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FFmpeg/libavcodec/wmadec.c
Michael Niedermayer caa336b4cc common.c -> bitstream.c (and the single non bitstream func -> utils.c) 
common.h -> common.h/bitstream.h

Originally committed as revision 3777 to svn://svn.ffmpeg.org/ffmpeg/trunk
2004-12-29 17:50:25 +00:00

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/*
* WMA compatible decoder
* Copyright (c) 2002 The FFmpeg Project.
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/**
* @file wmadec.c
* WMA compatible decoder.
* This decoder handles Microsoft Windows Media Audio data, versions 1 & 2.
* WMA v1 is identified by audio format 0x160 in Microsoft media files
* (ASF/AVI/WAV). WMA v2 is identified by audio format 0x161.
*
* To use this decoder, a calling application must supply the extra data
* bytes provided with the WMA data. These are the extra, codec-specific
* bytes at the end of a WAVEFORMATEX data structure. Transmit these bytes
* to the decoder using the extradata[_size] fields in AVCodecContext. There
* should be 4 extra bytes for v1 data and 6 extra bytes for v2 data.
*/
#include "avcodec.h"
#include "bitstream.h"
#include "dsputil.h"
/* size of blocks */
#define BLOCK_MIN_BITS 7
#define BLOCK_MAX_BITS 11
#define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS)
#define BLOCK_NB_SIZES (BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1)
/* XXX: find exact max size */
#define HIGH_BAND_MAX_SIZE 16
#define NB_LSP_COEFS 10
/* XXX: is it a suitable value ? */
#define MAX_CODED_SUPERFRAME_SIZE 4096
#define MAX_CHANNELS 2
#define NOISE_TAB_SIZE 8192
#define LSP_POW_BITS 7
typedef struct WMADecodeContext {
GetBitContext gb;
int sample_rate;
int nb_channels;
int bit_rate;
int version; /* 1 = 0x160 (WMAV1), 2 = 0x161 (WMAV2) */
int block_align;
int use_bit_reservoir;
int use_variable_block_len;
int use_exp_vlc; /* exponent coding: 0 = lsp, 1 = vlc + delta */
int use_noise_coding; /* true if perceptual noise is added */
int byte_offset_bits;
VLC exp_vlc;
int exponent_sizes[BLOCK_NB_SIZES];
uint16_t exponent_bands[BLOCK_NB_SIZES][25];
int high_band_start[BLOCK_NB_SIZES]; /* index of first coef in high band */
int coefs_start; /* first coded coef */
int coefs_end[BLOCK_NB_SIZES]; /* max number of coded coefficients */
int exponent_high_sizes[BLOCK_NB_SIZES];
int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];
VLC hgain_vlc;
/* coded values in high bands */
int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
/* there are two possible tables for spectral coefficients */
VLC coef_vlc[2];
uint16_t *run_table[2];
uint16_t *level_table[2];
/* frame info */
int frame_len; /* frame length in samples */
int frame_len_bits; /* frame_len = 1 << frame_len_bits */
int nb_block_sizes; /* number of block sizes */
/* block info */
int reset_block_lengths;
int block_len_bits; /* log2 of current block length */
int next_block_len_bits; /* log2 of next block length */
int prev_block_len_bits; /* log2 of prev block length */
int block_len; /* block length in samples */
int block_num; /* block number in current frame */
int block_pos; /* current position in frame */
uint8_t ms_stereo; /* true if mid/side stereo mode */
uint8_t channel_coded[MAX_CHANNELS]; /* true if channel is coded */
float exponents[MAX_CHANNELS][BLOCK_MAX_SIZE] __attribute__((aligned(16)));
float max_exponent[MAX_CHANNELS];
int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
float coefs[MAX_CHANNELS][BLOCK_MAX_SIZE] __attribute__((aligned(16)));
MDCTContext mdct_ctx[BLOCK_NB_SIZES];
float *windows[BLOCK_NB_SIZES];
FFTSample mdct_tmp[BLOCK_MAX_SIZE] __attribute__((aligned(16))); /* temporary storage for imdct */
/* output buffer for one frame and the last for IMDCT windowing */
float frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2] __attribute__((aligned(16)));
/* last frame info */
uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
