Audacity Forum

billw58 wrote:Try this exact sequence of steps.
New Audacity project
Import two MP3 files that should flow together
Delete the gap
Save the project
Exit Audacity
Start Audacity and open the project.

Is the gap back, or is it still gone?
-- Bill

Hi Bill, bear with me as I'm kind of new at this, I'm not sure I'm clear on your "deleting the gap" comment. I take it to mean, import, use the time shift tool to line up the second file right at the point the first ends, listen to an area near the end of the first and beginning of the second, delete any gap, then save, with the two files now becoming one. Correct?
If we're on the same page I am able to do that as I have done in the past. What I'm trying to get around doing is joing multiple files into one. I'd like to keep them as you usually see on a music cd - track 1, track 2, track 3 etc. As opposed to tying say the three tracks together into what would become track 1. If I want to listen to what was track 2 or get to the beginning of what was track 3 I'm kind of out of luck and have to do a lot of scanning.

DJO wrote:Moreover (and this goes out also to the senior forum member who previously answered my post) I swear I've done the same exact thing I'm trying to accomplish at least a couple of dozen times in the past and it worked... with the BETA version. I just can't figure out what changed and it's driving me crazy!

Both the current beta and the old 1.2 version can delete the silence from the beginning of an MP3.
If you then Export as a WAV file, (or OGG, FLAC, AIFF) or if you keep the audio as part of an Audacity Project, there is no problem.
I would guess that in the past you exported WAV files.

If you look closely at the start of any MP3 file you will find that they ALL (without exception) have a bit of silence at the beginning.
"Syntrillium" (the company that developed "Cool Edit Pro" - which later became "Adobe Audition") developed a variation of the MP3 format called "CEL" files (Cool Edit Loop format). The main difference between a .CEL file and an MP3 file is that the file format was slightly changed so that they could be decoded without any leading or trailing silence. As far as I'm aware, Cool Edit Pro and Adobe Audition are the only programs that claim to support the CEL format.

It's a shame that the OGG format is not used more widely as the quality is at least as good as MP3 and it does not have this problem.

If you are intending to burn these files to CD, Export from Audacity in WAV format. Not only will that solve the problem of added silence, but it will avoid lowering the sound quality that will occur if you re-encode in a lossy format such as MP3.

steve wrote:

DJO wrote:Moreover (and this goes out also to the senior forum member who previously answered my post) I swear I've done the same exact thing I'm trying to accomplish at least a couple of dozen times in the past and it worked... with the BETA version. I just can't figure out what changed and it's driving me crazy!

Both the current beta and the old 1.2 version can delete the silence from the beginning of an MP3.
If you then Export as a WAV file, (or OGG, FLAC, AIFF) or if you keep the audio as part of an Audacity Project, there is no problem.
I would guess that in the past you exported WAV files.

If you look closely at the start of any MP3 file you will find that they ALL (without exception) have a bit of silence at the beginning.
"Syntrillium" (the company that developed "Cool Edit Pro" - which later became "Adobe Audition") developed a variation of the MP3 format called "CEL" files (Cool Edit Loop format). The main difference between a .CEL file and an MP3 file is that the file format was slightly changed so that they could be decoded without any leading or trailing silence. As far as I'm aware, Cool Edit Pro and Adobe Audition are the only programs that claim to support the CEL format.

It's a shame that the OGG format is not used more widely as the quality is at least as good as MP3 and it does not have this problem.

If you are intending to burn these files to CD, Export from Audacity in WAV format. Not only will that solve the problem of added silence, but it will avoid lowering the sound quality that will occur if you re-encode in a lossy format such as MP3.

Steve - thanks for taking the time to give me your insight. Unfortunately though I've always exported using mp3 and never WAV and again I swear it worked. I'm pulling straws here as I've done this with pretty much the same size deletes, but is there something maybe that the audio part has to be a minimum length before it will delete? Maybe the time frames I'm dealing with on this current batch of tracks is so miniscule anything under a certain value is considered as not being selected at all.... even though I can see through zooming in, the selection get deleted, then I review the new track length, see that it is now shorter, save it, but when I go back to listen I have the same issue and when I pull the newly created file back up, the size has not really changed along the same mathematical lines as the piece I just witnessed deleting. ??????

use the time shift tool to line up the second file right at the point the first ends, listen to an area near the end of the first and beginning of the second, delete any gap, then save, with the two files now becoming one. Correct?

