| /* |
| * Real Audio 1.0 (14.4K) encoder |
| * Copyright (c) 2010 Francesco Lavra <francescolavra@interfree.it> |
| * |
| * 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 |
| * Real Audio 1.0 (14.4K) encoder |
| * @author Francesco Lavra <francescolavra@interfree.it> |
| */ |
| |
| #include <float.h> |
| |
| #include "avcodec.h" |
| #include "audio_frame_queue.h" |
| #include "celp_filters.h" |
| #include "internal.h" |
| #include "mathops.h" |
| #include "put_bits.h" |
| #include "ra144.h" |
| |
| static av_cold int ra144_encode_close(AVCodecContext *avctx) |
| { |
| RA144Context *ractx = avctx->priv_data; |
| ff_lpc_end(&ractx->lpc_ctx); |
| ff_af_queue_close(&ractx->afq); |
| return 0; |
| } |
| |
| |
| static av_cold int ra144_encode_init(AVCodecContext * avctx) |
| { |
| RA144Context *ractx; |
| int ret; |
| |
| if (avctx->channels != 1) { |
| av_log(avctx, AV_LOG_ERROR, "invalid number of channels: %d\n", |
| avctx->channels); |
| return -1; |
| } |
| avctx->frame_size = NBLOCKS * BLOCKSIZE; |
| avctx->initial_padding = avctx->frame_size; |
| avctx->bit_rate = 8000; |
| ractx = avctx->priv_data; |
| ractx->lpc_coef[0] = ractx->lpc_tables[0]; |
| ractx->lpc_coef[1] = ractx->lpc_tables[1]; |
| ractx->avctx = avctx; |
| ff_audiodsp_init(&ractx->adsp); |
| ret = ff_lpc_init(&ractx->lpc_ctx, avctx->frame_size, LPC_ORDER, |
| FF_LPC_TYPE_LEVINSON); |
| if (ret < 0) |
| goto error; |
| |
| ff_af_queue_init(avctx, &ractx->afq); |
| |
| return 0; |
| error: |
| ra144_encode_close(avctx); |
| return ret; |
| } |
| |
| |
| /** |
| * Quantize a value by searching a sorted table for the element with the |
| * nearest value |
| * |
| * @param value value to quantize |
| * @param table array containing the quantization table |
| * @param size size of the quantization table |
| * @return index of the quantization table corresponding to the element with the |
| * nearest value |
| */ |
| static int quantize(int value, const int16_t *table, unsigned int size) |
| { |
| unsigned int low = 0, high = size - 1; |
| |
| while (1) { |
| int index = (low + high) >> 1; |
| int error = table[index] - value; |
| |
| if (index == low) |
| return table[high] + error > value ? low : high; |
| if (error > 0) { |
| high = index; |
| } else { |
| low = index; |
| } |
| } |
| } |
| |
| |
| /** |
| * Orthogonalize a vector to another vector |
| * |
| * @param v vector to orthogonalize |
| * @param u vector against which orthogonalization is performed |
| */ |
| static void orthogonalize(float *v, const float *u) |
| { |
| int i; |
| float num = 0, den = 0; |
| |
| for (i = 0; i < BLOCKSIZE; i++) { |
| num += v[i] * u[i]; |
| den += u[i] * u[i]; |
| } |
| num /= den; |
| for (i = 0; i < BLOCKSIZE; i++) |
| v[i] -= num * u[i]; |
| } |
| |
| |
| /** |
| * Calculate match score and gain of an LPC-filtered vector with respect to |
| * input data, possibly othogonalizing it to up to 2 other vectors |
| * |
