X-Git-Url: https://git.pterodactylus.net/?a=blobdiff_plain;f=synfig-core%2Ftags%2Fsynfig_0_61_04%2Fsynfig-core%2Fsrc%2Fmodules%2Fmod_libavcodec%2Flibavcodec%2Fac3enc.c;fp=synfig-core%2Ftags%2Fsynfig_0_61_04%2Fsynfig-core%2Fsrc%2Fmodules%2Fmod_libavcodec%2Flibavcodec%2Fac3enc.c;h=0000000000000000000000000000000000000000;hb=6fa8f2f38d4b0b35f8539bf94e27ae27015c7689;hp=4093fb75d85ced6778ff98987e94acb4091b5f0a;hpb=47fce282611fbba1044921d22ca887f9b53ad91a;p=synfig.git diff --git a/synfig-core/tags/synfig_0_61_04/synfig-core/src/modules/mod_libavcodec/libavcodec/ac3enc.c b/synfig-core/tags/synfig_0_61_04/synfig-core/src/modules/mod_libavcodec/libavcodec/ac3enc.c deleted file mode 100644 index 4093fb7..0000000 --- a/synfig-core/tags/synfig_0_61_04/synfig-core/src/modules/mod_libavcodec/libavcodec/ac3enc.c +++ /dev/null @@ -1,1579 +0,0 @@ -/* - * The simplest AC3 encoder - * Copyright (c) 2000 Fabrice Bellard. - * - * 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 ac3enc.c - * The simplest AC3 encoder. - */ -//#define DEBUG -//#define DEBUG_BITALLOC -#include "avcodec.h" - -#include "ac3.h" - -typedef struct AC3EncodeContext { - PutBitContext pb; - int nb_channels; - int nb_all_channels; - int lfe_channel; - int bit_rate; - unsigned int sample_rate; - unsigned int bsid; - unsigned int frame_size_min; /* minimum frame size in case rounding is necessary */ - unsigned int frame_size; /* current frame size in words */ - int halfratecod; - unsigned int frmsizecod; - unsigned int fscod; /* frequency */ - unsigned int acmod; - int lfe; - unsigned int bsmod; - short last_samples[AC3_MAX_CHANNELS][256]; - unsigned int chbwcod[AC3_MAX_CHANNELS]; - int nb_coefs[AC3_MAX_CHANNELS]; - - /* bitrate allocation control */ - int sgaincod, sdecaycod, fdecaycod, dbkneecod, floorcod; - AC3BitAllocParameters bit_alloc; - int csnroffst; - int fgaincod[AC3_MAX_CHANNELS]; - int fsnroffst[AC3_MAX_CHANNELS]; - /* mantissa encoding */ - int mant1_cnt, mant2_cnt, mant4_cnt; -} AC3EncodeContext; - -#include "ac3tab.h" - -#define MDCT_NBITS 9 -#define N (1 << MDCT_NBITS) - -/* new exponents are sent if their Norm 1 exceed this number */ -#define EXP_DIFF_THRESHOLD 1000 - -static void fft_init(int ln); -static void ac3_crc_init(void); - -static inline int16_t fix15(float a) -{ - int v; - v = (int)(a * (float)(1 << 15)); - if (v < -32767) - v = -32767; - else if (v > 32767) - v = 32767; - return v; -} - -static inline int calc_lowcomp1(int a, int b0, int b1) -{ - if ((b0 + 256) == b1) { - a = 384 ; - } else if (b0 > b1) { - a = a - 64; - if (a < 0) a=0; - } - return a; -} - -static inline int calc_lowcomp(int a, int b0, int b1, int bin) -{ - if (bin < 7) { - if ((b0 + 256) == b1) { - a = 384 ; - } else if (b0 > b1) { - a = a - 64; - if (a < 0) a=0; - } - } else if (bin < 20) { - if ((b0 + 256) == b1) { - a = 320 ; - } else if (b0 > b1) { - a= a - 64; - if (a < 0) a=0; - } - } else { - a = a - 128; - if (a < 0) a=0; - } - return a; -} - -/* AC3 bit allocation. The algorithm is the one described in the AC3 - spec. */ -void ac3_parametric_bit_allocation(AC3BitAllocParameters *s, uint8_t *bap, - int8_t *exp, int start, int end, - int snroffset, int fgain, int is_lfe, - int deltbae,int deltnseg, - uint8_t *deltoffst, uint8_t *deltlen, uint8_t *deltba) -{ - int bin,i,j,k,end1,v,v1,bndstrt,bndend,lowcomp,begin; - int