0,0 → 1,795 |
/* |
* QCELP decoder |
* Copyright (c) 2007 Reynaldo H. Verdejo Pinochet |
* |
* This file is part of FFmpeg. |
* |
* FFmpeg is free software; you can redistribute it and/or |
* modify it under the terms of the GNU Lesser General Public |
* License as published by the Free Software Foundation; either |
* version 2.1 of the License, or (at your option) any later version. |
* |
* FFmpeg is distributed in the hope that it will be useful, |
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
* Lesser General Public License for more details. |
* |
* You should have received a copy of the GNU Lesser General Public |
* License along with FFmpeg; if not, write to the Free Software |
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
*/ |
|
/** |
* @file |
* QCELP decoder |
* @author Reynaldo H. Verdejo Pinochet |
* @remark FFmpeg merging spearheaded by Kenan Gillet |
* @remark Development mentored by Benjamin Larson |
*/ |
|
#include <stddef.h> |
|
#include "libavutil/avassert.h" |
#include "libavutil/channel_layout.h" |
#include "libavutil/float_dsp.h" |
#include "avcodec.h" |
#include "internal.h" |
#include "get_bits.h" |
#include "qcelpdata.h" |
#include "celp_filters.h" |
#include "acelp_filters.h" |
#include "acelp_vectors.h" |
#include "lsp.h" |
|
typedef enum { |
I_F_Q = -1, /**< insufficient frame quality */ |
SILENCE, |
RATE_OCTAVE, |
RATE_QUARTER, |
RATE_HALF, |
RATE_FULL |
} qcelp_packet_rate; |
|
typedef struct { |
GetBitContext gb; |
qcelp_packet_rate bitrate; |
QCELPFrame frame; /**< unpacked data frame */ |
|
uint8_t erasure_count; |
uint8_t octave_count; /**< count the consecutive RATE_OCTAVE frames */ |
float prev_lspf[10]; |
float predictor_lspf[10];/**< LSP predictor for RATE_OCTAVE and I_F_Q */ |
float pitch_synthesis_filter_mem[303]; |
float pitch_pre_filter_mem[303]; |
float rnd_fir_filter_mem[180]; |
float formant_mem[170]; |
float last_codebook_gain; |
int prev_g1[2]; |
int prev_bitrate; |
float pitch_gain[4]; |
uint8_t pitch_lag[4]; |
uint16_t first16bits; |
uint8_t warned_buf_mismatch_bitrate; |
|
/* postfilter */ |
float postfilter_synth_mem[10]; |
float postfilter_agc_mem; |
float postfilter_tilt_mem; |
} QCELPContext; |
|
/** |
* Initialize the speech codec according to the specification. |
* |
* TIA/EIA/IS-733 2.4.9 |
*/ |
static av_cold int qcelp_decode_init(AVCodecContext *avctx) |
{ |
QCELPContext *q = avctx->priv_data; |
int i; |
|
avctx->channels = 1; |
avctx->channel_layout = AV_CH_LAYOUT_MONO; |
avctx->sample_fmt = AV_SAMPLE_FMT_FLT; |
|
for (i = 0; i < 10; i++) |
q->prev_lspf[i] = (i + 1) / 11.0; |
|
return 0; |
} |
|
/** |
* Decode the 10 quantized LSP frequencies from the LSPV/LSP |
* transmission codes of any bitrate and check for badly received packets. |
* |
* @param q the context |
