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ffmpeg/libavcodec/wma.c

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/*
* WMA compatible codec
* Copyright (c) 2002-2007 The Libav Project
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/attributes.h"
#include "avcodec.h"
#include "sinewin.h"
#include "wma.h"
#include "wma_common.h"
#include "wma_freqs.h"
#include "wmadata.h"
#undef NDEBUG
#include <assert.h>
/* XXX: use same run/length optimization as mpeg decoders */
// FIXME maybe split decode / encode or pass flag
static av_cold int init_coef_vlc(VLC *vlc, uint16_t **prun_table,
float **plevel_table, uint16_t **pint_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, *int_table;
float *flevel_table;
int i, l, j, k, 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));
flevel_table = av_malloc(n * sizeof(*flevel_table));
int_table = av_malloc(n * sizeof(uint16_t));
if (!run_table || !level_table || !flevel_table || !int_table) {
av_freep(&run_table);
av_freep(&level_table);
av_freep(&flevel_table);
av_freep(&int_table);
return AVERROR(ENOMEM);
}
i = 2;
level = 1;
k = 0;
while (i < n) {
int_table[k] = i;
l = levels_table[k++];
for (j = 0; j < l; j++) {
run_table[i] = j;
level_table[i] = level;
flevel_table[i] = level;
i++;
}
level++;
}
*prun_table = run_table;
*plevel_table = flevel_table;
*pint_table = int_table;
av_free(level_table);
return 0;
}
av_cold int ff_wma_init(AVCodecContext *avctx, int flags2)
{
WMACodecContext *s = avctx->priv_data;
int i, ret;
float bps1, high_freq;
volatile float bps;
int sample_rate1;
int coef_vlc_table;
if (avctx->sample_rate <= 0 || avctx->sample_rate > 50000 ||
avctx->channels <= 0 || avctx->channels > 2 ||
avctx->bit_rate <= 0)
return -1;
avpriv_float_dsp_init(&s->fdsp, avctx->flags & CODEC_FLAG_BITEXACT);
if (avctx->codec->id == AV_CODEC_ID_WMAV1)
s->version = 1;
else
s->version = 2;
/* compute MDCT block size */
s->frame_len_bits = ff_wma_get_frame_len_bits(avctx->sample_rate,
s->version, 0);
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;
s->frame_len = 1 << s->frame_len_bits;
if (s->use_variable_block_len) {
int nb_max, nb;
nb = ((flags2 >> 3) & 3) + 1;
if ((avctx->bit_rate / avctx->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 dependent parameters */
s->use_noise_coding = 1;
high_freq = avctx->sample_rate * 0.5;
/* if version 2, then the rates are normalized */
sample_rate1 = avctx->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) avctx->bit_rate /
(float) (avctx->channels * avctx->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 (avctx->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;
}
av_dlog(s->avctx, "flags2=0x%x\n", flags2);
av_dlog(s->avctx, "version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
s->version, avctx->channels, avctx->sample_rate, avctx->bit_rate,
avctx->block_align);
av_dlog(s->avctx, "bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
bps, bps1, high_freq, s->byte_offset_bits);
av_dlog(s->avctx, "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 = ff_wma_critical_freqs[i];
b = avctx->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 (avctx->sample_rate >= 44100)
table = exponent_band_44100[a];
else if (avctx->sample_rate >= 32000)
table = exponent_band_32000[a];
else if (avctx->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 = ff_wma_critical_freqs[i];
b = avctx->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) /
avctx->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(s->avctx, "%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(s->avctx, " %d", s->exponent_high_bands[k][j]);
tprintf(s->avctx, "\n");
#endif /* 0 */
}
}
#ifdef TRACE
{
int i, j;
for (i = 0; i < s->nb_block_sizes; i++) {
tprintf(s->avctx, "%5d: n=%2d:",
s->frame_len >> i,
s->exponent_sizes[i]);
for (j = 0; j < s->exponent_sizes[i]; j++)
tprintf(s->avctx, " %d", s->exponent_bands[i][j]);