fastleak,slowleak,address,tmp; - int16_t psd[256]; /* scaled exponents */ - int16_t bndpsd[50]; /* interpolated exponents */ - int16_t excite[50]; /* excitation */ - int16_t mask[50]; /* masking value */ - - /* exponent mapping to PSD */ - for(bin=start;bin end) end1=end; - for(i=j;i= 0) { - adr=c >> 1; - if (adr > 255) adr=255; - v=v + latab[adr]; - } else { - adr=(-c) >> 1; - if (adr > 255) adr=255; - v=v1 + latab[adr]; - } - j++; - } - bndpsd[k]=v; - k++; - } while (end > bndtab[k]); - - /* excitation function */ - bndstrt = masktab[start]; - bndend = masktab[end-1] + 1; - - if (bndstrt == 0) { - lowcomp = 0; - lowcomp = calc_lowcomp1(lowcomp, bndpsd[0], bndpsd[1]) ; - excite[0] = bndpsd[0] - fgain - lowcomp ; - lowcomp = calc_lowcomp1(lowcomp, bndpsd[1], bndpsd[2]) ; - excite[1] = bndpsd[1] - fgain - lowcomp ; - begin = 7 ; - for (bin = 2; bin < 7; bin++) { - if (!(is_lfe && bin == 6)) - lowcomp = calc_lowcomp1(lowcomp, bndpsd[bin], bndpsd[bin+1]) ; - fastleak = bndpsd[bin] - fgain ; - slowleak = bndpsd[bin] - s->sgain ; - excite[bin] = fastleak - lowcomp ; - if (!(is_lfe && bin == 6)) { - if (bndpsd[bin] <= bndpsd[bin+1]) { - begin = bin + 1 ; - break ; - } - } - } - - end1=bndend; - if (end1 > 22) end1=22; - - for (bin = begin; bin < end1; bin++) { - if (!(is_lfe && bin == 6)) - lowcomp = calc_lowcomp(lowcomp, bndpsd[bin], bndpsd[bin+1], bin) ; - - fastleak -= s->fdecay ; - v = bndpsd[bin] - fgain; - if (fastleak < v) fastleak = v; - - slowleak -= s->sdecay ; - v = bndpsd[bin] - s->sgain; - if (slowleak < v) slowleak = v; - - v=fastleak - lowcomp; - if (slowleak > v) v=slowleak; - - excite[bin] = v; - } - begin = 22; - } else { - /* coupling channel */ - begin = bndstrt; - - fastleak = (s->cplfleak << 8) + 768; - slowleak = (s->cplsleak << 8) + 768; - } - - for (bin = begin; bin < bndend; bin++) { - fastleak -= s->fdecay ; - v = bndpsd[bin] - fgain; - if (fastleak < v) fastleak = v; - slowleak -= s->sdecay ; - v = bndpsd[bin] - s->sgain; - if (slowleak < v) slowleak = v; - - v=fastleak; - if (slowleak > v) v = slowleak; - excite[bin] = v; - } - - /* compute masking curve */ - - for (bin = bndstrt; bin < bndend; bin++) { - v1 = excite[bin]; - tmp = s->dbknee - bndpsd[bin]; - if (tmp > 0) { - v1 += tmp >> 2; - } - v=hth[bin >> s->halfratecod][s->fscod]; - if (v1 > v) v=v1; - mask[bin] = v; - } - - /* delta bit allocation */ - - if (deltbae == 0 || deltbae == 1) { - int band, seg, delta; - band = 0 ; - for (seg = 0; seg < deltnseg; seg++) { - band += deltoffst[seg] ; - if (deltba[seg] >= 4) { - delta = (deltba[seg] - 3) << 7; - } else { - delta = (deltba[seg] - 4) << 7; - } - for (k = 0; k < deltlen[seg]; k++) { - mask[band] += delta ; - band++ ; - } - } - } - - /* compute bit allocation */ - - i = start ; - j = masktab[start] ; - do { - v=mask[j]; - v -= snroffset ; - v -= s->floor ; - if (v < 0) v = 0; - v &= 0x1fe0 ; - v += s->floor ; - - end1=bndtab[j] + bndsz[j]; - if (end1 > end) end1=end; - - for (k = i; k < end1; k++) { - address = (psd[i] - v) >> 5 ; - if (address < 0) address=0; - else if (address > 63) address=63; - bap[i] = baptab[address]; - i++; - } - } while (end > bndtab[j++]) ; -} - -typedef struct IComplex { - short re,im; -} IComplex; - -static void fft_init(int ln) -{ - int i, j, m, n; - float alpha; - - n = 1 << ln; - - 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)); - } - - for(i=0;i> j) & 