* @file
* The simplest AC-3 encoder.
*/
+
//#define DEBUG
#include "libavcore/audioconvert.h"
#define MDCT_NBITS 9
#define MDCT_SAMPLES (1 << MDCT_NBITS)
-/* new exponents are sent if their Norm 1 exceed this number */
-#define EXP_DIFF_THRESHOLD 1000
-
#define FIX15(a) av_clip_int16(SCALE_FLOAT(a, 15))
typedef struct IComplex {
n = 1 << ln;
- for(i=0;i<(n/2);i++) {
- alpha = 2 * M_PI * (float)i / (float)n;
+ for (i = 0; i < n/2; i++) {
+ alpha = 2 * M_PI * (float)i / (float)n;
costab[i] = FIX15(cos(alpha));
sintab[i] = FIX15(sin(alpha));
}
fft_init(nbits - 2);
- for(i=0;i<n4;i++) {
- alpha = 2 * M_PI * (i + 1.0 / 8.0) / n;
+ for (i = 0; i < n4; i++) {
+ alpha = 2 * M_PI * (i + 1.0 / 8.0) / n;
xcos1[i] = FIX15(-cos(alpha));
xsin1[i] = FIX15(-sin(alpha));
}
}
/* butter fly op */
-#define BF(pre, pim, qre, qim, pre1, pim1, qre1, qim1) \
-{\
- int ax, ay, bx, by;\
- bx=pre1;\
- by=pim1;\
- ax=qre1;\
- ay=qim1;\
- pre = (bx + ax) >> 1;\
- pim = (by + ay) >> 1;\
- qre = (bx - ax) >> 1;\
- qim = (by - ay) >> 1;\
+#define BF(pre, pim, qre, qim, pre1, pim1, qre1, qim1) \
+{ \
+ int ax, ay, bx, by; \
+ bx = pre1; \
+ by = pim1; \
+ ax = qre1; \
+ ay = qim1; \
+ pre = (bx + ax) >> 1; \
+ pim = (by + ay) >> 1; \
+ qre = (bx - ax) >> 1; \
+ qim = (by - ay) >> 1; \
}
-#define CMUL(pre, pim, are, aim, bre, bim) \
-{\
- pre = (MUL16(are, bre) - MUL16(aim, bim)) >> 15;\
- pim = (MUL16(are, bim) + MUL16(bre, aim)) >> 15;\
+#define CMUL(pre, pim, are, aim, bre, bim) \
+{ \
+ pre = (MUL16(are, bre) - MUL16(aim, bim)) >> 15; \
+ pim = (MUL16(are, bim) + MUL16(bre, aim)) >> 15; \
}
/* do a 2^n point complex fft on 2^ln points. */
static void fft(IComplex *z, int ln)
{
- int j, l, np, np2;
- int nblocks, nloops;
+ int j, l, np, np2;
+ int nblocks, nloops;
register IComplex *p,*q;
int tmp_re, tmp_im;
np = 1 << ln;
/* reverse */
- for(j=0;j<np;j++) {
+ for (j = 0; j < np; j++) {
int k = av_reverse[j] >> (8 - ln);
if (k < j)
FFSWAP(IComplex, z[k], z[j]);
/* pass 0 */
- p=&z[0];
- j=(np >> 1);
+ p = &z[0];
+ j = np >> 1;
do {
BF(p[0].re, p[0].im, p[1].re, p[1].im,
p[0].re, p[0].im, p[1].re, p[1].im);
- p+=2;
- } while (--j != 0);
+ p += 2;
+ } while (--j);
/* pass 1 */
- p=&z[0];
- j=np >> 2;
+ p = &z[0];
+ j = np >> 2;
do {
- BF(p[0].re, p[0].im, p[2].re, p[2].im,
- p[0].re, p[0].im, p[2].re, p[2].im);
- BF(p[1].re, p[1].im, p[3].re, p[3].im,
+ BF(p[0].re, p[0].im, p[2].re, p[2].im,
+ p[0].re, p[0].im, p[2].re, p[2].im);
+ BF(p[1].re, p[1].im, p[3].re, p[3].im,
p[1].re, p[1].im, p[3].im, -p[3].re);
p+=4;
- } while (--j != 0);
+ } while (--j);
/* pass 2 .. ln-1 */
nblocks = np >> 3;
- nloops = 1 << 2;
- np2 = np >> 1;
+ nloops = 1 << 2;
+ np2 = np >> 1;
do {
p = z;
q = z + nloops;
- for (j = 0; j < nblocks; ++j) {
-
+ for (j = 0; j < nblocks; j++) {
BF(p->re, p->im, q->re, q->im,
p->re, p->im, q->re, q->im);
-
p++;
q++;
for(l = nblocks; l < np2; l += nblocks) {
CMUL(tmp_re, tmp_im, costab[l], -sintab[l], q->re, q->im);
- BF(p->re, p->im, q->re, q->im,
+ BF(p->re, p->im, q->re, q->im,
p->re, p->im, tmp_re, tmp_im);
p++;
q++;
q += nloops;
}
nblocks = nblocks >> 1;
- nloops = nloops << 1;
- } while (nblocks != 0);
