Maclife 13/MACLIFE13-No-93-1996.ISO.7z/MACLIFE13-No-93.ISO/FreeWare/ジャンル別紹介/MPEG⁄CD 2.0.5.sea/MPEG_CD 2.0.5/MANUAL

Text File | 1995-09-17 | 16KB | 385 lines

MPEG/CDｪ Features:

        ･ Easy to use CD player and document metaphor.
        ･ Realtime MPEG-1 Layer I/II decompression.
        ･ MPEG-1 Layer I/II to AIFF file encode/decode.
        ･ Automatic encode/decode on document double click.
        ･ Background audio encode/decode.
        ･ Decompression playlist queues multiple tunes for play.
        ･ Apple Event Aware provides browser support.
        ･ Audio CD to AIFF file copy.
        ･ Mic to AIFF recording.
        ･ □MPEG audio encoding of AIFF files.

Our Home...

  Please visit our home page for new product announcements:

         http://www.kauai.com/~bbal

CD-Audio Encoding

  With a PowerMac or supported 68K based Mac with compatible
  CD-ROM drive, you can immediately begin compressing your existing
  audio CD's into MPEG files. Follow these steps:

  1) Place an audio CD in your CD-ROM drive.

  2) Select "Record/Audio CD to AIFF...". A file open dialog will appear.
      Navigate to your CD drive (Audio CD 1) and select a given
      audio track from the CD (e.g., Track 1).

  3) Another file open dialog will appear.  Navigate back to your hard
      disk and click "Save".

  4) The entire CD track will be preserved in AIFF format on your hard
      disk (make certain you have the space...).

  5) Double click the icon of the newly created AIFF file, the file should begin
      to play.

  6) Now, select "List/Encode" or Command-E to MPEG encode the file at the default
      encoder settings. MPEG audio software-only compression takes time, be patient.

  7) A ".m1a" file is now created in the same directory as the AIFF file.

  8) Double click the newly created .m1a MPEG audio file. The file should now
      decompress in realtime.

  -- WARNING --

      Be aware, much audio material is copyrighted. Check with the content originator
      regarding rights to translation and distribution of said audio material in MPEG
      format.

Microphone Input Encoding

  1) Select "Record/Mic to AIFF". A file open dialog box will appear wherein
      you should navigate to where you want to save the AIFF file being created.

  2) The standard mac microphone transport functions appear. Select "record"
      and start recording your mic input (be certain to verify your Sound control
      panel "Sound In" Options are set to the Microphone as input).

  3) Click stop when done recording, then Save.

  4) Double-click the newly created AIFF file to listen.

  5) Enter "Command-E" to MPEG encode the file which will appear in the same
      folder as the AIFF file.

  6) Double click the newly created .m1a MPEG audio file. The file should now
      decompress in realtime.

  This feature is very useful for voice-mail. Speak into your microphone,
  encode, and send the compressed audio as a Eudora attachment.

  -- To obtain the fully authorized version of MPEG/CDE with unlimited encoding
      and decoding capability requires a full license. See below for instructions on
      obtaining a full MPEG/CDE license or registering your MPEG/CD copy. --

Evaluating Fidelity vs. Size Tradeoff issues

  1) Select File->Preferences Encoder (2/2) and enable the checkbox
      "Encode all Bitrates in Layer".

  2) Perform the sequence of steps outlined in CD-Audio Encoding above.
      This encodes your AIFF file in all bitrates applicable to your Preferences
      Encoder (1/2) settings based on the selected Mode and Layer. Be patient,
      as encoding can take a long time based on your AIFF filesize.

     To abort from this batch encoding mode use the Command-, sequence - i.e.
     hold down the Command and comma keys together.


Decoder Preferences

  MPEG/CDｪ maintains a default set of Preferences in the System Folder
  called MPEGDefaultConfig which are written on exit from the
  application.

  From within MPEG/CDｪ, pull down the "Edit" menu and select "Preferences".
  Read the following discussion to determine default settings based
  on your playback requirements.

  Realtime playback of full quality stereo MPEG Layer II audio requires
  a sufficiently strong machine, i.e. high end Quadra or PowerMac.
  However, MPEG/CDｪ provides several options to lighten processing load
  at the expense of time, memory, disk space, and audio quality, allowing
  realtime playback on lesser machines.

  Upon initial MPEG/CD launch, the Decoder Preferences are set for "Realtime"
  decompression. If, when you double-click the Astor-Basia file, sound
  is emitted but has intermittent gaps in play, your machine isn't fast enough
  for realtime decompression. You can reduce processor requirements in one
  of three ways to possibly squeeze realtime decompression from your
  machine:

  1) Try using one of the Decoder Preferences downsampling modes.  First,
      2x, then 4x, etc. This effectively drops audio samples - trading audio quality
      for decompression speed.

