| /* |
| * Enhanced Variable Rate Codec, Service Option 3 decoder |
| * Copyright (c) 2013 Paul B Mahol |
| * |
| * 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 |
| * Enhanced Variable Rate Codec, Service Option 3 decoder |
| * @author Paul B Mahol |
| */ |
| |
| #include "libavutil/mathematics.h" |
| #include "libavutil/opt.h" |
| #include "avcodec.h" |
| #include "internal.h" |
| #include "get_bits.h" |
| #include "evrcdata.h" |
| #include "acelp_vectors.h" |
| #include "lsp.h" |
| |
| #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 |
| |
| typedef enum { |
| RATE_ERRS = -1, |
| SILENCE, |
| RATE_QUANT, |
| RATE_QUARTER, |
| RATE_HALF, |
| RATE_FULL, |
| } evrc_packet_rate; |
| |
| /** |
| * EVRC-A unpacked data frame |
| */ |
| typedef struct EVRCAFrame { |
| uint8_t lpc_flag; ///< spectral change indicator |
| uint16_t lsp[4]; ///< index into LSP codebook |
| uint8_t pitch_delay; ///< pitch delay for entire frame |
| uint8_t delay_diff; ///< delay difference for entire frame |
| uint8_t acb_gain[3]; ///< adaptive codebook gain |
| uint16_t fcb_shape[3][4]; ///< fixed codebook shape |
| uint8_t fcb_gain[3]; ///< fixed codebook gain index |
| uint8_t energy_gain; ///< frame energy gain index |
| uint8_t tty; ///< tty baud rate bit |
| } EVRCAFrame; |
| |
| typedef struct EVRCContext { |
| AVClass *class; |
| |
| int postfilter; |
| |
| GetBitContext gb; |
| evrc_packet_rate bitrate; |
| evrc_packet_rate last_valid_bitrate; |
| EVRCAFrame frame; |
| |
| float lspf[FILTER_ORDER]; |
| float prev_lspf[FILTER_ORDER]; |
| float synthesis[FILTER_ORDER]; |
| float postfilter_fir[FILTER_ORDER]; |
| float postfilter_iir[FILTER_ORDER]; |
| float postfilter_residual[ACB_SIZE + SUBFRAME_SIZE]; |
| float pitch_delay; |
| float prev_pitch_delay; |
| float avg_acb_gain; ///< average adaptive codebook gain |
| float avg_fcb_gain; ///< average fixed codebook gain |
| float pitch[ACB_SIZE + FILTER_ORDER + SUBFRAME_SIZE]; |
| float pitch_back[ACB_SIZE]; |
| float interpolation_coeffs[136]; |
| float energy_vector[NB_SUBFRAMES]; |
| float fade_scale; |
| float last; |
| |
| uint8_t prev_energy_gain; |
| uint8_t prev_error_flag; |
| uint8_t warned_buf_mismatch_bitrate; |
| } EVRCContext; |
| |
| /** |
| * Frame unpacking for RATE_FULL, RATE_HALF and RATE_QUANT |
| * |
| * @param e the context |
| * |
| * TIA/IS-127 Table 4.21-1 |
| */ |
| static void unpack_frame(EVRCContext *e) |
| { |
| EVRCAFrame *frame = &e->frame; |
| GetBitContext *gb = &e->gb; |
| |
| switch (e->bitrate) { |
| case RATE_FULL: |
| frame->lpc_flag = get_bits1(gb); |
| frame->lsp[0] = get_bits(gb, 6); |
| frame->lsp[1] = get_bits(gb, 6); |
| frame->lsp[2] = get_bits(gb, 9); |
| frame->lsp[3] = get_bits(gb, 7); |
| frame->pitch_delay = get_bits(gb, 7); |
| frame->delay_diff = get_bits(gb, 5); |
| frame->acb_gain[0] = get_bits(gb, 3); |
| frame->fcb_shape[0][0] = get_bits(gb, 8); |
| frame->fcb_shape[0][1] = get_bits(gb, 8); |
| frame->fcb_shape[0][2] = get_bits(gb, 8); |
| frame->fcb_shape[0][3] = get_bits(gb, 11); |
| frame->fcb_gain[0] = get_bits(gb, 5); |
| frame->acb_gain[1] = get_bits(gb, 3); |
| frame->fcb_shape[1][0] = get_bits(gb, 8); |
| frame->fcb_shape[1][1] = get_bits(gb, 8); |
| frame->fcb_shape[1][2] = get_bits(gb, 8); |
| frame->fcb_shape[1][3] = get_bits(gb, 11); |
| frame->fcb_gain [1] = get_bits(gb, 5); |