+ nloops = nloops << 1;
+ } while (nblocks);
}
-/* do a 512 point mdct */
static void mdct512(int32_t *out, int16_t *in)
{
int i, re, im, re1, im1;
IComplex x[MDCT_SAMPLES/4];
/* shift to simplify computations */
- for(i=0;i<MDCT_SAMPLES/4;i++)
+ for (i = 0; i < MDCT_SAMPLES/4; i++)
rot[i] = -in[i + 3*MDCT_SAMPLES/4];
- for(i=MDCT_SAMPLES/4;i<MDCT_SAMPLES;i++)
- rot[i] = in[i - MDCT_SAMPLES/4];
+ for (;i < MDCT_SAMPLES; i++)
+ rot[i] = in[i - MDCT_SAMPLES/4];
/* pre rotation */
- for(i=0;i<MDCT_SAMPLES/4;i++) {
- re = ((int)rot[2*i] - (int)rot[MDCT_SAMPLES-1-2*i]) >> 1;
+ for (i = 0; i < MDCT_SAMPLES/4; i++) {
+ re = ((int)rot[ 2*i] - (int)rot[MDCT_SAMPLES -1-2*i]) >> 1;
im = -((int)rot[MDCT_SAMPLES/2+2*i] - (int)rot[MDCT_SAMPLES/2-1-2*i]) >> 1;
CMUL(x[i].re, x[i].im, re, im, -xcos1[i], xsin1[i]);
}
fft(x, MDCT_NBITS - 2);
/* post rotation */
- for(i=0;i<MDCT_SAMPLES/4;i++) {
+ for (i = 0; i < MDCT_SAMPLES/4; i++) {
re = x[i].re;
im = x[i].im;
CMUL(re1, im1, re, im, xsin1[i], xcos1[i]);
- out[2*i] = im1;
+ out[ 2*i] = im1;
out[MDCT_SAMPLES/2-1-2*i] = re1;
}
}
-/* XXX: use another norm ? */
static int calc_exp_diff(uint8_t *exp1, uint8_t *exp2, int n)
{
int sum, i;
sum = 0;
- for(i=0;i<n;i++) {
+ for (i = 0; i < n; i++)
sum += abs(exp1[i] - exp2[i]);
- }
return sum;
}
+/* new exponents are sent if their Norm 1 exceed this number */
+#define EXP_DIFF_THRESHOLD 1000
+
static void compute_exp_strategy(uint8_t exp_strategy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS],
uint8_t exp[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS],
int ch, int is_lfe)
/* estimate if the exponent variation & decide if they should be
reused in the next frame */
exp_strategy[0][ch] = EXP_NEW;
- for(i=1;i<AC3_MAX_BLOCKS;i++) {
+ for (i = 1; i < AC3_MAX_BLOCKS; i++) {
exp_diff = calc_exp_diff(exp[i][ch], exp[i-1][ch], AC3_MAX_COEFS);
if (exp_diff > EXP_DIFF_THRESHOLD)
exp_strategy[i][ch] = EXP_NEW;
j = i + 1;
while (j < AC3_MAX_BLOCKS && exp_strategy[j][ch] == EXP_REUSE)
j++;
- switch(j - i) {
+ switch (j - i) {
case 1:
exp_strategy[i][ch] = EXP_D45;
break;
static void exponent_min(uint8_t exp[AC3_MAX_COEFS], uint8_t exp1[AC3_MAX_COEFS], int n)
{
int i;
-
- for(i=0;i<n;i++) {
+ for (i = 0; i < n; i++) {
if (exp1[i] < exp[i])
exp[i] = exp1[i];
}
decode. Return the number of bits used to code the exponents */
static int encode_exp(uint8_t encoded_exp[AC3_MAX_COEFS],
uint8_t exp[AC3_MAX_COEFS],
- int nb_exps,
- int exp_strategy)
+ int nb_exps, int exp_strategy)
{
int group_size, nb_groups, i, j, k, exp_min;
uint8_t exp1[AC3_MAX_COEFS];
- switch(exp_strategy) {
+ switch (exp_strategy) {
case EXP_D15:
group_size = 1;
break;
/* for each group, compute the minimum exponent */
exp1[0] = exp[0]; /* DC exponent is handled separately */
k = 1;
- for(i=1;i<=nb_groups;i++) {
+ for (i = 1; i <= nb_groups; i++) {
exp_min = exp[k];
assert(exp_min >= 0 && exp_min <= 24);
- for(j=1;j<group_size;j++) {
+ for (j = 1; j < group_size; j++) {
if (exp[k+j] < exp_min)
exp_min = exp[k+j];
}
if (exp1[0] > 15)
exp1[0] = 15;
- /* Decrease the delta between each groups to within 2
- * so that they can be differentially encoded */