  2) If Channels is set to "Both", set instead to either "Left" or "Right. This
      effectively halves the amount of decompression processing required by your
      machine.

  3) If the above at 16x still can't decompress your audio realtime, then set your
      Downsampling back to "None" and select the "Decompress to AIFF file" checkbox.
      This will decompress the MPEG encoded audio file to an AIFF file (make certain
      you have enough hard disk space...). You can then double click the new AIFF file
      and you'll here the audio clip at the selected fidelity (full fidelity if licensed).

Encoder Preferences

   MPEG audio has three layers, I, II, and III. Currently only Layers
   I and II are supported. Within a given layer a number of bitrates
   are supported, expressed in kilobits per second or Kbps. Assuming
   32 Kbps bitrate is selected, each second of audio is compressed
   to 32,000 bits or 4,000 bytes.  Normally, an input 44.1 kHz sampled
   mono channel would contain 44,100 * 16 (bits/sample) = 705,600 bits.
   Thus, at the 32 Kbps rate this stream compresses to 705,600/32,000
   or appx 22:1.

   As another example, a standard 44.1 kHz sampled stereo stream uses
   44,100 * 16 (bits/sample) * 2 (channels) = 1,411,200 bits/second.
   Compressing this at a 64 Kbps bitrate yields 64,000 bits.
   Thus, the compression ratio in this case is again appx. 22:1.

   You can perform similar calculations to determine the effective
   compression ratios of the other bitrates.

   Some additional checkboxes exist to select the desired psychoacoustic
   model, emphasis, input audio sampling frequency, and encoding mode.
   When selecting the 32 Kbps bitrate, you can elect one of the
   MPEG-LBR rates to achieve two lower bitrates which are a superset of
   MPEG, and can "stream" over 14,400 and 28,800 baud modems using
   the MPEG/CDS client software.

 The List

  MPEG/CDｪ maintains a default List in the System Folder called
  "MPEGDefaultPlayList". If enterring MPEG/CDｪ through double-clicking
  the application, the default List is read. Any changes made to the
  List from inside MPEG/CD are written to MPEGDefaultPlayList upon
  exit.

  When double-clicking an .m1a or AIFF sound file from the Finder, the
  default List  is not  read (this also applies when clicking on an
  .mp2 or .AIFF file from within Netscape). This allows you to use the
  "Command-/" and "Command-r" commands (described below) to replay
  the tune following play, or cancel the tune during play.

Adding  a List entry

  Selecting "List/Show..." presents the current List. Enter "File/Add to List"
  to add a file to the List. Now you can do a "List/Show..." and see the
  tune in the list. Additonal entries can be added in a similar manner.

  All Highlighted entries in the List will be decompressed and/or encoded
  depending on whether it is an ".m1a" or "aiff" file. By default, an entry
  is selected when enterred into the List.

  Deleting a List entry

  To remove a List entry, first deselect all current entries that may be
  highlighted and select (highlight) only the entry(s) to be deleted by Command
  clicking the entry(s). Now, press the Delete key. The entry(s) is cleared from the
  List. Multiple entries can be deleted in this manner. Enter, "OK" to complete
  the deletion sequence.

  Deselecting a List entry

  By default each entry is selected for play when added to a List indicated
  by the highlighted entry. You can deselect the tune yet keep it in the List
  forcing MPEG/CDｪ to bypass the tune when selecting "Special/Decompress".
  To deselect a tune hold down the Command key and click the List entry.
  The text will no longer be highlighted indicating decompression for this file
  is disabled.

  Managing Multiple Lists

  The default List is managed by MPEG/CDｪ and preserved in the System
  Folder Preferences area and serves the needs of the typical user. However,
  any number of Lists can be created and preserved using "File/Save List".
  This "Disc Jockey" friendly feature allows numerous Lists to be preserved
  and recalled for subsequent use.

  Lists of AIFF files can be created for batch encoding or decoding. Lists of
  m1a files can be made for back-to-back decode/play.

Decompression

  When the "MPEG Decompress" progress dialog appears, you can abort the
  current file decompression at any time by enterring "Command-.",
  that's the Apple key and the period together - or use the "Cancel"
  button. To abort the current file decompression and quit the application,
  enter "Command-," - that's the Apple key and the comma together.

Decompression status window

  By selecting the "Status/Show Window" pull down, a blank status
  window appears. When a file is decompressed or played, the MPEG
  audio header information is displayed in the window to allow examining
  the utilized MPEG coding constraints. Following file decompression, the
  number of samples "clipped" during processing are displayed as Errors.
  If multiple files are queued in a playlist, information for each file is
  echoed and can be scrolled through following decompression. Clicking
  the window's close box or selecting "Status/Hide Window" removes the
  status window from the screen.

  Admittedly, the Status window is primitive. You can't type into the
  window or printing becomes "askew". Also, the status window
  isn't refreshed once another window (including the decompression
  status window) overlays it. Use this window as a reference and a
  progress monitor.

