evrcdec.c File Reference

Enhanced Variable Rate Codec, Service Option 3 decoder. More...

#include "libavutil/channel_layout.h"
#include "libavutil/mathematics.h"
#include "libavutil/opt.h"
#include "avcodec.h"
#include "codec_internal.h"
#include "decode.h"
#include "get_bits.h"
#include "evrcdata.h"
#include "acelp_vectors.h"
#include "lsp.h"

Go to the source code of this file.

Data Structures
struct	EVRCAFrame
	EVRC-A unpacked data frame. More...
struct	EVRCContext
struct	PfCoeff

Macros
#define	MIN_LSP_SEP   (0.05 / (2.0 * M_PI))
#define	MIN_DELAY   20
#define	MAX_DELAY   120
#define	NB_SUBFRAMES   3
#define	SUBFRAME_SIZE   54
#define	FILTER_ORDER   10
#define	ACB_SIZE   128
#define	OFFSET(x)
#define	AD   AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM

Enumerations
enum	evrc_packet_rate {   RATE_ERRS = -1 , SILENCE , RATE_QUANT , RATE_QUARTER ,   RATE_HALF , RATE_FULL }

Functions
static void	unpack_frame (EVRCContext *e)
	Frame unpacking for RATE_FULL, RATE_HALF and RATE_QUANT.
static evrc_packet_rate	buf_size2bitrate (const int buf_size)
static evrc_packet_rate	determine_bitrate (AVCodecContext *avctx, int *buf_size, const uint8_t **buf)
	Determine the bitrate from the frame size and/or the first byte of the frame.
static void	warn_insufficient_frame_quality (AVCodecContext *avctx, const char *message)
static av_cold int	evrc_decode_init (AVCodecContext *avctx)
	Initialize the speech codec according to the specification.
static int	decode_lspf (EVRCContext *e)
	Decode the 10 vector quantized line spectral pair frequencies from the LSP transmission codes of any bitrate and check for badly received packets.
static void	interpolate_lsp (float *ilsp, const float *lsp, const float *prev, int index)
static void	interpolate_delay (float *dst, float current, float prev, int index)
static void	decode_predictor_coeffs (const float *ilspf, float *ilpc)
static void	bl_intrp (EVRCContext *e, float *ex, float delay)
static void	acb_excitation (EVRCContext *e, float *excitation, float gain, const float delay[3], int length)
static void	decode_8_pulses_35bits (const uint16_t *fixed_index, float *cod)
static void	decode_3_pulses_10bits (uint16_t fixed_index, float *cod)
static void	fcb_excitation (EVRCContext *e, const uint16_t *codebook, float *excitation, float pitch_gain, int pitch_lag, int subframe_size)
static void	synthesis_filter (const float *in, const float *filter_coeffs, float *memory, int buffer_length, float *samples)
	Synthesis of the decoder output signal.
static void	bandwidth_expansion (float *coeff, const float *inbuf, float gamma)
static void	residual_filter (float *output, const float *input, const float *coef, float *memory, int length)
static void	postfilter (EVRCContext *e, float *in, const float *coeff, float *out, int idx, const struct PfCoeff *pfc, int length)
static void	frame_erasure (EVRCContext *e, float *samples)
static int	evrc_decode_frame (AVCodecContext *avctx, AVFrame *frame, int *got_frame_ptr, AVPacket *avpkt)

Variables
static const struct PfCoeff	postfilter_coeffs [5]
static const AVOption	options []
static const AVClass	evrcdec_class
const FFCodec	ff_evrc_decoder

Detailed Description

Enhanced Variable Rate Codec, Service Option 3 decoder.

Author

Paul B Mahol

Definition in file evrcdec.c.

Macro Definition Documentation

MIN_LSP_SEP

#define MIN_LSP_SEP   (0.05 / (2.0 * M_PI))

Definition at line 39 of file evrcdec.c.

Referenced by decode_lspf().

MIN_DELAY

#define MIN_DELAY   20

Definition at line 40 of file evrcdec.c.

Referenced by evrc_decode_frame(), frame_erasure(), and postfilter().

MAX_DELAY

#define MAX_DELAY   120

Definition at line 41 of file evrcdec.c.

