virtualenv/FFmpeg
1
0
Fork 0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-11-21 10:55:51 +02:00
Code Issues Releases Activity
3d7232ff00
FFmpeg/libavcodec/wmadec.c
Benjamin Larsson e7a6d5f313 Bug fix for crashes when SSE is used on unaligned arrays. 
No measureable change in speed. This gave random crashes on Win32
and BeOS. The cause for this bug is that gcc doesn't align the
stackframe. Linux and glibc always ensure this to be true thus
this never affected Linux.

Originally committed as revision 7318 to svn://svn.ffmpeg.org/ffmpeg/trunk
2006-12-14 17:50:23 +00:00

1338 lines
42 KiB
C
Raw Blame History

/*
* WMA compatible decoder
* Copyright (c) 2002 The FFmpeg Project.
*
* 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 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 16384
#define MAX_CHANNELS 2
#define NOISE_TAB_SIZE 8192
#define LSP_POW_BITS 7
#define VLCBITS 9
#define VLCMAX ((22+VLCBITS-1)/VLCBITS)
#define EXPVLCBITS 8
#define EXPMAX ((19+EXPVLCBITS-1)/EXPVLCBITS)
#define HGAINVLCBITS 9
#define HGAINMAX ((13+HGAINVLCBITS-1)/HGAINVLCBITS)
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 */
DECLARE_ALIGNED_16(float, exponents[MAX_CHANNELS][BLOCK_MAX_SIZE]);
float max_exponent[MAX_CHANNELS];
int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
DECLARE_ALIGNED_16(float, coefs[MAX_CHANNELS][BLOCK_MAX_SIZE]);
DECLARE_ALIGNED_16(FFTSample, output[BLOCK_MAX_SIZE * 2]);
DECLARE_ALIGNED_16(float, window[BLOCK_MAX_SIZE * 2]);
MDCTContext mdct_ctx[BLOCK_NB_SIZES];
float *windows[BLOCK_NB_SIZES];
DECLARE_ALIGNED_16(FFTSample, mdct_tmp[BLOCK_MAX_SIZE]); /* temporary storage for imdct */
/* output buffer for one frame and the last for IMDCT windowing */
DECLARE_ALIGNED_16(float, frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2]);
/* 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)];
DSPContext dsp;
#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, VLCBITS, 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;
dsputil_init(&s->dsp, avctx);
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 + 0.5)) + 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, HGAINVLCBITS, sizeof(hgain_huffbits),
hgain_huffbits, 1, 1,
hgain_huffcodes, 2, 2, 0);
}
if (s->use_exp_vlc) {
init_vlc(&s->exp_vlc, EXPVLCBITS, 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_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
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;
int nb_coefs[MAX_CHANNELS];
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_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX);
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 uint16_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_vlc2(&s->gb, coef_vlc->table, VLCBITS, VLCMAX);
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)
{
av_log(NULL, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n");
break;
}
*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 = s->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 = s->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]) {
float *ptr;
int n4, index, n;
n = s->block_len;
n4 = s->block_len / 2;
s->mdct_ctx[bsize].fft.imdct_calc(&s->mdct_ctx[bsize],
s->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 and add in the frame */
index = (s->frame_len / 2) + s->block_pos - n4;
ptr = &s->frame_out[ch][index];
s->dsp.vector_fmul_add_add(ptr,s->window,s->output,ptr,0,2*n,1);
/* 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];
s->dsp.vector_fmul_add_add(ptr,s->window,s->output,ptr,0,2*n,1);
}
}
}
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 > 7) {
*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,
};
Reference in New Issue View Git Blame Copy Permalink