int last_bitoffset;
int last_superframe_len;
float noise_table[NOISE_TAB_SIZE];
int noise_index;
float noise_mult; /* XXX: suppress that and integrate it in the noise array */
/* lsp_to_curve tables */
float lsp_cos_table[BLOCK_MAX_SIZE];
float lsp_pow_e_table[256];
float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
#ifdef TRACE
int frame_count;
#endif
} WMADecodeContext;
typedef struct CoefVLCTable {
int n; /* total number of codes */
const uint32_t *huffcodes; /* VLC bit values */
const uint8_t *huffbits; /* VLC bit size */
const uint16_t *levels; /* table to build run/level tables */
} CoefVLCTable;
static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len);
#include "wmadata.h"
#ifdef TRACE
static void dump_shorts(const char *name, const short *tab, int n)
{
int i;
tprintf("%s[%d]:\n", name, n);
for(i=0;i<n;i++) {
if ((i & 7) == 0)
tprintf("%4d: ", i);
tprintf(" %5d.0", tab[i]);
if ((i & 7) == 7)
tprintf("\n");
}
}
static void dump_floats(const char *name, int prec, const float *tab, int n)
{
int i;
tprintf("%s[%d]:\n", name, n);
for(i=0;i<n;i++) {
if ((i & 7) == 0)
tprintf("%4d: ", i);
tprintf(" %8.*f", prec, tab[i]);
if ((i & 7) == 7)
tprintf("\n");
}
if ((i & 7) != 0)
tprintf("\n");
}
#endif
/* XXX: use same run/length optimization as mpeg decoders */
static void init_coef_vlc(VLC *vlc,
uint16_t **prun_table, uint16_t **plevel_table,
const CoefVLCTable *vlc_table)
{
int n = vlc_table->n;
const uint8_t *table_bits = vlc_table->huffbits;
const uint32_t *table_codes = vlc_table->huffcodes;
const uint16_t *levels_table = vlc_table->levels;
uint16_t *run_table, *level_table;
const uint16_t *p;
int i, l, j, level;
init_vlc(vlc, 9, n, table_bits, 1, 1, table_codes, 4, 4, 0);
run_table = av_malloc(n * sizeof(uint16_t));
level_table = av_malloc(n * sizeof(uint16_t));
p = levels_table;
i = 2;
level = 1;
while (i < n) {
l = *p++;
for(j=0;j<l;j++) {
run_table[i] = j;
level_table[i] = level;
i++;
}
level++;
}
*prun_table = run_table;
*plevel_table = level_table;
}
static int wma_decode_init(AVCodecContext * avctx)
{
WMADecodeContext *s = avctx->priv_data;
int i, flags1, flags2;
float *window;
uint8_t *extradata;
float bps1, high_freq;
volatile float bps;
int sample_rate1;
int coef_vlc_table;
s->sample_rate = avctx->sample_rate;
s->nb_channels = avctx->channels;
s->bit_rate = avctx->bit_rate;
s->block_align = avctx->block_align;
if (avctx->codec->id == CODEC_ID_WMAV1) {
s->version = 1;
} else {
s->version = 2;
}
/* extract flag infos */
flags1 = 0;
flags2 = 0;
extradata = avctx->extradata;
if (s->version == 1 && avctx->extradata_size >= 4) {
flags1 = extradata[0] | (extradata[1] << 8);
flags2 = extradata[2] | (extradata[3] << 8);
} else if (s->version == 2 && avctx->extradata_size >= 6) {
flags1 = extradata[0] | (extradata[1] << 8) |
(extradata[2] << 16) | (extradata[3] << 24);
flags2 = extradata[4] | (extradata[5] << 8);
}
s->use_exp_vlc = flags2 & 0x0001;
s->use_bit_reservoir = flags2 & 0x0002;
s->use_variable_block_len = flags2 & 0x0004;
/* compute MDCT block size */
if (s->sample_rate <= 16000) {
s->frame_len_bits = 9;
} else if (s->sample_rate <= 22050 ||
(s->sample_rate <= 32000 && s->version == 1)) {
s->frame_len_bits = 10;
} else {
s->frame_len_bits = 11;
}
s->frame_len = 1 << s->frame_len_bits;
if (s->use_variable_block_len) {
int nb_max, nb;
nb = ((flags2 >> 3) & 3) + 1;
if ((s->bit_rate / s->nb_channels) >= 32000)
nb += 2;
nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
if (nb > nb_max)
nb = nb_max;
s->nb_block_sizes = nb + 1;
} else {
s->nb_block_sizes = 1;
}
/* init rate dependant parameters */
s->use_noise_coding = 1;
high_freq = s->sample_rate * 0.5;
/* if version 2, then the rates are normalized */
sample_rate1 = s->sample_rate;
if (s->version == 2) {
if (sample_rate1 >= 44100)
sample_rate1 = 44100;
else if (sample_rate1 >= 22050)
sample_rate1 = 22050;
else if (sample_rate1 >= 16000)