NB_SUBFRAMES

#define NB_SUBFRAMES   3

Definition at line 42 of file evrcdec.c.

Referenced by evrc_decode_frame(), and frame_erasure().

SUBFRAME_SIZE

#define SUBFRAME_SIZE   54

Definition at line 43 of file evrcdec.c.

Referenced by decode_frame(), decoder_init(), evrc_decode_frame(), ff_g729_postfilter(), frame_erasure(), g729d_get_new_exc(), long_term_filter(), and postfilter().

FILTER_ORDER

#define FILTER_ORDER   10

Definition at line 44 of file evrcdec.c.

Referenced by bandwidth_expansion(), decode_lspf(), decode_predictor_coeffs(), draw_curves(), equalizer(), evrc_decode_frame(), evrc_decode_init(), frame_erasure(), interpolate_lsp(), postfilter(), process_sample(), residual_filter(), and synthesis_filter().

ACB_SIZE

#define ACB_SIZE   128

Definition at line 45 of file evrcdec.c.

Referenced by evrc_decode_frame(), evrc_decode_init(), frame_erasure(), and postfilter().

OFFSET

#define OFFSET

(

x

)

Value:

offsetof(EVRCContext, x)

Definition at line 919 of file evrcdec.c.

AD

#define AD   AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM

Definition at line 920 of file evrcdec.c.

Referenced by interpolate().

Enumeration Type Documentation

evrc_packet_rate

enum evrc_packet_rate

Enumerator
RATE_ERRS
SILENCE
RATE_QUANT
RATE_QUARTER
RATE_HALF
RATE_FULL

Definition at line 47 of file evrcdec.c.

Function Documentation

unpack_frame()

static void unpack_frame ( EVRCContext * e )

static

Frame unpacking for RATE_FULL, RATE_HALF and RATE_QUANT.

Parameters

e	the context

TIA/IS-127 Table 4.21-1

Definition at line 110 of file evrcdec.c.

Referenced by evrc_decode_frame().

buf_size2bitrate()

static evrc_packet_rate buf_size2bitrate ( const int buf_size )

static

Definition at line 167 of file evrcdec.c.

Referenced by determine_bitrate().

determine_bitrate()

static evrc_packet_rate determine_bitrate ( AVCodecContext * avctx, int * buf_size, const uint8_t ** buf )

static

Determine the bitrate from the frame size and/or the first byte of the frame.

Parameters

avctx	the AV codec context
buf_size	length of the buffer
buf	the buffer

Returns

the bitrate on success, RATE_ERRS if the bitrate cannot be satisfactorily determined

Definition at line 190 of file evrcdec.c.

Referenced by evrc_decode_frame(), and qcelp_decode_frame().

warn_insufficient_frame_quality()

static void warn_insufficient_frame_quality ( AVCodecContext * avctx, const char * message )

static

Definition at line 221 of file evrcdec.c.

Referenced by evrc_decode_frame().

evrc_decode_init()

static av_cold int evrc_decode_init ( AVCodecContext * avctx )

static

Initialize the speech codec according to the specification.

TIA/IS-127 5.2

Definition at line 233 of file evrcdec.c.

decode_lspf()

static int decode_lspf ( EVRCContext * e )

static

Decode the 10 vector quantized line spectral pair frequencies from the LSP transmission codes of any bitrate and check for badly received packets.

Parameters

e	the context

Returns

0 on success, -1 if the packet is badly received

TIA/IS-127 5.2.1, 5.7.1

Definition at line 286 of file evrcdec.c.

Referenced by evrc_decode_frame().

interpolate_lsp()

static void interpolate_lsp ( float * ilsp, const float * lsp, const float * prev, int index )

static

Definition at line 319 of file evrcdec.c.

Referenced by evrc_decode_frame(), and frame_erasure().

interpolate_delay()

static void interpolate_delay ( float * dst, float current, float prev, int index )

static

Definition at line 333 of file evrcdec.c.

Referenced by evrc_decode_frame(), and frame_erasure().

decode_predictor_coeffs()

static void decode_predictor_coeffs ( const float * ilspf, float * ilpc )

static

Definition at line 350 of file evrcdec.c.

Referenced by evrc_decode_frame(), and frame_erasure().

bl_intrp()

static void bl_intrp ( EVRCContext * e, float * ex, float delay )

static

Definition at line 380 of file evrcdec.c.

