FFmpeg  4.0
Macros | Functions | Variables
g723_1dec.c File Reference

G.723.1 compatible decoder. More...

#include "libavutil/channel_layout.h"
#include "libavutil/mem.h"
#include "libavutil/opt.h"
#include "acelp_vectors.h"
#include "avcodec.h"
#include "celp_filters.h"
#include "celp_math.h"
#include "get_bits.h"
#include "internal.h"
#include "g723_1.h"

Go to the source code of this file.

Macros

#define BITSTREAM_READER_LE
 
#define CNG_RANDOM_SEED   12345
 
#define iir_filter(fir_coef, iir_coef, src, dest, width)
 Perform IIR filtering. More...
 
#define OFFSET(x)   offsetof(G723_1_Context, x)
 
#define AD   AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM
 

Functions

static av_cold int g723_1_decode_init (AVCodecContext *avctx)
 
static int unpack_bitstream (G723_1_Context *p, const uint8_t *buf, int buf_size)
 Unpack the frame into parameters. More...
 
static int16_t square_root (unsigned val)
 Bitexact implementation of sqrt(val/2). More...
 
static void gen_fcb_excitation (int16_t *vector, G723_1_Subframe *subfrm, enum Rate cur_rate, int pitch_lag, int index)
 Generate fixed codebook excitation vector. More...
 
static int autocorr_max (const int16_t *buf, int offset, int *ccr_max, int pitch_lag, int length, int dir)
 Estimate maximum auto-correlation around pitch lag. More...
 
static void comp_ppf_gains (int lag, PPFParam *ppf, enum Rate cur_rate, int tgt_eng, int ccr, int res_eng)
 Calculate pitch postfilter optimal and scaling gains. More...
 
static void comp_ppf_coeff (G723_1_Context *p, int offset, int pitch_lag, PPFParam *ppf, enum Rate cur_rate)
 Calculate pitch postfilter parameters. More...
 
static int comp_interp_index (G723_1_Context *p, int pitch_lag, int *exc_eng, int *scale)
 Classify frames as voiced/unvoiced. More...
 
static void residual_interp (int16_t *buf, int16_t *out, int lag, int gain, int *rseed)
 Perform residual interpolation based on frame classification. More...
 
static void gain_scale (G723_1_Context *p, int16_t *buf, int energy)
 Adjust gain of postfiltered signal. More...
 
static void formant_postfilter (G723_1_Context *p, int16_t *lpc, int16_t *buf, int16_t *dst)
 Perform formant filtering. More...
 
static int sid_gain_to_lsp_index (int gain)
 
static int cng_rand (int *state, int base)
 
static int estimate_sid_gain (G723_1_Context *p)
 
static void generate_noise (G723_1_Context *p)
 
static int g723_1_decode_frame (AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
 

Variables

static const AVOption options []
 
static const AVClass g723_1dec_class
 
AVCodec ff_g723_1_decoder
 

Detailed Description

G.723.1 compatible decoder.

Definition in file g723_1dec.c.

Macro Definition Documentation

◆ BITSTREAM_READER_LE

#define BITSTREAM_READER_LE

Definition at line 32 of file g723_1dec.c.

◆ CNG_RANDOM_SEED

#define CNG_RANDOM_SEED   12345

Definition at line 41 of file g723_1dec.c.

Referenced by g723_1_decode_frame(), and g723_1_decode_init().

◆ iir_filter

#define iir_filter (   fir_coef,
  iir_coef,
  src,
  dest,
  width 
)
Value:
{\
int m, n;\
int res_shift = 16 & ~-(width);\
int in_shift = 16 - res_shift;\
for (m = 0; m < SUBFRAME_LEN; m++) {\
int64_t filter = 0;\
for (n = 1; n <= LPC_ORDER; n++) {\
filter -= (fir_coef)[n - 1] * (src)[m - n] -\
(iir_coef)[n - 1] * ((dest)[m - n] >> in_shift);\
}\
\
(dest)[m] = av_clipl_int32(((src)[m] * 65536) + (filter * 8) +\
(1 << 15)) >> res_shift;\
}\
}
#define src
Definition: vp8dsp.c:254
static void filter(int16_t *output, ptrdiff_t out_stride, int16_t *low, ptrdiff_t low_stride, int16_t *high, ptrdiff_t high_stride, int len, int clip)
Definition: cfhd.c:114
#define LPC_ORDER
Definition: g723_1.h:40
uint16_t width
Definition: gdv.c:47
int n
Definition: avisynth_c.h:684
#define SUBFRAME_LEN
Definition: g723_1.h:36
for(j=16;j >0;--j)

Perform IIR filtering.