sample_rate1 = 16000;
else if (sample_rate1 >= 11025)
sample_rate1 = 11025;
else if (sample_rate1 >= 8000)
sample_rate1 = 8000;
}
bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate);
s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0)) + 2;
/* compute high frequency value and choose if noise coding should
be activated */
bps1 = bps;
if (s->nb_channels == 2)
bps1 = bps * 1.6;
if (sample_rate1 == 44100) {
if (bps1 >= 0.61)
s->use_noise_coding = 0;
else
high_freq = high_freq * 0.4;
} else if (sample_rate1 == 22050) {
if (bps1 >= 1.16)
s->use_noise_coding = 0;
else if (bps1 >= 0.72)
high_freq = high_freq * 0.7;
else
high_freq = high_freq * 0.6;
} else if (sample_rate1 == 16000) {
if (bps > 0.5)
high_freq = high_freq * 0.5;
else
high_freq = high_freq * 0.3;
} else if (sample_rate1 == 11025) {
high_freq = high_freq * 0.7;
} else if (sample_rate1 == 8000) {
if (bps <= 0.625) {
high_freq = high_freq * 0.5;
} else if (bps > 0.75) {
s->use_noise_coding = 0;
} else {
high_freq = high_freq * 0.65;
}
} else {
if (bps >= 0.8) {
high_freq = high_freq * 0.75;
} else if (bps >= 0.6) {
high_freq = high_freq * 0.6;
} else {
high_freq = high_freq * 0.5;
}
}
dprintf("flags1=0x%x flags2=0x%x\n", flags1, flags2);
dprintf("version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
s->version, s->nb_channels, s->sample_rate, s->bit_rate,
s->block_align);
dprintf("bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
bps, bps1, high_freq, s->byte_offset_bits);
dprintf("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
/* compute the scale factor band sizes for each MDCT block size */
{
int a, b, pos, lpos, k, block_len, i, j, n;
const uint8_t *table;
if (s->version == 1) {
s->coefs_start = 3;
} else {
s->coefs_start = 0;
}
for(k = 0; k < s->nb_block_sizes; k++) {
block_len = s->frame_len >> k;
if (s->version == 1) {
lpos = 0;
for(i=0;i<25;i++) {
a = wma_critical_freqs[i];
b = s->sample_rate;
pos = ((block_len * 2 * a) + (b >> 1)) / b;
if (pos > block_len)
pos = block_len;
s->exponent_bands[0][i] = pos - lpos;
if (pos >= block_len) {
i++;
break;
}
lpos = pos;
}
s->exponent_sizes[0] = i;
} else {
/* hardcoded tables */
table = NULL;
a = s->frame_len_bits - BLOCK_MIN_BITS - k;
if (a < 3) {
if (s->sample_rate >= 44100)
table = exponent_band_44100[a];
else if (s->sample_rate >= 32000)
table = exponent_band_32000[a];
else if (s->sample_rate >= 22050)
table = exponent_band_22050[a];
}
if (table) {
n = *table++;
for(i=0;i<n;i++)
s->exponent_bands[k][i] = table[i];
s->exponent_sizes[k] = n;
} else {
j = 0;
lpos = 0;
for(i=0;i<25;i++) {
a = wma_critical_freqs[i];
b = s->sample_rate;
pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
pos <<= 2;
if (pos > block_len)
pos = block_len;
if (pos > lpos)
s->exponent_bands[k][j++] = pos - lpos;
if (pos >= block_len)
break;
lpos = pos;
}
s->exponent_sizes[k] = j;
}
}
/* max number of coefs */
s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
/* high freq computation */
s->high_band_start[k] = (int)((block_len * 2 * high_freq) /
s->sample_rate + 0.5);
n = s->exponent_sizes[k];
j = 0;
pos = 0;
for(i=0;i<n;i++) {
int start, end;
start = pos;
pos += s->exponent_bands[k][i];
end = pos;
if (start < s->high_band_start[k])
start = s->high_band_start[k];
if (end > s->coefs_end[k])
end = s->coefs_end[k];
if (end > start)
s->exponent_high_bands[k][j++] = end - start;
}
s->exponent_high_sizes[k] = j;
#if 0
tprintf("%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
s->frame_len >> k,
s->coefs_end[k],
s->high_band_start[k],
s->exponent_high_sizes[k]);
for(j=0;j<s->exponent_high_sizes[k];j++)
tprintf(" %d", s->exponent_high_bands[k][j]);
tprintf("\n");
#endif
}
}
#ifdef TRACE
{
int i, j;
for(i = 0; i < s->nb_block_sizes; i++) {
tprintf("%5d: n=%2d:",
s->frame_len >> i,
s->exponent_sizes[i]);
for(j=0;j<s->exponent_sizes[i];j++)
tprintf(" %d", s->exponent_bands[i][j]);
tprintf("\n");
}
}
#endif
/* init MDCT */
