libavcodec/wma.c File Reference

#include "avcodec.h"
#include "sinewin.h"
#include "wma.h"
#include "wmadata.h"
#include <assert.h>

Go to the source code of this file.

Functions
static void	init_coef_vlc (VLC *vlc, uint16_t **prun_table, float **plevel_table, uint16_t **pint_table, const CoefVLCTable *vlc_table)
int av_cold	ff_wma_get_frame_len_bits (int sample_rate, int version, unsigned int decode_flags)
	Get the samples per frame for this stream.
int	ff_wma_init (AVCodecContext *avctx, int flags2)
int	ff_wma_total_gain_to_bits (int total_gain)
int	ff_wma_end (AVCodecContext *avctx)
unsigned int	ff_wma_get_large_val (GetBitContext *gb)
	Decode an uncompressed coefficient.
int	ff_wma_run_level_decode (AVCodecContext *avctx, GetBitContext *gb, VLC *vlc, const float *level_table, const uint16_t *run_table, int version, WMACoef *ptr, int offset, int num_coefs, int block_len, int frame_len_bits, int coef_nb_bits)
	Decode run level compressed coefficients.

---

Function Documentation

int ff_wma_end

(

AVCodecContext *

avctx

)

Definition at line 411 of file wma.c.

int av_cold ff_wma_get_frame_len_bits	(	int	sample_rate,
		int	version,
		unsigned int	decode_flags
	)

Get the samples per frame for this stream.

Parameters:

	sample_rate	output sample_rate
	version	wma version
	decode_flags	codec compression features

Returns:

log2 of the number of output samples per frame

Definition at line 77 of file wma.c.

Referenced by decode_init(), and ff_wma_init().

unsigned int ff_wma_get_large_val

(

GetBitContext *

gb

)

Decode an uncompressed coefficient.

Parameters:

gb

GetBitContext

Returns:

the decoded coefficient

consumes up to 34 bits

decode length

Definition at line 440 of file wma.c.

Referenced by decode_coeffs(), and ff_wma_run_level_decode().

int ff_wma_init	(	AVCodecContext *	avctx,
		int	flags2
	)

Definition at line 110 of file wma.c.

Referenced by encode_init(), and wma_decode_init().

int ff_wma_run_level_decode	(	AVCodecContext *	avctx,
		GetBitContext *	gb,
		VLC *	vlc,
		const float *	level_table,
		const uint16_t *	run_table,
		int	version,
		WMACoef *	ptr,
		int	offset,
		int	num_coefs,
		int	block_len,
		int	frame_len_bits,
		int	coef_nb_bits
	)

Decode run level compressed coefficients.

Parameters:

	avctx	codec context
	gb	bitstream reader context
	vlc	vlc table for get_vlc2
	level_table	level codes
	run_table	run codes
	version	0 for wma1,2 1 for wmapro
	ptr	output buffer
	offset	offset in the output buffer
	num_coefs	number of input coefficents
	block_len	input buffer length (2^n)
	frame_len_bits	number of bits for escaped run codes
	coef_nb_bits	number of bits for escaped level codes

Returns:

0 on success, -1 otherwise

normal code

EOB

escape

NOTE: this is rather suboptimal. reading block_len_bits would be better

escape decode

NOTE: EOB can be omitted

Definition at line 473 of file wma.c.

Referenced by decode_coeffs(), and wma_decode_block().

int ff_wma_total_gain_to_bits

(

int

total_gain

)

Definition at line 402 of file wma.c.

Referenced by encode_block(), and wma_decode_block().

static void init_coef_vlc	(	VLC *	vlc,
		uint16_t **	prun_table,
		float **	plevel_table,
		uint16_t **	pint_table,
		const CoefVLCTable *	vlc_table
	)			[static]

Definition at line 32 of file wma.c.