No. What you're doing is "Export", not "Save". "Save" means save the Audacity project.

Here's what I do.
Import the MP3s
Line them all up on the same track. They are now separate clips on the same track.
Delete the silent gap between songs. You now have multiple clips on one track, and each clip is a complete song without the annoying silent bits. (See before and after images at bottom of this post)
Double-click on each clip, do Tracks > Add Label at Selection: type the name of the song in the label
Do File > Edit Metadata and enter the Artist Name and Album Title information, clearing all other fields.
Do Edit > Preferences, go to the Import/Export tab and uncheck "Show Metadata Editor prior to export step"
Do File > Export Multiple. The default settings should export a separate file named according to each label.

Now, as Steve has pointed out, if you export as MP3 gaps will appear again. You can prove this to yourself by first exporting WAVs then exporting again as MP3s. Import a WAV and MP3 of the same song into a new Audacity project and compare them - the exported MP3 will have silents gaps at the beginning and end as shown below.
Also as Steve points out, if you are burning to CD, export as WAV. If you are importing into iTunes, I still recommend exporting as WAV and importing the WAVs into iTunes then use iTunes to create the MP3s. Not that iTunes does a better job, but it does it faster. The in iTunes select all the MP3s you just created and make them a "gapless album". iTunes will set some internal pointers or some such so that it eliminates the silent bits and the performance will flow as you intend.

If you intend to burn a CD, the WAVs you exported can be used for that purpose. Just be sure to set the between track "pause" in your burning software to zero for all but the first track.

Examples of before and after deleting the silent gap with songs on the same track -- Bill

DJO wrote, in a private message:

billw58 wrote:

Here's what I do.
Import the MP3s
Line them all up on the same track......

Bill - just to verify the above about lining them up on the same track..... I have experience using the time shift tool, but if I understand correctly when you import a file with one already open, it sets it on what is considered a separate track below the original file you opened. If that is considered a separate track would I just select the entire second track, cut, move cursor to track end on the top track and then paste so they are now side by side?

DJO - please let's keep this on the forum. Other users and support persons may benefit from reading our discussion.

Yes, when you import a file it comes in on it's own track. Using the time shift tool you can drag a clip from one track to another, then use the yellow snap line to abut the clip right up against the last clip on the other track. Note that if the entire clip is selected Audacity will not allow you to drag the clip to another track - this is a known glitch in Audacity. Your method of using cut/paste will work as well.

Please see: http://manual.audacityteam.org/man/Auda ... Clips#move

-- Bill

billw58 wrote:

Here's what I do.
Import the MP3s
Line them all up on the same track. They are now separate clips on the same track.
Delete the silent gap between songs. You now have multiple clips on one track, and each clip is a complete song without the annoying silent bits. (See before and after images at bottom of this post)
Double-click on each clip, do Tracks > Add Label at Selection: type the name of the song in the label
Do File > Edit Metadata and enter the Artist Name and Album Title information, clearing all other fields.
Do Edit > Preferences, go to the Import/Export tab and uncheck "Show Metadata Editor prior to export step"
Do File > Export Multiple. The default settings should export a separate file named according to each label.
-- Bill

Hi Bill - your a genius!! I tried your method and I think I've found success. I followed your exact steps above, pulled tracks into itunes, converted to mp3 and so far so good.

Couple of quick questions to round this out.

1. In this instance I'm working with about 14 tracks totalling anywhere from 3-6minutes each. Is there any known limitations to how many tracks in number or size you can string together, edit, label and export multiple? Reason I ask, is after lining up fourteen clips in the top track, it seemed that around the fourth clip I noticed while playing back the audio to test an edit, I would get spots of no audio even while I could see the normal graph of audio, I would then move the cursor farther down the line and the audio would re-appear but at a greatly reduced speed. Is this a known issue with the software or do you think it's a hardware limitation of some sort? Also, does it matter that say clip #3 may be 44hz and clip #4 48hz? My work around was to work with three tracks at a time and at the end of the third just delete as much dead space as I can see and hope for the best (while doing the same with the beg. of the next batch of clips) - seems to work even when listening to the third song going into what would be the first song of the next batch or technically song #4.

