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ffmpeg/libavcodec/nellymoserdec.c

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/*
* NellyMoser audio decoder
* Copyright (c) 2007 a840bda5870ba11f19698ff6eb9581dfb0f95fa5,
* 539459aeb7d425140b62a3ec7dbf6dc8e408a306, and
* 520e17cd55896441042b14df2566a6eb610ed444
* Copyright (c) 2007 Loic Minier <lool at dooz.org>
* Benjamin Larsson
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
/**
* @file nellymoserdec.c
* The 3 alphanumeric copyright notices are md5summed they are from the original
* implementors. The original code is available from http://code.google.com/p/nelly2pcm/
*/
#include "avcodec.h"
#include "random.h"
#include "dsputil.h"
#define ALT_BITSTREAM_READER_LE
#include "bitstream.h"
#define NELLY_BANDS 23
#define NELLY_BLOCK_LEN 64
#define NELLY_HEADER_BITS 116
#define NELLY_DETAIL_BITS 198
#define NELLY_BUF_LEN 128
#define NELLY_FILL_LEN 124
#define NELLY_BIT_CAP 6
#define NELLY_BASE_OFF 4228
#define NELLY_BASE_SHIFT 19
#define NELLY_SAMPLES (2 * NELLY_BUF_LEN)
static const float dequantization_table[127] = {
0.0000000000,-0.8472560048, 0.7224709988, -1.5247479677, -0.4531480074, 0.3753609955, 1.4717899561,
-1.9822579622, -1.1929379702, -0.5829370022, -0.0693780035, 0.3909569979,0.9069200158, 1.4862740040,
2.2215409279, -2.3887870312, -1.8067539930, -1.4105420113, -1.0773609877, -0.7995010018,-0.5558109879,
-0.3334020078, -0.1324490011, 0.0568020009, 0.2548770010, 0.4773550034, 0.7386850119, 1.0443060398,
1.3954459429, 1.8098750114, 2.3918759823,-2.3893830776, -1.9884680510, -1.7514040470, -1.5643119812,
-1.3922129869,-1.2164649963, -1.0469499826, -0.8905100226, -0.7645580173, -0.6454579830, -0.5259280205,
-0.4059549868, -0.3029719889, -0.2096900046, -0.1239869967, -0.0479229987, 0.0257730000, 0.1001340002,
0.1737180054, 0.2585540116, 0.3522900045, 0.4569880068, 0.5767750144, 0.7003160119, 0.8425520062,
1.0093879700, 1.1821349859, 1.3534560204, 1.5320819616, 1.7332619429, 1.9722349644, 2.3978140354,
-2.5756309032, -2.0573320389, -1.8984919786, -1.7727810144, -1.6662600040, -1.5742180347, -1.4993319511,
-1.4316639900, -1.3652280569, -1.3000990152, -1.2280930281, -1.1588579416, -1.0921250582, -1.0135740042,
-0.9202849865, -0.8287050128, -0.7374889851, -0.6447759867, -0.5590940118, -0.4857139885, -0.4110319912,
-0.3459700048, -0.2851159871, -0.2341620028, -0.1870580018, -0.1442500055, -0.1107169986, -0.0739680007,
-0.0365610011, -0.0073290002, 0.0203610007, 0.0479039997, 0.0751969963, 0.0980999991, 0.1220389977,
0.1458999962, 0.1694349945, 0.1970459968, 0.2252430022, 0.2556869984, 0.2870100141, 0.3197099864,
0.3525829911, 0.3889069855, 0.4334920049, 0.4769459963, 0.5204820037, 0.5644530058, 0.6122040153,
0.6685929894, 0.7341650128, 0.8032159805, 0.8784040213, 0.9566209912, 1.0397069454, 1.1293770075,
1.2211159468, 1.3080279827, 1.4024800062, 1.5056819916, 1.6227730513, 1.7724959850, 1.9430880547,
2.2903931141
};
static const uint8_t nelly_band_sizes_table[NELLY_BANDS] = {
2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 4, 4, 5, 6, 6, 7, 8, 9, 10, 12, 14, 15
};
static const uint16_t nelly_init_table[64] = {
3134, 5342, 6870, 7792, 8569, 9185, 9744, 10191, 10631, 11061, 11434, 11770,
12116, 12513, 12925, 13300, 13674, 14027, 14352, 14716, 15117, 15477, 15824,
16157, 16513, 16804, 17090, 17401, 17679, 17948, 18238, 18520, 18764, 19078,
19381, 19640, 19921, 20205, 20500, 20813, 21162, 21465, 21794, 22137, 22453,
22756, 23067, 23350, 23636, 23926, 24227, 24521, 24819, 25107, 25414, 25730,
26120, 26497, 26895, 27344, 27877, 28463, 29426, 31355
};
static const int16_t nelly_delta_table[32] = {