Parameters
fir_coefFIR coefficients
iir_coefIIR coefficients
srcsource vector
destdestination vector
widthwidth of the output, 16 bits(0) / 32 bits(1)

Definition at line 507 of file g723_1dec.c.

Referenced by formant_postfilter().

◆ OFFSET

#define OFFSET (   x)    offsetof(G723_1_Context, x)

Definition at line 1007 of file g723_1dec.c.

◆ AD

Definition at line 1008 of file g723_1dec.c.

Function Documentation

◆ g723_1_decode_init()

static av_cold int g723_1_decode_init ( AVCodecContext avctx)
static

Definition at line 43 of file g723_1dec.c.

◆ unpack_bitstream()

static int unpack_bitstream ( G723_1_Context p,
const uint8_t buf,
int  buf_size 
)
static

Unpack the frame into parameters.

Parameters
pthe context
bufpointer to the input buffer
buf_sizesize of the input buffer

Definition at line 68 of file g723_1dec.c.

Referenced by g723_1_decode_frame().

◆ square_root()

static int16_t square_root ( unsigned  val)
static

Bitexact implementation of sqrt(val/2).

Definition at line 183 of file g723_1dec.c.

Referenced by comp_ppf_gains(), gain_scale(), and generate_noise().

◆ gen_fcb_excitation()

static void gen_fcb_excitation ( int16_t *  vector,
G723_1_Subframe subfrm,
enum Rate  cur_rate,
int  pitch_lag,
int  index 
)
static

Generate fixed codebook excitation vector.

Parameters
vectordecoded excitation vector
subfrmcurrent subframe
cur_ratecurrent bitrate
pitch_lagclosed loop pitch lag
indexcurrent subframe index

Definition at line 199 of file g723_1dec.c.

Referenced by g723_1_decode_frame().

◆ autocorr_max()

static int autocorr_max ( const int16_t *  buf,
int  offset,
int ccr_max,
int  pitch_lag,
int  length,
int  dir 
)
static

Estimate maximum auto-correlation around pitch lag.

Parameters
bufbuffer with offset applied
offsetoffset of the excitation vector
ccr_maxpointer to the maximum auto-correlation
pitch_lagdecoded pitch lag
lengthlength of autocorrelation
dirforward lag(1) / backward lag(-1)

Definition at line 266 of file g723_1dec.c.

Referenced by comp_interp_index(), and comp_ppf_coeff().

◆ comp_ppf_gains()

static void comp_ppf_gains ( int  lag,
PPFParam ppf,
enum Rate  cur_rate,
int  tgt_eng,
int  ccr,
int  res_eng 
)
static

Calculate pitch postfilter optimal and scaling gains.

Parameters
lagpitch postfilter forward/backward lag
ppfpitch postfilter parameters
cur_ratecurrent bitrate
tgt_engtarget energy
ccrcross-correlation
res_engresidual energy

Definition at line 299 of file g723_1dec.c.

Referenced by comp_ppf_coeff().

◆ comp_ppf_coeff()

static void comp_ppf_coeff ( G723_1_Context p,
int  offset,
int  pitch_lag,
PPFParam ppf,
enum Rate  cur_rate 
)
static

Calculate pitch postfilter parameters.

Parameters
pthe context
offsetoffset of the excitation vector
pitch_lagdecoded pitch lag
ppfpitch postfilter parameters
cur_ratecurrent bitrate

Definition at line 347 of file g723_1dec.c.

Referenced by g723_1_decode_frame().

◆ comp_interp_index()

static int comp_interp_index ( G723_1_Context p,
int  pitch_lag,
int exc_eng,
int scale 
)
static

Classify frames as voiced/unvoiced.

