osmo-gmr 0.2.104-2b98 Osmocom GMR-1

Data Structures | Macros | Enumerations | Functions | Variables
private.h File Reference
AMBE vocoder » AMBE vocoder - internal API

Osmocom GMR-1 AMBE vocoder private header. More...

`#include <stdint.h>`

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## Data Structures
struct | ambe_raw_params
| AMBE encoded frame raw parameters. More...
struct | ambe_subframe
| AMBE subframe parameters. More...
struct | ambe_synth
| AMBE synthesizer state. More...
struct | ambe_decoder
| AMBE decoder state. More...

## Macros
#define | AMBE_RATE 8000
| AMBE sample rate (Hz)
#define | M_PIf (3.141592653589793f)
| Value of pi as a float.

## Enumerations
enum | ambe_frame_type { AMBE_SPEECH , AMBE_SILENCE , AMBE_TONE }
| AMBE possible frame types. More...

## Functions
void | ambe_decode_init (struct ambe_decoder *dec)
| Initializes decoder state. More...
void | ambe_decode_fini (struct ambe_decoder *dec)
| Release all resources associated with a decoder. More...
int | ambe_decode_frame (struct ambe_decoder *dec, int16_t *audio, int N, const uint8_t *frame, int bad)
| Decodes an AMBE frame to audio. More...
int | ambe_decode_dtx (struct ambe_decoder *dec, int16_t *audio, int N)
| Generates audio for DTX period. More...
void | ambe_frame_unpack_raw (struct ambe_raw_params *rp, const uint8_t *frame)
| Unpack a frame into its raw encoded parameters. More...
void | ambe_frame_decode_params (struct ambe_subframe *sf, struct ambe_subframe *sf_prev, struct ambe_raw_params *rp)
| Decodes the speech parameters for both subframes from raw params. More...
void | ambe_subframe_expand (struct ambe_subframe *sf)
| Expands the decoded subframe params to prepare for synthesis. More...
float | cosf_fast (float angle)
| Fast Cosinus approximation using a simple table. More...
float | sinf_fast (float angle)
| Fast Sinus approximation using a simple table. More...
void | ambe_fdct (float *out, float *in, int N, int M)
| Forward Discrete Cosine Transform (fDCT) More...
void | ambe_idct (float *out, float *in, int N, int M)
| Inverse Discrete Cosine Transform (iDCT) More...
void | ambe_fdft_fc (float *out_i, float *out_q, float *in, int N, int M)
| Forward Discrete Fourrier Transform (float->complex) More...
void | ambe_idft_cf (float *out, float *in_i, float *in_q, int N, int M)
| Inverse Discret Fourrier Transform (complex->float) More...
void | ambe_synth_init (struct ambe_synth *synth)
| Initialized Synthesizer state. More...
void | ambe_synth_enhance (struct ambe_synth *synth, struct ambe_subframe *sf)
| Apply the spectral magnitude enhancement on the subframe. More...
void | ambe_synth_audio (struct ambe_synth *synth, int16_t *audio, struct ambe_subframe *sf, struct ambe_subframe *sf_prev)
| Generate audio for a given subframe. More...
int | ambe_decode_tone (struct ambe_decoder *dec, int16_t *audio, int N, const uint8_t *frame)
| Decodes an AMBE tone frame. More...

## Variables
const uint8_t | ambe_hpg_tbl [48][4]
| Number of harmonics per group for a given L (starts at L=9)
const float | ambe_gain_tbl [256][2]
| Gain (subframe 0, subframe 1)
const uint16_t | ambe_v_uv_tbl [64]
| V/UV decisions (subframe 0 = low byte. MSBs = low freq)
const float | ambe_prba12_tbl [128][2]
| PRBA[1:2].
const float | ambe_prba34_tbl [64][2]
| PRBA[3:4].
const float | ambe_prba57_tbl [128][3]
| PRBA[5:7].
const float | ambe_hoc0_tbl [128][4]
| HOC for 1st frequency block.
const float | ambe_hoc1_tbl [64][4]
| HOC for 2nd frequency block.
const float | ambe_hoc2_tbl [64][4]
| HOC for 3rd frequency block.
const float | ambe_hoc3_tbl [64][4]
| HOC for last frequency block.
const float | ambe_sf0_interp_tbl [4]
| Interpolation ratios for subframe 0 magnitude prediction.
const float | ambe_sf0_perr14_tbl [64][4]
| Prediction Error [1:4] for subframe 0.
const float | ambe_sf0_perr58_tbl [32][4]
| Prediction Error [5:8] for subframe 0.

## Detailed Description

Osmocom GMR-1 AMBE vocoder private header.