* @param lspf line spectral pair frequencies |
* |
* @return 0 on success, -1 if the packet is badly received |
* |
* TIA/EIA/IS-733 2.4.3.2.6.2-2, 2.4.8.7.3 |
*/ |
static int decode_lspf(QCELPContext *q, float *lspf) |
{ |
int i; |
float tmp_lspf, smooth, erasure_coeff; |
const float *predictors; |
|
if (q->bitrate == RATE_OCTAVE || q->bitrate == I_F_Q) { |
predictors = q->prev_bitrate != RATE_OCTAVE && |
q->prev_bitrate != I_F_Q ? q->prev_lspf |
: q->predictor_lspf; |
|
if (q->bitrate == RATE_OCTAVE) { |
q->octave_count++; |
|
for (i = 0; i < 10; i++) { |
q->predictor_lspf[i] = |
lspf[i] = (q->frame.lspv[i] ? QCELP_LSP_SPREAD_FACTOR |
: -QCELP_LSP_SPREAD_FACTOR) + |
predictors[i] * QCELP_LSP_OCTAVE_PREDICTOR + |
(i + 1) * ((1 - QCELP_LSP_OCTAVE_PREDICTOR) / 11); |
} |
smooth = q->octave_count < 10 ? .875 : 0.1; |
} else { |
erasure_coeff = QCELP_LSP_OCTAVE_PREDICTOR; |
|
av_assert2(q->bitrate == I_F_Q); |
|
if (q->erasure_count > 1) |
erasure_coeff *= q->erasure_count < 4 ? 0.9 : 0.7; |
|
for (i = 0; i < 10; i++) { |
q->predictor_lspf[i] = |
lspf[i] = (i + 1) * (1 - erasure_coeff) / 11 + |
erasure_coeff * predictors[i]; |
} |
smooth = 0.125; |
} |
|
// Check the stability of the LSP frequencies. |
lspf[0] = FFMAX(lspf[0], QCELP_LSP_SPREAD_FACTOR); |
for (i = 1; i < 10; i++) |
lspf[i] = FFMAX(lspf[i], lspf[i - 1] + QCELP_LSP_SPREAD_FACTOR); |
|
lspf[9] = FFMIN(lspf[9], 1.0 - QCELP_LSP_SPREAD_FACTOR); |
for (i = 9; i > 0; i--) |
lspf[i - 1] = FFMIN(lspf[i - 1], lspf[i] - QCELP_LSP_SPREAD_FACTOR); |
|
// Low-pass filter the LSP frequencies. |
ff_weighted_vector_sumf(lspf, lspf, q->prev_lspf, smooth, 1.0 - smooth, 10); |
} else { |
q->octave_count = 0; |
|
tmp_lspf = 0.0; |
for (i = 0; i < 5; i++) { |
lspf[2 * i + 0] = tmp_lspf += qcelp_lspvq[i][q->frame.lspv[i]][0] * 0.0001; |
lspf[2 * i + 1] = tmp_lspf += qcelp_lspvq[i][q->frame.lspv[i]][1] * 0.0001; |
} |
|
// Check for badly received packets. |
if (q->bitrate == RATE_QUARTER) { |
if (lspf[9] <= .70 || lspf[9] >= .97) |
return -1; |
for (i = 3; i < 10; i++) |
if (fabs(lspf[i] - lspf[i - 2]) < .08) |
return -1; |
} else { |
if (lspf[9] <= .66 || lspf[9] >= .985) |
return -1; |
for (i = 4; i < 10; i++) |
if (fabs(lspf[i] - lspf[i - 4]) < .0931) |
return -1; |
} |
} |
return 0; |
} |
|
/** |
* Convert codebook transmission codes to GAIN and INDEX. |
* |
* @param q the context |
* @param gain array holding the decoded gain |
* |
* TIA/EIA/IS-733 2.4.6.2 |
*/ |
static void decode_gain_and_index(QCELPContext *q, float *gain) |
{ |
int i, subframes_count, g1[16]; |
float slope; |
|
if (q->bitrate >= RATE_QUARTER) { |
switch (q->bitrate) { |
case RATE_FULL: subframes_count = 16; break; |
case RATE_HALF: subframes_count = 4; break; |
default: subframes_count = 5; |
} |
for (i = 0; i < subframes_count; i++) { |
g1[i] = 4 * q->frame.cbgain[i]; |