for(i = 0; i < s->nb_block_sizes; i++)
ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1);
/* init MDCT windows : simple sinus window */
for(i = 0; i < s->nb_block_sizes; i++) {
int n, j;
float alpha;
n = 1 << (s->frame_len_bits - i);
window = av_malloc(sizeof(float) * n);
alpha = M_PI / (2.0 * n);
for(j=0;j<n;j++) {
window[n - j - 1] = sin((j + 0.5) * alpha);
}
s->windows[i] = window;
}
s->reset_block_lengths = 1;
if (s->use_noise_coding) {
/* init the noise generator */
if (s->use_exp_vlc)
s->noise_mult = 0.02;
else
s->noise_mult = 0.04;
#ifdef TRACE
for(i=0;i<NOISE_TAB_SIZE;i++)
s->noise_table[i] = 1.0 * s->noise_mult;
#else
{
unsigned int seed;
float norm;
seed = 1;
norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
for(i=0;i<NOISE_TAB_SIZE;i++) {
seed = seed * 314159 + 1;
s->noise_table[i] = (float)((int)seed) * norm;
}
}
#endif
init_vlc(&s->hgain_vlc, 9, sizeof(hgain_huffbits),
hgain_huffbits, 1, 1,
hgain_huffcodes, 2, 2, 0);
}
if (s->use_exp_vlc) {
init_vlc(&s->exp_vlc, 9, sizeof(scale_huffbits),
scale_huffbits, 1, 1,
scale_huffcodes, 4, 4, 0);
} else {
wma_lsp_to_curve_init(s, s->frame_len);
}
/* choose the VLC tables for the coefficients */
coef_vlc_table = 2;
if (s->sample_rate >= 32000) {
if (bps1 < 0.72)
coef_vlc_table = 0;
else if (bps1 < 1.16)
coef_vlc_table = 1;
}
init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0],
&coef_vlcs[coef_vlc_table * 2]);
init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1],
&coef_vlcs[coef_vlc_table * 2 + 1]);
return 0;
}
/* interpolate values for a bigger or smaller block. The block must
have multiple sizes */
static void interpolate_array(float *scale, int old_size, int new_size)
{
int i, j, jincr, k;
float v;
if (new_size > old_size) {
jincr = new_size / old_size;
j = new_size;
for(i = old_size - 1; i >=0; i--) {
v = scale[i];
k = jincr;
do {
scale[--j] = v;
} while (--k);
}
} else if (new_size < old_size) {
j = 0;
jincr = old_size / new_size;
for(i = 0; i < new_size; i++) {
scale[i] = scale[j];
j += jincr;
}
}
}
/* compute x^-0.25 with an exponent and mantissa table. We use linear
interpolation to reduce the mantissa table size at a small speed
expense (linear interpolation approximately doubles the number of
bits of precision). */
static inline float pow_m1_4(WMADecodeContext *s, float x)
{
union {
float f;
unsigned int v;
} u, t;
unsigned int e, m;
float a, b;
u.f = x;
e = u.v >> 23;
m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
/* build interpolation scale: 1 <= t < 2. */
t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
a = s->lsp_pow_m_table1[m];
b = s->lsp_pow_m_table2[m];
return s->lsp_pow_e_table[e] * (a + b * t.f);
}
static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len)
{
float wdel, a, b;
int i, e, m;
wdel = M_PI / frame_len;
for(i=0;i<frame_len;i++)
s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
/* tables for x^-0.25 computation */
for(i=0;i<256;i++) {
e = i - 126;
s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
}
/* NOTE: these two tables are needed to avoid two operations in
pow_m1_4 */
b = 1.0;
for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
m = (1 << LSP_POW_BITS) + i;
a = (float)m * (0.5 / (1 << LSP_POW_BITS));
a = pow(a, -0.25);
s->lsp_pow_m_table1[i] = 2 * a - b;
s->lsp_pow_m_table2[i] = b - a;
b = a;
}
#if 0
for(i=1;i<20;i++) {
float v, r1, r2;
v = 5.0 / i;
r1 = pow_m1_4(s, v);
r2 = pow(v,-0.25);
printf("%f^-0.25=%f e=%f\n", v, r1, r2 - r1);
}
#endif
}
/* NOTE: We use the same code as Vorbis here */
/* XXX: optimize it further with SSE/3Dnow */
static void wma_lsp_to_curve(WMADecodeContext *s,
float *out, float *val_max_ptr,
int n, float *lsp)
{
int i, j;
float p, q, w, v, val_max;
val_max = 0;
for(i=0;i<n;i++) {
p = 0.5f;
q = 0.5f;
w = s->lsp_cos_table[i];
for(j=1;j<NB_LSP_COEFS;j+=2){
q *= w - lsp[j - 1];
p *= w - lsp[j];
}
p *= p * (2.0f - w);
q *= q * (2.0f + w);
v = p + q;
v = pow_m1_4(s, v);