- for (i=1;i<=nb_groups;i++)
+ /* decrease the delta between each groups to within 2 so that they can be
+ differentially encoded */
+ for (i = 1; i <= nb_groups; i++)
exp1[i] = FFMIN(exp1[i], exp1[i-1] + 2);
- for (i=nb_groups-1;i>=0;i--)
+ for (i = nb_groups-1; i >= 0; i--)
exp1[i] = FFMIN(exp1[i], exp1[i+1] + 2);
/* now we have the exponent values the decoder will see */
encoded_exp[0] = exp1[0];
k = 1;
- for(i=1;i<=nb_groups;i++) {
- for(j=0;j<group_size;j++) {
+ for (i = 1; i <= nb_groups; i++) {
+ for (j = 0; j < group_size; j++)
encoded_exp[k+j] = exp1[i];
- }
k += group_size;
}
int bits, mant, i;
bits = 0;
- for(i=0;i<nb_coefs;i++) {
+ for (i = 0; i < nb_coefs; i++) {
mant = m[i];
- switch(mant) {
+ switch (mant) {
case 0:
/* nothing */
break;
int blk, ch;
int16_t band_psd[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][50];
- for(blk=0; blk<AC3_MAX_BLOCKS; blk++) {
- for(ch=0;ch<s->channels;ch++) {
+ for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
+ for (ch = 0; ch < s->channels; ch++) {
if(exp_strategy[blk][ch] == EXP_REUSE) {
memcpy(psd[blk][ch], psd[blk-1][ch], AC3_MAX_COEFS*sizeof(int16_t));
memcpy(mask[blk][ch], mask[blk-1][ch], 50*sizeof(int16_t));
snr_offset = (((coarse_snr_offset - 15) << 4) + fine_snr_offset) << 2;
- /* compute size */
- for(i=0;i<AC3_MAX_BLOCKS;i++) {
+ for (i = 0; i < AC3_MAX_BLOCKS; i++) {
s->mant1_cnt = 0;
s->mant2_cnt = 0;
s->mant4_cnt = 0;
- for(ch=0;ch<s->channels;ch++) {
+ for (ch = 0; ch < s->channels; ch++) {
ff_ac3_bit_alloc_calc_bap(mask[i][ch], psd[i][ch], 0,
s->nb_coefs[ch], snr_offset,
s->bit_alloc.floor, ff_ac3_bap_tab,
bap[i][ch]);
- frame_bits += compute_mantissa_size(s, bap[i][ch],
- s->nb_coefs[ch]);
+ frame_bits += compute_mantissa_size(s, bap[i][ch], s->nb_coefs[ch]);
}
}
return 16 * s->frame_size - frame_bits;
/* init default parameters */
s->slow_decay_code = 2;
s->fast_decay_code = 1;
- s->slow_gain_code = 1;
+ s->slow_gain_code = 1;
s->db_per_bit_code = 2;
- s->floor_code = 4;
- for(ch=0;ch<s->channels;ch++)
+ s->floor_code = 4;
+ for (ch = 0; ch < s->channels; ch++)
s->fast_gain_code[ch] = 4;
/* compute real values */
s->bit_alloc.slow_decay = ff_ac3_slow_decay_tab[s->slow_decay_code] >> s->bit_alloc.sr_shift;
s->bit_alloc.fast_decay = ff_ac3_fast_decay_tab[s->fast_decay_code] >> s->bit_alloc.sr_shift;
- s->bit_alloc.slow_gain = ff_ac3_slow_gain_tab[s->slow_gain_code];
+ s->bit_alloc.slow_gain = ff_ac3_slow_gain_tab[s->slow_gain_code];
s->bit_alloc.db_per_bit = ff_ac3_db_per_bit_tab[s->db_per_bit_code];
- s->bit_alloc.floor = ff_ac3_floor_tab[s->floor_code];
+ s->bit_alloc.floor = ff_ac3_floor_tab[s->floor_code];
/* header size */
frame_bits += 65;
frame_bits += frame_bits_inc[s->channel_mode];
/* audio blocks */
- for(i=0;i<AC3_MAX_BLOCKS;i++) {
+ for (i = 0; i < AC3_MAX_BLOCKS; i++) {
frame_bits += s->fbw_channels * 2 + 2; /* blksw * c, dithflag * c, dynrnge, cplstre */
if (s->channel_mode == AC3_CHMODE_STEREO) {
frame_bits++; /* rematstr */
- if(i==0) frame_bits += 4;
+ if (!i)
+ frame_bits += 4;
}
frame_bits += 2 * s->fbw_channels; /* chexpstr[2] * c */
if (s->lfe_on)
frame_bits++; /* lfeexpstr */
