Diffstat (limited to 'core/multimedia/opieplayer/libmpeg3/audio/mantissa.c') (more/less context) (ignore whitespace changes)
| -rw-r--r-- | core/multimedia/opieplayer/libmpeg3/audio/mantissa.c | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/core/multimedia/opieplayer/libmpeg3/audio/mantissa.c b/core/multimedia/opieplayer/libmpeg3/audio/mantissa.c new file mode 100644 index 0000000..05fe251 --- a/dev/null +++ b/core/multimedia/opieplayer/libmpeg3/audio/mantissa.c @@ -0,0 +1,387 @@ +/* + * + * mantissa.c Copyright (C) Aaron Holtzman - May 1999 + * + * + * This file is part of libmpeg3 + * + * libmpeg3 is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * libmpeg3 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GNU Make; see the file COPYING. If not, write to + * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. + * + */ + +#include "mpeg3audio.h" +#include "../libmpeg3.h" +#include "../mpeg3protos.h" + + +/* Lookup tables of 0.16 two's complement quantization values */ +static short mpeg3_q_1[3] = +{ + (-2 << 15) / 3, + 0, + (2 << 15) / 3 +}; + +static short mpeg3_q_2[5] = +{ + (-4 << 15) / 5, + ((-2 << 15) / 5) << 1, + 0, + (2 << 15) / 5, + ((4 << 15) / 5) << 1 +}; + +static short mpeg3_q_3[7] = +{ + (-6 << 15) / 7, + (-4 << 15) / 7, + (-2 << 15) / 7, + 0, + (2 << 15) / 7, + (4 << 15) / 7, + (6 << 15) / 7 +}; + +static short mpeg3_q_4[11] = +{ + (-10 << 15) / 11, + (-8 << 15) / 11, + (-6 << 15) / 11, + (-4 << 15) / 11, + (-2 << 15) / 11, + 0, + ( 2 << 15) / 11, + ( 4 << 15) / 11, + ( 6 << 15) / 11, + ( 8 << 15) / 11, + (10 << 15) / 11 +}; + +static short mpeg3_q_5[15] = +{ + (-14 << 15) / 15, + (-12 << 15) / 15, + (-10 << 15) / 15, + (-8 << 15) / 15, + (-6 << 15) / 15, + (-4 << 15) / 15, + (-2 << 15) / 15, + 0, + ( 2 << 15) / 15, + ( 4 << 15) / 15, + ( 6 << 15) / 15, + ( 8 << 15) / 15, + (10 << 15) / 15, + (12 << 15) / 15, + (14 << 15) / 15 +}; + +static short mpeg3_qnttztab[16] = {0, 0, 0, 3, 0, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 16}; + + +/* */ +/* Scale factors for tofloat */ +/* */ + +static const unsigned MPEG3_INT32 mpeg3_scale_factors[25] = +{ + 0x38000000, /*2 ^ -(0 + 15) */ + 0x37800000, /*2 ^ -(1 + 15) */ + 0x37000000, /*2 ^ -(2 + 15) */ + 0x36800000, /*2 ^ -(3 + 15) */ + 0x36000000, /*2 ^ -(4 + 15) */ + 0x35800000, /*2 ^ -(5 + 15) */ + 0x35000000, /*2 ^ -(6 + 15) */ + 0x34800000, /*2 ^ -(7 + 15) */ + 0x34000000, /*2 ^ -(8 + 15) */ + 0x33800000, /*2 ^ -(9 + 15) */ + 0x33000000, /*2 ^ -(10 + 15) */ + 0x32800000, /*2 ^ -(11 + 15) */ + 0x32000000, /*2 ^ -(12 + 15) */ + 0x31800000, /*2 ^ -(13 + 15) */ + 0x31000000, /*2 ^ -(14 + 15) */ + 0x30800000, /*2 ^ -(15 + 15) */ + 0x30000000, /*2 ^ -(16 + 15) */ + 0x2f800000, /*2 ^ -(17 + 15) */ + 0x2f000000, /*2 ^ -(18 + 15) */ + 0x2e800000, /*2 ^ -(19 + 15) */ + 0x2e000000, /*2 ^ -(20 + 15) */ + 0x2d800000, /*2 ^ -(21 + 15) */ + 0x2d000000, /*2 ^ -(22 + 15) */ + 0x2c800000, /*2 ^ -(23 + 15) */ + 0x2c000000 /*2 ^ -(24 + 15) */ +}; + +static MPEG3_FLOAT32 *mpeg3_scale_factor = (MPEG3_FLOAT32*)mpeg3_scale_factors; + +static inline mpeg3_real_t mpeg3audio_ac3_tofloat(unsigned short exponent, int mantissa) +{ + mpeg3_real_t x; + x = mantissa * mpeg3_scale_factor[exponent]; + return x; +} + +static inline void mpeg3audio_ac3_mantissa_reset(mpeg3_ac3_mantissa_t *mantissa) +{ + mantissa->m_1[2] = mantissa->m_1[1] = mantissa->m_1[0] = 