if (v > val_max)
val_max = v;
out[i] = v;
}
*val_max_ptr = val_max;
}
/* decode exponents coded with LSP coefficients (same idea as Vorbis) */
static void decode_exp_lsp(WMADecodeContext *s, int ch)
{
float lsp_coefs[NB_LSP_COEFS];
int val, i;
for(i = 0; i < NB_LSP_COEFS; i++) {
if (i == 0 || i >= 8)
val = get_bits(&s->gb, 3);
else
val = get_bits(&s->gb, 4);
lsp_coefs[i] = lsp_codebook[i][val];
}
wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
s->block_len, lsp_coefs);
}
/* decode exponents coded with VLC codes */
static int decode_exp_vlc(WMADecodeContext *s, int ch)
{
int last_exp, n, code;
const uint16_t *ptr, *band_ptr;
float v, *q, max_scale, *q_end;
band_ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
ptr = band_ptr;
q = s->exponents[ch];
q_end = q + s->block_len;
max_scale = 0;
if (s->version == 1) {
last_exp = get_bits(&s->gb, 5) + 10;
/* XXX: use a table */
v = pow(10, last_exp * (1.0 / 16.0));
max_scale = v;
n = *ptr++;
do {
*q++ = v;
} while (--n);
}
last_exp = 36;
while (q < q_end) {
code = get_vlc(&s->gb, &s->exp_vlc);
if (code < 0)
return -1;
/* NOTE: this offset is the same as MPEG4 AAC ! */
last_exp += code - 60;
/* XXX: use a table */
v = pow(10, last_exp * (1.0 / 16.0));
if (v > max_scale)
max_scale = v;
n = *ptr++;
do {
*q++ = v;
} while (--n);
}
s->max_exponent[ch] = max_scale;
return 0;
}
/* return 0 if OK. return 1 if last block of frame. return -1 if
unrecorrable error. */
static int wma_decode_block(WMADecodeContext *s)
{
int n, v, a, ch, code, bsize;
int coef_nb_bits, total_gain, parse_exponents;
float window[BLOCK_MAX_SIZE * 2];
// XXX: FIXME!! there's a bug somewhere which makes this mandatory under altivec
#ifdef HAVE_ALTIVEC
volatile int nb_coefs[MAX_CHANNELS] __attribute__((aligned(16)));
#else
int nb_coefs[MAX_CHANNELS];
#endif
float mdct_norm;
#ifdef TRACE
tprintf("***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
#endif
/* compute current block length */
if (s->use_variable_block_len) {
n = av_log2(s->nb_block_sizes - 1) + 1;
if (s->reset_block_lengths) {
s->reset_block_lengths = 0;
v = get_bits(&s->gb, n);
if (v >= s->nb_block_sizes)
return -1;
s->prev_block_len_bits = s->frame_len_bits - v;
v = get_bits(&s->gb, n);
if (v >= s->nb_block_sizes)
return -1;
s->block_len_bits = s->frame_len_bits - v;
} else {
/* update block lengths */
s->prev_block_len_bits = s->block_len_bits;
s->block_len_bits = s->next_block_len_bits;
}
v = get_bits(&s->gb, n);
if (v >= s->nb_block_sizes)
return -1;
s->next_block_len_bits = s->frame_len_bits - v;
} else {
/* fixed block len */
s->next_block_len_bits = s->frame_len_bits;
s->prev_block_len_bits = s->frame_len_bits;
s->block_len_bits = s->frame_len_bits;
}
/* now check if the block length is coherent with the frame length */
s->block_len = 1 << s->block_len_bits;
if ((s->block_pos + s->block_len) > s->frame_len)
return -1;
if (s->nb_channels == 2) {
s->ms_stereo = get_bits(&s->gb, 1);
}
v = 0;
for(ch = 0; ch < s->nb_channels; ch++) {
a = get_bits(&s->gb, 1);
s->channel_coded[ch] = a;
v |= a;
}
/* if no channel coded, no need to go further */
/* XXX: fix potential framing problems */
if (!v)
goto next;
bsize = s->frame_len_bits - s->block_len_bits;
/* read total gain and extract corresponding number of bits for
coef escape coding */
total_gain = 1;
for(;;) {
a = get_bits(&s->gb, 7);
total_gain += a;
if (a != 127)
break;
}
if (total_gain < 15)
coef_nb_bits = 13;
else if (total_gain < 32)
coef_nb_bits = 12;
else if (total_gain < 40)
coef_nb_bits = 11;
else if (total_gain < 45)
coef_nb_bits = 10;
else
coef_nb_bits = 9;
/* compute number of coefficients */
n = s->coefs_end[bsize] - s->coefs_start;
for(ch = 0; ch < s->nb_channels; ch++)
nb_coefs[ch] = n;
/* complex coding */
if (s->use_noise_coding) {
for(ch = 0; ch < s->nb_channels; ch++) {
if (s->channel_coded[ch]) {
int i, n, a;
n = s->exponent_high_sizes[bsize];
for(i=0;i<n;i++) {
a = get_bits(&s->gb, 1);