| frame->acb_gain [2] = get_bits(gb, 3); |
| frame->fcb_shape[2][0] = get_bits(gb, 8); |
| frame->fcb_shape[2][1] = get_bits(gb, 8); |
| frame->fcb_shape[2][2] = get_bits(gb, 8); |
| frame->fcb_shape[2][3] = get_bits(gb, 11); |
| frame->fcb_gain [2] = get_bits(gb, 5); |
| frame->tty = get_bits1(gb); |
| break; |
| case RATE_HALF: |
| frame->lsp [0] = get_bits(gb, 7); |
| frame->lsp [1] = get_bits(gb, 7); |
| frame->lsp [2] = get_bits(gb, 8); |
| frame->pitch_delay = get_bits(gb, 7); |
| frame->acb_gain [0] = get_bits(gb, 3); |
| frame->fcb_shape[0][0] = get_bits(gb, 10); |
| frame->fcb_gain [0] = get_bits(gb, 4); |
| frame->acb_gain [1] = get_bits(gb, 3); |
| frame->fcb_shape[1][0] = get_bits(gb, 10); |
| frame->fcb_gain [1] = get_bits(gb, 4); |
| frame->acb_gain [2] = get_bits(gb, 3); |
| frame->fcb_shape[2][0] = get_bits(gb, 10); |
| frame->fcb_gain [2] = get_bits(gb, 4); |
| break; |
| case RATE_QUANT: |
| frame->lsp [0] = get_bits(gb, 4); |
| frame->lsp [1] = get_bits(gb, 4); |
| frame->energy_gain = get_bits(gb, 8); |
| break; |
| } |
| } |
| |
| static evrc_packet_rate buf_size2bitrate(const int buf_size) |
| { |
| switch (buf_size) { |
| case 23: return RATE_FULL; |
| case 11: return RATE_HALF; |
| case 6: return RATE_QUARTER; |
| case 3: return RATE_QUANT; |
| case 1: return SILENCE; |
| } |
| |
| return RATE_ERRS; |
| } |
| |
| /** |
| * 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, |
| * RATE_ERRS if the bitrate cannot be satisfactorily determined |
| */ |
| static evrc_packet_rate determine_bitrate(AVCodecContext *avctx, |
| int *buf_size, |
| const uint8_t **buf) |
| { |
| evrc_packet_rate bitrate; |
| |
| if ((bitrate = buf_size2bitrate(*buf_size)) >= 0) { |
| if (bitrate > **buf) { |
| EVRCContext *e = avctx->priv_data; |
| if (!e->warned_buf_mismatch_bitrate) { |
| av_log(avctx, AV_LOG_WARNING, |
| "Claimed bitrate and buffer size mismatch.\n"); |
| e->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 RATE_ERRS; |
| } |
| (*buf)++; |
| *buf_size -= 1; |
| } else if ((bitrate = buf_size2bitrate(*buf_size + 1)) >= 0) { |
| av_log(avctx, AV_LOG_DEBUG, |
| "Bitrate byte is missing, guessing the bitrate from packet size.\n"); |
| } else |
| return RATE_ERRS; |
| |
| return bitrate; |
| } |
| |
| static void warn_insufficient_frame_quality(AVCodecContext *avctx, |
| const char *message) |
| { |
| av_log(avctx, AV_LOG_WARNING, "Frame #%d, %s\n", |
| avctx->frame_number, message); |
| } |
| |
| /** |
| * Initialize the speech codec according to the specification. |
| * |
| * TIA/IS-127 5.2 |
| */ |
| static av_cold int evrc_decode_init(AVCodecContext *avctx) |
| { |
| EVRCContext *e = avctx->priv_data; |
| int i, n, idx = 0; |
| float denom = 2.0 / (2.0 * 8.0 + 1.0); |
| |
| avctx->channels = 1; |
| avctx->channel_layout = AV_CH_LAYOUT_MONO; |
| avctx->sample_fmt = AV_SAMPLE_FMT_FLT; |
| |
| for (i = 0; i < FILTER_ORDER; i++) { |
| e->prev_lspf[i] = (i + 1) * 0.048; |
| e->synthesis[i] = 0.0; |
| } |
| |
| for (i = 0; i < ACB_SIZE; i++) |
| e->pitch[i] = e->pitch_back[i] = 0.0; |
| |
| e->last_valid_bitrate = RATE_QUANT; |
| e->prev_pitch_delay = 40.0; |
| e->fade_scale = 1.0; |
| e->prev_error_flag = 0; |
| e->avg_acb_gain = e->avg_fcb_gain = 0.0; |
| |
| for (i = 0; i < 8; i++) { |
| float tt = ((float)i - 8.0 / 2.0) / 8.0; |
