BUG Exporting LOF files

Audacity Help Forum Windows
1

Hello,
I am using the brilliant feature in Audacity that enables the import of an LOF List of Files with their offsets.

I have noticed 1 Bug and 1 Limitation.

Bug:
Exporting the LOF file to wav results in a file where the offset of the first wav in the LOF is ignored.
Instead of starting at the mentioned offset, the first wav is at zero time. The rest are fine in their relative positions.
This is only noticed after exporting the wave file. Upon opening the LOF file everything looks fine.

I have just found out that running this command (open LOF, export WAV) as a Chain, does not produce this error, which is a great workaround.
Normally, I am having to export the LOF as wav, then importing and manually adding the first offset and having to re-export.

Limitation:
My files consist of 2 second or 3 second clips at most and I am able to import only about 200 Files at a time.
Above this number, Audacity imports even upto 800 files, but upon attempting to export as Wav, throws an ‘out of memory’ error.
If this could be rectified, allowing the total number of files/tracks imported to have no limit, it would be great.
I can confirm that the length of the ‘stack’ is only about 2 hours. But the ‘out of memory error’ seems related to the number of files that are getting imported as separate tracks.

Currently I have to split my LOF files to contain only upto 200 clips. export each LOF to wav. then concatenate them again manually after adding the missing offset as mentioned above.

I would like to state again that this feature is a most brilliant one and allows audio to be manipulated and resynchronized in a simple manner.
Thanks in advance.

2

I’m finding your description hard to follow. LOF files are plain text, so the phrase “Exporting the LOF file to wav” does not make sense.
Perhaps you could give step by step instructions to reproduce the issue.

3

Sorry about the lack of clarity.

Windows 10. Audacity Version 2.2.2

LOF File

file 1 offset from zero
file 2 offset from zero

  1. Import LOF File into Audacity
    File 1 Visibly offset by offset amount
  2. File Export Wav
  3. File Import Wav
    File 1 starts at Zero time (first offset excluded in exported file)
    Other files within this wav are OK in their relative offset.

lof file
0 |--------offset1----------|file1 |------------|file2 |
0 |---------------offset 2--------------------|

exported wav file
0 |file1 |------------|file2 |

no silence offset before file 1

Hope this is clearer.

4

Yes, much clearer :slight_smile:

This is not a “bug”, because it does what it is intended to do, though in my opinion it is a poor design which I hope will be improved at some future time.
The problem is that export treats the start of the audio as the start of the file (leading silence is ignored).

Fortunately there are fairly easy workarounds. “Silence” (indicated by the blue waveform being a flat line) is “audio”.
By inserting some silence at the start of each track, export will treat the start of the silence as the start of the track.

--------|              |wwwwwww|
silence | empty space  | audio |

exports as:

-----------------------wwwwwww|

Alternatively, you can use “Tracks > Mix > Mix and Render” on each of the tracks (one at a time) to render the empty space as silence.