mp3DirectCut
    Frequently Asked Questions


    Contents
    Installation / Codecs
    Program usage / appearance
    Requests for new features
    Known bugs / more troubleshooting


    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.
    I can't edit a 40 hour file containing 600 tracks. mp3DirectCut since version 2.02 should handle files up to 4 GB. But this is not tested by the author. The maximum number of edit parts is 500.
    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? The program could not find a frame header where it was expeceted and had to search for the file position of this header. This can happen in corrupted files, at cut or paste positions, at a file end or in some cases within VBR files. Often a Re-sync does not mean that anything went wrong. But sometimes some frames in the output file may be skipped. As not all possible error and corruption constellations are examined it cannot be excluded that the program can hang or crash in some sync fail situations.
    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 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 the times of cues or selections are wrong. mp3DirectCut calculates the positions using an average bitrate and the "TOC" of the VBR header. But the relation between time and file position may still be incorrect, especially on longer files. Creating or importing a Cue sheet correctly for VBR files is not possible in many cases.
    After saving a VBR file 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.
    My saved Cue sheet files are empty! Only the split points with a cue flag are saved to the Cue sheet file. If a split point does not have a cue flag it will not be saved. The flag can be set easily by CTRL+Q or in the Names and properties dialog. On loaded Cue sheets the flags are set automatically. If an edit point has a cue flag set it is displayed as dotted line.
    Why can't the program record in 44.1 kHz Stereo at 128 kbit/sec or more? It can. But you seem to use a limited ACM (usually to 56 or 128 kbps). Get the free Lame encoder, copy the "Lame_enc.dll" to your Windows or mp3DirectCut folder and switch to Lame in the encoder settings.
    My recordings are empty. This problem is not mp3DirectCut related. If the VU meter does not move on record you'll have to check the signal flow and the input level by your sound device's mixer application. In mp3DirectCut you'll only have to choose the correct wave in device in the settings.
    Why are some silences shown with a constant high level (since version 2.01) ? This problem can occur on files encoded by Lame to Joint stereo but may also concern other formats. It seems at frames with absolute silence the main gain of an mpeg frame is irrelevant, and some encoders set it to a mad value. If mp3DirectCut's display would try to correct this, it could occur that also the level of some frames with normal level is not shown (happened in earlier versions). So we have to live with those ugly silences. But they can even be cut, as they are only silences ;)


    Feature requests
    I miss the "Append all/selection to..." save option! It's no longer necessarry since mp3DirectCut has virtual Cut, Copy & Paste. Open a second instance of the program where you copy the part you want to append. Then paste the selection the end of the other track. "Save all..." creates the combined file. You can also paste multiple selections. Before saving, the program does not copy real audio data, but only references. So you must keep every file until you saved the result file.
    Can you implement batch functions, especially for normalizing? The command line parameters since version 2.02 should allow you to use mp3DirectCut in a batch environment. For details using the command line parameters see the manuals of mp3DirectCut and your operating system.
    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 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 any new saved audio file, especially selections and split files.
    Play/prelisten
    • Cuts in MP3 files may sound noisy or squeaky, especially at lower bitrates. This is not an error. The MP3 format originally is not made for cutting, because some frames in a row often depend on each others. Solution: make cuts at silent positions and the noises 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). 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.
    • 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.


    Thanks for using mp3DirectCut!
    Copyright (c) 2000-2006 Martin Pesch