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ffmpeg/libavcodec/nellymoserenc.c

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/*
* Nellymoser encoder
* This code is developed as part of Google Summer of Code 2008 Program.
*
* Copyright (c) 2008 Bartlomiej Wolowiec
*
* 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 nellymoserenc.c
* Nellymoser encoder
* by Bartlomiej Wolowiec
*
* Generic codec information: libavcodec/nellymoserdec.c
*
* Some information also from: http://www1.mplayerhq.hu/ASAO/ASAO.zip
* (Copyright Joseph Artsimovich and UAB "DKD")
*
* for more information about nellymoser format, visit:
* http://wiki.multimedia.cx/index.php?title=Nellymoser
*/
#include "nellymoser.h"
#include "avcodec.h"
#include "dsputil.h"
#define BITSTREAM_WRITER_LE
#include "bitstream.h"
#define POW_TABLE_SIZE (1<<11)
#define POW_TABLE_OFFSET 3
typedef struct NellyMoserEncodeContext {
AVCodecContext *avctx;
int last_frame;
int bufsel;
int have_saved;
DSPContext dsp;
MDCTContext mdct_ctx;
DECLARE_ALIGNED_16(float, mdct_out[NELLY_SAMPLES]);
DECLARE_ALIGNED_16(float, buf[2][3 * NELLY_BUF_LEN]); ///< sample buffer
} NellyMoserEncodeContext;
static float pow_table[POW_TABLE_SIZE]; ///< -pow(2, -i / 2048.0 - 3.0);
static const uint8_t sf_lut[96] = {
0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 4, 4,
5, 5, 5, 6, 7, 7, 8, 8, 9, 10, 11, 11, 12, 13, 13, 14,
15, 15, 16, 17, 17, 18, 19, 19, 20, 21, 22, 22, 23, 24, 25, 26,
27, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40,
41, 41, 42, 43, 44, 45, 45, 46, 47, 48, 49, 50, 51, 52, 52, 53,
54, 55, 55, 56, 57, 57, 58, 59, 59, 60, 60, 60, 61, 61, 61, 62,
};
static const uint8_t sf_delta_lut[78] = {
0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 4, 4,
4, 5, 5, 5, 6, 6, 7, 7, 8, 8, 9, 10, 10, 11, 11, 12,
13, 13, 14, 15, 16, 17, 17, 18, 19, 19, 20, 21, 21, 22, 22, 23,
23, 24, 24, 25, 25, 25, 26, 26, 26, 26, 27, 27, 27, 27, 27, 28,
28, 28, 28, 28, 28, 29, 29, 29, 29, 29, 29, 29, 29, 30,
};
static const uint8_t quant_lut[230] = {
0,
0, 1, 2,
0, 1, 2, 3, 4, 5, 6,
0, 1, 1, 2, 2, 3, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11,
12, 13, 13, 13, 14,
0, 1, 1, 2, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 8,
8, 9, 10, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,
22, 23, 23, 24, 24, 25, 25, 26, 26, 27, 27, 28, 28, 29, 29, 29,
30,
0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3,
4, 4, 4, 5, 5, 5, 6, 6, 7, 7, 7, 8, 8, 9, 9, 9,
10, 10, 11, 11, 11, 12, 12, 13, 13, 13, 13, 14, 14, 14, 15, 15,
15, 15, 16, 16, 16, 17, 17, 17, 18, 18, 18, 19, 19, 20, 20, 20,
21, 21, 22, 22, 23, 23, 24, 25, 26, 26, 27, 28, 29, 30, 31, 32,
33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 42, 43, 44, 44, 45, 45,
46, 47, 47, 48, 48, 49, 49, 50, 50, 50, 51, 51, 51, 52, 52, 52,
53, 53, 53, 54, 54, 54, 55, 55, 55, 56, 56, 56, 57, 57, 57, 57,
58, 58, 58, 58, 59, 59, 59, 59, 60, 60, 60, 60, 60, 61, 61, 61,
61, 61, 61, 61, 62,
};
static const float quant_lut_mul[7] = { 0.0, 0.0, 2.0, 2.0, 5.0, 12.0, 36.6 };
static const float quant_lut_add[7] = { 0.0, 0.0, 2.0, 7.0, 21.0, 56.0, 157.0 };
static const uint8_t quant_lut_offset[8] = { 0, 0, 1, 4, 11, 32, 81, 230 };
void apply_mdct(NellyMoserEncodeContext *s)
{
DECLARE_ALIGNED_16(float, in_buff[NELLY_SAMPLES]);
memcpy(in_buff, s->buf[s->bufsel], NELLY_BUF_LEN * sizeof(float));
s->dsp.vector_fmul(in_buff, ff_sine_128, NELLY_BUF_LEN);