| |
| for (n = -8; n <= 8; n++, idx++) { |
| float arg1 = M_PI * 0.9 * (tt - n); |
| float arg2 = M_PI * (tt - n); |
| |
| e->interpolation_coeffs[idx] = 0.9; |
| if (arg1) |
| e->interpolation_coeffs[idx] *= (0.54 + 0.46 * cos(arg2 * denom)) * |
| sin(arg1) / arg1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * Decode the 10 vector quantized line spectral pair frequencies from the LSP |
| * transmission codes of any bitrate and check for badly received packets. |
| * |
| * @param e the context |
| * |
| * @return 0 on success, -1 if the packet is badly received |
| * |
| * TIA/IS-127 5.2.1, 5.7.1 |
| */ |
| static int decode_lspf(EVRCContext *e) |
| { |
| const float * const *codebooks = evrc_lspq_codebooks[e->bitrate]; |
| int i, j, k = 0; |
| |
| for (i = 0; i < evrc_lspq_nb_codebooks[e->bitrate]; i++) { |
| int row_size = evrc_lspq_codebooks_row_sizes[e->bitrate][i]; |
| const float *codebook = codebooks[i]; |
| |
| for (j = 0; j < row_size; j++) |
| e->lspf[k++] = codebook[e->frame.lsp[i] * row_size + j]; |
| } |
| |
| // check for monotonic LSPs |
| for (i = 1; i < FILTER_ORDER; i++) |
| if (e->lspf[i] <= e->lspf[i - 1]) |
| return -1; |
| |
| // check for minimum separation of LSPs at the splits |
| for (i = 0, k = 0; i < evrc_lspq_nb_codebooks[e->bitrate] - 1; i++) { |
| k += evrc_lspq_codebooks_row_sizes[e->bitrate][i]; |
| if (e->lspf[k] - e->lspf[k - 1] <= MIN_LSP_SEP) |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Interpolation of LSP parameters. |
| * |
| * TIA/IS-127 5.2.3.1, 5.7.3.2 |
| */ |
| static void interpolate_lsp(float *ilsp, const float *lsp, |
| const float *prev, int index) |
| { |
| static const float lsp_interpolation_factors[] = { 0.1667, 0.5, 0.8333 }; |
| ff_weighted_vector_sumf(ilsp, prev, lsp, |
| 1.0 - lsp_interpolation_factors[index], |
| lsp_interpolation_factors[index], FILTER_ORDER); |
| } |
| |
| /* |
| * Reconstruction of the delay contour. |
| * |
| * TIA/IS-127 5.2.2.3.2 |
| */ |
| static void interpolate_delay(float *dst, float current, float prev, int index) |
| { |
| static const float d_interpolation_factors[] = { 0, 0.3313, 0.6625, 1, 1 }; |
| dst[0] = (1.0 - d_interpolation_factors[index ]) * prev |
| + d_interpolation_factors[index ] * current; |
| dst[1] = (1.0 - d_interpolation_factors[index + 1]) * prev |
| + d_interpolation_factors[index + 1] * current; |
| dst[2] = (1.0 - d_interpolation_factors[index + 2]) * prev |
| + d_interpolation_factors[index + 2] * current; |
| } |
| |
| /* |
| * Convert the quantized, interpolated line spectral frequencies, |
| * to prediction coefficients. |
| * |
| * TIA/IS-127 5.2.3.2, 4.7.2.2 |
| */ |
| static void decode_predictor_coeffs(const float *ilspf, float *ilpc) |
| { |
| double lsp[FILTER_ORDER]; |
| float a[FILTER_ORDER / 2 + 1], b[FILTER_ORDER / 2 + 1]; |
| float a1[FILTER_ORDER / 2] = { 0 }; |
| float a2[FILTER_ORDER / 2] = { 0 }; |
| float b1[FILTER_ORDER / 2] = { 0 }; |
| float b2[FILTER_ORDER / 2] = { 0 }; |
| int i, k; |
| |
| ff_acelp_lsf2lspd(lsp, ilspf, FILTER_ORDER); |
| |
| for (k = 0; k <= FILTER_ORDER; k++) { |
| a[0] = k < 2 ? 0.25 : 0; |
| b[0] = k < 2 ? k < 1 ? 0.25 : -0.25 : 0; |
| |
| for (i = 0; i < FILTER_ORDER / 2; i++) { |
| a[i + 1] = a[i] - 2 * lsp[i * 2 ] * a1[i] + a2[i]; |
| b[i + 1] = b[i] - 2 * lsp[i * 2 + 1] * b1[i] + b2[i]; |
