ID3.au3 UDF - Problem reading TLEN

[gobsor]

Hello,

I was trying to get the length (playtime) of a MP3 file. I came across that on the ID3 website:

TLEN
    The 'Length' frame contains the length of the audiofile in milliseconds, represented as a numeric string.

Though i was searching the autoit-forums - et voila!:

exactly what I've been looking for.

So, first thing i did was downloading the ID3.au3 UDF and the example ID3_Example_GUI.au3. I modified the example

and added

MsgBox(0, "", "LENGTH: " & _ID3GetTagField("TLEN"))

to line 147. Though, when opening a MP3 file it shows the message box with content "LENGTH:" but apparently the _ID3GetTagField("TLEN") returns

"" - an empty string. Why? Did I do something wrong? When I view the MP3 file's information in WinAMP it shows playtime 194s. What am I doing wrong?

EDIT:

actually one doesn't need to add the MsgBox to line 147 since the example itself already contains a field on the GUI that should contain the playtime of the MP3 file after it got opened. Still the with the UDF provided example doesn't work for TLEN. Any suggestions?

Edited December 15, 2010 by gobsor

[BrewManNH]

I've found that the MP3 files I have don't have a TLEN field set in almost all of them. There are other ways of obtaining the information you're looking for though. Using the you can get the information you need. Here's an example script that will show you the length of an MP3 in seconds.

#include <bass.au3>
_Bass_Startup("Bass.dll")
_BASS_Init(0, -1, 44100, 0, "")
$Filename = FileOpenDialog("Select MP3 File", "::{20D04FE0-3AEA-1069-A2D8-08002B30309D}", "MP3 (*.mp3)", 1 + 4 )
$Bass_File = _BASS_StreamCreateFile(False, $Filename, 0, 0, 0)
$SetTime = _BASS_ChannelGetLength($Bass_File, $BASS_POS_BYTE)
$SetTime = _BASS_ChannelBytes2Seconds($Bass_File, $SetTime)
MsgBox(0, "", "LENGTH: " & $SetTime & " seconds")

Edited December 15, 2010 by BrewManNH

[Melba23]

gobsor,

If you look inside Sound.au3 you will find several ways to get the length of an mp3 file.

The _SoundOpen function first tries to get the time from the Windows properties of the file; if that fails tries to read the Xing header (needed to get the correct result for VBR encoded files); if that fails tries to read the TLEN tag; and if that fails asks the MCI DLL if it can produce anything (which will only be correct for a CBR encoded file). After that it gives up - because I could not find any another way to do it!

As I wrote those bits of the code, please feel free to use them if they are of use to you.

M23

[gobsor]

Thanks Brew, your example just works fine and gives me the exact length in seconds, I'll probably stick to that.

Hey M23, I had a look into Sound.au3 earlier, using it in other scripts, its definately great work! Though, it does not always give

me the exact length - for some mp3 files it fails and misses a few seconds - I compared the results to the length shown in WinAMP.

I just tested the Bass.au3 UDF on ~80 files and it seems to be very accurate.

Thanks though