Topic: SafetyTrackMerger (Windows + MacOS)

[joeldotc]

I do notice a strange jump in the delta between left channel main and safety track around the 124th minute! Before that, the left channel delta between main and safety was ~10.33dB, after that it suddenly became ~11.57dB. Remarkable! Fortunately the program very gradually follows the changes in delta, so it won't be bothered by such a jump.

Interesting! That is probably exactly where a track split was made by the recorder since it reached its 2 GB max file at around the 2h4m mark! I wonder why it would produce that difference though!

Makes sense that the combining only occurred in the first part of the recording, because I adjusted my levels after the first song since I noticed it was clipping and wasn’t sure how the program would do.

I’ll probably keep my levels high and let clipping happen in the future since this software you’ve made seems to work marvellously!

[TheJez]

I do notice a strange jump in the delta between left channel main and safety track around the 124th minute! Before that, the left channel delta between main and safety was ~10.33dB, after that it suddenly became ~11.57dB. Remarkable! Fortunately the program very gradually follows the changes in delta, so it won't be bothered by such a jump.

Interesting! That is probably exactly where a track split was made by the recorder since it reached its 2 GB max file at around the 2h4m mark! I wonder why it would produce that difference though!

Makes sense that the combining only occurred in the first part of the recording, because I adjusted my levels after the first song since I noticed it was clipping and wasn’t sure how the program would do.

I’ll probably keep my levels high and let clipping happen in the future since this software you’ve made seems to work marvellously!

Hi Joel, indeed remarkable that it's at the track split. I see no reason for the recorder to fiddle with the gain when splitting the track. It's especially remarkable that it's only on one channel!
It's a Roland R07 recording, right? Maybe, if you have the time and ability, you could load the first part and the second part into a DAW and do some amplitude statistics just before and just after the split to see if that confirms a difference. I cannot say if the safety track got less loud or if the main track got louder, as the program only calculates (and the compensates for) the difference in dB.
Thanks a bunch!

[joeldotc]

Maybe, if you have the time and ability, you could load the first part and the second part into a DAW and do some amplitude statistics just before and just after the split to see if that confirms a difference. I cannot say if the safety track got less loud or if the main track got louder, as the program only calculates (and the compensates for) the difference in dB.
Thanks a bunch!

Finally got around to this! I've attached two screenshots here:

- one showing amplitude stats for the entire files of all four recordings
- one showing amplitude stats for 15 seconds before/after the track split for each recording, respectively

It looks like the 11.58 dB difference is constant, so I wonder why the program isnt showing that 

I was thinking maybe I merged my two files incorrectly before putting the full thing through your software, but I don't notice any weirdness in the merged track around the 2h4m mark, so no clue what it could be!

Let me know if you have any questions at all. I can also send you the raw files if you'd like to experiment with them yourself

[TheJez]

Finally got around to this! I've attached two screenshots here:
Let me know if you have any questions at all. I can also send you the raw files if you'd like to experiment with them yourself

Hi Joel, thanks for the screenshots. I've had a very busy week, so it took a little while to have a look. It's hard to draw any conclusions from the screenshots. My program doesn't really care about the amplitude values of the tracks themselves, it only cares about the difference between the two and tries to avoid clipping parts to pollute the delta determination. I'd really like to take you up on your offer to provide the raw files. It would be very interesting to try to find out what's happening here... Please PM on how I can obtain them... Thanks a bunch!

[TheJez]

Finally got around to this! I've attached two screenshots here:
Let me know if you have any questions at all. I can also send you the raw files if you'd like to experiment with them yourself

Hi Joel, thanks for the screenshots. I've had a very busy week, so it took a little while to have a look. It's hard to draw any conclusions from the screenshots. My program doesn't really care about the amplitude values of the tracks themselves, it only cares about the difference between the two and tries to avoid clipping parts to pollute the delta determination. I'd really like to take you up on your offer to provide the raw files. It would be very interesting to try to find out what's happening here... Please PM on how I can obtain them... Thanks a bunch!

FYI: Joeldotc very kindly provided the original raw files straight from the recorder. I did some testing on these and was not able to reproduce the issue. Hence our combined conclusion was that probably some unintentional processing was done on the files before they were being fed to the SafetyTrackMerger program, causing a small amplitude change on one of the channels in one of the input files.
Hence a warning is given: The main and safety wav files shall not be processed in any way before feeding them to the program! Only in case the recording was split over multiple files (e.g. due to 2GB splits), please merge the parts together so there is just one main file and one safety file, and then feed these to the program.
Cheers!

[TheJez]

Also I see some error in the position reporting in the log file, when converting sample position to timestamp in hh:mm:ss.zzzzzz:

00:29:45.277666       85693328      Left Fade Out Safety                         
00:52:4338.42959244294968283      151871539       Left Fade In Safety                         
00:52:4338.42959274294967950      151871667      Left Fade Out Safety

I think this will be a logging-issue only and won't affect the inner workings or output of the program...

The issue with incorrect timestamps in the log file has been resolved in version 1.0.1 of the Windows-version of the program. It was an integer overflow issue when converting sample number to hh:mm:ss.zzzzzz. To upgrade, just replace the executable with the one attached to this post. As this is a fix of a cosmetic issue only, I'm not planning to create a MacOS executable of 1.0.1...