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Diffstat (limited to 'src/libfaad/rvlc_scale_factors.c')
| -rw-r--r-- | src/libfaad/rvlc_scale_factors.c | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/src/libfaad/rvlc_scale_factors.c b/src/libfaad/rvlc_scale_factors.c new file mode 100644 index 000000000..4a399c43c --- /dev/null +++ b/src/libfaad/rvlc_scale_factors.c @@ -0,0 +1,339 @@ +/* +** FAAD - Freeware Advanced Audio Decoder +** Copyright (C) 2002 M. Bakker +** +** This program 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 of the License, or +** (at your option) any later version. +** +** This program 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 this program; if not, write to the Free Software +** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. +** +** $Id: rvlc_scale_factors.c,v 1.1 2002/08/09 22:36:36 miguelfreitas Exp $ +**/ + +#include "common.h" +#include <stdlib.h> +#include "syntax.h" +#include "bits.h" +#include "rvlc_scale_factors.h" + + +#ifdef ERROR_RESILIENCE + +uint8_t rvlc_scale_factor_data(ic_stream *ics, bitfile *ld) +{ + uint8_t bits = 9; + + ics->sf_concealment = faad_get1bit(ld + DEBUGVAR(1,149,"rvlc_scale_factor_data(): sf_concealment")); + ics->rev_global_gain = faad_getbits(ld, 8 + DEBUGVAR(1,150,"rvlc_scale_factor_data(): rev_global_gain")); + + if (ics->window_sequence == EIGHT_SHORT_SEQUENCE) + bits = 11; + + /* the number of bits used for the huffman codewords */ + ics->length_of_rvlc_sf = faad_getbits(ld, bits + DEBUGVAR(1,151,"rvlc_scale_factor_data(): length_of_rvlc_sf")); + + if (ics->noise_used) + { + ics->dpcm_noise_nrg = faad_getbits(ld, 9 + DEBUGVAR(1,152,"rvlc_scale_factor_data(): dpcm_noise_nrg")); + + ics->length_of_rvlc_sf -= 9; + } + + ics->sf_escapes_present = faad_get1bit(ld + DEBUGVAR(1,153,"rvlc_scale_factor_data(): sf_escapes_present")); + + if (ics->sf_escapes_present) + { + ics->length_of_rvlc_escapes = faad_getbits(ld, 8 + DEBUGVAR(1,154,"rvlc_scale_factor_data(): length_of_rvlc_escapes")); + } + + if (ics->noise_used) + { + ics->dpcm_noise_last_position = faad_getbits(ld, 9 + DEBUGVAR(1,155,"rvlc_scale_factor_data(): dpcm_noise_last_position")); + } + + return 0; +} + +uint8_t rvlc_decode_scale_factors(ic_stream *ics, bitfile *ld) +{ + uint8_t result; + uint8_t *rvlc_sf_buffer = NULL; + uint8_t *rvlc_esc_buffer = NULL; + bitfile ld_rvlc_sf; + bitfile ld_rvlc_esc; + + if (ics->length_of_rvlc_sf > 0) + { + /* We read length_of_rvlc_sf bits here to put it in a + seperate bitfile. + */ + rvlc_sf_buffer = faad_getbitbuffer(ld, ics->length_of_rvlc_sf + DEBUGVAR(1,156,"rvlc_decode_scale_factors(): bitbuffer: length_of_rvlc_sf")); + + faad_initbits(&ld_rvlc_sf, (void*)rvlc_sf_buffer); + } + + if (ics->sf_escapes_present) + { + /* We read length_of_rvlc_escapes bits here to put it in a + seperate bitfile. + */ + rvlc_esc_buffer = faad_getbitbuffer(ld, ics->length_of_rvlc_escapes + DEBUGVAR(1,157,"rvlc_decode_scale_factors(): bitbuffer: length_of_rvlc_escapes")); + + faad_initbits(&ld_rvlc_esc, (void*)rvlc_esc_buffer); + } + + /* decode the rvlc scale factors and escapes */ + result = rvlc_decode_sf_forward(ics, &ld_rvlc_sf, &ld_rvlc_esc); + + + if (rvlc_esc_buffer) free(rvlc_esc_buffer); + if (rvlc_sf_buffer) free(rvlc_sf_buffer); + + return result; +} + +static uint8_t rvlc_decode_sf_forward(ic_stream *ics, bitfile *ld_sf, bitfile *ld_esc) +{ + uint8_t g, sfb; + int8_t t = 0; + int8_t error = 0; + int8_t noise_pcm_flag = 1; + + int16_t scale_factor = ics->global_gain; + int16_t is_position = 0; + int16_t noise_energy = ics->global_gain - 90; + + for (g = 0; g < ics->num_window_groups; g++) + { + for (sfb = 0; sfb < ics->max_sfb; sfb++) + { + if (error) + { + ics->scale_factors[g][sfb] = 0; + } else { + switch (ics->sfb_cb[g][sfb]) + { + case ZERO_HCB: /* zero book */ + ics->scale_factors[g][sfb] = 0; + break; + case