MP3 lengths variability (technical) (attn Bill)

[Stuart]

I've noticed during my project to stitch together the running order of the 1991 SL Tapes (which are split between guitar and dance) when trying to time the various bits of the 1991 shows, Bill's dance edits show up as a different length depending on how I view the file.

For example, L053.2, shows up in Windows Explorer as 49:55. If I load the file into Audacity, it shows up as a file of 43:48. If I play the file in MediaMonkey, the file appears to be 43:48 in file properties but actually plays on past this on the progress bar, with the time remaining becoming a negative number!

The MediaMonkey file properties show a bitrate of 256kbps and a file length of 43:48 though with VBR set to yes. I assume that the incorrect file lengths shown on the progress bar of MM when playing the file, or being viewed from Windows Explorer, are due to these elements assuming a fixed bit rate Assuming the 43:48 is the correct length!)

It must be that the ripping programme actually writes the file Stop time as a tag, which MediaMonkey displays in its file properties, but both the play progress bar in MM and the Windows Explorer do not use this, and estimate the length of the file from a fixed bit rate.

I also rip to vbr, 220-260, but with slightly different results. The lengths are consistent when viewed from different programs, though the bit rate as displayed on MediaMonkey properties is 251 kpbs. I assume this is written by my ripping program which is Audacity, and is the average bitrate of the file. I do notice that MediaMonkey and indeed WMP have trouble selecting an individual location, you can only fast forward in minute blocks, whereas with Bill's files, the usual fine control is available.

Bill, just wondered what ripping program and bit rates you are using?

Stuart