if (q->bitrate == RATE_FULL && !((i + 1) & 3)) { |
g1[i] += av_clip((g1[i - 1] + g1[i - 2] + g1[i - 3]) / 3 - 6, 0, 32); |
} |
|
gain[i] = qcelp_g12ga[g1[i]]; |
|
if (q->frame.cbsign[i]) { |
gain[i] = -gain[i]; |
q->frame.cindex[i] = (q->frame.cindex[i] - 89) & 127; |
} |
} |
|
q->prev_g1[0] = g1[i - 2]; |
q->prev_g1[1] = g1[i - 1]; |
q->last_codebook_gain = qcelp_g12ga[g1[i - 1]]; |
|
if (q->bitrate == RATE_QUARTER) { |
// Provide smoothing of the unvoiced excitation energy. |
gain[7] = gain[4]; |
gain[6] = 0.4 * gain[3] + 0.6 * gain[4]; |
gain[5] = gain[3]; |
gain[4] = 0.8 * gain[2] + 0.2 * gain[3]; |
gain[3] = 0.2 * gain[1] + 0.8 * gain[2]; |
gain[2] = gain[1]; |
gain[1] = 0.6 * gain[0] + 0.4 * gain[1]; |
} |
} else if (q->bitrate != SILENCE) { |
if (q->bitrate == RATE_OCTAVE) { |
g1[0] = 2 * q->frame.cbgain[0] + |
av_clip((q->prev_g1[0] + q->prev_g1[1]) / 2 - 5, 0, 54); |
subframes_count = 8; |
} else { |
av_assert2(q->bitrate == I_F_Q); |
|
g1[0] = q->prev_g1[1]; |
switch (q->erasure_count) { |
case 1 : break; |
case 2 : g1[0] -= 1; break; |
case 3 : g1[0] -= 2; break; |
default: g1[0] -= 6; |
} |
if (g1[0] < 0) |
g1[0] = 0; |
subframes_count = 4; |
} |
// This interpolation is done to produce smoother background noise. |
slope = 0.5 * (qcelp_g12ga[g1[0]] - q->last_codebook_gain) / subframes_count; |
for (i = 1; i <= subframes_count; i++) |
gain[i - 1] = q->last_codebook_gain + slope * i; |
|
q->last_codebook_gain = gain[i - 2]; |
q->prev_g1[0] = q->prev_g1[1]; |
q->prev_g1[1] = g1[0]; |
} |
} |
|
/** |
* If the received packet is Rate 1/4 a further sanity check is made of the |
* codebook gain. |
* |
* @param cbgain the unpacked cbgain array |
* @return -1 if the sanity check fails, 0 otherwise |
* |
* TIA/EIA/IS-733 2.4.8.7.3 |
*/ |
static int codebook_sanity_check_for_rate_quarter(const uint8_t *cbgain) |
{ |
int i, diff, prev_diff = 0; |
|
for (i = 1; i < 5; i++) { |
diff = cbgain[i] - cbgain[i-1]; |
if (FFABS(diff) > 10) |
return -1; |
else if (FFABS(diff - prev_diff) > 12) |
return -1; |
prev_diff = diff; |
} |
return 0; |
} |
|
/** |
* Compute the scaled codebook vector Cdn From INDEX and GAIN |
* for all rates. |
* |
* The specification lacks some information here. |
* |
* TIA/EIA/IS-733 has an omission on the codebook index determination |
* formula for RATE_FULL and RATE_HALF frames at section 2.4.8.1.1. It says |
* you have to subtract the decoded index parameter from the given scaled |
* codebook vector index 'n' to get the desired circular codebook index, but |
* it does not mention that you have to clamp 'n' to [0-9] in order to get |
* RI-compliant results. |
* |
* The reason for this mistake seems to be the fact they forgot to mention you |
* have to do these calculations per codebook subframe and adjust given |
* equation values accordingly. |