1) << (ln-j-1); - } - fft_rev[i]=m; - } -} - -/* 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 MUL16(a,b) ((a) * (b)) - -#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; - register IComplex *p,*q; - int tmp_re, tmp_im; - - np = 1 << ln; - - /* reverse */ - for(j=0;j> 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); - - /* pass 1 */ - - 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, - p[1].re, p[1].im, p[3].im, -p[3].re); - p+=4; - } while (--j != 0); - - /* pass 2 .. ln-1 */ - - nblocks = np >> 3; - nloops = 1 << 2; - np2 = np >> 1; - do { - p = z; - q = z + nloops; - 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, - p->re, p->im, tmp_re, tmp_im); - p++; - q++; - } - p += nloops; - q += nloops; - } - nblocks = nblocks >> 1; - nloops = nloops << 1; - } while (nblocks != 0); -} - -/* do a 512 point mdct */ -static void mdct512(int32_t *out, int16_t *in) -{ - int i, re, im, re1, im1; - int16_t rot[N]; - IComplex x[N/4]; - - /* shift to simplify computations */ - for(i=0;i> 1; - im = -((int)rot[N/2+2*i] - (int)rot[N/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 EXP_DIFF_THRESHOLD) - exp_strategy[i][ch] = EXP_NEW; - else - exp_strategy[i][ch] = EXP_REUSE; - } - if (is_lfe) - return; - - /* now select the encoding strategy type : if exponents are often - recoded, we use a coarse encoding */ - i = 0; - while (i < NB_BLOCKS) { - j = i + 1; - while (j < NB_BLOCKS && exp_strategy[j][ch] == EXP_REUSE) - j++; - switch(j - i) { - case 1: - exp_strategy[i][ch] = EXP_D45; - break; - case 2: - case 3: - exp_strategy[i][ch] = EXP_D25; - break; - default: - exp_strategy[i][ch] = EXP_D15; - break; - } - i = j; - } -} - -/* set exp[i] to min(exp[i], exp1[i]) */ -static void exponent_min(uint8_t exp[N/2], uint8_t exp1[N/2], int n) -{ - int i; - - for(i=0;i= 0 && exp_min <= 24); - for(j=1;j 15) - exp1[0] = 15; - - /* Iterate until the delta constraints between each groups are - satisfyed. I'm sure it is possible to find a better algorithm, - but I am lazy */ - do { - recurse = 0; - for(i=1;i<=nb_groups;i++) { - delta = exp1[i] - exp1[i-1]; - if (delta > 2) { - /* if delta too big, we encode a smaller exponent */ - exp1[i] = exp1[i-1] + 2; - } else if (delta < -2) { - /* if delta is too small, we must decrease the previous - exponent, which means we must recurse */ - recurse = 1; - exp1[i-1] = exp1[i] + 2; - } - } - } while (recurse); - - /* 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;jmant1_cnt == 0) - bits += 5; - if (++s->mant1_cnt == 3) - s->mant1_cnt = 0; - break; - case 2: - /* 3 mantissa in 7 bits */ - if (s->mant2_cnt == 0) - bits += 7; - if (++s->mant2_cnt == 3) - s->mant2_cnt = 0; - break; - case 3: - bits += 3; - break; - case 4: - /* 2 mantissa in 7 bits */ - if (s->mant4_cnt == 0) - bits += 7; - if (++s->mant4_cnt == 2) - s->mant4_cnt = 0; - break; - case 14: - bits += 14; - break; - case 15: - bits += 16; - break; - default: - bits += mant - 1; - break; - } - } - return bits; -} - - -static int bit_alloc(AC3EncodeContext *s, - uint8_t bap[NB_BLOCKS][AC3_MAX_CHANNELS][N/2], - uint8_t encoded_exp[NB_BLOCKS][AC3_MAX_CHANNELS][N/2], - uint8_t exp_strategy[NB_BLOCKS][AC3_MAX_CHANNELS], - int frame_bits, int csnroffst, int fsnroffst) -{ - int i, ch; - - /* compute size */ - for(i=0;imant1_cnt = 0; - s->mant2_cnt = 0; - s->mant4_cnt = 