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.


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.

sample_rate output sample_rate
version wma version
decode_flags codec compression features
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.

gb GetBitContext
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.

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
0 on success, -1 otherwise

normal code



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.

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