- for(ch=0;ch<s->fbw_channels;ch++) {
+ for (ch = 0; ch < s->fbw_channels; ch++) {
if (exp_strategy[i][ch] != EXP_REUSE)
frame_bits += 6 + 2; /* chbwcod[6], gainrng[2] */
}
av_log(NULL, AV_LOG_ERROR, "Bit allocation failed. Try increasing the bitrate.\n");
return -1;
}
- while ((coarse_snr_offset + SNR_INC1) <= 63 &&
+ while (coarse_snr_offset + SNR_INC1 <= 63 &&
bit_alloc(s, mask, psd, bap1, frame_bits,
coarse_snr_offset + SNR_INC1, 0) >= 0) {
coarse_snr_offset += SNR_INC1;
memcpy(bap, bap1, sizeof(bap1));
}
- while ((coarse_snr_offset + 1) <= 63 &&
+ while (coarse_snr_offset + 1 <= 63 &&
bit_alloc(s, mask, psd, bap1, frame_bits, coarse_snr_offset + 1, 0) >= 0) {
coarse_snr_offset++;
memcpy(bap, bap1, sizeof(bap1));
}
fine_snr_offset = 0;
- while ((fine_snr_offset + SNR_INC1) <= 15 &&
+ while (fine_snr_offset + SNR_INC1 <= 15 &&
bit_alloc(s, mask, psd, bap1, frame_bits,
coarse_snr_offset, fine_snr_offset + SNR_INC1) >= 0) {
fine_snr_offset += SNR_INC1;
memcpy(bap, bap1, sizeof(bap1));
}
- while ((fine_snr_offset + 1) <= 15 &&
+ while (fine_snr_offset + 1 <= 15 &&
bit_alloc(s, mask, psd, bap1, frame_bits,
coarse_snr_offset, fine_snr_offset + 1) >= 0) {
fine_snr_offset++;
}
s->coarse_snr_offset = coarse_snr_offset;
- for(ch=0;ch<s->channels;ch++)
+ for (ch = 0; ch < s->channels; ch++)
s->fine_snr_offset[ch] = fine_snr_offset;
return 0;
return -1;
}
- s->channel_map = ff_ac3_enc_channel_map[s->channel_mode][s->lfe_on];
+ s->channel_map = ff_ac3_enc_channel_map[s->channel_mode][s->lfe_on];
*channel_layout = ch_layout;
if (s->lfe_on)
*channel_layout |= AV_CH_LOW_FREQUENCY;
}
/* frequency */
- for(i=0;i<3;i++) {
- for(j=0;j<3;j++)
+ for (i = 0; i < 3; i++) {
+ for (j = 0; j < 3; j++)
if ((ff_ac3_sample_rate_tab[j] >> i) == freq)
goto found;
}
return -1;
found:
- s->sample_rate = freq;
+ s->sample_rate = freq;
s->bit_alloc.sr_shift = i;
- s->bit_alloc.sr_code = j;
- s->bitstream_id = 8 + s->bit_alloc.sr_shift;
- s->bitstream_mode = 0; /* complete main audio service */
+ s->bit_alloc.sr_code = j;
+ s->bitstream_id = 8 + s->bit_alloc.sr_shift;
+ s->bitstream_mode = 0; /* complete main audio service */
/* bitrate & frame size */
- for(i=0;i<19;i++) {
+ for (i = 0; i < 19; i++) {
if ((ff_ac3_bitrate_tab[i] >> s->bit_alloc.sr_shift)*1000 == bitrate)
break;
}
if (i == 19)
return -1;
- s->bit_rate = bitrate;
+ s->bit_rate = bitrate;
s->frame_size_code = i << 1;
- s->frame_size_min = ff_ac3_frame_size_tab[s->frame_size_code][s->bit_alloc.sr_code];
- s->bits_written = 0;
+ s->frame_size_min = ff_ac3_frame_size_tab[s->frame_size_code][s->bit_alloc.sr_code];
+ s->bits_written = 0;
s->samples_written = 0;
- s->frame_size = s->frame_size_min;
+ s->frame_size = s->frame_size_min;
- /* bit allocation init */
+ /* set bandwidth */
if(avctx->cutoff) {
/* calculate bandwidth based on user-specified cutoff frequency */
- int cutoff = av_clip(avctx->cutoff, 1, s->sample_rate >> 1);
+ int cutoff = av_clip(avctx->cutoff, 1, s->sample_rate >> 1);
int fbw_coeffs = cutoff * 2 * AC3_MAX_COEFS / s->sample_rate;
- bw_code = av_clip((fbw_coeffs - 73) / 3, 0, 60);
+ bw_code = av_clip((fbw_coeffs - 73) / 3, 0, 60);