0; + mantissa->m_2[2] = mantissa->m_2[1] = mantissa->m_2[0] = 0; + mantissa->m_4[1] = mantissa->m_4[0] = 0; +/* Force new groups to be loaded */ + mantissa->m_1_pointer = mantissa->m_2_pointer = mantissa->m_4_pointer = 3; +} + +/* + * Generate eight bits of pseudo-entropy using a 16 bit linear + * feedback shift register (LFSR). The primitive polynomial used + * is 1 + x^4 + x^14 + x^16. + * + * The distribution is uniform, over the range [-0.707,0.707] + * + */ +inline unsigned int mpeg3audio_ac3_dither_gen(mpeg3audio_t *audio) +{ + int i; + unsigned int state; + +/* explicitly bring the state into a local var as gcc > 3.0? */ +/* doesn't know how to optimize out the stores */ + state = audio->ac3_lfsr_state; + +/* Generate eight pseudo random bits */ + for(i = 0; i < 8; i++) + { + state <<= 1; + + if(state & 0x10000) + state ^= 0xa011; + } + + audio->ac3_lfsr_state = state; + return (((((int)state << 8) >> 8) * (int)(0.707106f * 256.0f)) >> 16); +} + + +/* Fetch an unpacked, left justified, and properly biased/dithered mantissa value */ +static inline unsigned short mpeg3audio_ac3_mantissa_get(mpeg3audio_t *audio, + unsigned short bap, + unsigned short dithflag) +{ + unsigned short mantissa; + unsigned int group_code; + mpeg3_ac3_mantissa_t *mantissa_struct = &(audio->ac3_mantissa); + +/* If the bap is 0-5 then we have special cases to take care of */ + switch(bap) + { + case 0: + if(dithflag) + mantissa = mpeg3audio_ac3_dither_gen(audio); + else + mantissa = 0; + break; + + case 1: + if(mantissa_struct->m_1_pointer > 2) + { + group_code = mpeg3bits_getbits(audio->astream, 5); + + if(group_code > 26) + { +/* FIXME do proper block error handling */ + fprintf(stderr, "mpeg3audio_ac3_mantissa_get: Invalid mantissa 1 %d\n", group_code); + return 0; + } + + mantissa_struct->m_1[0] = group_code / 9; + mantissa_struct->m_1[1] = (group_code % 9) / 3; + mantissa_struct->m_1[2] = (group_code % 9) % 3; + mantissa_struct->m_1_pointer = 0; + } + mantissa = mantissa_struct->m_1[mantissa_struct->m_1_pointer++]; + mantissa = mpeg3_q_1[mantissa]; + break; + + case 2: + if(mantissa_struct->m_2_pointer > 2) + { + group_code = mpeg3bits_getbits(audio->astream, 7); + + if(group_code > 124) + { + fprintf(stderr, "mpeg3audio_ac3_mantissa_get: Invalid mantissa 2 %d\n", group_code); + return 0; + } + + mantissa_struct->m_2[0] = group_code / 25; + mantissa_struct->m_2[1] = (group_code % 25) / 5; + mantissa_struct->m_2[2] = (group_code % 25) % 5; + mantissa_struct->m_2_pointer = 0; + } + mantissa = mantissa_struct->m_2[mantissa_struct->m_2_pointer++]; + mantissa = mpeg3_q_2[mantissa]; + break; + + case 3: + mantissa = mpeg3bits_getbits(audio->astream, 3); + + if(mantissa > 6) + { + fprintf(stderr, "mpeg3audio_ac3_mantissa_get: Invalid mantissa 3 %d\n", mantissa); + return 0; + } + + mantissa = mpeg3_q_3[mantissa]; + break; + + case 4: + if(mantissa_struct->m_4_pointer > 1) + { + group_code = mpeg3bits_getbits(audio->astream, 7); + + if(group_code > 120) + { + fprintf(stderr, "mpeg3audio_ac3_mantissa_get: Invalid mantissa 4 %d\n", group_code); + return 0; + } + + mantissa_struct->m_4[0] = group_code / 11; + mantissa_struct->m_4[1] = group_code % 11; + mantissa_struct->m_4_pointer = 0; + } + mantissa = mantissa_struct->m_4[mantissa_struct->m_4_pointer++]; + mantissa = mpeg3_q_4[mantissa]; + break; + + case 5: + mantissa = mpeg3bits_getbits(audio->astream, 4); + + if(mantissa > 14) + { +/* FIXME do proper block error handling */ + fprintf(stderr, "mpeg3audio_ac3_mantissa_get: Invalid mantissa 5 %d\n", mantissa); + return 0; + } + + mantissa = mpeg3_q_5[mantissa]; + break; + + default: + mantissa = mpeg3bits_getbits(audio->astream, mpeg3_qnttztab[bap]); + mantissa <<= 16 - mpeg3_qnttztab[bap]; + } + return mantissa; +} + +void mpeg3audio_ac3_uncouple_channel(mpeg3audio_t *audio, + mpeg3_real_t samples[], + mpeg3_ac3bsi_t *bsi, + mpeg3_ac3audblk_t *audblk, + unsigned int ch) +{ + unsigned int bnd = 0; + unsigned int sub_bnd = 0; + unsigned int i, j; + MPEG3_FLOAT32 cpl_coord = 1.0; + unsigned int cpl_exp_tmp; + unsigned int cpl_mant_tmp; + short mantissa; + + for(i = audblk->cplstrtmant; i < audblk->cplendmant; ) + { + if(!audblk->cplbndstrc[sub_bnd++]) + { + cpl_exp_tmp = audblk->cplcoexp[ch][bnd] + 3 * audblk->mstrcplco[ch]; + if(audblk->cplcoexp[ch][bnd] == 15) + cpl_mant_tmp = (audblk->cplcomant[ch][bnd]) << 11; + else + cpl_mant_tmp = ((0x10) | audblk->cplcomant[ch][bnd]) << 10; + + cpl_coord = mpeg3audio_ac3_tofloat(cpl_exp_tmp, cpl_mant_tmp) * 8.0f; + +/*Invert the phase for the right channel if necessary */ + if(bsi->acmod == 0x2 && audblk->phsflginu && ch == 1 && audblk->phsflg[bnd]) + cpl_coord *= -1; + + bnd++; + } + + for(j = 0; j < 12; j++) + { +/* Get new dither values for each channel if necessary, so */ +/* the channels are uncorrelated */ + if(audblk->dithflag[ch] && audblk->cpl_bap[i] == 0) + mantissa = mpeg3audio_ac3_dither_gen(audio); + else + mantissa = audblk->cplmant[i]; + + samples[i] = cpl_coord * mpeg3audio_ac3_tofloat(audblk->cpl_exp[i], mantissa);; + + i++; + } + } + return; +} + +int mpeg3audio_ac3_coeff_unpack(mpeg3audio_t *audio, + mpeg3_ac3bsi_t *bsi, + mpeg3_ac3audblk_t *audblk, + mpeg3ac3_stream_samples_t samples) +{ + int i, j; + int done_cpl = 0; + short mantissa; + + mpeg3audio_ac3_mantissa_reset(&(audio->ac3_mantissa)); + + for(i = 0; i < bsi->nfchans && !mpeg3bits_error(audio->astream); i++) + { + for(j = 0; j < audblk->endmant[i] && !mpeg3bits_error(audio->astream); j++) + { + mantissa = mpeg3audio_ac3_mantissa_get(audio, audblk->fbw_bap[i][j], audblk->dithflag[i]); + samples[i][j] = mpeg3audio_ac3_tofloat(audblk->fbw_exp[i][j], mantissa); + } + + if(audblk->cplinu && audblk->chincpl[i] && !(done_cpl) && !mpeg3bits_error(audio->astream)) + { +/* ncplmant is equal to 12 * ncplsubnd */ +/* Don't dither coupling channel until channel separation so that + * interchannel noise is uncorrelated */ + for(j = audblk->cplstrtmant; + j < audblk->cplendmant && !mpeg3bits_error(audio->astream); + j++) + { + audblk->cplmant[j] = mpeg3audio_ac3_mantissa_get(audio, audblk->cpl_bap[j], 0); + } + done_cpl = 1; + } + } + +/* Uncouple the channel */ + if(audblk->cplinu) + { + if(audblk->chincpl[i]) + mpeg3audio_ac3_uncouple_channel(audio, samples[i], bsi, audblk, i); + } + + if(bsi->lfeon && !mpeg3bits_error(audio->astream)) + { +/* There are always 7 mantissas for lfe, no dither for lfe */ + for(j = 0; j < 7 && !mpeg3bits_error(audio->astream); j++) + mantissa = mpeg3audio_ac3_mantissa_get(audio, audblk->lfe_bap[j], 0); + samples[5][j] = mpeg3audio_ac3_tofloat(audblk->lfe_exp[j], mantissa); + } + + return mpeg3bits_error(audio->astream); +} |