File Creators and files

  m1a

  After completely playing an MPEG encoded audio file the first time,
  MPEG/CD stamps the file creator as KAU1 with a filetype of M1A.
  From this point on you can double-click the file in the Finder to start
  audio playback - similar to Macintosh Finder sound files.

  When properly configured, Netscape stamps an MPEG .m1a audio file
  with the KAU1 creator and M1A file type when using "File/Save
  Next Link as..." from within Netscape. Users should be aware Netscape
  always implicitly places downloaded audio files in the System Folder, i.e.
  if you click on a .m1a file hyperlink, the file is transferred to your
  System Folder and subsequently realtime played (if MPEG/CD Preferences
  are appropriately set). Thus, you're required to have enough space on
  your hard disk to minimally hold the audio file for subsequent play.
  When "File/Save Next Link as..." is not used, the temporary audio files in
  the System Folder are deleted when exitting Netscape. Files
  downloaded by Netscape are directly double-click playable by MPEG/CDｪ.

  If, however, you download the .m1a audio files to your machine using
  ftp, Fetch, or another method, the file appears as a document with
  the standard TeachText document icon. To stamp the file creator
  with KAU1 and filetype M1A you must first add the downloaded
  file to an  MPEG/CDｪ List using  "File/Add to List" and
  completely decompress the file. When the m1a file is closed by MPEG/CDｪ
  the creator and file type are set to the appropriate values and the file
  is now eligible for subsequent double-click play and has the familiar
  MPEG/CDｪ icon.

  AIFF

  Double clicking an MPEG/CDｪ created AIFF file from the Finder launches
  MPEG/CDｪ and plays the audio file. The application remains open
  following play. Set your default Preferences for realtime decompression
  prior to double clicking.

Drag and Drop Play

  Dropping an MPEG/CDｪ tagged m1a or AIFF file onto the MPEG/CDｪ application
  initiates audio  play of the sound file. Keep the MPEG/CDｪ application icon
  (or alias) on your desktop and drop CD's into the player when you
  want background music while you work in other applications!

  An .m1a or .AIFF file dropped on the MPEG/CDｪ application forces MPEG/CDｪ to
  temporarily create a list with only the requested AIFF tune(s). Thus,
  replay (Command-R) will replay only the currently playing tune.

Drag and Drop Encode

  AIFF file(s) created by MPEG/CD through "Mic to AIFF" or "Audio CD to AIFF"
  can be encoded by dragging the AIFF files on top of the MPEG/CD application
  icon. The files will be successively encoded each using the current Encoder
  Preference settings. This allows for overnite batch MPEG audio encoding of
  several tunes.

  It's beyond the scope of this document to describe MPEG. Experiment with the
  encoder bitrate settings and encode the same file under several settings. For
  lower bitrates, files will be smaller and of lesser fidelity. The reverse is
  true for the larger bitrates.

  Eventually I'll write a description of the encoder settings, and will provide
  licensed MPEG/CDE users with the in-depth information.

Aborting Encode/Decode

  Both encode and decode progress bar windows have a cancel key which can
  be clicked at any time to abort encode or play. The resulting file created to
  the point of cancel is "valid" and is playable (m1a or aiff). You can also use the
  standard Mac Command-. to kill the encode/decode.

Sample Audio Site

  A good place to locate MPEG encoded music on the net is
  at the "Internet Underground Music Archive" (IUMA):

                                                    http://www.iuma.com/

  With MPEG/CDE you can now join the ranks of a growing number of
  audio web sites...

Difficulties

  If you're having difficulty decompressing a file, download the file once
  again to rule out transmission errors over your service provider's line. If
  still unsuccessful, send the audio file URL to our email address below
  and we'll look into it as time permits.

Modern Memory Manager

  There's been reports that MPEG/CDｪ doesn't operate correctly on
  PowerMac platforms when the Memory Control Panel "Modern Memory
  Manager" Radio Button is set to "Off". A temporary workaround is to
  keep this setting to "On" until further notice.

Scriptability

Let us know your requirements.

Command Reference

File

  Command-O          Open List
  Command-A          Add to List
  Command-I           Import to List
  Command-S          Save List
  Command-K          Create File Alias
  Command-Q          Quit

Status

  Command-W         Show/Hide Window

Record

  Command-M          Mic to AIFF
  Command-C          Audio CD to AIFF

List

  Command-E          Encode
  Command-D          Decode
  Command-L          Show


During Play Operation

  Command-/          Skip current PlayList entry
  Command-R          Replay current PlayList entry
  Command-.           Abort current encode/decode in progress
  Command-,           Abort current batch encode/decode in progress


  Send any suggestions and/or questions to [e-mail]

  Send all orders  and registration fees to:

                Kauai Media
                c/o MPEG/CD Registration
                3790 Via de la Valle
                Suite 204
                Del Mar, CA 92014