} else {
/* use default bandwidth setting */
/* XXX: should compute the bandwidth according to the frame
for(ch=0;ch<s->fbw_channels;ch++) {
/* bandwidth for each channel */
s->bandwidth_code[ch] = bw_code;
- s->nb_coefs[ch] = bw_code * 3 + 73;
- }
- if (s->lfe_on) {
- s->nb_coefs[s->lfe_channel] = 7; /* fixed */
+ s->nb_coefs[ch] = bw_code * 3 + 73;
}
+ if (s->lfe_on)
+ s->nb_coefs[s->lfe_channel] = 7; /* LFE channel always has 7 coefs */
+
/* initial snr offset */
s->coarse_snr_offset = 40;
{
init_put_bits(&s->pb, frame, AC3_MAX_CODED_FRAME_SIZE);
- put_bits(&s->pb, 16, 0x0b77); /* frame header */
- put_bits(&s->pb, 16, 0); /* crc1: will be filled later */
- put_bits(&s->pb, 2, s->bit_alloc.sr_code);
- put_bits(&s->pb, 6, s->frame_size_code + (s->frame_size - s->frame_size_min));
- put_bits(&s->pb, 5, s->bitstream_id);
- put_bits(&s->pb, 3, s->bitstream_mode);
- put_bits(&s->pb, 3, s->channel_mode);
+ put_bits(&s->pb, 16, 0x0b77); /* frame header */
+ put_bits(&s->pb, 16, 0); /* crc1: will be filled later */
+ put_bits(&s->pb, 2, s->bit_alloc.sr_code);
+ put_bits(&s->pb, 6, s->frame_size_code + (s->frame_size - s->frame_size_min));
+ put_bits(&s->pb, 5, s->bitstream_id);
+ put_bits(&s->pb, 3, s->bitstream_mode);
+ put_bits(&s->pb, 3, s->channel_mode);
if ((s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO)
- put_bits(&s->pb, 2, 1); /* XXX -4.5 dB */
+ put_bits(&s->pb, 2, 1); /* XXX -4.5 dB */
if (s->channel_mode & 0x04)
- put_bits(&s->pb, 2, 1); /* XXX -6 dB */
+ put_bits(&s->pb, 2, 1); /* XXX -6 dB */
if (s->channel_mode == AC3_CHMODE_STEREO)
- put_bits(&s->pb, 2, 0); /* surround not indicated */
+ put_bits(&s->pb, 2, 0); /* surround not indicated */
put_bits(&s->pb, 1, s->lfe_on); /* LFE */
- put_bits(&s->pb, 5, 31); /* dialog norm: -31 db */
- put_bits(&s->pb, 1, 0); /* no compression control word */
- put_bits(&s->pb, 1, 0); /* no lang code */
- put_bits(&s->pb, 1, 0); /* no audio production info */
- put_bits(&s->pb, 1, 0); /* no copyright */
- put_bits(&s->pb, 1, 1); /* original bitstream */
- put_bits(&s->pb, 1, 0); /* no time code 1 */
- put_bits(&s->pb, 1, 0); /* no time code 2 */
- put_bits(&s->pb, 1, 0); /* no additional bit stream info */
+ put_bits(&s->pb, 5, 31); /* dialog norm: -31 db */
+ put_bits(&s->pb, 1, 0); /* no compression control word */
+ put_bits(&s->pb, 1, 0); /* no lang code */
+ put_bits(&s->pb, 1, 0); /* no audio production info */
+ put_bits(&s->pb, 1, 0); /* no copyright */
+ put_bits(&s->pb, 1, 1); /* original bitstream */
+ put_bits(&s->pb, 1, 0); /* no time code 1 */
+ put_bits(&s->pb, 1, 0); /* no time code 2 */
+ put_bits(&s->pb, 1, 0); /* no additional bit stream info */
}
/* symetric quantization on 'levels' levels */
uint16_t *qmant1_ptr, *qmant2_ptr, *qmant4_ptr;
int delta0, delta1, delta2;
- for(ch=0;ch<s->fbw_channels;ch++)
- put_bits(&s->pb, 1, 0); /* 512 point MDCT */
- for(ch=0;ch<s->fbw_channels;ch++)
+ for (ch = 0; ch < s->fbw_channels; ch++)
+ put_bits(&s->pb, 1, 0); /* no block switching */
+ for (ch = 0; ch < s->fbw_channels; ch++)
put_bits(&s->pb, 1, 1); /* no dither */
- put_bits(&s->pb, 1, 0); /* no dynamic range */
