I have just discovered an issue with importing a large audio file in Myriad, Autotrack and AutoImporter.

One of our syndicated shows is provided as a 3 hour MP3. Normally it imports without an issue but this week it wouldn’t play. The audio would import without any errors but when you looked at the audio in the cart it was empty. At first I thought it might be a corrupted file so I opened it in Adobe Audition and it played fine. I then tried converting it to a WAV file but when I tried to imported it again I got the same issue.

After pulling my hair out I eventually discovered that the file had 20 minutes of silence on the end. I removed the silence and it then imported without an issue.
I have tried this in both v4.23 and v4.24 and get the same issue. If P Squared would like to see the file I would be happy to share it.

Gavin

 
Gavin Davis
HotHitsUK.com

Hi Gavin,

Was the only difference to the normal file that imports OK the 20mins of silence on the end?
How did you convert the file from mp3 to wav, was this inside Adobe Audition?
Did you see how large the final file was when you converted to wav (including the silence)? I'm wondering if the final up converted .wav is larger than the single file size Windows can handle (but Adobe does something clever?)


Regards

David Boulton
Brand Manager
Broadcast Radio Ltd

Hi,
From what I have worked out from other audio programs is that there is an issue with mp3 files with a duration longer then 3 hours and 22 minutes this is due to an mp3 encoder/decoder.

Anything up to that duration should be fine anything over then you have issue's in some programs but adobe audition and cool edit are fine not sure how.

Hope this helps?

Regards Oliver

Hi Oliver,
if you start Myriad recording (right click over a blank cart), you'll see that our free drive space indicator is also 3hours, 22mins and (off the top of my head 57 seconds), this is the most that we store into a single PCM .wav file (roughly 2gb file size). Historically this goes back to the maximum file size limits in the FAT16 and FAT32 formats of the earlier Hard Drives.

Therefore I suspect that the import of the previous mp3 file as described by Gavin would result in a larger than 2gb file, as we are reading and converting the data in as we go thru the file (rather than spending time scanning the file before converting), I suspect we are not able to correctly write the .wav at the end of the process.
I'll have a chat with the development team to see if there is any message we can display at this point.

Gavin, did you check the AutoImporter logfile, to see if there was an error message when this file failed to import?


Regards

David Boulton
Brand Manager
Broadcast Radio Ltd

Hi David,

The only difference between the file that imported correctly and the one that didn’t was that the one that didn’t import was an MP3 file with 20 mins of silence on the end and the one that worked fine was a WAV file with the silence removed. However, I don’t think the file type is relevant since I tried re-saving the file back as a WAV with the silence intact and it still wouldn’t play. Once I had removed the silence it would import and play as a WAV or MP3.

As suggested, I think it is something to do with the file size, but I will have to check as I don’t have access to the file at the moment. I’ll also check the AutoImporter log file later this week.

Gavin

 
Gavin Davis
HotHitsUK.com

Hi Gavin,

sorry I didn't make myself clear enough.

On the weeks where the mp3 file does import correctly vs the one that didn't, what are the differences?

I think the most likely candidate is the file size when up converted back to linear .wav, but it might be worth seeing if there is anything else that's different.

Regards

David Boulton
Brand Manager
Broadcast Radio Ltd

Hi David,
The only difference was the one that didn't play had the 20 mins of silence on the end hence the length was longer. A working recording was 180 mins but the non-working was 200 mins. Bit rates were the same.

Cheers

Gavin



 
Gavin Davis
HotHitsUK.com

Hi David,

I have just checked the size of the audio files. The original 3 hour MP3 file, with the additional 20 mins of silence, was only 197Mb but once it was converted to a WAV file it increased to 2.07Gb. When the silence was removed from the WAV file the size decreased to 1.77Gb and file imported without a problem.

UPDATE: Just noticed that the length of silence was 30 minutes rather than 20 as first reported. I have also checked the log files and it doesn't show any errors:
08/03/2015 21:19:24 GRP:8ecided to import '8039 SB-BPM165.mp3' into Cart 8039 : Because it's there - i.e. not been imported+deleted already
08/03/2015 21:22:05 GRP:8:Imported '8039 SB-BPM165.mp3' into Cart 8039 (The Epic Mix, Length: 03:31:01)
08/03/2015 21:22:05 GRP:8:Successfully deleted 'C:\Import\8039 SB-BPM165.mp3'

Regards

Gavin

 
Gavin Davis
HotHitsUK.com

Yep, that explains that then - 2GB is the maximum supported size for a wav file - glad you got to the bottom of it

------------
Peter Jarrett, Technical Director
Broadcast Radio Ltd.

Bill Bailey: No win, no fee, no basis in reality. Just a room above a minicab office in Acton and a steady stream of greedy simpletons whose delusion is only matched by their clumsiness

Perhaps we could have an error or warning message in future releases that tells us when the limit has been exceeded.

Cheers

Gavin

 
Gavin Davis
HotHitsUK.com