2. Once I've completed the edit process, exported multiple, brought into itunes, converted to mp3's.... what if I decide I want to change the amplification of the song, eq etc..... if I go back in audacity and pull up the new mp3 file, make my changes and export as an mp3 do I risk going back to the same problem with having newly added blank space at the beginning or end of my tracks? I know it probably makes sense to decide what editing I want to do all at one time instead of going back and forth, but I do have some tracks that upon listening to I'd like to brighten up a little. What do you suggest, bring up the mp3, edit, export as wav, bring up in itunes and convert back to mp3?

Thank you very much for your help. I look forward to your answers on the above.

Dan

DJO wrote:...it seemed that around the fourth clip I noticed while playing back the audio to test an edit, I would get spots of no audio even while I could see the normal graph of audio .... Is this a known issue with the software or do you think it's a hardware limitation of some sort? Also, does it matter that say clip #3 may be 44hz and clip #4 48hz?

That is not right - there should not be any gaps in the audio. Why are the clips at different sample rates?
Try this next time. After you import all the MP3 into their separate tracks, for any that are not at 44100 Hz sample rate, convert them to that rate using the Track Drop Down Menu.
http://manual.audacityteam.org/man/Track_Drop-Down_Menu
Then drag them all onto the first track.

DJO wrote:Once I've completed the edit process, exported multiple, brought into itunes, converted to mp3's.... what if I decide I want to change the amplification of the song, eq etc..... if I go back in audacity and pull up the new mp3 file, make my changes and export as an mp3 do I risk going back to the same problem with having newly added blank space at the beginning or end of my tracks? I know it probably makes sense to decide what editing I want to do all at one time instead of going back and forth, but I do have some tracks that upon listening to I'd like to brighten up a little. What do you suggest, bring up the mp3, edit, export as wav, bring up in itunes and convert back to mp3?

Save the Audacity project. If you want to change something, such as EQ, open that project and make the changes there. Then select the songs you've changed one by one and do File > Export Selection.

-- Bill

billw58 wrote:
That is not right - there should not be any gaps in the audio. Why are the clips at different sample rates?
Try this next time. After you import all the MP3 into their separate tracks, for any that are not at 44100 Hz sample rate, convert them to that rate using the Track Drop Down Menu.
http://manual.audacityteam.org/man/Track_Drop-Down_Menu
Then drag them all onto the first track.

The reason they're at different rates is because when I started on this path, out of the 14 tracks I only had a handful that were not flowing smoothly, so I thought I could take your theory and just apply it to the tracks I felt were flawed, export as a wav etc. The files I exported as a wav for some reason (audacity default? or a default in the itunes mp3 convert?) saved at 44100 (the original tracks were 48000). After listening to my finished product (some orig. mp3's with some newly created wav files converted to mp3) I came to the conclusion that I still had an issue with silence gaps and decided I needed to use your theory on all tracks. When importing, I used the original 48000 tracks that I didn't mess with and imported the remaining ones that I had already "exported multiple" as wav's, thinking I had already done the correct edit's so I could make use of them.
I'll have to look to confirm, but I wonder if the issue appears going from a say 44 to 48 clip or vice versus. Like I said, I could still see the usual sound wave and the pointer was moving through the track - but no sound. Then I'd move the pointer up a little ways forward, hit play and get the exact opposite of alvin and the chipmunks! I do know that it happened on various different tracks, but then again it could've been the same scenario 44 to 48 or vice versa.

Your thoughts?

billw58 wrote:
Save the Audacity project. If you want to change something, such as EQ, open that project and make the changes there. Then select the songs you've changed one by one and do File > Export Selection.

-- Bill

When I Export, should I export as a wav file, import into itunes "convert to mp3" or is it safe to export as an mp3 right from audacity?

Going back to the gaps - does the gap always occur in the same place?

About iTunes and MP3 - like I said, I use iTunes to do the conversion simply because it is faster.

-- Bill