- if (block_num == 0) {
- /* for block 0, even if no coupling, we must say it. This is a
- waste of bit :-) */
+ put_bits(&s->pb, 1, 0); /* no dynamic range */
+ if (!block_num) {
put_bits(&s->pb, 1, 1); /* coupling strategy present */
put_bits(&s->pb, 1, 0); /* no coupling strategy */
} else {
put_bits(&s->pb, 1, 0); /* no new coupling strategy */
}
- if (s->channel_mode == AC3_CHMODE_STEREO)
- {
- if(block_num==0)
- {
- /* first block must define rematrixing (rematstr) */
+ if (s->channel_mode == AC3_CHMODE_STEREO) {
+ if (!block_num) {
+ /* first block must define rematrixing (rematstr) */
put_bits(&s->pb, 1, 1);
/* dummy rematrixing rematflg(1:4)=0 */
- for (rbnd=0;rbnd<4;rbnd++)
- put_bits(&s->pb, 1, 0);
- }
- else
- {
+ for (rbnd = 0; rbnd < 4; rbnd++)
+ put_bits(&s->pb, 1, 0);
+ } else {
/* no matrixing (but should be used in the future) */
put_bits(&s->pb, 1, 0);
- }
- }
+ }
+ }
/* exponent strategy */
- for(ch=0;ch<s->fbw_channels;ch++) {
+ for (ch = 0; ch < s->fbw_channels; ch++)
put_bits(&s->pb, 2, exp_strategy[ch]);
- }
- if (s->lfe_on) {
+ if (s->lfe_on)
put_bits(&s->pb, 1, exp_strategy[s->lfe_channel]);
- }
- for(ch=0;ch<s->fbw_channels;ch++) {
+ /* bandwidth */
+ for (ch = 0; ch < s->fbw_channels; ch++) {
if (exp_strategy[ch] != EXP_REUSE)
put_bits(&s->pb, 6, s->bandwidth_code[ch]);
}
/* exponents */
for (ch = 0; ch < s->channels; ch++) {
- switch(exp_strategy[ch]) {
+ switch (exp_strategy[ch]) {
case EXP_REUSE:
continue;
case EXP_D15:
put_bits(&s->pb, 4, exp1);
/* next ones are delta encoded */
- for(i=0;i<nb_groups;i++) {
+ for (i = 0; i < nb_groups; i++) {
/* merge three delta in one code */
- exp0 = exp1;
- exp1 = p[0];
- p += group_size;
+ exp0 = exp1;
+ exp1 = p[0];
+ p += group_size;
delta0 = exp1 - exp0 + 2;
- exp0 = exp1;
- exp1 = p[0];
- p += group_size;
+ exp0 = exp1;
+ exp1 = p[0];
+ p += group_size;
delta1 = exp1 - exp0 + 2;
- exp0 = exp1;
- exp1 = p[0];
- p += group_size;
+ exp0 = exp1;
+ exp1 = p[0];
+ p += group_size;
delta2 = exp1 - exp0 + 2;
put_bits(&s->pb, 7, ((delta0 * 5 + delta1) * 5) + delta2);
}
/* snr offset */
- put_bits(&s->pb, 1, baie); /* always present with bai */
+ put_bits(&s->pb, 1, baie);
if (baie) {
put_bits(&s->pb, 6, s->coarse_snr_offset);
- for(ch=0;ch<s->channels;ch++) {
+ for (ch = 0; ch < s->channels; ch++) {
put_bits(&s->pb, 4, s->fine_snr_offset[ch]);
put_bits(&s->pb, 3, s->fast_gain_code[ch]);
}
for (ch = 0; ch < s->channels; ch++) {
int b, c, e, v;
- for(i=0;i<s->nb_coefs[ch];i++) {
+ for (i = 0; i < s->nb_coefs[ch]; i++) {
c = mdct_coefs[ch][i];
e = encoded_exp[ch][i] - global_exp[ch];
b = bap[ch][i];
- switch(b) {
+ switch (b) {
case 0:
v = 0;
break;
case 1:
v = sym_quant(c, e, 3);
- switch(mant1_cnt) {
+ switch (mant1_cnt) {
case 0:
qmant1_ptr = &qmant[ch][i];
v = 9 * v;
break;
case 2:
v = sym_quant(c, e, 5);
- switch(mant2_cnt) {
+ switch (mant2_cnt) {
case 0:
qmant2_ptr = &qmant[ch][i];
v = 25 * v;
break;
case 4:
v = sym_quant(c, e, 11);
- switch(mant4_cnt) {
+ switch (mant4_cnt) {
case 0:
qmant4_ptr = &qmant[ch][i];
v = 11 * v;
for (ch = 0; ch < s->channels; ch++) {
int b, q;
- for(i=0;i<s->nb_coefs[ch];i++) {