0; - for(ch=0;chnb_all_channels;ch++) { - ac3_parametric_bit_allocation(&s->bit_alloc, - bap[i][ch], (int8_t *)encoded_exp[i][ch], - 0, s->nb_coefs[ch], - (((csnroffst-15) << 4) + - fsnroffst) << 2, - fgaintab[s->fgaincod[ch]], - ch == s->lfe_channel, - 2, 0, NULL, NULL, NULL); - frame_bits += compute_mantissa_size(s, bap[i][ch], - s->nb_coefs[ch]); - } - } -#if 0 - printf("csnr=%d fsnr=%d frame_bits=%d diff=%d\n", - csnroffst, fsnroffst, frame_bits, - 16 * s->frame_size - ((frame_bits + 7) & ~7)); -#endif - return 16 * s->frame_size - frame_bits; -} - -#define SNR_INC1 4 - -static int compute_bit_allocation(AC3EncodeContext *s, - uint8_t bap[NB_BLOCKS][AC3_MAX_CHANNELS][N/2], - uint8_t encoded_exp[NB_BLOCKS][AC3_MAX_CHANNELS][N/2], - uint8_t exp_strategy[NB_BLOCKS][AC3_MAX_CHANNELS], - int frame_bits) -{ - int i, ch; - int csnroffst, fsnroffst; - uint8_t bap1[NB_BLOCKS][AC3_MAX_CHANNELS][N/2]; - static int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 }; - - /* init default parameters */ - s->sdecaycod = 2; - s->fdecaycod = 1; - s->sgaincod = 1; - s->dbkneecod = 2; - s->floorcod = 4; - for(ch=0;chnb_all_channels;ch++) - s->fgaincod[ch] = 4; - - /* compute real values */ - s->bit_alloc.fscod = s->fscod; - s->bit_alloc.halfratecod = s->halfratecod; - s->bit_alloc.sdecay = sdecaytab[s->sdecaycod] >> s->halfratecod; - s->bit_alloc.fdecay = fdecaytab[s->fdecaycod] >> s->halfratecod; - s->bit_alloc.sgain = sgaintab[s->sgaincod]; - s->bit_alloc.dbknee = dbkneetab[s->dbkneecod]; - s->bit_alloc.floor = floortab[s->floorcod]; - - /* header size */ - frame_bits += 65; - // if (s->acmod == 2) - // frame_bits += 2; - frame_bits += frame_bits_inc[s->acmod]; - - /* audio blocks */ - for(i=0;inb_channels * 2 + 2; /* blksw * c, dithflag * c, dynrnge, cplstre */ - if (s->acmod == 2) - frame_bits++; /* rematstr */ - frame_bits += 2 * s->nb_channels; /* chexpstr[2] * c */ - if (s->lfe) - frame_bits++; /* lfeexpstr */ - for(ch=0;chnb_channels;ch++) { - if (exp_strategy[i][ch] != EXP_REUSE) - frame_bits += 6 + 2; /* chbwcod[6], gainrng[2] */ - } - frame_bits++; /* baie */ - frame_bits++; /* snr */ - frame_bits += 2; /* delta / skip */ - } - frame_bits++; /* cplinu for block 0 */ - /* bit alloc info */ - /* sdcycod[2], fdcycod[2], sgaincod[2], dbpbcod[2], floorcod[3] */ - /* csnroffset[6] */ - /* (fsnoffset[4] + fgaincod[4]) * c */ - frame_bits += 2*4 + 3 + 6 + s->nb_all_channels * (4 + 3); - - /* CRC */ - frame_bits += 16; - - /* now the big work begins : do the bit allocation. Modify the snr - offset until we can pack everything in the requested frame size */ - - csnroffst = s->csnroffst; - while (csnroffst >= 0 && - bit_alloc(s, bap, encoded_exp, exp_strategy, frame_bits, csnroffst, 0) < 0) - csnroffst -= SNR_INC1; - if (csnroffst < 0) { - fprintf(stderr, "Yack, Error !!!\n"); - return -1; - } - while ((csnroffst + SNR_INC1) <= 63 && - bit_alloc(s, bap1, encoded_exp, exp_strategy, frame_bits, - csnroffst + SNR_INC1, 0) >= 0) { - csnroffst += SNR_INC1; - memcpy(bap, bap1, sizeof(bap1)); - } - while ((csnroffst + 1) <= 63 && - bit_alloc(s, bap1, encoded_exp, exp_strategy, frame_bits, csnroffst + 1, 0) >= 0) { - csnroffst++; - memcpy(bap, bap1, sizeof(bap1)); - } - - fsnroffst = 0; - while ((fsnroffst + SNR_INC1) <= 15 && - bit_alloc(s, bap1, encoded_exp, exp_strategy, frame_bits, - csnroffst, fsnroffst + SNR_INC1) >= 