Hello, 

I'm trying to export a project from my Timeline and I keep getting this message

"The selected item contains MP2 audio, which cannot be exported.  In order for the item to be exported the audio needs to be relinked to an uncompressed audio format.

I've never come across this before and would really appreciate some guidance.

Thanks in advance,

John

Do a mix down in the time line view and export that file 

Thanks Tom,

Sorry for the delayed response but my system has been down.  I just tried doing a mixdown and I got this message.

'An Audio Mixdown cannot be performed because the selected tracks contain MP2 audio.'

Is there another way?

 

John:

Is there another way?

My suggestion would be to duplicate your timeline into a new bin.
From the bin hamburger menu choose "Set Bin Display" 
Check the option to "Show Media relatives"
Then from the hamburger menu select "Choose Columns"
Then add "Audio Format"
From this bin display you should be able to identify any MP2 audio files that are used in your sequence.

Do a full Import of those files selecting MXF for your media option. Replace the MP2 files with the new imports.
Assuming the MP2 files in the timeline were Linked in the first place the In time for the clip in the timeline should be within a couple of frames of the In time needed for the new import clip.

All of this has  done in a duplicate sequence so you will not be messing with your existing timeline.
When you are happy with the edit in the duplicate timeline you should be able to export from there. 

FWIW I would turn off the "Show media relatives" as soon as I had imported the new MXF audio.  

Thanks Andrew.  However, I don't see that option in Bin Display.  The closest thing I see is 'Show reference clips.'

John:

'Show reference clips.'

That is the one

This is what I'm seeing.

I would import all the H264 files and the AVC long GOP file to a DNx resolution of your choice.

Try testing by making a new timeline, with 10 seconds or so of an existing linked clip, and export that.  (It should fail with your error message.)
Import that clip to DNx resolution and repeat the export test. (It should now work)
Assuming it does import the rest of those clips.

Warning these imports will take up a large amount of media disk space compared to the original H264 files.

Okay.  I imported all of the H264 files to DNxHD 100 exported a test from the timeline and it worked just fine.  However, I still have the H.264 files in the bin and they are linked to the sequence I'm trying to import.  Do I have that right?  I should now get rid of those?  And link the sequence to the new clips?

Thanks.

John:

I should now get rid of those?  And link the sequence to the new clips?

My suggestion would be to duplicate the Sequence linked to H264 into a new bin and rename the duplicate sequence.

In the bin with the linked H264 clips in add a clip colour to just those H264 clips.  (or in Clip colour (see below) select Linked clips)
In the bin with your new clips in it add a different clip colour to these new clips.
Open the renamed duplicate sequence.
From the timeline hamburger menu choose Clip Colour then check "Source"
In the Record Timecode window (above the record monitor) click on the doen arrow far left Choose "Source" Then the A or V track your linked clip in on, then on TC1.

Mark IO around the first linked clip. Use Q key to go to Mark In.   ust set up.
Load the new DNxHD clip with the same name as the linked clip you are working with into the Source monitor.
With the Source monitor selected type in the Source TC  from the Timecode window above the Record window you just setup.
This should bring up the same frame as the Mark in in your timeline.
Set up new Audio and video tracks as required to edit this source to new tracks in your timeline. 
Patch you source Audio (and Video?) to the new tracks and edit the new media into your timeline. Make sure no other timeline tracks are active.
This action SHOULD NOT overwrite any media in the timeline.
You can now easily check the sync accuracy of the new media to the existing Linked media. Video by changing monitoring between the linked and DNxHD video tracks.
If the replacement is audio only you can check sync after editing in the new DNxHD track by playing it back whilst monitoring both Linked and DNx. Out of sync will  be revealed with an echo effect.

Repeat until you have new media matching each of the existing linked clips.
Open a new timeline with appropriate numbers of Audio and Video tracks.
Drag the timeline you have just finished into the Source monitor.
Patch the source tracks with DNxHD clips on them to the new timeline tracks.
Mark In at the start of the Source timeline and Out at the end of its timeline. Mark In at the start of the new record timeline.
Edit the source into the record timeline.
You should have a new accurate master timeline with all the clips coloured with you DNxHD source clip colour.

Using the above method you can also check by Loading your original timeline into the Source monitor and setting the Ttimeline Position Indicator (blue line) at the start.   With your new master in the Record monitor move the TPI  to the start.
Use the GANG button below the Record monitor to lock the Source and Record timelines together (when they are stationary) Play the record timeline then pause and the source will jump to the same frame.