s->high_band_coded[ch][i] = a;
/* if noise coding, the coefficients are not transmitted */
if (a)
nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
}
}
}
for(ch = 0; ch < s->nb_channels; ch++) {
if (s->channel_coded[ch]) {
int i, n, val, code;
n = s->exponent_high_sizes[bsize];
val = (int)0x80000000;
for(i=0;i<n;i++) {
if (s->high_band_coded[ch][i]) {
if (val == (int)0x80000000) {
val = get_bits(&s->gb, 7) - 19;
} else {
code = get_vlc(&s->gb, &s->hgain_vlc);
if (code < 0)
return -1;
val += code - 18;
}
s->high_band_values[ch][i] = val;
}
}
}
}
}
/* exposant can be interpolated in short blocks. */
parse_exponents = 1;
if (s->block_len_bits != s->frame_len_bits) {
parse_exponents = get_bits(&s->gb, 1);
}
if (parse_exponents) {
for(ch = 0; ch < s->nb_channels; ch++) {
if (s->channel_coded[ch]) {
if (s->use_exp_vlc) {
if (decode_exp_vlc(s, ch) < 0)
return -1;
} else {
decode_exp_lsp(s, ch);
}
}
}
} else {
for(ch = 0; ch < s->nb_channels; ch++) {
if (s->channel_coded[ch]) {
interpolate_array(s->exponents[ch], 1 << s->prev_block_len_bits,
s->block_len);
}
}
}
/* parse spectral coefficients : just RLE encoding */
for(ch = 0; ch < s->nb_channels; ch++) {
if (s->channel_coded[ch]) {
VLC *coef_vlc;
int level, run, sign, tindex;
int16_t *ptr, *eptr;
const int16_t *level_table, *run_table;
/* special VLC tables are used for ms stereo because
there is potentially less energy there */
tindex = (ch == 1 && s->ms_stereo);
coef_vlc = &s->coef_vlc[tindex];
run_table = s->run_table[tindex];
level_table = s->level_table[tindex];
/* XXX: optimize */
ptr = &s->coefs1[ch][0];
eptr = ptr + nb_coefs[ch];
memset(ptr, 0, s->block_len * sizeof(int16_t));
for(;;) {
code = get_vlc(&s->gb, coef_vlc);
if (code < 0)
return -1;
if (code == 1) {
/* EOB */
break;
} else if (code == 0) {
/* escape */
level = get_bits(&s->gb, coef_nb_bits);
/* NOTE: this is rather suboptimal. reading
block_len_bits would be better */
run = get_bits(&s->gb, s->frame_len_bits);
} else {
/* normal code */
run = run_table[code];
level = level_table[code];
}
sign = get_bits(&s->gb, 1);
if (!sign)
level = -level;
ptr += run;
if (ptr >= eptr)
return -1;
*ptr++ = level;
/* NOTE: EOB can be omitted */
if (ptr >= eptr)
break;
}
}
if (s->version == 1 && s->nb_channels >= 2) {
align_get_bits(&s->gb);
}
}
/* normalize */
{
int n4 = s->block_len / 2;
mdct_norm = 1.0 / (float)n4;
if (s->version == 1) {
mdct_norm *= sqrt(n4);
}
}
/* finally compute the MDCT coefficients */
for(ch = 0; ch < s->nb_channels; ch++) {
if (s->channel_coded[ch]) {
int16_t *coefs1;
float *coefs, *exponents, mult, mult1, noise, *exp_ptr;
int i, j, n, n1, last_high_band;
float exp_power[HIGH_BAND_MAX_SIZE];
coefs1 = s->coefs1[ch];
exponents = s->exponents[ch];
mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
mult *= mdct_norm;
coefs = s->coefs[ch];
if (s->use_noise_coding) {
mult1 = mult;
/* very low freqs : noise */
for(i = 0;i < s->coefs_start; i++) {
*coefs++ = s->noise_table[s->noise_index] * (*exponents++) * mult1;
s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
}
n1 = s->exponent_high_sizes[bsize];
/* compute power of high bands */
exp_ptr = exponents +
s->high_band_start[bsize] -
s->coefs_start;
last_high_band = 0; /* avoid warning */
for(j=0;j<n1;j++) {
n = s->exponent_high_bands[s->frame_len_bits -
s->block_len_bits][j];
if (s->high_band_coded[ch][j]) {
float e2, v;
e2 = 0;
for(i = 0;i < n; i++) {
v = exp_ptr[i];
e2 += v * v;
}
exp_power[j] = e2 / n;
last_high_band = j;
tprintf("%d: power=%f (%d)\n", j, exp_power[j], n);
}
exp_ptr += n;
}
/* main freqs and high freqs */
for(j=-1;j<n1;j++) {
if (j < 0) {
n = s->high_band_start[bsize] -
s->coefs_start;
} else {
n = s->exponent_high_bands[s->frame_len_bits -
s->block_len_bits][j];
}
if (j >= 0 && s->high_band_coded[ch][j]) {
/* use noise with specified power */
mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
/* XXX: use a table */
mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
mult1 *= mdct_norm;
for(i = 0;i < n; i++) {
noise = s->noise_table[s->noise_index];
s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
*coefs++ = (*exponents++) * noise * mult1;
}
} else {
/* coded values + small noise */
for(i = 0;i < n; i++) {
noise = s->noise_table[s->noise_index];
s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
*coefs++ = ((*coefs1++) + noise) * (*exponents++) * mult;
}
}
}
/* very high freqs : noise */
n = s->block_len - s->coefs_end[bsize];
mult1 = mult * exponents[-1];
for(i = 0; i < n; i++) {
*coefs++ = s->noise_table[s->noise_index] * mult1;
s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
}
} else {
/* XXX: optimize more */
for(i = 0;i < s->coefs_start; i++)
*coefs++ = 0.0;
n = nb_coefs[ch];
for(i = 0;i < n; i++) {
*coefs++ = coefs1[i] * exponents[i] * mult;
}
n = s->block_len - s->coefs_end[bsize];
for(i = 0;i < n; i++)
*coefs++ = 0.0;
}
}
}
#ifdef TRACE
for(ch = 0; ch < s->nb_channels; ch++) {
if (s->channel_coded[ch]) {
dump_floats("exponents", 3, s->exponents[ch], s->block_len);
dump_floats("coefs", 1, s->coefs[ch], s->block_len);
}
}
#endif
if (s->ms_stereo && s->channel_coded[1]) {
float a, b;
int i;
/* nominal case for ms stereo: we do it before mdct */
/* no need to optimize this case because it should almost
never happen */
if (!s->channel_coded[0]) {
tprintf("rare ms-stereo case happened\n");
memset(s->coefs[0], 0, sizeof(float) * s->block_len);
s->channel_coded[0] = 1;
}
for(i = 0; i < s->block_len; i++) {
a = s->coefs[0][i];
b = s->coefs[1][i];
s->coefs[0][i] = a + b;
s->coefs[1][i] = a - b;
}
}
/* build the window : we ensure that when the windows overlap
their squared sum is always 1 (MDCT reconstruction rule) */
/* XXX: merge with output */
{
int i, next_block_len, block_len, prev_block_len, n;
float *wptr;
block_len = s->block_len;
prev_block_len = 1 << s->prev_block_len_bits;
next_block_len = 1 << s->next_block_len_bits;
/* right part */
wptr = window + block_len;
if (block_len <= next_block_len) {
for(i=0;i<block_len;i++)
*wptr++ = s->windows[bsize][i];
} else {
/* overlap */
n = (block_len / 2) - (next_block_len / 2);
for(i=0;i<n;i++)
*wptr++ = 1.0;
for(i=0;i<next_block_len;i++)
*wptr++ = s->windows[s->frame_len_bits - s->next_block_len_bits][i];
for(i=0;i<n;i++)
*wptr++ = 0.0;
}
/* left part */
wptr = window + block_len;
if (block_len <= prev_block_len) {
for(i=0;i<block_len;i++)
*--wptr = s->windows[bsize][i];
} else {
/* overlap */
n = (block_len / 2) - (prev_block_len / 2);
for(i=0;i<n;i++)
*--wptr = 1.0;
for(i=0;i<prev_block_len;i++)
*--wptr = s->windows[s->frame_len_bits - s->prev_block_len_bits][i];
for(i=0;i<n;i++)
*--wptr = 0.0;
}
}
for(ch = 0; ch < s->nb_channels; ch++) {
if (s->channel_coded[ch]) {
FFTSample output[BLOCK_MAX_SIZE * 2] __attribute__((aligned(16)));
float *ptr;
int i, n4, index, n;
n = s->block_len;
n4 = s->block_len / 2;
ff_imdct_calc(&s->mdct_ctx[bsize],
output, s->coefs[ch], s->mdct_tmp);
/* XXX: optimize all that by build the window and
multipying/adding at the same time */
/* multiply by the window */
for(i=0;i<n * 2;i++) {
output[i] *= window[i];
}
/* add in the frame */
index = (s->frame_len / 2) + s->block_pos - n4;
ptr = &s->frame_out[ch][index];
for(i=0;i<n * 2;i++) {
*ptr += output[i];
ptr++;
}
/* specific fast case for ms-stereo : add to second
channel if it is not coded */
if (s->ms_stereo && !s->channel_coded[1]) {
ptr = &s->frame_out[1][index];
for(i=0;i<n * 2;i++) {
*ptr += output[i];
ptr++;
}
}
}
}
next:
/* update block number */
s->block_num++;
s->block_pos += s->block_len;
if (s->block_pos >= s->frame_len)
return 1;
else
return 0;
}
/* decode a frame of frame_len samples */
static int wma_decode_frame(WMADecodeContext *s, int16_t *samples)
{
int ret, i, n, a, ch, incr;
int16_t *ptr;
float *iptr;
#ifdef TRACE
tprintf("***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
#endif