0) { - fsnroffst += SNR_INC1; - memcpy(bap, bap1, sizeof(bap1)); - } - while ((fsnroffst + 1) <= 15 && - bit_alloc(s, bap1, encoded_exp, exp_strategy, frame_bits, - csnroffst, fsnroffst + 1) >= 0) { - fsnroffst++; - memcpy(bap, bap1, sizeof(bap1)); - } - - s->csnroffst = csnroffst; - for(ch=0;chnb_all_channels;ch++) - s->fsnroffst[ch] = fsnroffst; -#if defined(DEBUG_BITALLOC) - { - int j; - - for(i=0;i<6;i++) { - for(ch=0;chnb_all_channels;ch++) { - printf("Block #%d Ch%d:\n", i, ch); - printf("bap="); - for(j=0;jnb_coefs[ch];j++) { - printf("%d ",bap[i][ch][j]); - } - printf("\n"); - } - } - } -#endif - return 0; -} - -void ac3_common_init(void) -{ - int i, j, k, l, v; - /* compute bndtab and masktab from bandsz */ - k = 0; - l = 0; - for(i=0;i<50;i++) { - bndtab[i] = l; - v = bndsz[i]; - for(j=0;jsample_rate; - int bitrate = avctx->bit_rate; - int channels = avctx->channels; - AC3EncodeContext *s = avctx->priv_data; - int i, j, ch; - float alpha; - static const uint8_t acmod_defs[6] = { - 0x01, /* C */ - 0x02, /* L R */ - 0x03, /* L C R */ - 0x06, /* L R SL SR */ - 0x07, /* L C R SL SR */ - 0x07, /* L C R SL SR (+LFE) */ - }; - - avctx->frame_size = AC3_FRAME_SIZE; - - /* number of channels */ - if (channels < 1 || channels > 6) - return -1; - s->acmod = acmod_defs[channels - 1]; - s->lfe = (channels == 6) ? 1 : 0; - s->nb_all_channels = channels; - s->nb_channels = channels > 5 ? 5 : channels; - s->lfe_channel = s->lfe ? 5 : -1; - - /* frequency */ - for(i=0;i<3;i++) { - for(j=0;j<3;j++) - if ((ac3_freqs[j] >> i) == freq) - goto found; - } - return -1; - found: - s->sample_rate = freq; - s->halfratecod = i; - s->fscod = j; - s->bsid = 8 + s->halfratecod; - s->bsmod = 0; /* complete main audio service */ - - /* bitrate & frame size */ - bitrate /= 1000; - for(i=0;i<19;i++) { - if ((ac3_bitratetab[i] >> s->halfratecod) == bitrate) - break; - } - if (i == 19) - return -1; - s->bit_rate = bitrate; - s->frmsizecod = i << 1; - s->frame_size_min = (bitrate * 1000 * AC3_FRAME_SIZE) / (freq * 16); - /* for now we do not handle fractional sizes */ - s->frame_size = s->frame_size_min; - - /* bit allocation init */ - for(ch=0;chnb_channels;ch++) { - /* bandwidth for each channel */ - /* XXX: should compute the bandwidth according to the frame - size, so that we avoid anoying high freq artefacts */ - s->chbwcod[ch] = 50; /* sample bandwidth as mpeg audio layer 2 table 0 */ - s->nb_coefs[ch] = ((s->chbwcod[ch] + 12) * 3) + 37; - } - if (s->lfe) { - s->nb_coefs[s->lfe_channel] = 7; /* fixed */ - } - /* initial snr offset */ - s->csnroffst = 40; - - ac3_common_init(); - - /* mdct init */ - fft_init(MDCT_NBITS - 2); - for(i=0;icoded_frame= avcodec_alloc_frame(); - avctx->coded_frame->key_frame= 1; - - return 0; -} - -/* output the AC3 frame header */ -static void output_frame_header(AC3EncodeContext *s, unsigned char *frame) -{ - init_put_bits(&s->pb, frame, AC3_MAX_CODED_FRAME_SIZE, NULL, NULL); - - 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->fscod); - put_bits(&s->pb, 6, s->frmsizecod + (s->frame_size - s->frame_size_min)); - put_bits(&s->pb, 5, s->bsid); - put_bits(&s->pb, 3, s->bsmod); - put_bits(&s->pb, 3, s->acmod); - if ((s->acmod & 0x01) && s->acmod != 0x01) - put_bits(&s->pb, 2, 1); /* XXX -4.5 dB */ - if (s->acmod & 0x04) - put_bits(&s->pb, 2, 1); /* XXX -6 dB */ - if (s->acmod == 0x02) - put_bits(&s->pb, 