* |
* @param q the context |
* @param gain array holding the 4 pitch subframe gain values |
* @param cdn_vector array for the generated scaled codebook vector |
*/ |
static void compute_svector(QCELPContext *q, const float *gain, |
float *cdn_vector) |
{ |
int i, j, k; |
uint16_t cbseed, cindex; |
float *rnd, tmp_gain, fir_filter_value; |
|
switch (q->bitrate) { |
case RATE_FULL: |
for (i = 0; i < 16; i++) { |
tmp_gain = gain[i] * QCELP_RATE_FULL_CODEBOOK_RATIO; |
cindex = -q->frame.cindex[i]; |
for (j = 0; j < 10; j++) |
*cdn_vector++ = tmp_gain * qcelp_rate_full_codebook[cindex++ & 127]; |
} |
break; |
case RATE_HALF: |
for (i = 0; i < 4; i++) { |
tmp_gain = gain[i] * QCELP_RATE_HALF_CODEBOOK_RATIO; |
cindex = -q->frame.cindex[i]; |
for (j = 0; j < 40; j++) |
*cdn_vector++ = tmp_gain * qcelp_rate_half_codebook[cindex++ & 127]; |
} |
break; |
case RATE_QUARTER: |
cbseed = (0x0003 & q->frame.lspv[4]) << 14 | |
(0x003F & q->frame.lspv[3]) << 8 | |
(0x0060 & q->frame.lspv[2]) << 1 | |
(0x0007 & q->frame.lspv[1]) << 3 | |
(0x0038 & q->frame.lspv[0]) >> 3; |
rnd = q->rnd_fir_filter_mem + 20; |
for (i = 0; i < 8; i++) { |
tmp_gain = gain[i] * (QCELP_SQRT1887 / 32768.0); |
for (k = 0; k < 20; k++) { |
cbseed = 521 * cbseed + 259; |
*rnd = (int16_t) cbseed; |
|
// FIR filter |
fir_filter_value = 0.0; |
for (j = 0; j < 10; j++) |
fir_filter_value += qcelp_rnd_fir_coefs[j] * |
(rnd[-j] + rnd[-20+j]); |
|
fir_filter_value += qcelp_rnd_fir_coefs[10] * rnd[-10]; |
*cdn_vector++ = tmp_gain * fir_filter_value; |
rnd++; |
} |
} |
memcpy(q->rnd_fir_filter_mem, q->rnd_fir_filter_mem + 160, |
20 * sizeof(float)); |
break; |
case RATE_OCTAVE: |
cbseed = q->first16bits; |
for (i = 0; i < 8; i++) { |
tmp_gain = gain[i] * (QCELP_SQRT1887 / 32768.0); |
for (j = 0; j < 20; j++) { |
cbseed = 521 * cbseed + 259; |
*cdn_vector++ = tmp_gain * (int16_t) cbseed; |
} |
} |
break; |
case I_F_Q: |
cbseed = -44; // random codebook index |
for (i = 0; i < 4; i++) { |
tmp_gain = gain[i] * QCELP_RATE_FULL_CODEBOOK_RATIO; |
for (j = 0; j < 40; j++) |
*cdn_vector++ = tmp_gain * qcelp_rate_full_codebook[cbseed++ & 127]; |
} |
break; |
case SILENCE: |
memset(cdn_vector, 0, 160 * sizeof(float)); |
break; |
} |
} |
|
/** |
* Apply generic gain control. |
* |
* @param v_out output vector |
* @param v_in gain-controlled vector |
* @param v_ref vector to control gain of |
* |
* TIA/EIA/IS-733 2.4.8.3, 2.4.8.6 |
*/ |
static void apply_gain_ctrl(float *v_out, const float *v_ref, const float *v_in) |
{ |
int i; |
|
for (i = 0; i < 160; i += 40) { |
float res = avpriv_scalarproduct_float_c(v_ref + i, v_ref + i, 40); |
ff_scale_vector_to_given_sum_of_squares(v_out + i, v_in + i, res, 40); |
} |
} |
|
/** |
* Apply filter in pitch-subframe steps. |
* |
* @param memory buffer for the previous state of the filter |