/* read each block */
s->block_num = 0;
s->block_pos = 0;
for(;;) {
ret = wma_decode_block(s);
if (ret < 0)
return -1;
if (ret)
break;
}
/* convert frame to integer */
n = s->frame_len;
incr = s->nb_channels;
for(ch = 0; ch < s->nb_channels; ch++) {
ptr = samples + ch;
iptr = s->frame_out[ch];
for(i=0;i<n;i++) {
a = lrintf(*iptr++);
if (a > 32767)
a = 32767;
else if (a < -32768)
a = -32768;
*ptr = a;
ptr += incr;
}
/* prepare for next block */
memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
s->frame_len * sizeof(float));
/* XXX: suppress this */
memset(&s->frame_out[ch][s->frame_len], 0,
s->frame_len * sizeof(float));
}
#ifdef TRACE
dump_shorts("samples", samples, n * s->nb_channels);
#endif
return 0;
}
static int wma_decode_superframe(AVCodecContext *avctx,
void *data, int *data_size,
uint8_t *buf, int buf_size)
{
WMADecodeContext *s = avctx->priv_data;
int nb_frames, bit_offset, i, pos, len;
uint8_t *q;
int16_t *samples;
tprintf("***decode_superframe:\n");
if(buf_size==0){
s->last_superframe_len = 0;
return 0;
}
samples = data;
init_get_bits(&s->gb, buf, buf_size*8);
if (s->use_bit_reservoir) {
/* read super frame header */
get_bits(&s->gb, 4); /* super frame index */
nb_frames = get_bits(&s->gb, 4) - 1;
bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
if (s->last_superframe_len > 0) {
// printf("skip=%d\n", s->last_bitoffset);
/* add bit_offset bits to last frame */
if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
MAX_CODED_SUPERFRAME_SIZE)
goto fail;
q = s->last_superframe + s->last_superframe_len;
len = bit_offset;
while (len > 0) {
*q++ = (get_bits)(&s->gb, 8);
len -= 8;
}
if (len > 0) {
*q++ = (get_bits)(&s->gb, len) << (8 - len);
}
/* XXX: bit_offset bits into last frame */
init_get_bits(&s->gb, s->last_superframe, MAX_CODED_SUPERFRAME_SIZE*8);
/* skip unused bits */
if (s->last_bitoffset > 0)
skip_bits(&s->gb, s->last_bitoffset);
/* this frame is stored in the last superframe and in the
current one */
if (wma_decode_frame(s, samples) < 0)
goto fail;
samples += s->nb_channels * s->frame_len;
}
/* read each frame starting from bit_offset */
pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
init_get_bits(&s->gb, buf + (pos >> 3), (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3))*8);
len = pos & 7;
if (len > 0)
skip_bits(&s->gb, len);
s->reset_block_lengths = 1;
for(i=0;i<nb_frames;i++) {
if (wma_decode_frame(s, samples) < 0)
goto fail;
samples += s->nb_channels * s->frame_len;
}
/* we copy the end of the frame in the last frame buffer */
pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
s->last_bitoffset = pos & 7;
pos >>= 3;
len = buf_size - pos;
if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
goto fail;
}
s->last_superframe_len = len;
memcpy(s->last_superframe, buf + pos, len);
} else {
/* single frame decode */
if (wma_decode_frame(s, samples) < 0)
goto fail;
samples += s->nb_channels * s->frame_len;
}
*data_size = (int8_t *)samples - (int8_t *)data;
return s->block_align;
fail:
/* when error, we reset the bit reservoir */
s->last_superframe_len = 0;
return -1;
}
static int wma_decode_end(AVCodecContext *avctx)
{
WMADecodeContext *s = avctx->priv_data;
int i;
for(i = 0; i < s->nb_block_sizes; i++)
ff_mdct_end(&s->mdct_ctx[i]);
for(i = 0; i < s->nb_block_sizes; i++)
av_free(s->windows[i]);
if (s->use_exp_vlc) {
free_vlc(&s->exp_vlc);
}
if (s->use_noise_coding) {
free_vlc(&s->hgain_vlc);
}
for(i = 0;i < 2; i++) {
free_vlc(&s->coef_vlc[i]);
av_free(s->run_table[i]);
av_free(s->level_table[i]);
}
return 0;
}
AVCodec wmav1_decoder =
{
"wmav1",
CODEC_TYPE_AUDIO,
CODEC_ID_WMAV1,
sizeof(WMADecodeContext),
wma_decode_init,
NULL,
wma_decode_end,
wma_decode_superframe,
};
AVCodec wmav2_decoder =
{
"wmav2",
CODEC_TYPE_AUDIO,
CODEC_ID_WMAV2,
sizeof(WMADecodeContext),
wma_decode_init,
NULL,
wma_decode_end,
wma_decode_superframe,
};
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