DETERMINE the duration of an MP3 audio file

[ChrisGreaves]

There are numerous VBA samples for reading the duration of an audio file from the stored file properties, but I've not seen of a method to determine the duration of a file when the duration has not been lodged with the file in the first place. (see screen snapshot below)
Size-in-bytes is a rough guide, but MP3 files vary in construction, I gather: method of compression, also I assume that there is a fixed overhead.
I have been using, as a rough guide, a factor of 7000 bytes per millisecond (I divide the file size in bytes by 7 and then SLEEP the program for that many milliseconds).
Hans has previously pointed to John Walkenbach's DisplayMP3Info procedure, which works fine ( ) except that it cannot read the duration from the file information if the information has not previously been stored there.

I need a reasonably good way to partition a set of files into groups that will constitute about 80 minutes playing time; I will MOVE each group from a source folder into individual BURN folders prior to using CDBurnerXP to create CDs that are chock-full of music.

Untitled.png

[HansV]

John Walkenbach has a newer version of that workbook - see MP3 File Lister. It works OK for me on Windows 7.

[ChrisGreaves]

John Walkenbach has a newer version of that workbook - see MP3 File Lister. It works OK for me on Windows 7.

Thanks Hans, I'll take a look.
(Minutes later: (see image below))

In the meantime I RTM and discovered that CDBurnerXP will burn to multiple CDs, "Disk Spanning" they call it.
http://www.howtogeek.com/76264/how-to-burn-data-across-multiple-dvd-or-cd-discs/

Untitled.png

[Rudi]

So strange to see the "B:\" drive listing...

Don't tell me your music is still being stored on those old 3.5" floppies???

[ChrisGreaves]

So strange to see the "B:\" drive listing... Don't tell me your music is still being stored on those old 3.5" floppies???

Anything for you, Rudi.
OK: "My music is not still being stored on those old 3.5 inch floppies" (although you did ask me NOT to tell you that they WERE ...).

No. The B-drive on my computer is a SUBST drive, points to a folder on my T drive.

Code: Select all

::
:: Make the daily blotter folder as drive "B"lotter
::
		call T:\BatLap\setdate
		call T:\BatLap\settime
		T:
		CD T:\Blotter\
		if exist %yr%%mt%%dy% GoTo NotFirstBoot
		echo First boot
		MD %yr%%mt%%dy%
		subst B: T:\Blotter\%Daily%
%pause%
		call T:\BatLap\Lap_FirstBoot.bat
%pause%

:NotFirstBoot
		subst B: T:\Blotter\%Daily%

%pause%

Today the B: points to "T:\Blotter\20131125\", and will be used as a throw-away area for experimental files; typical use is storing, from MSPaint, the Untitled.PNG which will be used for a few minutes only to u/l an image to The Lounge. Or even over a period of about 48 hours, a duplicate copy of MP3 files which will be automatically tagged my my latest whiz-bang efforts in Word VBA.

"Blotter" because I am (ahem!) old enough to remember the cleaning ladies who removed the top sheet of blotting paper from the holder on the executive's desk. The top sheet carried yesterday's doodles & scribblings, and important phone numbers before they were copied into the back of the executive's (paper) diary.

T: is, of course, the drive letter of the TrueCrypt drive once I've entered in the appropriate password.

Code: Select all

::
::	Mount the encrypted drive
::
		if not exist T: "C:\Program Files\TrueCrypt\TrueCrypt.exe" /q /lT  /v\Device\Harddisk0\Partition3

It all is well-managed by a finely-tuned set of DOS batch files.

Which are themselves backed up by one of their own!

Code: Select all

title %0 - robocopy t:\ y:\LAP291  /s /r:0 /w:0
:: Backing up the current data to the old backup.

set pause=

"C:\Program Files\TrueCrypt\TrueCrypt.exe" /q /lY  /v\Device\Harddisk2\Partition1
%pause%

if exist Y:\nul goto 20Backup
echo I could not mount the backup drive
pause
goto 99exit

:20Backup
robocopy t:\ y:\LAP291  /s /r:0 /w:0
%pause%

"C:\Program Files\TrueCrypt\TrueCrypt.exe" /dismount Y /force /q
%pause%

:99exit

[Rudi]

Wow...that is a lengthy (and detailed) reply Chris.
I feel quite guilty replying with a simple .... OK.

[ChrisGreaves]

Wow...that is a lengthy (and detailed) reply Chris.
I feel quite guilty replying with a simple .... OK.

To B: or not to B:, that is the (driving) question ...
Whether 'tis nobler in the RamDisk [ed: Thanks Chris; we'll let you know ...]