| a2[i] = a1[i]; |
| a1[i] = a[i]; |
| b2[i] = b1[i]; |
| b1[i] = b[i]; |
| } |
| |
| if (k) |
| ilpc[k - 1] = 2.0 * (a[FILTER_ORDER / 2] + b[FILTER_ORDER / 2]); |
| } |
| } |
| |
| static void bl_intrp(EVRCContext *e, float *ex, float delay) |
| { |
| float *f; |
| int offset, i, coef_idx; |
| int16_t t; |
| |
| offset = lrintf(delay); |
| |
| t = (offset - delay + 0.5) * 8.0 + 0.5; |
| if (t == 8) { |
| t = 0; |
| offset--; |
| } |
| |
| f = ex - offset - 8; |
| |
| coef_idx = t * (2 * 8 + 1); |
| |
| ex[0] = 0.0; |
| for (i = 0; i < 2 * 8 + 1; i++) |
| ex[0] += e->interpolation_coeffs[coef_idx + i] * f[i]; |
| } |
| |
| /* |
| * Adaptive codebook excitation. |
| * |
| * TIA/IS-127 5.2.2.3.3, 4.12.5.2 |
| */ |
| static void acb_excitation(EVRCContext *e, float *excitation, float gain, |
| const float delay[3], int length) |
| { |
| float denom, locdelay, dpr, invl; |
| int i; |
| |
| invl = 1.0 / ((float) length); |
| dpr = length; |
| |
| /* first at-most extra samples */ |
| denom = (delay[1] - delay[0]) * invl; |
| for (i = 0; i < dpr; i++) { |
| locdelay = delay[0] + i * denom; |
| bl_intrp(e, excitation + i, locdelay); |
| } |
| |
| denom = (delay[2] - delay[1]) * invl; |
| /* interpolation */ |
| for (i = dpr; i < dpr + 10; i++) { |
| locdelay = delay[1] + (i - dpr) * denom; |
| bl_intrp(e, excitation + i, locdelay); |
| } |
| |
| for (i = 0; i < length; i++) |
| excitation[i] *= gain; |
| } |
| |
| static void decode_8_pulses_35bits(const uint16_t *fixed_index, float *cod) |
| { |
| int i, pos1, pos2, offset; |
| |
| offset = (fixed_index[3] >> 9) & 3; |
| |
| for (i = 0; i < 3; i++) { |
| pos1 = ((fixed_index[i] & 0x7f) / 11) * 5 + ((i + offset) % 5); |
| pos2 = ((fixed_index[i] & 0x7f) % 11) * 5 + ((i + offset) % 5); |
| |
| cod[pos1] = (fixed_index[i] & 0x80) ? -1.0 : 1.0; |
| |
| if (pos2 < pos1) |
| cod[pos2] = -cod[pos1]; |
| else |
| cod[pos2] += cod[pos1]; |
| } |
| |
| pos1 = ((fixed_index[3] & 0x7f) / 11) * 5 + ((3 + offset) % 5); |
| pos2 = ((fixed_index[3] & 0x7f) % 11) * 5 + ((4 + offset) % 5); |
| |
| cod[pos1] = (fixed_index[3] & 0x100) ? -1.0 : 1.0; |
| cod[pos2] = (fixed_index[3] & 0x80 ) ? -1.0 : 1.0; |
| } |
| |
| static void decode_3_pulses_10bits(uint16_t fixed_index, float *cod) |
| { |
| float sign; |
| int pos; |
| |
| sign = (fixed_index & 0x200) ? -1.0 : 1.0; |
| |
| pos = ((fixed_index & 0x7) * 7) + 4; |
| cod[pos] += sign; |
| pos = (((fixed_index >> 3) & 0x7) * 7) + 2; |
| cod[pos] -= sign; |
| pos = (((fixed_index >> 6) & 0x7) * 7); |
| cod[pos] += sign; |
| } |
| |
| /* |
| * Reconstruction of ACELP fixed codebook excitation for full and half rate. |
| * |
| * TIA/IS-127 5.2.3.7 |
| */ |
| static void fcb_excitation(EVRCContext *e, const uint16_t *codebook, |
| float *excitation, float pitch_gain, |
| int pitch_lag, int subframe_size) |
| { |
| int i; |
| |
| if (e->bitrate == RATE_FULL) |
| decode_8_pulses_35bits(codebook, excitation); |
| else |
| decode_3_pulses_10bits(*codebook, excitation); |
| |
| pitch_gain = av_clipf(pitch_gain, 0.2, 0.9); |
| |
| for (i = pitch_lag; i < subframe_size; i++) |
| excitation[i] += pitch_gain * excitation[i - pitch_lag]; |
| } |
| |
| /** |
| * Synthesis of the decoder output signal. |
| * |
| * param[in] in input signal |
| * param[in] filter_coeffs LPC coefficients |
| * param[in/out] memory synthesis filter memory |