+ for (i = 0; i < s->nb_coefs[ch]; i++) {
q = qmant[ch][i];
b = bap[ch][i];
- switch(b) {
- case 0:
- break;
- case 1:
- if (q != 128)
- put_bits(&s->pb, 5, q);
- break;
- case 2:
- if (q != 128)
- put_bits(&s->pb, 7, q);
- break;
- case 3:
- put_bits(&s->pb, 3, q);
- break;
- case 4:
- if (q != 128)
- put_bits(&s->pb, 7, q);
- break;
- case 14:
- put_bits(&s->pb, 14, q);
- break;
- case 15:
- put_bits(&s->pb, 16, q);
- break;
- default:
- put_bits(&s->pb, b - 1, q);
- break;
+ switch (b) {
+ case 0: break;
+ case 1: if (q != 128) put_bits(&s->pb, 5, q); break;
+ case 2: if (q != 128) put_bits(&s->pb, 7, q); break;
+ case 3: put_bits(&s->pb, 3, q); break;
+ case 4: if (q != 128) put_bits(&s->pb, 7, q); break;
+ case 14: put_bits(&s->pb, 14, q); break;
+ case 15: put_bits(&s->pb, 16, q); break;
+ default: put_bits(&s->pb, b-1, q); break;
}
}
}
int i, v;
v = 0;
- for(i=0;i<n;i++) {
+ for (i = 0; i < n; i++)
v |= abs(tab[i]);
- }
+
return av_log2(v);
}
int i;
if (lshift > 0) {
- for(i=0;i<n;i++) {
+ for(i = 0; i < n; i++)
tab[i] <<= lshift;
- }
} else if (lshift < 0) {
lshift = -lshift;
- for(i=0;i<n;i++) {
+ for (i = 0; i < n; i++)
tab[i] >>= lshift;
- }
}
}
frame = s->pb.buf;
n = 2 * s->frame_size - (put_bits_ptr(&s->pb) - frame) - 2;
assert(n >= 0);
- if(n>0)
- memset(put_bits_ptr(&s->pb), 0, n);
+ if (n > 0)
+ memset(put_bits_ptr(&s->pb), 0, n);
/* Now we must compute both crcs : this is not so easy for crc1
because it is at the beginning of the data... */
frame_size_58 = (frame_size >> 1) + (frame_size >> 3);
+
crc1 = av_bswap16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0,
- frame + 4, 2 * frame_size_58 - 4));
+ frame + 4, 2 * frame_size_58 - 4));
+
/* XXX: could precompute crc_inv */
crc_inv = pow_poly((CRC16_POLY >> 1), (16 * frame_size_58) - 16, CRC16_POLY);
- crc1 = mul_poly(crc_inv, crc1, CRC16_POLY);
- AV_WB16(frame+2,crc1);
+ crc1 = mul_poly(crc_inv, crc1, CRC16_POLY);
+ AV_WB16(frame + 2, crc1);
crc2 = av_bswap16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0,
- frame + 2 * frame_size_58,
- (frame_size - frame_size_58) * 2 - 2));
- AV_WB16(frame+2*frame_size-2,crc2);
+ frame + 2 * frame_size_58,
+ (frame_size - frame_size_58) * 2 - 2));
+ AV_WB16(frame + 2*frame_size - 2, crc2);
- // printf("n=%d frame_size=%d\n", n, frame_size);
return frame_size * 2;
}
int frame_bits;
frame_bits = 0;
- for(ch=0;ch<s->channels;ch++) {
+ for (ch = 0; ch < s->channels; ch++) {
int ich = s->channel_map[ch];
/* fixed mdct to the six sub blocks & exponent computation */
- for(i=0;i<AC3_MAX_BLOCKS;i++) {
+ for (i = 0; i < AC3_MAX_BLOCKS; i++) {
const int16_t *sptr;
int sinc;
memcpy(input_samples, s->last_samples[ich], AC3_BLOCK_SIZE * sizeof(int16_t));
sinc = s->channels;
sptr = samples + (sinc * AC3_BLOCK_SIZE * i) + ich;
- for(j=0;j<AC3_BLOCK_SIZE;j++) {
+ for (j = 0; j < AC3_BLOCK_SIZE; j++) {
v = *sptr;
input_samples[j + AC3_BLOCK_SIZE] = v;
s->last_samples[ich][j] = v;
}
/* apply the MDCT window */
- for(j=0;j<AC3_BLOCK_SIZE;j++) {
- input_samples[j] = MUL16(input_samples[j],
- ff_ac3_window[j]) >> 15;
+ for (j = 0; j < AC3_BLOCK_SIZE; j++) {
+ input_samples[j] = MUL16(input_samples[j],
