Custom mp3 bitrate

[Cedric Dawnhawk]

I accidentally saved my audio in Cool Edit in 44100Hz, 102kbps CBR mp3 format. When I used this in a Pictures to Exe project, the waveform display and the actual music gradually went out of sync as the music played. Eventually I worked out what was happening and saved the mp3 file in a more standard format and things were fine.

For an experiment I added the 102kbps mp3 file and the more standard mp3 file to different tracks of the audio. The standard was shown as 4:26 long, the 102kbps as 4:43. However the waveform displays were identical except for an additional "flat line" section on the 102kbps to make up the 17s difference. When I played them together the audio gradually went out of sync as expected.

Opening both files in Media player showed them as 4:26 long.

Is there a restriction on the mp3 formats that can be used in Pictures to Exe? Should there be a warning if this sort of thing is going to happen?

[denisb]

Not sure , but when your mp3 is with V ariable Bit Rate, and not Constant Bit Rate, problems like you describe occurs.

PTE need Constant Bit Rate.

Denis

[Gilio]

Cedric, I use Lame mp3, 256 kbps for better Quality sound!

[PGA]

I suspect that the problem may have been caused by the choice of bitrate. When exporting an MP3 file from Audacity the available bitrates around the 100 mark are 96 and 112. 102kbps would appear to be a very non-standard setting.

Peter

[Igor]

Cedric,

In future we plan to replace our existing MP3 decoder and probably the new decoder will accept MP3 files with non-standard audio bitrate.

Please send me a link to a sample MP3 file at102kbps I'll check up. Probably we'll fix it for next version.

[Cedric Dawnhawk]

Thanks for the replies

Igor: The offending mp3 file can be downloaded from http://www.newlandeng.karoo.net/ReverieMixDown102.mp3

denisb: This was a CBR format

PGA: Yes I gathered it was to do with the 'non-standard' bit rate. My point was that either PTE should cope with it or refuse or warn about using it in the first place.

[Igor]

Cedric,

Thanks for the file!

Media Player Classic HomeCinema shows 96kbps for this file and it plays fine in PicturesToExe as I quickly tested.

Here is a test project:

https://dl.dropboxusercontent.com/u/27544810/temp/Project1.exe

[Cedric Dawnhawk]

Igor

Are you sure Media Player Classic HomeCinema has not auto-converted it to a more standard format?

On my Windows XP workstation:

Windows Media Player 11 reports 101kbps. 4:26

Windows Explorer says 101kbps

On my Windows 7 laptop

Windows Media Player 12 says102kbps. 4:25.

Windows Explorer says 102kbps

If I add the music to a new project using PTE 8.01 on either the workstation or the laptop, the audio tab on Project options reports the length as 4:43

If I view the timeline with waveform showing, the waveform shaded area extends to 4:43. However the waveform itself only extends to 4:25. When I play the music it plays as though its length is 4:43 so it gradually gets out of sync with the waveform.

Unfortunately the test project you sent is not long enough to see if the music is in fact playing more slowly than it should