| * param buffer_length amount of data to process |
| * param[out] samples output samples |
| * |
| * TIA/IS-127 5.2.3.15, 5.7.3.4 |
| */ |
| static void synthesis_filter(const float *in, const float *filter_coeffs, |
| float *memory, int buffer_length, float *samples) |
| { |
| int i, j; |
| |
| for (i = 0; i < buffer_length; i++) { |
| samples[i] = in[i]; |
| for (j = FILTER_ORDER - 1; j > 0; j--) { |
| samples[i] -= filter_coeffs[j] * memory[j]; |
| memory[j] = memory[j - 1]; |
| } |
| samples[i] -= filter_coeffs[0] * memory[0]; |
| memory[0] = samples[i]; |
| } |
| } |
| |
| static void bandwidth_expansion(float *coeff, const float *inbuf, float gamma) |
| { |
| double fac = gamma; |
| int i; |
| |
| for (i = 0; i < FILTER_ORDER; i++) { |
| coeff[i] = inbuf[i] * fac; |
| fac *= gamma; |
| } |
| } |
| |
| static void residual_filter(float *output, const float *input, |
| const float *coef, float *memory, int length) |
| { |
| float sum; |
| int i, j; |
| |
| for (i = 0; i < length; i++) { |
| sum = input[i]; |
| |
| for (j = FILTER_ORDER - 1; j > 0; j--) { |
| sum += coef[j] * memory[j]; |
| memory[j] = memory[j - 1]; |
| } |
| sum += coef[0] * memory[0]; |
| memory[0] = input[i]; |
| output[i] = sum; |
| } |
| } |
| |
| /* |
| * TIA/IS-127 Table 5.9.1-1. |
| */ |
| static const struct PfCoeff { |
| float tilt; |
| float ltgain; |
| float p1; |
| float p2; |
| } postfilter_coeffs[5] = { |
| { 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 }, |
| }; |
| |
| /* |
| * Adaptive postfilter. |
| * |
| * TIA/IS-127 5.9 |
| */ |
| static void postfilter(EVRCContext *e, float *in, const float *coeff, |
| float *out, int idx, const struct PfCoeff *pfc, |
| int length) |
| { |
| float wcoef1[FILTER_ORDER], wcoef2[FILTER_ORDER], |
| scratch[SUBFRAME_SIZE], temp[SUBFRAME_SIZE], |
| mem[SUBFRAME_SIZE]; |
| float sum1 = 0.0, sum2 = 0.0, gamma, gain; |
| float tilt = pfc->tilt; |
| int i, n, best; |
| |
| bandwidth_expansion(wcoef1, coeff, pfc->p1); |
| bandwidth_expansion(wcoef2, coeff, pfc->p2); |
| |
| /* Tilt compensation filter, TIA/IS-127 5.9.1 */ |
| for (i = 0; i < length - 1; i++) |
| sum2 += in[i] * in[i + 1]; |
| if (sum2 < 0.0) |
| tilt = 0.0; |
| |
| for (i = 0; i < length; i++) { |
| scratch[i] = in[i] - tilt * e->last; |
| e->last = in[i]; |
| } |
| |
| /* Short term residual filter, TIA/IS-127 5.9.2 */ |
| residual_filter(&e->postfilter_residual[ACB_SIZE], scratch, wcoef1, e->postfilter_fir, length); |
| |
| /* Long term postfilter */ |
| best = idx; |
| for (i = FFMIN(MIN_DELAY, idx - 3); i <= FFMAX(MAX_DELAY, idx + 3); i++) { |
| for (n = ACB_SIZE, sum2 = 0; n < ACB_SIZE + length; n++) |
| sum2 += e->postfilter_residual[n] * e->postfilter_residual[n - i]; |
| if (sum2 > sum1) { |
| sum1 = sum2; |
| best = i; |
| } |
| } |
| |
| for (i = ACB_SIZE, sum1 = 0; i < ACB_SIZE + length; i++) |
| sum1 += e->postfilter_residual[i - best] * e->postfilter_residual[i - best]; |
| for (i = ACB_SIZE, sum2 = 0; i < ACB_SIZE + length; i++) |
| sum2 += e->postfilter_residual[i] * e->postfilter_residual[i - best]; |
| |
| if (sum2 * sum1 == 0 || e->bitrate == RATE_QUANT) { |
| memcpy(temp, e->postfilter_residual + ACB_SIZE, length * sizeof(float)); |
| } else { |
| gamma = sum2 / sum1; |
| if (gamma < 0.5) |
| memcpy(temp, e->postfilter_residual + ACB_SIZE, length * sizeof(float)); |
