Linspire Audio Binary API - Revision history

130.240.197.203 at 20:36, 7 February 2006

2006-02-07T20:36:31Z

← Older revision		Revision as of 13:36, 7 February 2006
Line 40:		Line 40:
	* private_data: A private data structure used to store the internal decoder state. The libavcodec glue code declares this as an array of 1024 bytes.		* private_data: A private data structure used to store the internal decoder state. The libavcodec glue code declares this as an array of 1024 bytes.
	* The wma3end function returns an integer that can be returned from the libavcodec end function as part of the normal libavcodec API.		* The wma3end function returns an integer that can be returned from the libavcodec end function as part of the normal libavcodec API.

			== Original Source ==

			Download the reference source here [http://software.linspire.com/pool-src/m/mplayer/]
			Any mplayer package should do, the relevant files are libavcodec/wma3dec.c and libavcodec/wmv3dec.c.

	[[Category:Multimedia APIs]]		[[Category:Multimedia APIs]]

DonDiego: link fix

2006-02-05T12:28:36Z

link fix

← Older revision		Revision as of 05:28, 5 February 2006
Line 12:		Line 12:

	* private_data: A private data structure used to store the internal decoder state. The libavcodec glue code declares this as an array of 1024 bytes.		* private_data: A private data structure used to store the internal decoder state. The libavcodec glue code declares this as an array of 1024 bytes.
	* extradata: The extradata bytes at the end of the [[WAVEFORMATEX]] header from the Microsoft media file ([[Microsoft Audio/Video ~~Interlaced~~\|AVI]] or [[Microsoft Advanced Streaming Format\|ASF]]).		* extradata: The extradata bytes at the end of the [[WAVEFORMATEX]] header from the Microsoft media file ([[Microsoft Audio/Video Interleaved\|AVI]] or [[Microsoft Advanced Streaming Format\|ASF]]).
	* extradata_size: The size of the buffer indicated by extradata.		* extradata_size: The size of the buffer indicated by extradata.
	* sample_rate: The sampling frequency of the decompressed PCM audio.		* sample_rate: The sampling frequency of the decompressed PCM audio.

Multimedia Mike at 01:51, 5 February 2006

2006-02-05T01:51:09Z

New page

[[Linspire]] is a Linux distribution that aims to rival [[Microsoft]] in desktop ease of use for the end-user. To that end, they have licensed certain of Microsoft's audio and video codecs that are not yet supported in open source. The binary decoder modules distributed with Linspire are Windows Media Audio 2 and 3. As of this writing, only Windows Media Audio 3 (WMA3) is called by the libavcodec glue code. However, both "Pro" and "Lossless" variants are supported with ths module.

The binary decoder for the WMA3 codec links into [[FFmpeg]]'s libavcodec. The binary module has three interface functions: wma3init, wma3packet, and wma3end.

== Initialization ==

The wma3init function has the following declaration:

int wma3init(void *private_data, unsigned char *extradata,
long extradata_size, long sample_rate, long block_size,
int wma3pro);

* private_data: A private data structure used to store the internal decoder state. The libavcodec glue code declares this as an array of 1024 bytes.
* extradata: The extradata bytes at the end of the [[WAVEFORMATEX]] header from the Microsoft media file ([[Microsoft Audio/Video Interlaced|AVI]] or [[Microsoft Advanced Streaming Format|ASF]]).
* extradata_size: The size of the buffer indicated by extradata.
* sample_rate: The sampling frequency of the decompressed PCM audio.
* block_size: The length of an individual block of encoded audio data.
* wma3pro: This flag is set to 1 if initializing the decoder for decoding WMA3 "Pro" data. The flag is 0 if initializing the decoder for decoding WMA3 "Lossless" data.

== Decoding ==

The wma3packet function has the following declaration:

int wma3packet(void *private_data, void *data, int *data_size, unsigned char *buf, int buf_size);

* private_data: A private data structure used to store the internal decoder state. The libavcodec glue code declares this as an array of 1024 bytes.
* data: The void *data parameter passed into the libavcodec decoding function.
* data_size: The int data_size parameter passed into the libavcodec decoding function.
* buf: The encoded bytestream passed in from libavcodec.
* buf_size: The size of the encoded bytestream.
The packet function returns an integer that can be returned from the
libavcodec decode_packet function as part of the normal libavcodec API.

== Cleanup ==

The wma3end function has the following declaration:

int wma3end(void *private_data);

* private_data: A private data structure used to store the internal decoder state. The libavcodec glue code declares this as an array of 1024 bytes.
* The wma3end function returns an integer that can be returned from the libavcodec end function as part of the normal libavcodec API.

[[Category:Multimedia APIs]]