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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 libavcodec/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 "nellymoser.h"
#include "libavutil/lfg.h"
#include "libavutil/random_seed.h"
#include "avcodec.h"
#include "dsputil.h"
#define ALT_BITSTREAM_READER_LE
#include "get_bits.h"
typedef struct NellyMoserDecodeContext {
AVCodecContext* avctx;
DECLARE_ALIGNED_16(float,float_buf)[NELLY_SAMPLES];
float state[128];
AVLFG random_state;
GetBitContext gb;
int add_bias;
float scale_bias;
DSPContext dsp;
FFTContext imdct_ctx;
DECLARE_ALIGNED_16(float,imdct_out)[NELLY_BUF_LEN * 2];
} NellyMoserDecodeContext;
static void overlap_and_window(NellyMoserDecodeContext *s, float *state, float *audio, float *a_in)
{
int bot, top;
bot = 0;
top = NELLY_BUF_LEN-1;
while (bot < NELLY_BUF_LEN) {
audio[bot] = a_in [bot]*ff_sine_128[bot]
+state[bot]*ff_sine_128[top] + s->add_bias;
bot++;
top--;
}
memcpy(state, a_in + NELLY_BUF_LEN, sizeof(float)*NELLY_BUF_LEN);
}
static 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 = ff_nelly_init_table[get_bits(&s->gb, 6)];
for (i=0 ; i<NELLY_BANDS ; i++) {
if (i > 0)
val += ff_nelly_delta_table[get_bits(&s->gb, 5)];
pval = -pow(2, val/2048) * s->scale_bias;
for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {
*bptr++ = val;
*pptr++ = pval;
}
}
ff_nelly_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_long(&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_lfg_get(&s->random_state) & 1)
aptr[j] *= -1.0;
} else {
v = get_bits(&s->gb, bits[j]);
aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];
}
}
memset(&aptr[NELLY_FILL_LEN], 0,
(NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
ff_imdct_calc(&s->imdct_ctx, s->imdct_out, aptr);
/* XXX: overlapping and windowing should be part of a more
generic imdct function */
overlap_and_window(s, s->state, aptr, s->imdct_out);
}
}
static av_cold int decode_init(AVCodecContext * avctx) {
NellyMoserDecodeContext *s = avctx->priv_data;
s->avctx = avctx;
av_lfg_init(&s->random_state, 0);
ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);
dsputil_init(&s->dsp, avctx);
if(s->dsp.float_to_int16 == ff_float_to_int16_c) {
s->add_bias = 385;
s->scale_bias = 1.0/(8*32768);
} else {
s->add_bias = 0;
s->scale_bias = 1.0/(1*8);
}
/* Generate overlap window */
if (!ff_sine_128[127])
ff_init_ff_sine_windows(7);
avctx->sample_fmt = SAMPLE_FMT_S16;
avctx->channel_layout = CH_LAYOUT_MONO;
return 0;
}
static int decode_tag(AVCodecContext * avctx,
void *data, int *data_size,
AVPacket *avpkt) {
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->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 192: // 16000Hz
blocks = 3; break;
case 256: // 22050Hz
blocks = 4; break;
case 512: // 44100Hz
blocks = 8; break;
default:
av_log(avctx, AV_LOG_DEBUG, "Tag size %d.\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 av_cold 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,
.long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
};
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