| else { |
| gamma = FFMIN(gamma, 1.0); |
| |
| for (i = 0; i < length; i++) { |
| temp[i] = e->postfilter_residual[ACB_SIZE + i] + gamma * |
| pfc->ltgain * e->postfilter_residual[ACB_SIZE + i - best]; |
| } |
| } |
| } |
| |
| memcpy(scratch, temp, length * sizeof(float)); |
| memcpy(mem, e->postfilter_iir, FILTER_ORDER * sizeof(float)); |
| synthesis_filter(scratch, wcoef2, mem, length, scratch); |
| |
| /* Gain computation, TIA/IS-127 5.9.4-2 */ |
| for (i = 0, sum1 = 0, sum2 = 0; i < length; i++) { |
| sum1 += in[i] * in[i]; |
| sum2 += scratch[i] * scratch[i]; |
| } |
| gain = sum2 ? sqrt(sum1 / sum2) : 1.0; |
| |
| for (i = 0; i < length; i++) |
| temp[i] *= gain; |
| |
| /* Short term postfilter */ |
| synthesis_filter(temp, wcoef2, e->postfilter_iir, length, out); |
| |
| memmove(e->postfilter_residual, |
| e->postfilter_residual + length, ACB_SIZE * sizeof(float)); |
| } |
| |
| static void frame_erasure(EVRCContext *e, float *samples) |
| { |
| float ilspf[FILTER_ORDER], ilpc[FILTER_ORDER], idelay[NB_SUBFRAMES], |
| tmp[SUBFRAME_SIZE + 6], f; |
| int i, j; |
| |
| for (i = 0; i < FILTER_ORDER; i++) { |
| if (e->bitrate != RATE_QUANT) |
| e->lspf[i] = e->prev_lspf[i] * 0.875 + 0.125 * (i + 1) * 0.048; |
| else |
| e->lspf[i] = e->prev_lspf[i]; |
| } |
| |
| if (e->prev_error_flag) |
| e->avg_acb_gain *= 0.75; |
| if (e->bitrate == RATE_FULL) |
| memcpy(e->pitch_back, e->pitch, ACB_SIZE * sizeof(float)); |
| if (e->last_valid_bitrate == RATE_QUANT) |
| e->bitrate = RATE_QUANT; |
| else |
| e->bitrate = RATE_FULL; |
| |
| if (e->bitrate == RATE_FULL || e->bitrate == RATE_HALF) { |
| e->pitch_delay = e->prev_pitch_delay; |
| } else { |
| float sum = 0; |
| |
| idelay[0] = idelay[1] = idelay[2] = MIN_DELAY; |
| |
| for (i = 0; i < NB_SUBFRAMES; i++) |
| sum += evrc_energy_quant[e->prev_energy_gain][i]; |
| sum /= (float) NB_SUBFRAMES; |
| sum = pow(10, sum); |
| for (i = 0; i < NB_SUBFRAMES; i++) |
| e->energy_vector[i] = sum; |
| } |
| |
| if (fabs(e->pitch_delay - e->prev_pitch_delay) > 15) |
| e->prev_pitch_delay = e->pitch_delay; |
| |
| for (i = 0; i < NB_SUBFRAMES; i++) { |
| int subframe_size = subframe_sizes[i]; |
| int pitch_lag; |
| |
| interpolate_lsp(ilspf, e->lspf, e->prev_lspf, i); |
| |
| if (e->bitrate != RATE_QUANT) { |
| if (e->avg_acb_gain < 0.3) { |
| idelay[0] = estimation_delay[i]; |
| idelay[1] = estimation_delay[i + 1]; |
| idelay[2] = estimation_delay[i + 2]; |
| } else { |
| interpolate_delay(idelay, e->pitch_delay, e->prev_pitch_delay, i); |
| } |
| } |
| |
| pitch_lag = lrintf((idelay[1] + idelay[0]) / 2.0); |
| decode_predictor_coeffs(ilspf, ilpc); |
| |
| if (e->bitrate != RATE_QUANT) { |
| acb_excitation(e, e->pitch + ACB_SIZE, |
| e->avg_acb_gain, idelay, subframe_size); |
| for (j = 0; j < subframe_size; j++) |
| e->pitch[ACB_SIZE + j] *= e->fade_scale; |
| e->fade_scale = FFMAX(e->fade_scale - 0.05, 0.0); |
| } else { |
| for (j = 0; j < subframe_size; j++) |
| e->pitch[ACB_SIZE + j] = e->energy_vector[i]; |
| } |
| |
| memmove(e->pitch, e->pitch + subframe_size, ACB_SIZE * sizeof(float)); |
| |
| if (e->bitrate != RATE_QUANT && e->avg_acb_gain < 0.4) { |
| f = 0.1 * e->avg_fcb_gain; |
| for (j = 0; j < subframe_size; j++) |
| e->pitch[ACB_SIZE + j] += f; |
| } else if (e->bitrate == RATE_QUANT) { |