* - must be able to contain 303 elements |
* - the 143 first elements are from the previous state |
* - the next 160 are for output |
* @param v_in input filter vector |
* @param gain per-subframe gain array, each element is between 0.0 and 2.0 |
* @param lag per-subframe lag array, each element is |
* - between 16 and 143 if its corresponding pfrac is 0, |
* - between 16 and 139 otherwise |
* @param pfrac per-subframe boolean array, 1 if the lag is fractional, 0 |
* otherwise |
* |
* @return filter output vector |
*/ |
static const float *do_pitchfilter(float memory[303], const float v_in[160], |
const float gain[4], const uint8_t *lag, |
const uint8_t pfrac[4]) |
{ |
int i, j; |
float *v_lag, *v_out; |
const float *v_len; |
|
v_out = memory + 143; // Output vector starts at memory[143]. |
|
for (i = 0; i < 4; i++) { |
if (gain[i]) { |
v_lag = memory + 143 + 40 * i - lag[i]; |
for (v_len = v_in + 40; v_in < v_len; v_in++) { |
if (pfrac[i]) { // If it is a fractional lag... |
for (j = 0, *v_out = 0.0; j < 4; j++) |
*v_out += qcelp_hammsinc_table[j] * (v_lag[j - 4] + v_lag[3 - j]); |
} else |
*v_out = *v_lag; |
|
*v_out = *v_in + gain[i] * *v_out; |
|
v_lag++; |
v_out++; |
} |
} else { |
memcpy(v_out, v_in, 40 * sizeof(float)); |
v_in += 40; |
v_out += 40; |
} |
} |
|
memmove(memory, memory + 160, 143 * sizeof(float)); |
return memory + 143; |
} |
|
/** |
* Apply pitch synthesis filter and pitch prefilter to the scaled codebook vector. |
* TIA/EIA/IS-733 2.4.5.2, 2.4.8.7.2 |
* |
* @param q the context |
* @param cdn_vector the scaled codebook vector |
*/ |
static void apply_pitch_filters(QCELPContext *q, float *cdn_vector) |
{ |
int i; |
const float *v_synthesis_filtered, *v_pre_filtered; |
|
if (q->bitrate >= RATE_HALF || q->bitrate == SILENCE || |
(q->bitrate == I_F_Q && (q->prev_bitrate >= RATE_HALF))) { |
|
if (q->bitrate >= RATE_HALF) { |
// Compute gain & lag for the whole frame. |
for (i = 0; i < 4; i++) { |
q->pitch_gain[i] = q->frame.plag[i] ? (q->frame.pgain[i] + 1) * 0.25 : 0.0; |
|
q->pitch_lag[i] = q->frame.plag[i] + 16; |
} |
} else { |
float max_pitch_gain; |
|
if (q->bitrate == I_F_Q) { |
if (q->erasure_count < 3) |
max_pitch_gain = 0.9 - 0.3 * (q->erasure_count - 1); |
else |
max_pitch_gain = 0.0; |
} else { |
av_assert2(q->bitrate == SILENCE); |
max_pitch_gain = 1.0; |
} |
for (i = 0; i < 4; i++) |
q->pitch_gain[i] = FFMIN(q->pitch_gain[i], max_pitch_gain); |
|
memset(q->frame.pfrac, 0, sizeof(q->frame.pfrac)); |
} |
|
// pitch synthesis filter |
v_synthesis_filtered = do_pitchfilter(q->pitch_synthesis_filter_mem, |
cdn_vector, q->pitch_gain, |
q->pitch_lag, q->frame.pfrac); |
|
// pitch prefilter update |
for (i = 0; i < 4; i++) |
q->pitch_gain[i] = 0.5 * FFMIN(q->pitch_gain[i], 1.0); |
|
v_pre_filtered = do_pitchfilter(q->pitch_pre_filter_mem, |
