Subject:RE: latency with cut list, SF8b
Reply by: ForumAdmin
Date:11/10/2005 7:24:53 AM
Please fill in your system specs. What sound card and driver model? Does changing the driver model make any difference? J. |
Subject:RE: latency with cut list, SF8b
Reply by: johi
Date:11/11/2005 2:43:20 AM
Sorry, forgot to fill in the specs - done. No effect observed when I change the driver. The problem occurs on different machines with different hardware. Since there is no latency with the Play Normal button I assume that it's not a driver problem. An older SF version (v5) didn't show this effect and ran on the same machine. Thanks, Johi |
Subject:RE: latency with cut list, SF8b
Reply by: ForumAdmin
Date:11/14/2005 6:43:46 AM
Does anything show in the meters when this occurs? Are you using a compressed format? If so, I expect this is the source of the problem. Certain compressed formats are not very good at random seeking (which obviously occurs during cutlist playback). For certain formats, the problem could get progressively worse as Sound Forge attempts to seek further into the file. Older versions of Sound Forge (like 5.0) would always create an uncompressed proxy of the file to get around this type of issue. You can force this behavior in Sound Forge 8.0 by navigating to Options->Preferences->General and enabling the checkbox labeled "Always proxy compressed formats." Alternatively, you can just save a working copy of the file as an uncompressed .wav and recompress to .mp3 or whatever you are using when you are done editing. J. Message last edited on11/14/2005 6:59:14 AM byForumAdmin. |
Subject:RE: latency with cut list, SF8b
Reply by: johi
Date:11/15/2005 8:19:43 AM
Hello J, Thanks for all the hints! - the playmeters show nothing during the latency, only the cursor moves - we're using uncompressed PCM wav files However, I guess I found a clue. It seems to depend on the number of entries in the cutlist. If you have ~60 regions defined, you treat the playlist as cutlist, and click the "play as cutlist" button you'll get a latency of ~0.5s. With ~400 regions it's already <2s. It's hard to work around this limitation. Do you have further hints? Thx, Jo.- |
Subject:RE: latency with cut list, SF8b
Reply by: ForumAdmin
Date:11/15/2005 9:57:14 AM
Ah, yes, I see it now. This is definitely triggered by the (relatively) large number of cutlist regions and the position you start playback from. I will enter this as a bug in our database. The safest workaround is to simple reduce the number of regions the playback engine sees. You can do this by breaking the file into smaller sections while you are working on it or by simply using selection to limit the playback range. If that is not suitable for your task/material, another option is to adjust the default buffer settings. If your device offers an ASIO driver, enabling that with a relatively short latency should improve things. If you are using MS Sound Mapper or Wave Classic, you can go to the Advanced page and experiment by increasing the number of buffers, reducing the buffer size, or some combination of both. With these adjustments, I still get a short hiccup on my system once I'm well into hundreds of regions, but it's much better than the lengthy latency you are reporting. J. Message last edited on11/15/2005 10:02:01 AM byForumAdmin. |
Subject:RE: latency with cut list, SF8b
Reply by: johi
Date:11/16/2005 12:48:23 AM
Thx - glad we could reproduce it. I'll wait for the fix... |