| for (j = 0; j < subframe_size; j++) |
| e->pitch[ACB_SIZE + j] = e->energy_vector[i]; |
| } |
| |
| synthesis_filter(e->pitch + ACB_SIZE, ilpc, |
| e->synthesis, subframe_size, tmp); |
| postfilter(e, tmp, ilpc, samples, pitch_lag, |
| &postfilter_coeffs[e->bitrate], subframe_size); |
| |
| samples += subframe_size; |
| } |
| } |
| |
| static int evrc_decode_frame(AVCodecContext *avctx, void *data, |
| int *got_frame_ptr, AVPacket *avpkt) |
| { |
| const uint8_t *buf = avpkt->data; |
| AVFrame *frame = data; |
| EVRCContext *e = avctx->priv_data; |
| int buf_size = avpkt->size; |
| float ilspf[FILTER_ORDER], ilpc[FILTER_ORDER], idelay[NB_SUBFRAMES]; |
| float *samples; |
| int i, j, ret, error_flag = 0; |
| |
| frame->nb_samples = 160; |
| if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) |
| return ret; |
| samples = (float *)frame->data[0]; |
| |
| if ((e->bitrate = determine_bitrate(avctx, &buf_size, &buf)) == RATE_ERRS) { |
| warn_insufficient_frame_quality(avctx, "bitrate cannot be determined."); |
| goto erasure; |
| } |
| if (e->bitrate <= SILENCE || e->bitrate == RATE_QUARTER) |
| goto erasure; |
| if (e->bitrate == RATE_QUANT && e->last_valid_bitrate == RATE_FULL |
| && !e->prev_error_flag) |
| goto erasure; |
| |
| if ((ret = init_get_bits8(&e->gb, buf, buf_size)) < 0) |
| return ret; |
| memset(&e->frame, 0, sizeof(EVRCAFrame)); |
| |
| unpack_frame(e); |
| |
| if (e->bitrate != RATE_QUANT) { |
| uint8_t *p = (uint8_t *) &e->frame; |
| for (i = 0; i < sizeof(EVRCAFrame); i++) { |
| if (p[i]) |
| break; |
| } |
| if (i == sizeof(EVRCAFrame)) |
| goto erasure; |
| } else if (e->frame.lsp[0] == 0xf && |
| e->frame.lsp[1] == 0xf && |
| e->frame.energy_gain == 0xff) { |
| goto erasure; |
| } |
| |
| if (decode_lspf(e) < 0) |
| goto erasure; |
| |
| if (e->bitrate == RATE_FULL || e->bitrate == RATE_HALF) { |
| /* Pitch delay parameter checking as per TIA/IS-127 5.1.5.1 */ |
| if (e->frame.pitch_delay > MAX_DELAY - MIN_DELAY) |
| goto erasure; |
| |
| e->pitch_delay = e->frame.pitch_delay + MIN_DELAY; |
| |
| /* Delay diff parameter checking as per TIA/IS-127 5.1.5.2 */ |
| if (e->frame.delay_diff) { |
| int p = e->pitch_delay - e->frame.delay_diff + 16; |
| if (p < MIN_DELAY || p > MAX_DELAY) |
| goto erasure; |
| } |
| |
| /* Delay contour reconstruction as per TIA/IS-127 5.2.2.2 */ |
| if (e->frame.delay_diff && |
| e->bitrate == RATE_FULL && e->prev_error_flag) { |
| float delay; |
| |
| memcpy(e->pitch, e->pitch_back, ACB_SIZE * sizeof(float)); |
| |
| delay = e->prev_pitch_delay; |
| e->prev_pitch_delay = delay - e->frame.delay_diff + 16.0; |
| |
| if (fabs(e->pitch_delay - delay) > 15) |
| delay = e->pitch_delay; |
| |
| for (i = 0; i < NB_SUBFRAMES; i++) { |
| int subframe_size = subframe_sizes[i]; |
| |
| interpolate_delay(idelay, delay, e->prev_pitch_delay, i); |
| acb_excitation(e, e->pitch + ACB_SIZE, e->avg_acb_gain, idelay, subframe_size); |
| memmove(e->pitch, e->pitch + subframe_size, ACB_SIZE * sizeof(float)); |
| } |
| } |
| |
| /* Smoothing of the decoded delay as per TIA/IS-127 5.2.2.5 */ |
| if (fabs(e->pitch_delay - e->prev_pitch_delay) > 15) |
| e->prev_pitch_delay = e->pitch_delay; |
| |
| e->avg_acb_gain = e->avg_fcb_gain = 0.0; |
| } else { |
| idelay[0] = idelay[1] = idelay[2] = MIN_DELAY; |
| |
| /* Decode frame energy vectors as per TIA/IS-127 5.7.2 */ |
