mp3DirectCut
Frequently Asked Questions


Contents
Installation / Codecs
Program usage / appearance
Requests for new features
Known bugs / 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
mp3DirectCut runs even under Linux/Wine (tested with Knoppix 3.2 and mpglib.dll).
How do I install and uninstall the software? Simply extract the files of the archive into an empty folder of your choice. To let the program appear in Windows' Start menu or on the desktop you must create a shortcut on your own. To use the language support the language files must be in the subfolder Languages (should be created on extracting). You can also associate the supported file types (mp3, mp2, cue, mpd) to mp3DirectCut if you want 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. Please check if the mpglib.dll is activated in the program settings. Under "Settings" => "Configure..." => "Devices" => "MPEG decoder": "mpglib.dll" must be selected.
Where can I get an ACM Codec for MP3? There are several applications that bring along an MP3 Codec for the Windows ACM (= "Audio Compression Manager"). And there are different MP3 ACM Codecs (free and non-free ones, mere decoders and de-/encoders). The Codec (*.acm in System dir) must be installed by an application installer. Then it can be used by any software that wants to access it. Windows XP is already supplied with a decoding MP3 ACM.


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 not be greater than 500K. Otherwise take another program to remove the ID3v2.
Why can't I keep ID3v2 Tags? Because the program in the current version is not able to adapt length informations of some header types, as ID3v2. If you shorten an MP3 and keep the unchanged header it would have incorrect length informations. Then it is better to have no length informations. Missing headers DO NOT destroy an MP3. mp3DirectCut supports only the "Xing" VBR header which is also used by Lame and many other programs.
What happens if the file info says '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 'Re-syncs' on saving, what do they mean? Usually that the program could not find a frame header. In the output file the correct frame structure should be restored and some frames may be skipped. The program saves your file/selection to the end. 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 one Re-sync 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 position. Increasing the 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? 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.
On VBR after saving or appending the length seems to be wrong. Maybe the VBR header was not written correctly. You should try to open the complete file and save it again to write a new VBR header. If even this does not help you can disable writing the header by unchecking the option in the Tag/Info dialog.
Why can't the program encode in 44.1 kHz Stereo at 128 kbit/sec or more? It can. But you seem to use a limited ACM (usually to 56kbps). Get the free Lame encoder, copy the "Lame_enc.dll" to your Windows or mp3DirectCut folder and switch to Lame in the encoder settings.
How can I insert a piece of audio or some silence? Insert works olny if you compile a file by appending pieces. To add silence record a piece of it and save some seconds to a new file, then append something to this silence. And so on.


Feature requests
Can you implement batch functions, especially for normalizing? Maybe some time. Not soon.
Can you add Ogg Vorbis support? Vorbis seems much more difficult to cut than MP3. An MP3 can be cut nearly everywhere and it's still playable. Cutting an Ogg file without adapting anything here and there will produce broken files. By now I could not find an understandable documentation of a structure in Vorbis files.
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. Don't ask if a silence appears as mountain...
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 rare cases the program crashed a whole system, especially at intense scrolling while playing or after frequent play/stop with ACM usage.
  • 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 to 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.
Contact
    For reporting undocumented errors or if you find mistakes in the manual you can contact the author here. You can also send suggestions. But please remind it's Freeware. I read every mail, but can't promise to reply (quickly) on every. Please keep your message brief, don't change the subject and don't send large attachments (mails over 10 KB do not arrive!).


Thanks for using mp3DirectCut!
Copyright (c) 2000-2005 Martin Pesch