/* * AAC decoder * Copyright (c) 2005-2006 Oded Shimon ( ods15 ods15 dyndns org ) * Copyright (c) 2006-2007 Maxim Gavrilov ( maxim.gavrilov gmail com ) * Copyright (c) 2008-2013 Alex Converse * * AAC LATM decoder * Copyright (c) 2008-2010 Paul Kendall * Copyright (c) 2010 Janne Grunau * * AAC decoder fixed-point implementation * Copyright (c) 2013 * MIPS Technologies, Inc., California. * * 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 */ /** * linear congruential pseudorandom number generator * * @param previous_val pointer to the current state of the generator * * @return Returns a 32-bit pseudorandom integer */ static av_always_inline int lcg_random(unsigned previous_val) { union { unsigned u; int s; } v = { previous_val * 1664525u + 1013904223 }; return v.s; } /** * Decode spectral data; reference: table 4.50. * Dequantize and scale spectral data; reference: 4.6.3.3. * * @param coef array of dequantized, scaled spectral data * @param sf array of scalefactors or intensity stereo positions * @param pulse_present set if pulses are present * @param pulse pointer to pulse data struct * @param band_type array of the used band type * * @return Returns error status. 0 - OK, !0 - error */ static int AAC_RENAME(decode_spectrum_and_dequant)(AACDecContext *ac, GetBitContext *gb, const Pulse *pulse, SingleChannelElement *sce) { int i, k, g, idx = 0; INTFLOAT *coef = sce->AAC_RENAME(coeffs); IndividualChannelStream *ics = &sce->ics; const int c = 1024 / ics->num_windows; const uint16_t *offsets = ics->swb_offset; const INTFLOAT *sf = sce->AAC_RENAME(sf); const enum BandType *band_type = sce->band_type; INTFLOAT *coef_base = coef; for (g = 0; g < ics->num_windows; g++) memset(coef + g * 128 + offsets[ics->max_sfb], 0, sizeof(INTFLOAT) * (c - offsets[ics->max_sfb])); for (g = 0; g < ics->num_window_groups; g++) { unsigned g_len = ics->group_len[g]; for (i = 0; i < ics->max_sfb; i++, idx++) { const unsigned cbt_m1 = band_type[idx] - 1; INTFLOAT *cfo = coef + offsets[i]; int off_len = offsets[i + 1] - offsets[i]; int group; if (cbt_m1 >= INTENSITY_BT2 - 1) { for (group = 0; group < (AAC_SIGNE)g_len; group++, cfo+=128) { memset(cfo, 0, off_len * sizeof(*cfo)); } } else if (cbt_m1 == NOISE_BT - 1) { for (group = 0; group < (AAC_SIGNE)g_len; group++, cfo+=128) { INTFLOAT band_energy; #if USE_FIXED for (k = 0; k < off_len; k++) { ac->random_state = lcg_random(ac->random_state); cfo[k] = ac->random_state >> 3; } band_energy = ac->fdsp->scalarproduct_fixed(cfo, cfo, off_len); band_energy = fixed_sqrt(band_energy, 31); noise_scale(cfo, sf[idx], band_energy, off_len); #else float scale; for (k = 0; k < off_len; k++) { ac->random_state = lcg_random(ac->random_state); cfo[k] = ac->random_state; } band_energy = ac->fdsp->scalarproduct_float(cfo, cfo, off_len); scale = sf[idx] / sqrtf(band_energy); ac->fdsp->vector_fmul_scalar(cfo, cfo, scale, off_len); #endif /* USE_FIXED */ } } else { #if !USE_FIXED const float *vq = ff_aac_codebook_vector_vals[cbt_m1]; #endif /* !USE_FIXED */ const VLCElem *vlc_tab = ff_vlc_spectral[cbt_m1]; OPEN_READER(re, gb); switch (cbt_m1 >> 1) { case 0: for (group = 0; group < (AAC_SIGNE)g_len; group++, cfo+=128) { INTFLOAT *cf = cfo; int len = off_len; do { int code; unsigned cb_idx; UPDATE_CACHE(re, gb); GET_VLC(code, re, gb, vlc_tab, 8, 2); cb_idx = code; #if USE_FIXED cf = DEC_SQUAD(cf, cb_idx); #else cf = VMUL4(cf, vq, cb_idx, sf + idx); #endif /* USE_FIXED */ } while (len -= 4); } break; case 1: for (group = 0; group < (AAC_SIGNE)g_len; group++, cfo+=128) { INTFLOAT *cf = cfo; int len = off_len; do { int code; unsigned nnz; unsigned cb_idx; uint32_t bits; UPDATE_CACHE(re, gb); GET_VLC(code, re, gb, vlc_tab, 8, 2); cb_idx = code; nnz = cb_idx >> 8 & 15; bits = nnz ? GET_CACHE(re, gb) : 0; LAST_SKIP_BITS(re, gb, nnz); #if USE_FIXED cf = DEC_UQUAD(cf, cb_idx, bits); #else cf = VMUL4S(cf, vq, cb_idx, bits, sf + idx); #endif /* USE_FIXED */ } while (len -= 4); } break; case 2: for (group = 0; group < (AAC_SIGNE)g_len; group++, cfo+=128) { INTFLOAT *cf = cfo; int len = off_len; do { int code; unsigned cb_idx; UPDATE_CACHE(re, gb); GET_VLC(code, re, gb, vlc_tab, 8, 2); cb_idx = code; #if USE_FIXED cf = DEC_SPAIR(cf, cb_idx); #else cf = VMUL2(cf, vq, cb_idx, sf + idx); #endif /* USE_FIXED */ } while (len -= 2); } break; case 3: case 4: for (group = 0; group < (AAC_SIGNE)g_len; group++, cfo+=128) { INTFLOAT *cf = cfo; int len = off_len; do { int code; unsigned nnz; unsigned cb_idx; unsigned sign; UPDATE_CACHE(re, gb); GET_VLC(code, re, gb, vlc_tab, 8, 2); cb_idx = code; nnz = cb_idx >> 8 & 15; sign = nnz ? SHOW_UBITS(re, gb, nnz) << (cb_idx >> 12) : 0; LAST_SKIP_BITS(re, gb, nnz); #if USE_FIXED cf = DEC_UPAIR(cf, cb_idx, sign); #else cf = VMUL2S(cf, vq, cb_idx, sign, sf + idx); #endif /* USE_FIXED */ } while (len -= 2); } break; default: for (group = 0; group < (AAC_SIGNE)g_len; group++, cfo+=128) { #if USE_FIXED int *icf = cfo; int v; #else float *cf = cfo; uint32_t *icf = (uint32_t *) cf; #endif /* USE_FIXED */ int len = off_len; do { int code; unsigned nzt, nnz; unsigned cb_idx; uint32_t bits; int j; UPDATE_CACHE(re, gb); GET_VLC(code, re, gb, vlc_tab, 8, 2); cb_idx = code; if (cb_idx == 0x0000) { *icf++ = 0; *icf++ = 0; continue; } nnz = cb_idx >> 12; nzt = cb_idx >> 8; bits = SHOW_UBITS(re, gb, nnz) << (32-nnz); LAST_SKIP_BITS(re, gb, nnz); for (j = 0; j < 2; j++) { if (nzt & 1< 8) { av_log(ac->avctx, AV_LOG_ERROR, "error in spectral data, ESC overflow\n"); return AVERROR_INVALIDDATA; } SKIP_BITS(re, gb, b + 1); b += 4; n = (1 << b) + SHOW_UBITS(re, gb, b); LAST_SKIP_BITS(re, gb, b); #if USE_FIXED v = n; if (bits & 1U<<31) v = -v; *icf++ = v; #else *icf++ = ff_cbrt_tab[n] | (bits & 1U<<31); #endif /* USE_FIXED */ bits <<= 1; } else { #if USE_FIXED v = cb_idx & 15; if (bits & 1U<<31) v = -v; *icf++ = v; #else unsigned v = ((const uint32_t*)vq)[cb_idx & 15]; *icf++ = (bits & 1U<<31) | v; #endif /* USE_FIXED */ bits <<= !!v; } cb_idx >>= 4; } } while (len -= 2); #if !USE_FIXED ac->fdsp->vector_fmul_scalar(cfo, cfo, sf[idx], off_len); #endif /* !USE_FIXED */ } } CLOSE_READER(re, gb); } } coef += g_len << 7; } if (pulse) { idx = 0; for (i = 0; i < pulse->num_pulse; i++) { INTFLOAT co = coef_base[ pulse->pos[i] ]; while (offsets[idx + 1] <= pulse->pos[i]) idx++; if (band_type[idx] != NOISE_BT && sf[idx]) { INTFLOAT ico = -pulse->amp[i]; #if USE_FIXED if (co) { ico = co + (co > 0 ? -ico : ico); } coef_base[ pulse->pos[i] ] = ico; #else if (co) { co /= sf[idx]; ico = co / sqrtf(sqrtf(fabsf(co))) + (co > 0 ? -ico : ico); } coef_base[ pulse->pos[i] ] = cbrtf(fabsf(ico)) * ico * sf[idx]; #endif /* USE_FIXED */ } } } #if USE_FIXED coef = coef_base; idx = 0; for (g = 0; g < ics->num_window_groups; g++) { unsigned g_len = ics->group_len[g]; for (i = 0; i < ics->max_sfb; i++, idx++) { const unsigned cbt_m1 = band_type[idx] - 1; int *cfo = coef + offsets[i]; int off_len = offsets[i + 1] - offsets[i]; int group; if (cbt_m1 < NOISE_BT - 1) { for (group = 0; group < (int)g_len; group++, cfo+=128) { vector_pow43(cfo, off_len); subband_scale(cfo, cfo, sf[idx], 34, off_len, ac->avctx); } } } coef += g_len << 7; } #endif /* USE_FIXED */ return 0; } /** * Decode coupling_channel_element; reference: table 4.8. * * @return Returns error status. 0 - OK, !0 - error */ static int AAC_RENAME(decode_cce)(AACDecContext *ac, GetBitContext *gb, ChannelElement *che) { int num_gain = 0; int c, g, sfb, ret; int sign; INTFLOAT scale; SingleChannelElement *sce = &che->ch[0]; ChannelCoupling *coup = &che->coup; coup->coupling_point = 2 * get_bits1(gb); coup->num_coupled = get_bits(gb, 3); for (c = 0; c <= coup->num_coupled; c++) { num_gain++; coup->type[c] = get_bits1(gb) ? TYPE_CPE : TYPE_SCE; coup->id_select[c] = get_bits(gb, 4); if (coup->type[c] == TYPE_CPE) { coup->ch_select[c] = get_bits(gb, 2); if (coup->ch_select[c] == 3) num_gain++; } else coup->ch_select[c] = 2; } coup->coupling_point += get_bits1(gb) || (coup->coupling_point >> 1); sign = get_bits(gb, 1); #if USE_FIXED scale = get_bits(gb, 2); #else scale = cce_scale[get_bits(gb, 2)]; #endif if ((ret = ff_aac_decode_ics(ac, sce, gb, 0, 0))) return ret; for (c = 0; c < num_gain; c++) { int idx = 0; int cge = 1; int gain = 0; INTFLOAT gain_cache = FIXR10(1.); if (c) { cge = coup->coupling_point == AFTER_IMDCT ? 1 : get_bits1(gb); gain = cge ? get_vlc2(gb, ff_vlc_scalefactors, 7, 3) - 60: 0; gain_cache = GET_GAIN(scale, gain); #if USE_FIXED if ((abs(gain_cache)-1024) >> 3 > 30) return AVERROR(ERANGE); #endif } if (coup->coupling_point == AFTER_IMDCT) { coup->gain[c][0] = gain_cache; } else { for (g = 0; g < sce->ics.num_window_groups; g++) { for (sfb = 0; sfb < sce->ics.max_sfb; sfb++, idx++) { if (sce->band_type[idx] != ZERO_BT) { if (!cge) { int t = get_vlc2(gb, ff_vlc_scalefactors, 7, 3) - 60; if (t) { int s = 1; t = gain += t; if (sign) { s -= 2 * (t & 0x1); t >>= 1; } gain_cache = GET_GAIN(scale, t) * s; #if USE_FIXED if ((abs(gain_cache)-1024) >> 3 > 30) return AVERROR(ERANGE); #endif } } coup->gain[c][idx] = gain_cache; } } } } } return 0; } static av_cold void AAC_RENAME(aac_proc_init)(AACDecProc *aac_proc) { #define SET(member) aac_proc->member = AAC_RENAME(member) SET(decode_spectrum_and_dequant); SET(decode_cce); #undef SET #define SET(member) aac_proc->member = AV_JOIN(ff_aac_, AAC_RENAME(member)); SET(sbr_ctx_alloc_init); SET(sbr_decode_extension); SET(sbr_apply); SET(sbr_ctx_close); #undef SET }