| * @param work array used to calculate the filtered vector |
| * @param coefs coefficients of the LPC filter |
| * @param vect original vector |
| * @param ortho1 first vector against which orthogonalization is performed |
| * @param ortho2 second vector against which orthogonalization is performed |
| * @param data input data |
| * @param score pointer to variable where match score is returned |
| * @param gain pointer to variable where gain is returned |
| */ |
| static void get_match_score(float *work, const float *coefs, float *vect, |
| const float *ortho1, const float *ortho2, |
| const float *data, float *score, float *gain) |
| { |
| float c, g; |
| int i; |
| |
| ff_celp_lp_synthesis_filterf(work, coefs, vect, BLOCKSIZE, LPC_ORDER); |
| if (ortho1) |
| orthogonalize(work, ortho1); |
| if (ortho2) |
| orthogonalize(work, ortho2); |
| c = g = 0; |
| for (i = 0; i < BLOCKSIZE; i++) { |
| g += work[i] * work[i]; |
| c += data[i] * work[i]; |
| } |
| if (c <= 0) { |
| *score = 0; |
| return; |
| } |
| *gain = c / g; |
| *score = *gain * c; |
| } |
| |
| |
| /** |
| * Create a vector from the adaptive codebook at a given lag value |
| * |
| * @param vect array where vector is stored |
| * @param cb adaptive codebook |
| * @param lag lag value |
| */ |
| static void create_adapt_vect(float *vect, const int16_t *cb, int lag) |
| { |
| int i; |
| |
| cb += BUFFERSIZE - lag; |
| for (i = 0; i < FFMIN(BLOCKSIZE, lag); i++) |
| vect[i] = cb[i]; |
| if (lag < BLOCKSIZE) |
| for (i = 0; i < BLOCKSIZE - lag; i++) |
| vect[lag + i] = cb[i]; |
| } |
| |
| |
| /** |
| * Search the adaptive codebook for the best entry and gain and remove its |
| * contribution from input data |
| * |
| * @param adapt_cb array from which the adaptive codebook is extracted |
| * @param work array used to calculate LPC-filtered vectors |
| * @param coefs coefficients of the LPC filter |
| * @param data input data |
| * @return index of the best entry of the adaptive codebook |
| */ |
| static int adaptive_cb_search(const int16_t *adapt_cb, float *work, |
| const float *coefs, float *data) |
| { |
| int i, av_uninit(best_vect); |
| float score, gain, best_score, av_uninit(best_gain); |
| float exc[BLOCKSIZE]; |
| |
| gain = best_score = 0; |
| for (i = BLOCKSIZE / 2; i <= BUFFERSIZE; i++) { |
| create_adapt_vect(exc, adapt_cb, i); |
| get_match_score(work, coefs, exc, NULL, NULL, data, &score, &gain); |
| if (score > best_score) { |
| best_score = score; |
| best_vect = i; |
| best_gain = gain; |
| } |
| } |
| if (!best_score) |
| return 0; |
| |
| /** |
| * Re-calculate the filtered vector from the vector with maximum match score |
| * and remove its contribution from input data. |
| */ |
| create_adapt_vect(exc, adapt_cb, best_vect); |
| ff_celp_lp_synthesis_filterf(work, coefs, exc, BLOCKSIZE, LPC_ORDER); |
| for (i = 0; i < BLOCKSIZE; i++) |
| data[i] -= best_gain * work[i]; |
| return best_vect - BLOCKSIZE / 2 + 1; |
| } |
| |
| |
| /** |