-11725, -9420, -7910, -6801, -5948, -5233, -4599, -4039, -3507, -3030, -2596,
-2170, -1774, -1383, -1016, -660, -329, -1, 337, 696, 1085, 1512, 1962, 2433,
2968, 3569, 4314, 5279, 6622, 8154, 10076, 12975
};
typedef struct NellyMoserDecodeContext {
AVCodecContext* avctx;
DECLARE_ALIGNED_16(float,float_buf[NELLY_SAMPLES]);
float state[64];
AVRandomState random_state;
GetBitContext gb;
int add_bias;
int scale_bias;
DSPContext dsp;
MDCTContext imdct_ctx;
DECLARE_ALIGNED_16(float,imdct_tmp[NELLY_BUF_LEN]);
DECLARE_ALIGNED_16(float,imdct_out[NELLY_BUF_LEN * 2]);
} NellyMoserDecodeContext;
static DECLARE_ALIGNED_16(float,sine_window[128]);
static inline int signed_shift(int i, int shift) {
if (shift > 0)
return i << shift;
return i >> -shift;
}
static void overlap_and_window(NellyMoserDecodeContext *s, float *state, float *audio)
{
int bot, mid_up, mid_down, top;
float s_bot, s_top;
bot = 0;
top = NELLY_BUF_LEN-1;
mid_up = NELLY_BUF_LEN/2;
mid_down = (NELLY_BUF_LEN/2)-1;
while (bot < NELLY_BUF_LEN/4) {
s_bot = audio[bot];
s_top = -audio[top];
audio[bot] = (-audio[mid_up]*sine_window[bot]-state[bot ]*sine_window[top])/s->scale_bias + s->add_bias;
audio[top] = (-state[bot ]*sine_window[bot]+audio[mid_up]*sine_window[top])/s->scale_bias + s->add_bias;
state[bot] = audio[mid_down];
audio[mid_down] = (s_top *sine_window[mid_down]-state[mid_down]*sine_window[mid_up])/s->scale_bias + s->add_bias;
audio[mid_up ] = (-state[mid_down]*sine_window[mid_down]-s_top *sine_window[mid_up])/s->scale_bias + s->add_bias;
state[mid_down] = s_bot;
bot++;
mid_up++;
mid_down--;
top--;
}
}
static int sum_bits(short *buf, short shift, short off)
{
int b, i = 0, ret = 0;
for (i = 0; i < NELLY_FILL_LEN; i++) {
b = buf[i]-off;
b = ((b>>(shift-1))+1)>>1;
ret += av_clip(b, 0, NELLY_BIT_CAP);
}
return ret;
}
static int headroom(int *la)
{
int l;
if (*la == 0) {
return 31;
}
l = 30 - av_log2(FFABS(*la));
*la <<= l;
return l;
}
static void get_sample_bits(const float *buf, int *bits)
{
int i, j;
short sbuf[128];
int bitsum = 0, last_bitsum, small_bitsum, big_bitsum;
short shift, shift_saved;
int max, sum, last_off, tmp;
int big_off, small_off;
int off;
max = 0;
for (i = 0; i < NELLY_FILL_LEN; i++) {
max = FFMAX(max, buf[i]);
}
shift = -16;
shift += headroom(&max);
sum = 0;
for (i = 0; i < NELLY_FILL_LEN; i++) {
sbuf[i] = signed_shift(buf[i], shift);
sbuf[i] = (3*sbuf[i])>>2;
sum += sbuf[i];
}
shift += 11;
shift_saved = shift;
sum -= NELLY_DETAIL_BITS << shift;
shift += headroom(&sum);
small_off = (NELLY_BASE_OFF * (sum>>16)) >> 15;
shift = shift_saved - (NELLY_BASE_SHIFT+shift-31);
small_off = signed_shift(small_off, shift);
bitsum = sum_bits(sbuf, shift_saved, small_off);
if (bitsum != NELLY_DETAIL_BITS) {
shift = 0;
off = bitsum - NELLY_DETAIL_BITS;
for(shift=0; FFABS(off) <= 16383; shift++)
off *= 2;
off = (off * NELLY_BASE_OFF) >> 15;
shift = shift_saved-(NELLY_BASE_SHIFT+shift-15);
off = signed_shift(off, shift);
for (j = 1; j < 20; j++) {
last_off = small_off;
small_off += off;
last_bitsum = bitsum;
bitsum = sum_bits(sbuf, shift_saved, small_off);
if ((bitsum-NELLY_DETAIL_BITS) * (last_bitsum-NELLY_DETAIL_BITS) <= 0)
break;
}
if (bitsum > NELLY_DETAIL_BITS) {
big_off = small_off;
small_off = last_off;
big_bitsum=bitsum;
small_bitsum=last_bitsum;
} else {
big_off = last_off;
big_bitsum=last_bitsum;
small_bitsum=bitsum;
}
while (bitsum != NELLY_DETAIL_BITS && j <= 19) {
off = (big_off+small_off)>>1;
bitsum = sum_bits(sbuf, shift_saved, off);
if (bitsum > NELLY_DETAIL_BITS) {
big_off=off;
big_bitsum=bitsum;
} else {
small_off = off;
small_bitsum=bitsum;
}
j++;
}
if (abs(big_bitsum-NELLY_DETAIL_BITS) >=
