NAME

 Audio::SoundFile::Writer - Writer class for various sound formats

SYNOPSIS

 use Audio::SoundFile;
 use Audio::SoundFile::Header;

 $header = new Audio::SoundFile::Header(...);
 $writer = new Audio::SoundFile::Writer($target, $header);

 $length = $writer->bwrite_raw($buffer);
 $length = $writer->bwrite_pdl($buffer);

 $writer->fseek(1024, SEEK_SET); # seek by frame
 $writer->fseek(1024, SEEK_CUR); # seek by frame
 $writer->fseek(1024, SEEK_END); # seek by frame

 $writer->bseek(1024, SEEK_SET); # seek by block
 $writer->bseek(1024, SEEK_CUR); # seek by block
 $writer->bseek(1024, SEEK_END); # seek by block

 $writer->close;

DESCRIPTION

This module provides an interface to write various sound formats supported by libsndfile.

In addition to usual I/O interface, it provides direct interface to write PDL object without making a copy of data in pure-Perl space. This is an advantage on both speed and memory, and is a recommended way to handle sound data.

Currently supported methods are:

$writer = new Audio::SoundFile::Writer($target, $header);

Constructor. Returns output stream object that writes to given target in a format specified by $header.

$writer->close;

Closes output stream. This object will be unusable after this method is called.

$offset = $writer->fseek($offset, $whence);

Moves next writing position to a point where specified by $offset and $whence. Note $offset is not a length in bytes, but a number of frames to skip (frame is a block of data containing data of all channels at given moment).

Return value (which should be a new position in number of frames) is currently unreliable.

$offset = $writer->bseek($offset, $whence);

Moves next writing position to a point where specified by $offset and $whence. Note $offset is not a length in bytes, but a number of blocks to skip (block is a bulk of data containing data of one channel at given moment).

Return value (which should be a new position in number of blocks) is currently unreliable.

$length = $write->bwrite_raw($buffer, $wanted);

Writes $wanted blocks of data from $buffer, which should be a Perl scalar.

Returns length of the data actually written, or -1 on error.

$length = $reader->bwrite_pdl($buffer, $wanted);

Writes $wanted blocks of data from $buffer, which should be a PDL object.

Returns length of the data actually written, or -1 on error.

NOTES

If you mix bseek/bwrite and fseek/fwrite, things might get confusing due to shift in internal offset - please do it with your responsibility.

AUTHORS / CONTRIBUTORS

Taisuke Yamada <tai@imasy.or.jp>

COPYRIGHT

Copyright (C) 2001. All rights reserved.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.