| * Find the best vector of a fixed codebook by applying an LPC filter to |
| * codebook entries, possibly othogonalizing them to up to 2 other vectors and |
| * matching the results with input data |
| * |
| * @param work array used to calculate the filtered vectors |
| * @param coefs coefficients of the LPC filter |
| * @param cb fixed codebook |
| * @param ortho1 first vector against which orthogonalization is performed |
| * @param ortho2 second vector against which orthogonalization is performed |
| * @param data input data |
| * @param idx pointer to variable where the index of the best codebook entry is |
| * returned |
| * @param gain pointer to variable where the gain of the best codebook entry is |
| * returned |
| */ |
| static void find_best_vect(float *work, const float *coefs, |
| const int8_t cb[][BLOCKSIZE], const float *ortho1, |
| const float *ortho2, float *data, int *idx, |
| float *gain) |
| { |
| int i, j; |
| float g, score, best_score; |
| float vect[BLOCKSIZE]; |
| |
| *idx = *gain = best_score = 0; |
| for (i = 0; i < FIXED_CB_SIZE; i++) { |
| for (j = 0; j < BLOCKSIZE; j++) |
| vect[j] = cb[i][j]; |
| get_match_score(work, coefs, vect, ortho1, ortho2, data, &score, &g); |
| if (score > best_score) { |
| best_score = score; |
| *idx = i; |
| *gain = g; |
| } |
| } |
| } |
| |
| |
| /** |
| * Search the two fixed codebooks for the best entry and gain |
| * |
| * @param work array used to calculate LPC-filtered vectors |
| * @param coefs coefficients of the LPC filter |
| * @param data input data |
| * @param cba_idx index of the best entry of the adaptive codebook |
| * @param cb1_idx pointer to variable where the index of the best entry of the |
| * first fixed codebook is returned |
| * @param cb2_idx pointer to variable where the index of the best entry of the |
| * second fixed codebook is returned |
| */ |
| static void fixed_cb_search(float *work, const float *coefs, float *data, |
| int cba_idx, int *cb1_idx, int *cb2_idx) |
| { |
| int i, ortho_cb1; |
| float gain; |
| float cba_vect[BLOCKSIZE], cb1_vect[BLOCKSIZE]; |
| float vect[BLOCKSIZE]; |
| |
| /** |
| * The filtered vector from the adaptive codebook can be retrieved from |
| * work, because this function is called just after adaptive_cb_search(). |
| */ |
| if (cba_idx) |
| memcpy(cba_vect, work, sizeof(cba_vect)); |
| |
| find_best_vect(work, coefs, ff_cb1_vects, cba_idx ? cba_vect : NULL, NULL, |
| data, cb1_idx, &gain); |
| |
| /** |
| * Re-calculate the filtered vector from the vector with maximum match score |
| * and remove its contribution from input data. |
| */ |
| if (gain) { |
| for (i = 0; i < BLOCKSIZE; i++) |
| vect[i] = ff_cb1_vects[*cb1_idx][i]; |
| ff_celp_lp_synthesis_filterf(work, coefs, vect, BLOCKSIZE, LPC_ORDER); |
| if (cba_idx) |
| orthogonalize(work, cba_vect); |
| for (i = 0; i < BLOCKSIZE; i++) |
| data[i] -= gain * work[i]; |
| memcpy(cb1_vect, work, sizeof(cb1_vect)); |
| ortho_cb1 = 1; |
| } else |
| ortho_cb1 = 0; |