v_synthesis_filtered, |
q->pitch_gain, q->pitch_lag, |
q->frame.pfrac); |
|
apply_gain_ctrl(cdn_vector, v_synthesis_filtered, v_pre_filtered); |
} else { |
memcpy(q->pitch_synthesis_filter_mem, cdn_vector + 17, 143 * sizeof(float)); |
memcpy(q->pitch_pre_filter_mem, cdn_vector + 17, 143 * sizeof(float)); |
memset(q->pitch_gain, 0, sizeof(q->pitch_gain)); |
memset(q->pitch_lag, 0, sizeof(q->pitch_lag)); |
} |
} |
|
/** |
* Reconstruct LPC coefficients from the line spectral pair frequencies |
* and perform bandwidth expansion. |
* |
* @param lspf line spectral pair frequencies |
* @param lpc linear predictive coding coefficients |
* |
* @note: bandwidth_expansion_coeff could be precalculated into a table |
* but it seems to be slower on x86 |
* |
* TIA/EIA/IS-733 2.4.3.3.5 |
*/ |
static void lspf2lpc(const float *lspf, float *lpc) |
{ |
double lsp[10]; |
double bandwidth_expansion_coeff = QCELP_BANDWIDTH_EXPANSION_COEFF; |
int i; |
|
for (i = 0; i < 10; i++) |
lsp[i] = cos(M_PI * lspf[i]); |
|
ff_acelp_lspd2lpc(lsp, lpc, 5); |
|
for (i = 0; i < 10; i++) { |
lpc[i] *= bandwidth_expansion_coeff; |
bandwidth_expansion_coeff *= QCELP_BANDWIDTH_EXPANSION_COEFF; |
} |
} |
|
/** |
* Interpolate LSP frequencies and compute LPC coefficients |
* for a given bitrate & pitch subframe. |
* |
* TIA/EIA/IS-733 2.4.3.3.4, 2.4.8.7.2 |
* |
* @param q the context |
* @param curr_lspf LSP frequencies vector of the current frame |
* @param lpc float vector for the resulting LPC |
* @param subframe_num frame number in decoded stream |
*/ |
static void interpolate_lpc(QCELPContext *q, const float *curr_lspf, |
float *lpc, const int subframe_num) |
{ |
float interpolated_lspf[10]; |
float weight; |
|
if (q->bitrate >= RATE_QUARTER) |
weight = 0.25 * (subframe_num + 1); |
else if (q->bitrate == RATE_OCTAVE && !subframe_num) |
weight = 0.625; |
else |
weight = 1.0; |
|
if (weight != 1.0) { |
ff_weighted_vector_sumf(interpolated_lspf, curr_lspf, q->prev_lspf, |
weight, 1.0 - weight, 10); |
lspf2lpc(interpolated_lspf, lpc); |
} else if (q->bitrate >= RATE_QUARTER || |
(q->bitrate == I_F_Q && !subframe_num)) |
lspf2lpc(curr_lspf, lpc); |
else if (q->bitrate == SILENCE && !subframe_num) |
lspf2lpc(q->prev_lspf, lpc); |
} |
|
static qcelp_packet_rate buf_size2bitrate(const int buf_size) |
{ |
switch (buf_size) { |
case 35: return RATE_FULL; |
case 17: return RATE_HALF; |
case 8: return RATE_QUARTER; |
case 4: return RATE_OCTAVE; |
case 1: return SILENCE; |
} |
|
return I_F_Q; |
} |
|
/** |
* Determine the bitrate from the frame size and/or the first byte of the frame. |
* |
* @param avctx the AV codec context |
* @param buf_size length of the buffer |
* @param buf the bufffer |
* |
* @return the bitrate on success, |
* I_F_Q if the bitrate cannot be satisfactorily determined |