s->dsp.vector_fmul_reverse(in_buff + NELLY_BUF_LEN, s->buf[s->bufsel] + NELLY_BUF_LEN, ff_sine_128,
NELLY_BUF_LEN);
ff_mdct_calc(&s->mdct_ctx, s->mdct_out, in_buff);
s->dsp.vector_fmul(s->buf[s->bufsel] + NELLY_BUF_LEN, ff_sine_128, NELLY_BUF_LEN);
s->dsp.vector_fmul_reverse(s->buf[s->bufsel] + 2 * NELLY_BUF_LEN, s->buf[1 - s->bufsel], ff_sine_128,
NELLY_BUF_LEN);
ff_mdct_calc(&s->mdct_ctx, s->mdct_out + NELLY_BUF_LEN, s->buf[s->bufsel] + NELLY_BUF_LEN);
}
static av_cold int encode_init(AVCodecContext *avctx)
{
NellyMoserEncodeContext *s = avctx->priv_data;
int i;
if (avctx->channels != 1) {
av_log(avctx, AV_LOG_ERROR, "Nellymoser supports only 1 channel\n");
return -1;
}
if (avctx->sample_rate != 8000 && avctx->sample_rate != 11025 &&
avctx->sample_rate != 22050 && avctx->sample_rate != 44100 &&
avctx->strict_std_compliance >= FF_COMPLIANCE_NORMAL) {
av_log(avctx, AV_LOG_ERROR, "Nellymoser works only with 8000, 11025, 22050 and 44100 sample rate\n");
return -1;
}
avctx->frame_size = NELLY_SAMPLES;
s->avctx = avctx;
ff_mdct_init(&s->mdct_ctx, 8, 0);
dsputil_init(&s->dsp, avctx);
/* Generate overlap window */
ff_sine_window_init(ff_sine_128, 128);
for (i = 0; i < POW_TABLE_SIZE; i++)
pow_table[i] = -pow(2, -i / 2048.0 - 3.0 + POW_TABLE_OFFSET);
return 0;
}
static av_cold int encode_end(AVCodecContext *avctx)
{
NellyMoserEncodeContext *s = avctx->priv_data;
ff_mdct_end(&s->mdct_ctx);
return 0;
}
#define find_best(val, table, LUT, LUT_add, LUT_size) \
best_idx = \
LUT[av_clip ((lrintf(val) >> 8) + LUT_add, 0, LUT_size - 1)]; \
if (fabs(val - table[best_idx]) > fabs(val - table[best_idx + 1])) \
best_idx++;
static void get_exponent_greedy(NellyMoserEncodeContext *s, float *cand, int *idx_table)
{
int band, best_idx, power_idx = 0;
float power_candidate;
//base exponent
find_best(cand[0], ff_nelly_init_table, sf_lut, -20, 96);
idx_table[0] = best_idx;
power_idx = ff_nelly_init_table[best_idx];
for (band = 1; band < NELLY_BANDS; band++) {
power_candidate = cand[band] - power_idx;
find_best(power_candidate, ff_nelly_delta_table, sf_delta_lut, 37, 78);
idx_table[band] = best_idx;
power_idx += ff_nelly_delta_table[best_idx];
}
}
#define OPT_SIZE ((1<<15) + 3000)
static inline float distance(float x, float y, int band)
{
//return pow(fabs(x-y), 2.0);
float tmp = x - y;
return tmp * tmp;
}
static void get_exponent_dynamic(NellyMoserEncodeContext *s, float *cand, int *idx_table)
{
int i, j, band, best_idx;
float power_candidate, best_val;
float opt[NELLY_BANDS][OPT_SIZE];
int path[NELLY_BANDS][OPT_SIZE];
for (i = 0; i < NELLY_BANDS * OPT_SIZE; i++) {
opt[0][i] = INFINITY;
}
for (i = 0; i < 64; i++) {
opt[0][ff_nelly_init_table[i]] = distance(cand[0], ff_nelly_init_table[i], 0);
path[0][ff_nelly_init_table[i]] = i;
}
for (band = 1; band < NELLY_BANDS; band++) {
int q, c = 0;
float tmp;
int idx_min, idx_max, idx;
power_candidate = cand[band];
for (q = 1000; !c && q < OPT_SIZE; q <<= 2) {
idx_min = FFMAX(0, cand[band] - q);
idx_max = FFMIN(OPT_SIZE, cand[band - 1] + q);
for (i = FFMAX(0, cand[band - 1] - q); i < FFMIN(OPT_SIZE, cand[band - 1] + q); i++) {
if ( isinf(opt[band - 1][i]) )
continue;
for (j = 0; j < 32; j++) {
idx = i + ff_nelly_delta_table[j];
if (idx > idx_max)
break;
if (idx >= idx_min) {
tmp = opt[band - 1][i] + distance(idx, power_candidate, band);
if (opt[band][idx] > tmp) {
opt[band][idx] = tmp;
path[band][idx] = j;
c = 1;
}
}
}
}
}
assert(c); //FIXME
}
best_val = INFINITY;
best_idx = -1;
band = NELLY_BANDS - 1;