| |
| find_best_vect(work, coefs, ff_cb2_vects, cba_idx ? cba_vect : NULL, |
| ortho_cb1 ? cb1_vect : NULL, data, cb2_idx, &gain); |
| } |
| |
| |
| /** |
| * Encode a subblock of the current frame |
| * |
| * @param ractx encoder context |
| * @param sblock_data input data of the subblock |
| * @param lpc_coefs coefficients of the LPC filter |
| * @param rms RMS of the reflection coefficients |
| * @param pb pointer to PutBitContext of the current frame |
| */ |
| static void ra144_encode_subblock(RA144Context *ractx, |
| const int16_t *sblock_data, |
| const int16_t *lpc_coefs, unsigned int rms, |
| PutBitContext *pb) |
| { |
| float data[BLOCKSIZE] = { 0 }, work[LPC_ORDER + BLOCKSIZE]; |
| float coefs[LPC_ORDER]; |
| float zero[BLOCKSIZE], cba[BLOCKSIZE], cb1[BLOCKSIZE], cb2[BLOCKSIZE]; |
| int cba_idx, cb1_idx, cb2_idx, gain; |
| int i, n; |
| unsigned m[3]; |
| float g[3]; |
| float error, best_error; |
| |
| for (i = 0; i < LPC_ORDER; i++) { |
| work[i] = ractx->curr_sblock[BLOCKSIZE + i]; |
| coefs[i] = lpc_coefs[i] * (1/4096.0); |
| } |
| |
| /** |
| * Calculate the zero-input response of the LPC filter and subtract it from |
| * input data. |
| */ |
| ff_celp_lp_synthesis_filterf(work + LPC_ORDER, coefs, data, BLOCKSIZE, |
| LPC_ORDER); |
| for (i = 0; i < BLOCKSIZE; i++) { |
| zero[i] = work[LPC_ORDER + i]; |
| data[i] = sblock_data[i] - zero[i]; |
| } |
| |
| /** |
| * Codebook search is performed without taking into account the contribution |
| * of the previous subblock, since it has been just subtracted from input |
| * data. |
| */ |
| memset(work, 0, LPC_ORDER * sizeof(*work)); |
| |
| cba_idx = adaptive_cb_search(ractx->adapt_cb, work + LPC_ORDER, coefs, |
| data); |
| if (cba_idx) { |
| /** |
| * The filtered vector from the adaptive codebook can be retrieved from |
| * work, see implementation of adaptive_cb_search(). |
| */ |
| memcpy(cba, work + LPC_ORDER, sizeof(cba)); |
| |
| ff_copy_and_dup(ractx->buffer_a, ractx->adapt_cb, cba_idx + BLOCKSIZE / 2 - 1); |
| m[0] = (ff_irms(&ractx->adsp, ractx->buffer_a) * rms) >> 12; |
| } |
| fixed_cb_search(work + LPC_ORDER, coefs, data, cba_idx, &cb1_idx, &cb2_idx); |
| for (i = 0; i < BLOCKSIZE; i++) { |
| cb1[i] = ff_cb1_vects[cb1_idx][i]; |
| cb2[i] = ff_cb2_vects[cb2_idx][i]; |
| } |
| ff_celp_lp_synthesis_filterf(work + LPC_ORDER, coefs, cb1, BLOCKSIZE, |
| LPC_ORDER); |
| memcpy(cb1, work + LPC_ORDER, sizeof(cb1)); |
| m[1] = (ff_cb1_base[cb1_idx] * rms) >> 8; |
| ff_celp_lp_synthesis_filterf(work + LPC_ORDER, coefs, cb2, BLOCKSIZE, |
| LPC_ORDER); |
| memcpy(cb2, work + LPC_ORDER, sizeof(cb2)); |
| m[2] = (ff_cb2_base[cb2_idx] * rms) >> 8; |
| best_error = FLT_MAX; |
| gain = 0; |
| for (n = 0; n < 256; n++) { |
| g[1] = ((ff_gain_val_tab[n][1] * m[1]) >> ff_gain_exp_tab[n]) * |
| (1/4096.0); |
| g[2] = ((ff_gain_val_tab[n][2] * m[2]) >> ff_gain_exp_tab[n]) * |
| (1/4096.0); |
| error = 0; |
| if (cba_idx) { |
