summaryrefslogtreecommitdiff
path: root/libavcodec/evrcdec.c
diff options
context:
space:
mode:
Diffstat (limited to 'libavcodec/evrcdec.c')
-rw-r--r--libavcodec/evrcdec.c917
1 files changed, 917 insertions, 0 deletions
diff --git a/libavcodec/evrcdec.c b/libavcodec/evrcdec.c
new file mode 100644
index 0000000000..f104e3313b
--- /dev/null
+++ b/libavcodec/evrcdec.c
@@ -0,0 +1,917 @@
+/*
+ * 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 "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 {
+ 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 **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;
+
+ init_get_bits(&e->gb, buf, 8 * buf_size);
+ 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, tmp);
+ 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;
+}
+
+AVCodec ff_evrc_decoder = {
+ .name = "evrc",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .id = AV_CODEC_ID_EVRC,
+ .init = evrc_decode_init,
+ .decode = evrc_decode_frame,
+ .capabilities = CODEC_CAP_DR1,
+ .priv_data_size = sizeof(EVRCContext),
+ .long_name = NULL_IF_CONFIG_SMALL("EVRC (Enhanced Variable Rate Codec)"),
+};