for (i = 0; i < OPT_SIZE; i++) {
if (best_val > opt[band][i]) {
best_val = opt[band][i];
best_idx = i;
}
}
for (band = NELLY_BANDS - 1; band >= 0; band--) {
idx_table[band] = path[band][best_idx];
if (band) {
best_idx -= ff_nelly_delta_table[path[band][best_idx]];
}
}
}
/**
* Encodes NELLY_SAMPLES samples. It assumes, that samples contains 3 * NELLY_BUF_LEN values
* @param s encoder context
* @param output output buffer
* @param output_size size of output buffer
*/
static void encode_block(NellyMoserEncodeContext *s, unsigned char *output, int output_size)
{
PutBitContext pb;
int i, j, band, block, best_idx, power_idx = 0;
float power_val, coeff, coeff_sum;
float pows[NELLY_FILL_LEN];
int bits[NELLY_BUF_LEN], idx_table[NELLY_BANDS];
float cand[NELLY_BANDS];
apply_mdct(s);
init_put_bits(&pb, output, output_size * 8);
i = 0;
for (band = 0; band < NELLY_BANDS; band++) {
coeff_sum = 0;
for (j = 0; j < ff_nelly_band_sizes_table[band]; i++, j++) {
coeff_sum += s->mdct_out[i ] * s->mdct_out[i ]
+ s->mdct_out[i + NELLY_BUF_LEN] * s->mdct_out[i + NELLY_BUF_LEN];
}
cand[band] =
log(FFMAX(1.0, coeff_sum / (ff_nelly_band_sizes_table[band] << 7))) * 1024.0 / M_LN2;
}
if (s->avctx->trellis) {
get_exponent_dynamic(s, cand, idx_table);
} else {
get_exponent_greedy(s, cand, idx_table);
}
i = 0;
for (band = 0; band < NELLY_BANDS; band++) {
if (band) {
power_idx += ff_nelly_delta_table[idx_table[band]];
put_bits(&pb, 5, idx_table[band]);
} else {
power_idx = ff_nelly_init_table[idx_table[0]];
put_bits(&pb, 6, idx_table[0]);
}
power_val = pow_table[power_idx & 0x7FF] / (1 << ((power_idx >> 11) + POW_TABLE_OFFSET));
for (j = 0; j < ff_nelly_band_sizes_table[band]; i++, j++) {
s->mdct_out[i] *= power_val;
s->mdct_out[i + NELLY_BUF_LEN] *= power_val;
pows[i] = power_idx;
}
}
ff_nelly_get_sample_bits(pows, bits);
for (block = 0; block < 2; block++) {
for (i = 0; i < NELLY_FILL_LEN; i++) {
if (bits[i] > 0) {
const float *table = ff_nelly_dequantization_table + (1 << bits[i]) - 1;
coeff = s->mdct_out[block * NELLY_BUF_LEN + i];
best_idx =
quant_lut[av_clip (
coeff * quant_lut_mul[bits[i]] + quant_lut_add[bits[i]],
quant_lut_offset[bits[i]],
quant_lut_offset[bits[i]+1] - 1
)];
if (fabs(coeff - table[best_idx]) > fabs(coeff - table[best_idx + 1]))
best_idx++;
put_bits(&pb, bits[i], best_idx);
}
}
if (!block)
put_bits(&pb, NELLY_HEADER_BITS + NELLY_DETAIL_BITS - put_bits_count(&pb), 0);
}
}
static int encode_frame(AVCodecContext *avctx, uint8_t *frame, int buf_size, void *data)
{
NellyMoserEncodeContext *s = avctx->priv_data;
int16_t *samples = data;
int i;
if (s->last_frame)
return 0;
if (data) {
for (i = 0; i < avctx->frame_size; i++) {
s->buf[s->bufsel][i] = samples[i];
}
for (; i < NELLY_SAMPLES; i++) {
s->buf[s->bufsel][i] = 0;
}
s->bufsel = 1 - s->bufsel;
if (!s->have_saved) {
s->have_saved = 1;
return 0;
}
} else {
memset(s->buf[s->bufsel], 0, sizeof(s->buf[0][0]) * NELLY_BUF_LEN);
s->bufsel = 1 - s->bufsel;
s->last_frame = 1;
}
if (s->have_saved) {
encode_block(s, frame, buf_size);
return NELLY_BLOCK_LEN;
}
return 0;
}
AVCodec nellymoser_encoder = {
.name = "nellymoser",
.type = CODEC_TYPE_AUDIO,
.id = CODEC_ID_NELLYMOSER,
.priv_data_size = sizeof(NellyMoserEncodeContext),
.init = encode_init,
.encode = encode_frame,
.close = encode_end,
.capabilities = CODEC_CAP_SMALL_LAST_FRAME | CODEC_CAP_DELAY,
.long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao Codec"),
};
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