* |
* TIA/EIA/IS-733 2.4.8.7.1 |
*/ |
static qcelp_packet_rate determine_bitrate(AVCodecContext *avctx, |
const int buf_size, |
const uint8_t **buf) |
{ |
qcelp_packet_rate bitrate; |
|
if ((bitrate = buf_size2bitrate(buf_size)) >= 0) { |
if (bitrate > **buf) { |
QCELPContext *q = avctx->priv_data; |
if (!q->warned_buf_mismatch_bitrate) { |
av_log(avctx, AV_LOG_WARNING, |
"Claimed bitrate and buffer size mismatch.\n"); |
q->warned_buf_mismatch_bitrate = 1; |
} |
bitrate = **buf; |
} else if (bitrate < **buf) { |
av_log(avctx, AV_LOG_ERROR, |
"Buffer is too small for the claimed bitrate.\n"); |
return I_F_Q; |
} |
(*buf)++; |
} else if ((bitrate = buf_size2bitrate(buf_size + 1)) >= 0) { |
av_log(avctx, AV_LOG_WARNING, |
"Bitrate byte is missing, guessing the bitrate from packet size.\n"); |
} else |
return I_F_Q; |
|
if (bitrate == SILENCE) { |
// FIXME: Remove this warning when tested with samples. |
avpriv_request_sample(avctx, "Blank frame handling"); |
} |
return bitrate; |
} |
|
static void warn_insufficient_frame_quality(AVCodecContext *avctx, |
const char *message) |
{ |
av_log(avctx, AV_LOG_WARNING, "Frame #%d, IFQ: %s\n", |
avctx->frame_number, message); |
} |
|
static void postfilter(QCELPContext *q, float *samples, float *lpc) |
{ |
static const float pow_0_775[10] = { |
0.775000, 0.600625, 0.465484, 0.360750, 0.279582, |
0.216676, 0.167924, 0.130141, 0.100859, 0.078166 |
}, pow_0_625[10] = { |
0.625000, 0.390625, 0.244141, 0.152588, 0.095367, |
0.059605, 0.037253, 0.023283, 0.014552, 0.009095 |
}; |
float lpc_s[10], lpc_p[10], pole_out[170], zero_out[160]; |
int n; |
|
for (n = 0; n < 10; n++) { |
lpc_s[n] = lpc[n] * pow_0_625[n]; |
lpc_p[n] = lpc[n] * pow_0_775[n]; |
} |
|
ff_celp_lp_zero_synthesis_filterf(zero_out, lpc_s, |
q->formant_mem + 10, 160, 10); |
memcpy(pole_out, q->postfilter_synth_mem, sizeof(float) * 10); |
ff_celp_lp_synthesis_filterf(pole_out + 10, lpc_p, zero_out, 160, 10); |
memcpy(q->postfilter_synth_mem, pole_out + 160, sizeof(float) * 10); |
|
ff_tilt_compensation(&q->postfilter_tilt_mem, 0.3, pole_out + 10, 160); |
|
ff_adaptive_gain_control(samples, pole_out + 10, |
avpriv_scalarproduct_float_c(q->formant_mem + 10, |
q->formant_mem + 10, |
160), |
160, 0.9375, &q->postfilter_agc_mem); |
} |
|
static int qcelp_decode_frame(AVCodecContext *avctx, void *data, |
int *got_frame_ptr, AVPacket *avpkt) |
{ |
const uint8_t *buf = avpkt->data; |
int buf_size = avpkt->size; |
QCELPContext *q = avctx->priv_data; |
AVFrame *frame = data; |
float *outbuffer; |
int i, ret; |
float quantized_lspf[10], lpc[10]; |
float gain[16]; |
float *formant_mem; |
|
/* get output buffer */ |
frame->nb_samples = 160; |
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) |
return ret; |
outbuffer = (float *)frame->data[0]; |
|