Parameters
pthe context
pitch_lagdecoded pitch_lag
exc_engexcitation energy estimation
scalescaling factor of exc_eng
Returns
residual interpolation index if voiced, 0 otherwise

Definition at line 433 of file g723_1dec.c.

Referenced by g723_1_decode_frame().

◆ residual_interp()

static void residual_interp ( int16_t *  buf,
int16_t *  out,
int  lag,
int  gain,
int rseed 
)
static

Perform residual interpolation based on frame classification.

Parameters
bufdecoded excitation vector
outoutput vector
lagdecoded pitch lag
gaininterpolated gain
rseedseed for random number generator

Definition at line 478 of file g723_1dec.c.

Referenced by g723_1_decode_frame().

◆ gain_scale()

static void gain_scale ( G723_1_Context p,
int16_t *  buf,
int  energy 
)
static

Adjust gain of postfiltered signal.

Parameters
pthe context
bufpostfiltered output vector
energyinput energy coefficient

Definition at line 532 of file g723_1dec.c.

Referenced by formant_postfilter().

◆ formant_postfilter()

static void formant_postfilter ( G723_1_Context p,
int16_t *  lpc,
int16_t *  buf,
int16_t *  dst 
)
static

Perform formant filtering.

Parameters
pthe context
lpcquantized lpc coefficients
bufinput buffer
dstoutput buffer

Definition at line 575 of file g723_1dec.c.

Referenced by g723_1_decode_frame().

◆ sid_gain_to_lsp_index()

static int sid_gain_to_lsp_index ( int  gain)
static

Definition at line 642 of file g723_1dec.c.

Referenced by g723_1_decode_frame().

◆ cng_rand()

static int cng_rand ( int state,
int  base 
)
inlinestatic

Definition at line 652 of file g723_1dec.c.

Referenced by generate_noise().

◆ estimate_sid_gain()

static int estimate_sid_gain ( G723_1_Context p)
static

Definition at line 658 of file g723_1dec.c.

Referenced by g723_1_decode_frame().

◆ generate_noise()

static void generate_noise ( G723_1_Context p)
static

Definition at line 718 of file g723_1dec.c.

Referenced by g723_1_decode_frame().

◆ g723_1_decode_frame()

static int g723_1_decode_frame ( AVCodecContext avctx,
void data,
int got_frame_ptr,
AVPacket avpkt 
)
static

Definition at line 843 of file g723_1dec.c.

Variable Documentation

◆ options

const AVOption options[]
static
Initial value:
= {
{ "postfilter", "enable postfilter", OFFSET(postfilter), AV_OPT_TYPE_BOOL,
{ .i64 = 1 }, 0, 1, AD },
{ NULL }
}
#define NULL
Definition: coverity.c:32
static void postfilter(AMRContext *p, float *lpc, float *buf_out)
Perform adaptive post-filtering to enhance the quality of the speech.
Definition: amrnbdec.c:904
#define OFFSET(x)
Definition: g723_1dec.c:1007
#define AD
Definition: g723_1dec.c:1008

Definition at line 1010 of file g723_1dec.c.

◆ g723_1dec_class

const AVClass g723_1dec_class
static
Initial value:
= {
.class_name = "G.723.1 decoder",
.item_name = av_default_item_name,
.option = options,
}
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:191
static const AVOption options[]
Definition: g723_1dec.c:1010

Definition at line 1017 of file g723_1dec.c.

◆ ff_g723_1_decoder

AVCodec ff_g723_1_decoder
Initial value:
= {
.name = "g723_1",
.long_name = NULL_IF_CONFIG_SMALL("G.723.1"),
.priv_data_size = sizeof(G723_1_Context),
.priv_class = &g723_1dec_class,
}
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
static const AVClass g723_1dec_class
Definition: g723_1dec.c:1017
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:42
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
#define AV_CODEC_CAP_SUBFRAMES
Codec can output multiple frames per AVPacket Normally demuxers return one frame at a time...
Definition: avcodec.h:1002
static av_cold int g723_1_decode_init(AVCodecContext *avctx)
Definition: g723_1dec.c:43
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:959
static int g723_1_decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
Definition: g723_1dec.c:843

Definition at line 1024 of file g723_1dec.c.