| for (i = 0; i < NB_SUBFRAMES; i++) |
| e->energy_vector[i] = pow(10, evrc_energy_quant[e->frame.energy_gain][i]); |
| e->prev_energy_gain = e->frame.energy_gain; |
| } |
| |
| for (i = 0; i < NB_SUBFRAMES; i++) { |
| float tmp[SUBFRAME_SIZE + 6] = { 0 }; |
| int subframe_size = subframe_sizes[i]; |
| int pitch_lag; |
| |
| interpolate_lsp(ilspf, e->lspf, e->prev_lspf, i); |
| |
| if (e->bitrate != RATE_QUANT) |
| interpolate_delay(idelay, e->pitch_delay, e->prev_pitch_delay, i); |
| |
| pitch_lag = lrintf((idelay[1] + idelay[0]) / 2.0); |
| decode_predictor_coeffs(ilspf, ilpc); |
| |
| /* Bandwidth expansion as per TIA/IS-127 5.2.3.3 */ |
| if (e->frame.lpc_flag && e->prev_error_flag) |
| bandwidth_expansion(ilpc, ilpc, 0.75); |
| |
| if (e->bitrate != RATE_QUANT) { |
| float acb_sum, f; |
| |
| f = exp((e->bitrate == RATE_HALF ? 0.5 : 0.25) |
| * (e->frame.fcb_gain[i] + 1)); |
| acb_sum = pitch_gain_vq[e->frame.acb_gain[i]]; |
| e->avg_acb_gain += acb_sum / NB_SUBFRAMES; |
| e->avg_fcb_gain += f / NB_SUBFRAMES; |
| |
| acb_excitation(e, e->pitch + ACB_SIZE, |
| acb_sum, idelay, subframe_size); |
| fcb_excitation(e, e->frame.fcb_shape[i], tmp, |
| acb_sum, pitch_lag, subframe_size); |
| |
| /* Total excitation generation as per TIA/IS-127 5.2.3.9 */ |
| for (j = 0; j < subframe_size; j++) |
| e->pitch[ACB_SIZE + j] += f * tmp[j]; |
| e->fade_scale = FFMIN(e->fade_scale + 0.2, 1.0); |
| } else { |
| for (j = 0; j < subframe_size; j++) |
| e->pitch[ACB_SIZE + j] = e->energy_vector[i]; |
| } |
| |
| memmove(e->pitch, e->pitch + subframe_size, ACB_SIZE * sizeof(float)); |
| |
| synthesis_filter(e->pitch + ACB_SIZE, ilpc, |
| e->synthesis, subframe_size, |
| e->postfilter ? tmp : samples); |
| if (e->postfilter) |
| postfilter(e, tmp, ilpc, samples, pitch_lag, |
| &postfilter_coeffs[e->bitrate], subframe_size); |
| |
| samples += subframe_size; |
| } |
| |
| if (error_flag) { |
| erasure: |
| error_flag = 1; |
| av_log(avctx, AV_LOG_WARNING, "frame erasure\n"); |
| frame_erasure(e, samples); |
| } |
| |
| memcpy(e->prev_lspf, e->lspf, sizeof(e->prev_lspf)); |
| e->prev_error_flag = error_flag; |
| e->last_valid_bitrate = e->bitrate; |
| |
| if (e->bitrate != RATE_QUANT) |
| e->prev_pitch_delay = e->pitch_delay; |
| |
| samples = (float *)frame->data[0]; |
| for (i = 0; i < 160; i++) |
| samples[i] /= 32768; |
| |
| *got_frame_ptr = 1; |
| |
| return avpkt->size; |
| } |
| |
| #define OFFSET(x) offsetof(EVRCContext, x) |
| #define AD AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM |
| |
| static const AVOption options[] = { |
| { "postfilter", "enable postfilter", OFFSET(postfilter), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, AD }, |
| { NULL } |
| }; |
| |
| static const AVClass evrcdec_class = { |
| .class_name = "evrc", |
| .item_name = av_default_item_name, |
| .option = options, |
| .version = LIBAVUTIL_VERSION_INT, |
| }; |
| |
| AVCodec ff_evrc_decoder = { |
| .name = "evrc", |
| .long_name = NULL_IF_CONFIG_SMALL("EVRC (Enhanced Variable Rate Codec)"), |
| .type = AVMEDIA_TYPE_AUDIO, |
| .id = AV_CODEC_ID_EVRC, |
| .init = evrc_decode_init, |
| .decode = evrc_decode_frame, |
| .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF, |
| .priv_data_size = sizeof(EVRCContext), |
| .priv_class = &evrcdec_class, |
| }; |