mp3DirectCut
Frequently Asked Questions


Contents
Installation, Codecs
Program usage, appearance
Requests for new features
Known problems and more troubleshooting
Contact


Installation, Codecs
Sytem requirements The program is tested and reported to run under Windows 9x, NT, 2K, XP.
Editing (without play!) should work on every machine.
For playback you need at least: 200 MHz, an MP3 ACM or the mpglib.dll
For recording you need at least: 400-500 MHz, an MP3 ACM or the Lame_enc.dll
How do I install and uninstall the software? Simply put the files of the archive into an empty folder of your choice. To let the program appear in Windows' Start menu you must create a link there. You can also link known file types (mp3, mp2, cue, mpd) to mp3DirectCut to open them easily from the explorer.
To uninstall the program delete the delivered files, the .ini file (created by mp3DirectCut) and the Start menu link if you made one. The program does not write to the Registry or to system folders.
Where must I put the mpglib.dll and the lame_enc.dll? These decoding/encoding libraries must be either in a directory that is in your PATH (like "C:\Windows" or "C:\Windows\System") or you can put it into mp3DirectCut's directory.
I have no MP3 ACM and the mpglib.dll seems not to work Did you activate the mpglib.dll in the program settings? Settings menu: "Configure...", go to "Devices" an under "MPEG decoder" select mpglib.dll.
Where can I get an ACM Codec for MP3? There are several applications that bring along an MP3 Codec for the ACM (= "Audio Compression Manager"). And there are different MP3 ACM Codecs (free and non-free ones). Originally they come from the Fraunhofer Institute, developer of the MP3 format.
The Codec (*.acm in System dir) must be installed by an application or an installer. Then it can be used by any software that wants to access it. Note: mp3DirectCut can use an ACM Codec but doesn't have to. If you can't get or install it you should use the mglib.dll provided on the Homepage.


Program usage, appearance
My MP3 file cannot be opened If the file is 'pure' MPEG audio the program should open it. A file open error may be caused by too large ID3v2 Tags. They must be smaller than 500K (200K in earlier versions of mp3DirectCut). Otherwise take another program to remove the ID3v2.
Why can't I keep ID3v2 Tags or VBR headers? Because the program in the current version is not able to adapt lenth informations that occur in those tags. If you shorten an MP3 and keep the unchanged header it will have incorrect length informations. It is better to have no length informations than wrong lengths. Because every intelligent player can calculate (or at least estimate on VBR) the duration of an MP3 when it is opened. Missing VBR/Length Tags DO NOT destroy an MP3.
What happens if the file info says 'Sync lost'/'No sync' or the MPEG graph shortly disappears? Nothing bad if your MP3 is not corrupted. An MPEG audio file consists of a frame structure (about 38 frames per second). The program always looks for a frame beginning when you scroll, select or cut. In some rare cases the program is confused by something that looks like a frame header but isn't it. If you scroll further the program should re-sync.
I got 'Sync errors' on saving, what do they mean? Usually that the program passed by file corruptions and could not find a frame header. In the output file the correct frame structure should be restored but there will be some frames missing. The program saves your file/selection to the end. The progress dialog stays to notify you of the errors. That's how it should be. But as not all possible errors and corruptions are examined it cannot be excluded that the program can hang or crash in some sync fail situations. If only 1 Sync error is reported this often means that just the first or the last frame of the whole file was incomplete (occurs with some encoders).
Why can't I zoom out further than these three steps? Because mp3DirectCut is always accessing everything directly. The program is designed not to care about the file size and shows a fixed area around the current/play position. More zooming out levels would cause longer file scannings every time the display is updated.
Why does the selection not begin where I point to on VBR files? It is more difficult to display variable bitrate files than CBR files. As a workaround you should drag the selection to reach a position or cut your MP3 "by ear" with the "Set begin" and "Set end" buttons.
Why does the position cursor rock, especially on VBR files? Since version 1.31 the cursor is placed dynamically in the graphic view to compensate the variable displacements of VBR visualisation. It was the best solution to keep the file access fast and provide an acurate position pointer.
Why can't the program encode in 44.1 kHz Stereo at 128 kbit/sec? It can. But you seem to use a limited ACM (usually to 56kbps). Get the free Lame encoder, copy "Lame_enc.dll" to your Windows or mp3DirectCut folder and switch to Lame in the recording settings.


Requests for new features
Can you implement batch functions, especially for normalizing? Maybe some time. Not soon.
Can you add Ogg Vorbis support? I would, but Vorbis seems to be much more difficult to cut than MP3. An MP3 can be cut everywhere and it's still playable. Cutting an Ogg file without adapting anything here and there will produce broken files. I could not find any understandable documentation of a structure in Vorbis files. If you know such docs, please let me know.
Can you add WAV/PCM support? This has low pri and will be complicated. I can't say when there's time for making it.
Can I have the source code? No. mp3DirectCut is not Open Source.


Known problems and more troubleshooting
General
  • mp3DirectCut is tested with many different MP3/MP2 types. In some cases it can still behave strange or crash. As there are many differences in the apearence of MPEG audio files it is not easy to predict which errors might occur.
MPEG Visualisation
  • The main MP3 graph does not show the correct audio level. But this is not an error! The graph contains only higher frequencies. It can also be too high or too low over the whole file. In rare cases the display doesn't show anything.
  • Visualisation of Layer 2 is (much) worse than Layer 3. Occasionaly silences may appear as mountains...
Editing, Saving
  • The last two or three frames can only be selected together.
  • The Duration threshold on silence detection is not accurate. Silences below 2 seconds may not be detected reliably.
  • Saving a selection or splitting a file may in rare cases use incorrect ranges. It's recommended always to check saved selections and split files.
Play/prelisten
  • Cuts in MP3 files may sound noisy or squeaky, especially at lower bitrates. This is not an error. Originally MP3 is not made for cutting, because some frames in a row often depend on each other. Solution: make cuts at silent positions and they will be less perceptable.
  • If your computer is too slow for decoding in realtime and working the graphics the player will hang. Set the "frames per buffer" value to max (8) and then decrease it as far as possible. Zoom in a step. You should also make the window smaller. If your machine is fast enough but the sound is noisy or interrupted try varying the "Maximum wave buffer". The "High priority" option may reduce sound interruptions if other cpu intense applications work in the background. But not if your system is too slow for real time playback!
  • If the MP3 file is not on a local harddrive playing and scrolling the file may be interrupted.
  • Large files may fill up Windows' file cache. It is (generally) recommended to prevent Windows from using all the RAM for file caching (e.g. with the Freeware Cacheman).
Program crashs/hangs
  • In some rare cases the program crashed a whole system, especially at intense scrolling while a file was playing.
  • Some users reported that trying to save selections from large files after a file position of about 60..80 MB caused the program or the system to crash. Others reported, saving files of seven hours works excellent. As there isn't an extensive file corruption management unforeseen errors may occur. Which types of errors seems also depend on different Windows versions.
  • There are several reports that the program does not work at all and opens with a General Protection Fault. In these cases try to close other processes and applications which may interfere with this one.


If you still have questions or if you found an undocumented error you can contact the author here.

But please be sure to read the documentation and FAQ first. For basic program usage get the "HTML manual for mp3DirectCut 1.14" from the homepage.

Note: I read every mail, but I can't promise to reply (quickly) on every. Please keep your questions, bug reports or suggestions brief and don't send large attachments (mails over 10KB do not arrive).

Thanks for using mp3DirectCut!

Copyright (c) 2000-2003 Martin Pesch