tprintf(s->avctx, "\n");
}
}
#endif /* TRACE */
/* init MDCT windows : simple sine window */
for (i = 0; i < s->nb_block_sizes; i++) {
ff_init_ff_sine_windows(s->frame_len_bits - i);
s->windows[i] = ff_sine_windows[s->frame_len_bits - i];
}
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 /* TRACE */
}
/* choose the VLC tables for the coefficients */
coef_vlc_table = 2;
if (avctx->sample_rate >= 32000) {
if (bps1 < 0.72)
coef_vlc_table = 0;
else if (bps1 < 1.16)
coef_vlc_table = 1;
}
s->coef_vlcs[0] = &coef_vlcs[coef_vlc_table * 2];
s->coef_vlcs[1] = &coef_vlcs[coef_vlc_table * 2 + 1];
ret = init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0],
&s->int_table[0], s->coef_vlcs[0]);
if (ret < 0)
return ret;
return init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1],
&s->int_table[1], s->coef_vlcs[1]);
}
int ff_wma_total_gain_to_bits(int total_gain)
{
if (total_gain < 15)
return 13;
else if (total_gain < 32)
return 12;
else if (total_gain < 40)
return 11;
else if (total_gain < 45)
return 10;
else
return 9;
}
int ff_wma_end(AVCodecContext *avctx)
{
WMACodecContext *s = avctx->priv_data;
int i;
for (i = 0; i < s->nb_block_sizes; i++)
ff_mdct_end(&s->mdct_ctx[i]);
if (s->use_exp_vlc)
ff_free_vlc(&s->exp_vlc);
if (s->use_noise_coding)
ff_free_vlc(&s->hgain_vlc);
for (i = 0; i < 2; i++) {
ff_free_vlc(&s->coef_vlc[i]);
av_free(s->run_table[i]);
av_free(s->level_table[i]);
av_free(s->int_table[i]);
}
return 0;
}
/**
* Decode an uncompressed coefficient.
* @param gb GetBitContext
* @return the decoded coefficient
*/
unsigned int ff_wma_get_large_val(GetBitContext *gb)
{
/** consumes up to 34 bits */
int n_bits = 8;
/** decode length */
if (get_bits1(gb)) {
n_bits += 8;
if (get_bits1(gb)) {
n_bits += 8;
if (get_bits1(gb))
n_bits += 7;
}
}
return get_bits_long(gb, n_bits);
}
/**
* Decode run level compressed coefficients.
* @param avctx codec context
* @param gb bitstream reader context
* @param vlc vlc table for get_vlc2
* @param level_table level codes
* @param run_table run codes
* @param version 0 for wma1,2 1 for wmapro
* @param ptr output buffer
* @param offset offset in the output buffer
* @param num_coefs number of input coefficents
* @param block_len input buffer length (2^n)
* @param frame_len_bits number of bits for escaped run codes
* @param coef_nb_bits number of bits for escaped level codes
* @return 0 on success, -1 otherwise
*/
int ff_wma_run_level_decode(AVCodecContext *avctx, GetBitContext *gb,
VLC *vlc, const float *level_table,
const uint16_t *run_table, int version,
WMACoef *ptr, int offset, int num_coefs,
int block_len, int frame_len_bits,
int coef_nb_bits)
{
int code, level, sign;
const uint32_t *ilvl = (const uint32_t *) level_table;
uint32_t *iptr = (uint32_t *) ptr;
const unsigned int coef_mask = block_len - 1;
for (; offset < num_coefs; offset++) {
code = get_vlc2(gb, vlc->table, VLCBITS, VLCMAX);
if (code > 1) {
/** normal code */
offset += run_table[code];
sign = get_bits1(gb) - 1;
iptr[offset & coef_mask] = ilvl[code] ^ sign << 31;
} else if (code == 1) {
/** EOB */
break;
} else {
/** escape */
if (!version) {
level = get_bits(gb, coef_nb_bits);
/** NOTE: this is rather suboptimal. reading
* block_len_bits would be better */
offset += get_bits(gb, frame_len_bits);
} else {
level = ff_wma_get_large_val(gb);
/** escape decode */
if (get_bits1(gb)) {
if (get_bits1(gb)) {
if (get_bits1(gb)) {
av_log(avctx, AV_LOG_ERROR,
"broken escape sequence\n");
return -1;
} else
offset += get_bits(gb, frame_len_bits) + 4;
} else
offset += get_bits(gb, 2) + 1;
}
}
sign = get_bits1(gb) - 1;
ptr[offset & coef_mask] = (level ^ sign) - sign;
}
}
/** NOTE: EOB can be omitted */
if (offset > num_coefs) {
av_log(avctx, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n");
return -1;
}
return 0;
}
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