Outdated egg! (historical revision 32807)

You are looking at historical revision 32807 of this page. It may differ significantly from its current revision.

Outdated egg!

This is an egg for CHICKEN 3, the unsupported old release. You're almost certainly looking for the CHICKEN 4 version of this egg, if it exists.

If it does not exist, there may be equivalent functionality provided by another egg; have a look at the egg index. Otherwise, please consider porting this egg to the current version of CHICKEN.

eggs

mpeg3

Outdated egg!
mpeg3

Introduction

The MPEG3 is a thin wrapper around the libmpeg3 C library.

The official documentation for the C library is available here:

http://heroinewarrior.com/libmpeg3/index.html

Examples

Show information of an MPEG3 audio file

(use mpeg3 format-modular)

(define *path* "/tmp/file.mp3")

; Verify that the file has the right signature:

(unless (mpeg3-check-sig *path*)
  (error "Invalid file type"))

; Open the file:

(define *file* (mpeg3-open *path*))

; Make sure the file has audio:

(unless (mpeg3-has-audio *file*)
  (error "File doesn't have audio"))

; Get the total number of audio streams in the file:

(define *total-streams* (mpeg3-total-astreams *file*))

; Print information for each audio stream in the file:

(let loop ((stream 0))
  (unless (= stream *total-streams*)
    (format #t "Stream: ~A~%  Channels: ~A~%  Sample rate: ~A~%  Samples: ~A~%"
            stream
            (mpeg3-audio-channels *file* stream)
            (mpeg3-sample-rate *file* stream)
            (mpeg3-audio-samples *file* stream))
    (loop (+ stream 1))))

; Close the file.  This step is optional: if you don't do it, Chicken
; will close it when it no longer is required.  However, if you open
; a lot of files you will want to close them as soon as you know you'll
; no longer require them.

(mpeg3-close *file*)

Authors

The mpeg3 egg was created by Alejandro Forero Cuervo.

The mpeg3 egg is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

The mpeg3 egg is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with the mpeg3 egg; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

Version History

0.2: Include documentation from the wiki.
0.1: Initial release