if ((q->bitrate = determine_bitrate(avctx, buf_size, &buf)) == I_F_Q) { |
warn_insufficient_frame_quality(avctx, "bitrate cannot be determined."); |
goto erasure; |
} |
|
if (q->bitrate == RATE_OCTAVE && |
(q->first16bits = AV_RB16(buf)) == 0xFFFF) { |
warn_insufficient_frame_quality(avctx, "Bitrate is 1/8 and first 16 bits are on."); |
goto erasure; |
} |
|
if (q->bitrate > SILENCE) { |
const QCELPBitmap *bitmaps = qcelp_unpacking_bitmaps_per_rate[q->bitrate]; |
const QCELPBitmap *bitmaps_end = qcelp_unpacking_bitmaps_per_rate[q->bitrate] + |
qcelp_unpacking_bitmaps_lengths[q->bitrate]; |
uint8_t *unpacked_data = (uint8_t *)&q->frame; |
|
init_get_bits(&q->gb, buf, 8 * buf_size); |
|
memset(&q->frame, 0, sizeof(QCELPFrame)); |
|
for (; bitmaps < bitmaps_end; bitmaps++) |
unpacked_data[bitmaps->index] |= get_bits(&q->gb, bitmaps->bitlen) << bitmaps->bitpos; |
|
// Check for erasures/blanks on rates 1, 1/4 and 1/8. |
if (q->frame.reserved) { |
warn_insufficient_frame_quality(avctx, "Wrong data in reserved frame area."); |
goto erasure; |
} |
if (q->bitrate == RATE_QUARTER && |
codebook_sanity_check_for_rate_quarter(q->frame.cbgain)) { |
warn_insufficient_frame_quality(avctx, "Codebook gain sanity check failed."); |
goto erasure; |
} |
|
if (q->bitrate >= RATE_HALF) { |
for (i = 0; i < 4; i++) { |
if (q->frame.pfrac[i] && q->frame.plag[i] >= 124) { |
warn_insufficient_frame_quality(avctx, "Cannot initialize pitch filter."); |
goto erasure; |
} |
} |
} |
} |
|
decode_gain_and_index(q, gain); |
compute_svector(q, gain, outbuffer); |
|
if (decode_lspf(q, quantized_lspf) < 0) { |
warn_insufficient_frame_quality(avctx, "Badly received packets in frame."); |
goto erasure; |
} |
|
apply_pitch_filters(q, outbuffer); |
|
if (q->bitrate == I_F_Q) { |
erasure: |
q->bitrate = I_F_Q; |
q->erasure_count++; |
decode_gain_and_index(q, gain); |
compute_svector(q, gain, outbuffer); |
decode_lspf(q, quantized_lspf); |
apply_pitch_filters(q, outbuffer); |
} else |
q->erasure_count = 0; |
|
formant_mem = q->formant_mem + 10; |
for (i = 0; i < 4; i++) { |
interpolate_lpc(q, quantized_lspf, lpc, i); |
ff_celp_lp_synthesis_filterf(formant_mem, lpc, outbuffer + i * 40, 40, 10); |
formant_mem += 40; |
} |
|
// postfilter, as per TIA/EIA/IS-733 2.4.8.6 |
postfilter(q, outbuffer, lpc); |
|
memcpy(q->formant_mem, q->formant_mem + 160, 10 * sizeof(float)); |
|
memcpy(q->prev_lspf, quantized_lspf, sizeof(q->prev_lspf)); |
q->prev_bitrate = q->bitrate; |
|
*got_frame_ptr = 1; |
|
return buf_size; |
} |
|
AVCodec ff_qcelp_decoder = { |
.name = "qcelp", |
.long_name = NULL_IF_CONFIG_SMALL("QCELP / PureVoice"), |
.type = AVMEDIA_TYPE_AUDIO, |
.id = AV_CODEC_ID_QCELP, |
.init = qcelp_decode_init, |
.decode = qcelp_decode_frame, |
.capabilities = CODEC_CAP_DR1, |
.priv_data_size = sizeof(QCELPContext), |
}; |