| g[0] = ((ff_gain_val_tab[n][0] * m[0]) >> ff_gain_exp_tab[n]) * |
| (1/4096.0); |
| for (i = 0; i < BLOCKSIZE; i++) { |
| data[i] = zero[i] + g[0] * cba[i] + g[1] * cb1[i] + |
| g[2] * cb2[i]; |
| error += (data[i] - sblock_data[i]) * |
| (data[i] - sblock_data[i]); |
| } |
| } else { |
| for (i = 0; i < BLOCKSIZE; i++) { |
| data[i] = zero[i] + g[1] * cb1[i] + g[2] * cb2[i]; |
| error += (data[i] - sblock_data[i]) * |
| (data[i] - sblock_data[i]); |
| } |
| } |
| if (error < best_error) { |
| best_error = error; |
| gain = n; |
| } |
| } |
| put_bits(pb, 7, cba_idx); |
| put_bits(pb, 8, gain); |
| put_bits(pb, 7, cb1_idx); |
| put_bits(pb, 7, cb2_idx); |
| ff_subblock_synthesis(ractx, lpc_coefs, cba_idx, cb1_idx, cb2_idx, rms, |
| gain); |
| } |
| |
| |
| static int ra144_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, |
| const AVFrame *frame, int *got_packet_ptr) |
| { |
| static const uint8_t sizes[LPC_ORDER] = {64, 32, 32, 16, 16, 8, 8, 8, 8, 4}; |
| static const uint8_t bit_sizes[LPC_ORDER] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2}; |
| RA144Context *ractx = avctx->priv_data; |
| PutBitContext pb; |
| int32_t lpc_data[NBLOCKS * BLOCKSIZE]; |
| int32_t lpc_coefs[LPC_ORDER][MAX_LPC_ORDER]; |
| int shift[LPC_ORDER]; |
| int16_t block_coefs[NBLOCKS][LPC_ORDER]; |
| int lpc_refl[LPC_ORDER]; /**< reflection coefficients of the frame */ |
| unsigned int refl_rms[NBLOCKS]; /**< RMS of the reflection coefficients */ |
| const int16_t *samples = frame ? (const int16_t *)frame->data[0] : NULL; |
| int energy = 0; |
| int i, idx, ret; |
| |
| if (ractx->last_frame) |
| return 0; |
| |
| if ((ret = ff_alloc_packet2(avctx, avpkt, FRAME_SIZE, 0)) < 0) |
| return ret; |
| |
| /** |
| * Since the LPC coefficients are calculated on a frame centered over the |
| * fourth subframe, to encode a given frame, data from the next frame is |
| * needed. In each call to this function, the previous frame (whose data are |
| * saved in the encoder context) is encoded, and data from the current frame |
| * are saved in the encoder context to be used in the next function call. |
| */ |
| for (i = 0; i < (2 * BLOCKSIZE + BLOCKSIZE / 2); i++) { |
| lpc_data[i] = ractx->curr_block[BLOCKSIZE + BLOCKSIZE / 2 + i]; |
| energy += (lpc_data[i] * lpc_data[i]) >> 4; |
| } |
| if (frame) { |
| int j; |
| for (j = 0; j < frame->nb_samples && i < NBLOCKS * BLOCKSIZE; i++, j++) { |
| lpc_data[i] = samples[j] >> 2; |
| energy += (lpc_data[i] * lpc_data[i]) >> 4; |
| } |
| } |
| if (i < NBLOCKS * BLOCKSIZE) |
| memset(&lpc_data[i], 0, (NBLOCKS * BLOCKSIZE - i) * sizeof(*lpc_data)); |
| energy = ff_energy_tab[quantize(ff_t_sqrt(energy >> 5) >> 10, ff_energy_tab, |
| 32)]; |
| |
| ff_lpc_calc_coefs(&ractx->lpc_ctx, lpc_data, NBLOCKS * BLOCKSIZE, LPC_ORDER, |
| LPC_ORDER, 16, lpc_coefs, shift, FF_LPC_TYPE_LEVINSON, |
| 0, ORDER_METHOD_EST, 12, 0); |
| for (i = 0; i < LPC_ORDER; i++) |
| block_coefs[NBLOCKS - 1][i] = -(lpc_coefs[LPC_ORDER - 1][i] << |
