diff options
Diffstat (limited to 'libfaad2/huffman.c')
| -rw-r--r-- | libfaad2/huffman.c | 57 |
1 files changed, 49 insertions, 8 deletions
diff --git a/libfaad2/huffman.c b/libfaad2/huffman.c index e3b238bcdb..af2b8caa90 100644 --- a/libfaad2/huffman.c +++ b/libfaad2/huffman.c @@ -22,7 +22,7 @@ ** Commercial non-GPL licensing of this software is possible. ** For more info contact Ahead Software through Mpeg4AAClicense@nero.com. ** -** $Id: huffman.c,v 1.20 2004/03/10 19:45:41 menno Exp $ +** $Id: huffman.c,v 1.22 2004/09/04 14:56:28 menno Exp $ **/ #include "common.h" @@ -50,6 +50,7 @@ static uint8_t huffman_binary_quad_sign(uint8_t cb, bitfile *ld, int16_t *sp); static uint8_t huffman_binary_pair(uint8_t cb, bitfile *ld, int16_t *sp); static uint8_t huffman_binary_pair_sign(uint8_t cb, bitfile *ld, int16_t *sp); static int16_t huffman_codebook(uint8_t i); +static void vcb11_check_LAV(uint8_t cb, int16_t *sp); int8_t huffman_scale_factor(bitfile *ld) { @@ -310,6 +311,26 @@ static int16_t huffman_codebook(uint8_t i) else return (int16_t)data & 0xFFFF; } +static void vcb11_check_LAV(uint8_t cb, int16_t *sp) +{ + static const uint16_t vcb11_LAV_tab[] = { + 16, 31, 47, 63, 95, 127, 159, 191, 223, + 255, 319, 383, 511, 767, 1023, 2047 + }; + uint16_t max = 0; + + if (cb < 16 || cb > 31) + return; + + max = vcb11_LAV_tab[cb - 16]; + + if ((abs(sp[0]) > max) || (abs(sp[1]) > max)) + { + sp[0] = 0; + sp[1] = 0; + } +} + uint8_t huffman_spectral_data(uint8_t cb, bitfile *ld, int16_t *sp) { switch (cb) @@ -336,18 +357,28 @@ uint8_t huffman_spectral_data(uint8_t cb, bitfile *ld, int16_t *sp) sp[0] = huffman_codebook(0); sp[1] = huffman_codebook(1); return err; } case 11: + { + uint8_t err = huffman_2step_pair_sign(11, ld, sp); + sp[0] = huffman_getescape(ld, sp[0]); + sp[1] = huffman_getescape(ld, sp[1]); + return err; + } #ifdef ERROR_RESILIENCE /* VCB11 uses codebook 11 */ case 16: case 17: case 18: case 19: case 20: case 21: case 22: case 23: case 24: case 25: case 26: case 27: case 28: case 29: case 30: case 31: - /* TODO: If ER is used, some extra error checking should be done */ -#endif { uint8_t err = huffman_2step_pair_sign(11, ld, sp); sp[0] = huffman_getescape(ld, sp[0]); sp[1] = huffman_getescape(ld, sp[1]); + + /* check LAV (Largest Absolute Value) */ + /* this finds errors in the ESCAPE signal */ + vcb11_check_LAV(cb, sp); + return err; } +#endif default: /* Non existent codebook number, something went wrong */ return 11; @@ -369,7 +400,7 @@ int8_t huffman_spectral_data_2(uint8_t cb, bits_t *ld, int16_t *sp) uint32_t cw; uint16_t offset = 0; uint8_t extra_bits; - uint8_t i; + uint8_t i, vcb11 = 0; switch (cb) @@ -406,9 +437,12 @@ int8_t huffman_spectral_data_2(uint8_t cb, bits_t *ld, int16_t *sp) case 16: case 17: case 18: case 19: case 20: case 21: case 22: case 23: case 24: case 25: case 26: case 27: case 28: case 29: case 30: case 31: - /* TODO: If ER is used, some extra error checking should be done */ if (cb >= 16) + { + /* store the virtual codebook */ + vcb11 = cb; cb = 11; + } cw = showbits_hcr(ld, hcbN[cb]); offset = hcb_table[cb][cw].offset; @@ -463,8 +497,8 @@ int8_t huffman_spectral_data_2(uint8_t cb, bits_t *ld, int16_t *sp) } /* decode sign bits */ - if (unsigned_cb[cb]) { - + if (unsigned_cb[cb]) + { for(i = 0; i < ((cb < FIRST_PAIR_HCB) ? QUAD_LEN : PAIR_LEN); i++) { if(sp[i]) @@ -500,13 +534,20 @@ int8_t huffman_spectral_data_2(uint8_t cb, bits_t *ld, int16_t *sp) if (b == 0) break; } -// TODO: here we would need to test "off" if VCB11 is used! + if (getbits_hcr(ld, i, &off)) return -1; j = off + (1<<i); sp[k] = (int16_t)((neg) ? -j : j); } } + + if (vcb11 != 0) + { + /* check LAV (Largest Absolute Value) */ + /* this finds errors in the ESCAPE signal */ + vcb11_check_LAV(vcb11, sp); + } } return ld->len; } |