Referenced by acb_excitation().

acb_excitation()

static void acb_excitation ( EVRCContext * e, float * excitation, float gain, const float delay[3], int length )

static

Definition at line 408 of file evrcdec.c.

Referenced by evrc_decode_frame(), and frame_erasure().

decode_8_pulses_35bits()

static void decode_8_pulses_35bits ( const uint16_t * fixed_index, float * cod )

static

Definition at line 435 of file evrcdec.c.

Referenced by fcb_excitation().

decode_3_pulses_10bits()

static void decode_3_pulses_10bits ( uint16_t fixed_index, float * cod )

static

Definition at line 460 of file evrcdec.c.

Referenced by fcb_excitation().

fcb_excitation()

static void fcb_excitation ( EVRCContext * e, const uint16_t * codebook, float * excitation, float pitch_gain, int pitch_lag, int subframe_size )

static

Definition at line 480 of file evrcdec.c.

Referenced by evrc_decode_frame().

synthesis_filter()

static void synthesis_filter ( const float * in, const float * filter_coeffs, float * memory, int buffer_length, float * samples )

static

Synthesis of the decoder output signal.

Parameters

[in]	in	input signal
[in]	filter_coeffs	LPC coefficients
	[in/out]	memory synthesis filter memory
	buffer_length	amount of data to process
[out]	samples	output samples

TIA/IS-127 5.2.3.15, 5.7.3.4

Definition at line 508 of file evrcdec.c.

Referenced by evrc_decode_frame(), frame_erasure(), and postfilter().

bandwidth_expansion()

static void bandwidth_expansion ( float * coeff, const float * inbuf, float gamma )

static

Definition at line 524 of file evrcdec.c.

Referenced by evrc_decode_frame(), and postfilter().

residual_filter()

static void residual_filter ( float * output, const float * input, const float * coef, float * memory, int length )

static

Definition at line 535 of file evrcdec.c.

Referenced by postfilter().

postfilter()

static void postfilter ( EVRCContext * e, float * in, const float * coeff, float * out, int idx, const struct PfCoeff * pfc, int length )

static

Definition at line 575 of file evrcdec.c.

Referenced by evrc_decode_frame(), and frame_erasure().

frame_erasure()

static void frame_erasure ( EVRCContext * e, float * samples )

static

Definition at line 656 of file evrcdec.c.

Referenced by decode_frame(), and evrc_decode_frame().

evrc_decode_frame()

static int evrc_decode_frame ( AVCodecContext * avctx, AVFrame * frame, int * got_frame_ptr, AVPacket * avpkt )

static

Definition at line 746 of file evrcdec.c.

Variable Documentation

postfilter_coeffs

const struct PfCoeff postfilter_coeffs[5]

static

Initial value:

= {
    { 0.0 , 0.0 , 0.0 , 0.0  },
    { 0.0 , 0.0 , 0.57, 0.57 },
    { 0.0 , 0.0 , 0.0 , 0.0  },
    { 0.35, 0.50, 0.50, 0.75 },
    { 0.20, 0.50, 0.57, 0.75 },
}

Referenced by evrc_decode_frame(), and frame_erasure().

options

const AVOption options[]

static

Initial value:

= {
    { "postfilter", "enable postfilter", OFFSET(postfilter), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, AD },
    { NULL }
}

Definition at line 922 of file evrcdec.c.

evrcdec_class

const AVClass evrcdec_class

static

Initial value:

= {
    .class_name = "evrc",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
}

Definition at line 927 of file evrcdec.c.

ff_evrc_decoder

const FFCodec ff_evrc_decoder

Initial value:

= {
    .p.name         = "evrc",
    CODEC_LONG_NAME("EVRC (Enhanced Variable Rate Codec)"),
    .p.type         = AVMEDIA_TYPE_AUDIO,
    .p.id           = AV_CODEC_ID_EVRC,
    .init           = evrc_decode_init,
    FF_CODEC_DECODE_CB(evrc_decode_frame),
    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
    .priv_data_size = sizeof(EVRCContext),
    .p.priv_class   = &evrcdec_class,
}

Definition at line 934 of file evrcdec.c.