2, 0); /* surround not indicated */ - put_bits(&s->pb, 1, s->lfe); /* 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 addtional bit stream info */ -} - -/* symetric quantization on 'levels' levels */ -static inline int sym_quant(int c, int e, int levels) -{ - int v; - - if (c >= 0) { - v = (levels * (c << e)) >> 24; - v = (v + 1) >> 1; - v = (levels >> 1) + v; - } else { - v = (levels * ((-c) << e)) >> 24; - v = (v + 1) >> 1; - v = (levels >> 1) - v; - } - assert (v >= 0 && v < levels); - return v; -} - -/* asymetric quantization on 2^qbits levels */ -static inline int asym_quant(int c, int e, int qbits) -{ - int lshift, m, v; - - lshift = e + qbits - 24; - if (lshift >= 0) - v = c << lshift; - else - v = c >> (-lshift); - /* rounding */ - v = (v + 1) >> 1; - m = (1 << (qbits-1)); - if (v >= m) - v = m - 1; - assert(v >= -m); - return v & ((1 << qbits)-1); -} - -/* Output one audio block. There are NB_BLOCKS audio blocks in one AC3 - frame */ -static void output_audio_block(AC3EncodeContext *s, - uint8_t exp_strategy[AC3_MAX_CHANNELS], - uint8_t encoded_exp[AC3_MAX_CHANNELS][N/2], - uint8_t bap[AC3_MAX_CHANNELS][N/2], - int32_t mdct_coefs[AC3_MAX_CHANNELS][N/2], - int8_t global_exp[AC3_MAX_CHANNELS], - int block_num) -{ - int ch, nb_groups, group_size, i, baie, rbnd; - uint8_t *p; - uint16_t qmant[AC3_MAX_CHANNELS][N/2]; - int exp0, exp1; - int mant1_cnt, mant2_cnt, mant4_cnt; - uint16_t *qmant1_ptr, *qmant2_ptr, *qmant4_ptr; - int delta0, delta1, delta2; - - for(ch=0;chnb_channels;ch++) - put_bits(&s->pb, 1, 0); /* 512 point MDCT */ - for(ch=0;chnb_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, 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->acmod == 2) - { - if(block_num==0) - { - /* 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 - { - /* no matrixing (but should be used in the future) */ - put_bits(&s->pb, 1, 0); - } - } - -#if defined(DEBUG) - { - static int count = 0; - printf("Block #%d (%d)\n", block_num, count++); - } -#endif - /* exponent strategy */ - for(ch=0;chnb_channels;ch++) { - put_bits(&s->pb, 2, exp_strategy[ch]); - } - - if (s->lfe) { - put_bits(&s->pb, 1, exp_strategy[s->lfe_channel]); - } - - for(ch=0;chnb_channels;ch++) { - if (exp_strategy[ch] != EXP_REUSE) - put_bits(&s->pb, 6, s->chbwcod[ch]); - } - - /* exponents */ - for (ch = 0; ch < s->nb_all_channels; ch++) { - switch(exp_strategy[ch]) { - case EXP_REUSE: - continue; - case EXP_D15: - group_size = 1; - break; - case EXP_D25: - group_size = 2; - break; - default: - case EXP_D45: - group_size = 4; - break; - } - nb_groups = (s->nb_coefs[ch] + (group_size * 3) - 4) / (3 * group_size); - p = encoded_exp[ch]; - - /* first exponent */ - exp1 = *p++; - put_bits(&s->pb, 4, exp1); - - /* next ones are delta encoded */ - for(i=0;ipb, 7, ((delta0 * 5 + delta1) * 5) + delta2); - } - - if (ch != s->lfe_channel) - put_bits(&s->pb, 2, 0); /* no gain range info */ - } - - /* bit allocation info */ - baie = (block_num == 0); - put_bits(&s->pb, 1, baie); - if (baie) { - put_bits(&s->pb, 2, s->sdecaycod); - put_bits(&s->pb, 2, s->fdecaycod); - put_bits(&s->pb, 2, s->sgaincod); - put_bits(&s->pb, 2, s->dbkneecod); - put_bits(&s->pb, 3, s->floorcod); - } - - /* snr offset */ - put_bits(&s->pb, 1, baie); /* always present with bai */ - if (baie) { - put_bits(&s->pb, 