| (12 - shift[LPC_ORDER - 1])); |
| |
| /** |
| * TODO: apply perceptual weighting of the input speech through bandwidth |
| * expansion of the LPC filter. |
| */ |
| |
| if (ff_eval_refl(lpc_refl, block_coefs[NBLOCKS - 1], avctx)) { |
| /** |
| * The filter is unstable: use the coefficients of the previous frame. |
| */ |
| ff_int_to_int16(block_coefs[NBLOCKS - 1], ractx->lpc_coef[1]); |
| if (ff_eval_refl(lpc_refl, block_coefs[NBLOCKS - 1], avctx)) { |
| /* the filter is still unstable. set reflection coeffs to zero. */ |
| memset(lpc_refl, 0, sizeof(lpc_refl)); |
| } |
| } |
| init_put_bits(&pb, avpkt->data, avpkt->size); |
| for (i = 0; i < LPC_ORDER; i++) { |
| idx = quantize(lpc_refl[i], ff_lpc_refl_cb[i], sizes[i]); |
| put_bits(&pb, bit_sizes[i], idx); |
| lpc_refl[i] = ff_lpc_refl_cb[i][idx]; |
| } |
| ractx->lpc_refl_rms[0] = ff_rms(lpc_refl); |
| ff_eval_coefs(ractx->lpc_coef[0], lpc_refl); |
| refl_rms[0] = ff_interp(ractx, block_coefs[0], 1, 1, ractx->old_energy); |
| refl_rms[1] = ff_interp(ractx, block_coefs[1], 2, |
| energy <= ractx->old_energy, |
| ff_t_sqrt(energy * ractx->old_energy) >> 12); |
| refl_rms[2] = ff_interp(ractx, block_coefs[2], 3, 0, energy); |
| refl_rms[3] = ff_rescale_rms(ractx->lpc_refl_rms[0], energy); |
| ff_int_to_int16(block_coefs[NBLOCKS - 1], ractx->lpc_coef[0]); |
| put_bits(&pb, 5, quantize(energy, ff_energy_tab, 32)); |
| for (i = 0; i < NBLOCKS; i++) |
| ra144_encode_subblock(ractx, ractx->curr_block + i * BLOCKSIZE, |
| block_coefs[i], refl_rms[i], &pb); |
| flush_put_bits(&pb); |
| ractx->old_energy = energy; |
| ractx->lpc_refl_rms[1] = ractx->lpc_refl_rms[0]; |
| FFSWAP(unsigned int *, ractx->lpc_coef[0], ractx->lpc_coef[1]); |
| |
| /* copy input samples to current block for processing in next call */ |
| i = 0; |
| if (frame) { |
| for (; i < frame->nb_samples; i++) |
| ractx->curr_block[i] = samples[i] >> 2; |
| |
| if ((ret = ff_af_queue_add(&ractx->afq, frame)) < 0) |
| return ret; |
| } else |
| ractx->last_frame = 1; |
| memset(&ractx->curr_block[i], 0, |
| (NBLOCKS * BLOCKSIZE - i) * sizeof(*ractx->curr_block)); |
| |
| /* Get the next frame pts/duration */ |
| ff_af_queue_remove(&ractx->afq, avctx->frame_size, &avpkt->pts, |
| &avpkt->duration); |
| |
| avpkt->size = FRAME_SIZE; |
| *got_packet_ptr = 1; |
| return 0; |
| } |
| |
| |
| AVCodec ff_ra_144_encoder = { |
| .name = "real_144", |
| .long_name = NULL_IF_CONFIG_SMALL("RealAudio 1.0 (14.4K)"), |
| .type = AVMEDIA_TYPE_AUDIO, |
| .id = AV_CODEC_ID_RA_144, |
| .priv_data_size = sizeof(RA144Context), |
| .init = ra144_encode_init, |
| .encode2 = ra144_encode_frame, |
| .close = ra144_encode_close, |
| .capabilities = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_SMALL_LAST_FRAME, |
| .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16, |
| AV_SAMPLE_FMT_NONE }, |
| .supported_samplerates = (const int[]){ 8000, 0 }, |
| .channel_layouts = (const uint64_t[]) { AV_CH_LAYOUT_MONO, 0 }, |
| }; |