abs(small_bitsum-NELLY_DETAIL_BITS)) {
bitsum = small_bitsum;
} else {
small_off = big_off;
bitsum = big_bitsum;
}
}
for (i = 0; i < NELLY_FILL_LEN; i++) {
tmp = sbuf[i]-small_off;
tmp = ((tmp>>(shift_saved-1))+1)>>1;
bits[i] = av_clip(tmp, 0, NELLY_BIT_CAP);
}
if (bitsum > NELLY_DETAIL_BITS) {
tmp = i = 0;
while (tmp < NELLY_DETAIL_BITS) {
tmp += bits[i];
i++;
}
bits[i-1] -= tmp - NELLY_DETAIL_BITS;
for(; i < NELLY_FILL_LEN; i++)
bits[i] = 0;
}
}
void nelly_decode_block(NellyMoserDecodeContext *s, const unsigned char block[NELLY_BLOCK_LEN], float audio[NELLY_SAMPLES])
{
int i,j;
float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
float *aptr, *bptr, *pptr, val, pval;
int bits[NELLY_BUF_LEN];
unsigned char v;
init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
bptr = buf;
pptr = pows;
val = nelly_init_table[get_bits(&s->gb, 6)];
for (i=0 ; i<NELLY_BANDS ; i++) {
if (i > 0)
val += nelly_delta_table[get_bits(&s->gb, 5)];
pval = pow(2, val/2048);
for (j = 0; j < nelly_band_sizes_table[i]; j++) {
*bptr++ = val;
*pptr++ = pval;
}
}
get_sample_bits(buf, bits);
for (i = 0; i < 2; i++) {
aptr = audio + i * NELLY_BUF_LEN;
init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
skip_bits(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS);
for (j = 0; j < NELLY_FILL_LEN; j++) {
if (bits[j] <= 0) {
aptr[j] = M_SQRT1_2*pows[j];
if (av_random(&s->random_state) & 1)
aptr[j] *= -1.0;
} else {
v = get_bits(&s->gb, bits[j]);
aptr[j] = dequantization_table[(1<<bits[j])-1+v]*pows[j];
}
}
memset(&aptr[NELLY_FILL_LEN], 0,
(NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
s->imdct_ctx.fft.imdct_calc(&s->imdct_ctx, s->imdct_out,
aptr, s->imdct_tmp);
/* XXX: overlapping and windowing should be part of a more
generic imdct function */
memcpy(&aptr[0],&s->imdct_out[NELLY_BUF_LEN+NELLY_BUF_LEN/2], (NELLY_BUF_LEN/2)*sizeof(float));
memcpy(&aptr[NELLY_BUF_LEN / 2],&s->imdct_out[0],(NELLY_BUF_LEN/2)*sizeof(float));
overlap_and_window(s, s->state, aptr);
}
}
static int decode_init(AVCodecContext * avctx) {
NellyMoserDecodeContext *s = avctx->priv_data;
int i;
s->avctx = avctx;
av_init_random(0, &s->random_state);
ff_mdct_init(&s->imdct_ctx, 8, 1);
dsputil_init(&s->dsp, avctx);
if(s->dsp.float_to_int16 == ff_float_to_int16_c) {
s->add_bias = 385;
s->scale_bias = 8*32768;
} else {
s->add_bias = 0;
s->scale_bias = 1*8;
}
/* Generate overlap window */
if (!sine_window[0])
for (i=0 ; i<128; i++) {
sine_window[i] = sin((i + 0.5) / 256.0 * M_PI);
}
return 0;
}
static int decode_tag(AVCodecContext * avctx,
void *data, int *data_size,
const uint8_t * buf, int buf_size) {
NellyMoserDecodeContext *s = avctx->priv_data;
int blocks, i;
int16_t* samples;
*data_size = 0;
samples = (int16_t*)data;
if (buf_size < avctx->block_align)
return buf_size;
switch (buf_size) {
case 64: // 8000Hz
blocks = 1; break;
case 128: // 11025Hz
blocks = 2; break;
case 256: // 22050Hz
blocks = 4; break;
case 512: // 44100Hz
blocks = 8; break;
default:
av_log(avctx, AV_LOG_ERROR, "Tag size %d unknown, report sample!\n", buf_size);
return buf_size;
}
for (i=0 ; i<blocks ; i++) {
nelly_decode_block(s, &buf[i*NELLY_BLOCK_LEN], s->float_buf);
s->dsp.float_to_int16(&samples[i*NELLY_SAMPLES], s->float_buf, NELLY_SAMPLES);
*data_size += NELLY_SAMPLES*sizeof(int16_t);
}
return buf_size;
}
static int decode_end(AVCodecContext * avctx) {
NellyMoserDecodeContext *s = avctx->priv_data;
ff_mdct_end(&s->imdct_ctx);
return 0;
}
AVCodec nellymoser_decoder = {
"nellymoser",
CODEC_TYPE_AUDIO,
CODEC_ID_NELLYMOSER,
sizeof(NellyMoserDecodeContext),
decode_init,
NULL,
decode_end,
decode_tag,
};
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