6, s->csnroffst); - for(ch=0;chnb_all_channels;ch++) { - put_bits(&s->pb, 4, s->fsnroffst[ch]); - put_bits(&s->pb, 3, s->fgaincod[ch]); - } - } - - put_bits(&s->pb, 1, 0); /* no delta bit allocation */ - put_bits(&s->pb, 1, 0); /* no data to skip */ - - /* mantissa encoding : we use two passes to handle the grouping. A - one pass method may be faster, but it would necessitate to - modify the output stream. */ - - /* first pass: quantize */ - mant1_cnt = mant2_cnt = mant4_cnt = 0; - qmant1_ptr = qmant2_ptr = qmant4_ptr = NULL; - - for (ch = 0; ch < s->nb_all_channels; ch++) { - int b, c, e, v; - - for(i=0;inb_coefs[ch];i++) { - c = mdct_coefs[ch][i]; - e = encoded_exp[ch][i] - global_exp[ch]; - b = bap[ch][i]; - switch(b) { - case 0: - v = 0; - break; - case 1: - v = sym_quant(c, e, 3); - switch(mant1_cnt) { - case 0: - qmant1_ptr = &qmant[ch][i]; - v = 9 * v; - mant1_cnt = 1; - break; - case 1: - *qmant1_ptr += 3 * v; - mant1_cnt = 2; - v = 128; - break; - default: - *qmant1_ptr += v; - mant1_cnt = 0; - v = 128; - break; - } - break; - case 2: - v = sym_quant(c, e, 5); - switch(mant2_cnt) { - case 0: - qmant2_ptr = &qmant[ch][i]; - v = 25 * v; - mant2_cnt = 1; - break; - case 1: - *qmant2_ptr += 5 * v; - mant2_cnt = 2; - v = 128; - break; - default: - *qmant2_ptr += v; - mant2_cnt = 0; - v = 128; - break; - } - break; - case 3: - v = sym_quant(c, e, 7); - break; - case 4: - v = sym_quant(c, e, 11); - switch(mant4_cnt) { - case 0: - qmant4_ptr = &qmant[ch][i]; - v = 11 * v; - mant4_cnt = 1; - break; - default: - *qmant4_ptr += v; - mant4_cnt = 0; - v = 128; - break; - } - break; - case 5: - v = sym_quant(c, e, 15); - break; - case 14: - v = asym_quant(c, e, 14); - break; - case 15: - v = asym_quant(c, e, 16); - break; - default: - v = asym_quant(c, e, b - 1); - break; - } - qmant[ch][i] = v; - } - } - - /* second pass : output the values */ - for (ch = 0; ch < s->nb_all_channels; ch++) { - int b, q; - - for(i=0;inb_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; - } - } - } -} - -/* compute the ac3 crc */ - -#define CRC16_POLY ((1 << 0) | (1 << 2) | (1 << 15) | (1 << 16)) - -static void ac3_crc_init(void) -{ - unsigned int c, n, k; - - for(n=0;n<256;n++) { - c = n << 8; - for (k = 0; k < 8; k++) { - if (c & (1 << 15)) - c = ((c << 1) & 0xffff) ^ (CRC16_POLY & 0xffff); - else - c = c << 1; - } - crc_table[n] = c; - } -} - -static unsigned int ac3_crc(uint8_t *data, int n, unsigned int crc) -{ - int i; - for(i=0;i> 8)] ^ (crc << 8)) & 0xffff; - } - return crc; -} - -static unsigned int mul_poly(unsigned int a, unsigned int b, unsigned int poly) -{ - unsigned int c; - - c = 0; - while (a) { - if (a & 1) - c ^= b; - a = a >> 1; - b = b << 1; - if (b & (1 << 16)) - b ^= poly; - } - return c; -} - -static unsigned int pow_poly(unsigned int a, unsigned int n, unsigned int poly) -{ - unsigned int r; - r = 1; - while (n) { - if (n & 1) - r = mul_poly(r, a, poly); - a = mul_poly(a, a, poly); - n >>= 1; - } - return r; -} - - -/* compute log2(max(abs(tab[]))) */ -static int log2_tab(int16_t *tab, int n) -{ - int i, v; - - v = 0; - for(i=0;i 0) { - for(i=0;i>= lshift; - } - } -} - -/* fill the end of the frame and compute the two crcs */ -static int output_frame_end(AC3EncodeContext *s) -{ - int frame_size, frame_size_58, n, crc1, crc2, crc_inv; - uint8_t *frame; - - frame_size = s->frame_size; /* frame size in words */ - /* align to 