INTENSITY_HCB: /* intensity books */ + case INTENSITY_HCB2: + + /* decode intensity position */ + t = rvlc_huffman_sf(ld_sf, ld_esc); + + is_position += t; + ics->scale_factors[g][sfb] = is_position; + + break; + case NOISE_HCB: /* noise books */ + + /* decode noise energy */ + if (noise_pcm_flag) + { + int8_t n = ics->dpcm_noise_nrg; + noise_pcm_flag = 0; + noise_energy += n; + } else { + t = rvlc_huffman_sf(ld_sf, ld_esc); + noise_energy += t; + } + + ics->scale_factors[g][sfb] = noise_energy; + + break; + case BOOKSCL: /* invalid books */ + return 3; + default: /* spectral books */ + + /* decode scale factor */ + t = rvlc_huffman_sf(ld_sf, ld_esc); + + scale_factor += t; + if (scale_factor < 0) + return 4; + + ics->scale_factors[g][sfb] = scale_factor; + + break; + } + if (t == 99) + { + error = 1; + } + } + } + } + + return 0; +} + +/* index == 99 means not allowed codeword */ +static rvlc_huff_table book_rvlc[] = { + /*index length codeword */ + { 0, 1, 0 }, /* 0 */ + { -1, 3, 5 }, /* 101 */ + { 1, 3, 7 }, /* 111 */ + { -2, 4, 9 }, /* 1001 */ + { -3, 5, 17 }, /* 10001 */ + { 2, 5, 27 }, /* 11011 */ + { -4, 6, 33 }, /* 100001 */ + { 99, 6, 50 }, /* 110010 */ + { 3, 6, 51 }, /* 110011 */ + { 99, 6, 52 }, /* 110100 */ + { -7, 7, 65 }, /* 1000001 */ + { 99, 7, 96 }, /* 1100000 */ + { 99, 7, 98 }, /* 1100010 */ + { 7, 7, 99 }, /* 1100011 */ + { 4, 7, 107 }, /* 1101011 */ + { -5, 8, 129 }, /* 10000001 */ + { 99, 8, 194 }, /* 11000010 */ + { 5, 8, 195 }, /* 11000011 */ + { 99, 8, 212 }, /* 11010100 */ + { 99, 9, 256 }, /* 100000000 */ + { -6, 9, 257 }, /* 100000001 */ + { 99, 9, 426 }, /* 110101010 */ + { 6, 9, 427 }, /* 110101011 */ + { 99, 10, 0 } /* Shouldn't come this far */ +}; + +static rvlc_huff_table book_escape[] = { + /*index length codeword */ + { 1, 2, 0 }, + { 0, 2, 2 }, + { 3, 3, 2 }, + { 2, 3, 6 }, + { 4, 4, 14 }, + { 7, 5, 13 }, + { 6, 5, 15 }, + { 5, 5, 31 }, + { 11, 6, 24 }, + { 10, 6, 25 }, + { 9, 6, 29 }, + { 8, 6, 61 }, + { 13, 7, 56 }, + { 12, 7, 120 }, + { 15, 8, 114 }, + { 14, 8, 242 }, + { 17, 9, 230 }, + { 16, 9, 486 }, + { 19, 10, 463 }, + { 18, 10, 974 }, + { 22, 11, 925 }, + { 20, 11, 1950 }, + { 21, 11, 1951 }, + { 23, 12, 1848 }, + { 25, 13, 3698 }, + { 24, 14, 7399 }, + { 26, 15, 14797 }, + { 49, 19, 236736 }, + { 50, 19, 236737 }, + { 51, 19, 236738 }, + { 52, 19, 236739 }, + { 53, 19, 236740 }, + { 27, 20, 473482 }, + { 28, 20, 473483 }, + { 29, 20, 473484 }, + { 30, 20, 473485 }, + { 31, 20, 473486 }, + { 32, 20, 473487 }, + { 33, 20, 473488 }, + { 34, 20, 473489 }, + { 35, 20, 473490 }, + { 36, 20, 473491 }, + { 37, 20, 473492 }, + { 38, 20, 473493 }, + { 39, 20, 473494 }, + { 40, 20, 473495 }, + { 41, 20, 473496 }, + { 42, 20, 473497 }, + { 43, 20, 473498 }, + { 44, 20, 473499 }, + { 45, 20, 473500 }, + { 46, 20, 473501 }, + { 47, 20, 473502 }, + { 48, 20, 473503 }, + { 99, 21, 0 } /* Shouldn't come this far */ +}; + +static int8_t rvlc_huffman_sf(bitfile *ld_sf, bitfile *ld_esc) +{ + uint8_t i, j; + int8_t index; + uint32_t cw; + rvlc_huff_table *h = book_rvlc; + + i = h->len; + cw = faad_getbits(ld_sf, i); + + while ((cw != h->cw) + && (i < 10)) + { + h++; + j = h->len-i; + i += j; + cw <<= j; + cw |= faad_getbits(ld_sf, j); + } + + index = h->index; + + if (index == +ESC_VAL) + { + int8_t esc = rvlc_huffman_esc(ld_esc); + if (esc == 99) + return 99; + index += esc; + } + if (index == -ESC_VAL) + { + int8_t esc = rvlc_huffman_esc(ld_esc); + if (esc == 99) + return 99; + index -= esc; + } + + return index; +} + +static int8_t rvlc_huffman_esc(bitfile *ld) +{ + uint8_t i, j; + uint32_t cw; + rvlc_huff_table *h = book_escape; + + i = h->len; + cw = faad_getbits(ld, i); + + while ((cw != h->cw) + && (i < 21)) + { + h++; + j = h->len-i; + i += j; + cw <<= j; + cw |= faad_getbits(ld, j); + } + + return h->index; +} + +#endif
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