+ ff_ac3_window[j]) >> 15;
input_samples[AC3_WINDOW_SIZE-j-1] = MUL16(input_samples[AC3_WINDOW_SIZE-j-1],
- ff_ac3_window[j]) >> 15;
+ ff_ac3_window[j]) >> 15;
}
- /* Normalize the samples to use the maximum available
- precision */
+ /* Normalize the samples to use the maximum available precision */
v = 14 - log2_tab(input_samples, AC3_WINDOW_SIZE);
if (v < 0)
v = 0;
/* do the MDCT */
mdct512(mdct_coef[i][ch], input_samples);
- /* compute "exponents". We take into account the
- normalization there */
- for(j=0;j<AC3_MAX_COEFS;j++) {
+ /* compute "exponents". We take into account the normalization there */
+ for (j = 0; j < AC3_MAX_COEFS; j++) {
int e;
v = abs(mdct_coef[i][ch][j]);
if (v == 0)
exp[i][ch], s->nb_coefs[ch],
exp_strategy[i][ch]);
/* copy encoded exponents for reuse case */
- for(k=i+1;k<j;k++) {
+ for (k = i+1; k < j; k++) {
memcpy(encoded_exp[k][ch], encoded_exp[i][ch],
s->nb_coefs[ch] * sizeof(uint8_t));
}
}
/* adjust for fractional frame sizes */
- while(s->bits_written >= s->bit_rate && s->samples_written >= s->sample_rate) {
- s->bits_written -= s->bit_rate;
+ while (s->bits_written >= s->bit_rate && s->samples_written >= s->sample_rate) {
+ s->bits_written -= s->bit_rate;
s->samples_written -= s->sample_rate;
}
s->frame_size = s->frame_size_min + (s->bits_written * s->sample_rate < s->samples_written * s->bit_rate);
- s->bits_written += s->frame_size * 16;
+ s->bits_written += s->frame_size * 16;
s->samples_written += AC3_FRAME_SIZE;
compute_bit_allocation(s, bap, encoded_exp, exp_strategy, frame_bits);
/* everything is known... let's output the frame */
output_frame_header(s, frame);
- for(i=0;i<AC3_MAX_BLOCKS;i++) {
+ for (i = 0; i < AC3_MAX_BLOCKS; i++) {
output_audio_block(s, exp_strategy[i], encoded_exp[i],
bap[i], mdct_coef[i], exp_samples[i], i);
}
int k, n, i;
float sum_re, sum_im, a;
- /* FFT test */
-
- for(i=0;i<FN;i++) {
+ for (i = 0; i < FN; i++) {
in[i].re = av_lfg_get(lfg) % 65535 - 32767;
in[i].im = av_lfg_get(lfg) % 65535 - 32767;
- in1[i] = in[i];
+ in1[i] = in[i];
}
fft(in, 7);
/* do it by hand */
- for(k=0;k<FN;k++) {
+ for (k = 0; k < FN; k++) {
sum_re = 0;
sum_im = 0;
- for(n=0;n<FN;n++) {
+ for (n = 0; n < FN; n++) {
a = -2 * M_PI * (n * k) / FN;
sum_re += in1[n].re * cos(a) - in1[n].im * sin(a);
sum_im += in1[n].re * sin(a) + in1[n].im * cos(a);
float s, a, err, e, emax;
int i, k, n;
- for(i=0;i<MDCT_SAMPLES;i++) {
- input[i] = (av_lfg_get(lfg) % 65535 - 32767) * 9 / 10;
+ for (i = 0; i < MDCT_SAMPLES; i++) {
+ input[i] = (av_lfg_get(lfg) % 65535 - 32767) * 9 / 10;
input1[i] = input[i];
}
mdct512(output, input);
/* do it by hand */
- for(k=0;k<AC3_MAX_COEFS;k++) {
+ for (k = 0; k < AC3_MAX_COEFS; k++) {
s = 0;
- for(n=0;n<MDCT_SAMPLES;n++) {
+ for (n = 0; n < MDCT_SAMPLES; n++) {
a = (2*M_PI*(2*n+1+MDCT_SAMPLES/2)*(2*k+1) / (4 * MDCT_SAMPLES));
s += input1[n] * cos(a);
}
output1[k] = -2 * s / MDCT_SAMPLES;
}
- err = 0;
+ err = 0;
emax = 0;
- for(i=0;i<AC3_MAX_COEFS;i++) {
+ for (i = 0; i < AC3_MAX_COEFS; i++) {
av_log(NULL, AV_LOG_DEBUG, "%3d: %7d %7.0f\n", i, output[i], output1[i]);
e = output[i] - output1[i];
if (e > emax)