8 bits */ - flush_put_bits(&s->pb); - /* add zero bytes to reach the frame size */ - frame = s->pb.buf; - n = 2 * s->frame_size - (pbBufPtr(&s->pb) - frame) - 2; - assert(n >= 0); - if(n>0) - memset(pbBufPtr(&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 = ac3_crc(frame + 4, (2 * frame_size_58) - 4, 0); - /* 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); - frame[2] = crc1 >> 8; - frame[3] = crc1; - - crc2 = ac3_crc(frame + 2 * frame_size_58, (frame_size - frame_size_58) * 2 - 2, 0); - frame[2*frame_size - 2] = crc2 >> 8; - frame[2*frame_size - 1] = crc2; - - // printf("n=%d frame_size=%d\n", n, frame_size); - return frame_size * 2; -} - -static int AC3_encode_frame(AVCodecContext *avctx, - unsigned char *frame, int buf_size, void *data) -{ - AC3EncodeContext *s = avctx->priv_data; - short *samples = data; - int i, j, k, v, ch; - int16_t input_samples[N]; - int32_t mdct_coef[NB_BLOCKS][AC3_MAX_CHANNELS][N/2]; - uint8_t exp[NB_BLOCKS][AC3_MAX_CHANNELS][N/2]; - uint8_t exp_strategy[NB_BLOCKS][AC3_MAX_CHANNELS]; - uint8_t encoded_exp[NB_BLOCKS][AC3_MAX_CHANNELS][N/2]; - uint8_t bap[NB_BLOCKS][AC3_MAX_CHANNELS][N/2]; - int8_t exp_samples[NB_BLOCKS][AC3_MAX_CHANNELS]; - int frame_bits; - - frame_bits = 0; - for(ch=0;chnb_all_channels;ch++) { - /* fixed mdct to the six sub blocks & exponent computation */ - for(i=0;ilast_samples[ch], N/2 * sizeof(int16_t)); - sinc = s->nb_all_channels; - sptr = samples + (sinc * (N/2) * i) + ch; - for(j=0;jlast_samples[ch][j] = v; - sptr += sinc; - } - - /* apply the MDCT window */ - for(j=0;j> 15; - input_samples[N-j-1] = MUL16(input_samples[N-j-1], - ac3_window[j]) >> 15; - } - - /* Normalize the samples to use the maximum available - precision */ - v = 14 - log2_tab(input_samples, N); - if (v < 0) - v = 0; - exp_samples[i][ch] = v - 8; - lshift_tab(input_samples, N, v); - - /* do the MDCT */ - mdct512(mdct_coef[i][ch], input_samples); - - /* compute "exponents". We take into account the - normalization there */ - for(j=0;j= 24) { - e = 24; - mdct_coef[i][ch][j] = 0; - } - } - exp[i][ch][j] = e; - } - } - - compute_exp_strategy(exp_strategy, exp, ch, ch == s->lfe_channel); - - /* compute the exponents as the decoder will see them. The - EXP_REUSE case must be handled carefully : we select the - min of the exponents */ - i = 0; - while (i < NB_BLOCKS) { - j = i + 1; - while (j < NB_BLOCKS && exp_strategy[j][ch] == EXP_REUSE) { - exponent_min(exp[i][ch], exp[j][ch], s->nb_coefs[ch]); - j++; - } - frame_bits += encode_exp(encoded_exp[i][ch], - exp[i][ch], s->nb_coefs[ch], - exp_strategy[i][ch]); - /* copy encoded exponents for reuse case */ - for(k=i+1;knb_coefs[ch] * sizeof(uint8_t)); - } - i = j; - } - } - - 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;icoded_frame); - return 0; -} - -#if 0 -/*************************************************************************/ -/* TEST */ - -#define FN (N/4) - -void fft_test(void) -{ - IComplex in[FN], in1[FN]; - int k, n, i; - float sum_re, sum_im, a; - - /* FFT test */ - - for(i=0;i emax) - emax = e; - err += e * e; - } - printf("err2=%f emax=%f\n", err / (N/2), emax); -} - -void test_ac3(void) -{ - AC3EncodeContext ctx; - unsigned char frame[AC3_MAX_CODED_FRAME_SIZE]; - short samples[AC3_FRAME_SIZE]; - int ret, i; - - AC3_encode_init(&ctx, 44100, 64000, 1); - - fft_test(); - mdct_test(); - - for(i=0;i