diff options
Diffstat (limited to 'libfaad2/bits.h')
| -rw-r--r-- | libfaad2/bits.h | 141 |
1 files changed, 120 insertions, 21 deletions
diff --git a/libfaad2/bits.h b/libfaad2/bits.h index 809084aa84..3d4bd811ea 100644 --- a/libfaad2/bits.h +++ b/libfaad2/bits.h @@ -79,6 +79,7 @@ void faad_initbits_rev(bitfile *ld, void *buffer, uint32_t bits_in_buffer); uint8_t faad_byte_align(bitfile *ld); uint32_t faad_get_processed_bits(bitfile *ld); +void faad_flushbits_ex(bitfile *ld, uint32_t bits); void faad_rewindbits(bitfile *ld); uint8_t *faad_getbitbuffer(bitfile *ld, uint32_t bits DEBUGDEC); @@ -104,10 +105,10 @@ static INLINE uint32_t faad_showbits(bitfile *ld, uint32_t bits) if (bits <= ld->bits_left) { return (ld->bufa >> (ld->bits_left - bits)) & bitmask[bits]; - } else { + } + bits -= ld->bits_left; return ((ld->bufa & bitmask[ld->bits_left]) << bits) | (ld->bufb >> (32 - bits)); - } } static INLINE void faad_flushbits(bitfile *ld, uint32_t bits) @@ -120,21 +121,7 @@ static INLINE void faad_flushbits(bitfile *ld, uint32_t bits) { ld->bits_left -= bits; } else { - uint32_t tmp; - - ld->bufa = ld->bufb; - tmp = getdword(ld->tail); - ld->tail++; -#ifndef ARCH_IS_BIG_ENDIAN - BSWAP(tmp); -#endif - ld->bufb = tmp; - ld->bits_left += (32 - bits); - ld->bytes_used += 4; - if (ld->bytes_used == ld->buffer_size) - ld->no_more_reading = 1; - if (ld->bytes_used > ld->buffer_size) - ld->error = 1; + faad_flushbits_ex(ld, bits); } } @@ -143,10 +130,7 @@ static INLINE uint32_t faad_getbits(bitfile *ld, uint32_t n DEBUGDEC) { uint32_t ret; - if (ld->no_more_reading) - return 0; - - if (n == 0) + if (ld->no_more_reading || n == 0) return 0; ret = faad_showbits(ld, n); @@ -253,6 +237,121 @@ static INLINE uint32_t faad_getbits_rev(bitfile *ld, uint32_t n return ret; } +#ifdef DRM +static uint8_t faad_check_CRC(bitfile *ld, uint16_t len) +{ + uint8_t CRC; + uint16_t r=255; /* Initialize to all ones */ + + /* CRC polynome used x^8 + x^4 + x^3 + x^2 +1 */ +#define GPOLY 0435 + + faad_rewindbits(ld); + + CRC = ~faad_getbits(ld, 8 + DEBUGVAR(1,999,"faad_check_CRC(): CRC")); /* CRC is stored inverted */ + + for (; len>0; len--) + { + r = ( (r << 1) ^ (( ( faad_get1bit(ld + DEBUGVAR(1,998,"")) & 1) ^ ((r >> 7) & 1)) * GPOLY )) & 0xFF; + } + + if (r != CRC) + { + return 8; + } else { + return 0; + } +} + +static uint8_t tabFlipbits[256] = { + 0,128,64,192,32,160,96,224,16,144,80,208,48,176,112,240, + 8,136,72,200,40,168,104,232,24,152,88,216,56,184,120,248, + 4,132,68,196,36,164,100,228,20,148,84,212,52,180,116,244, + 12,140,76,204,44,172,108,236,28,156,92,220,60,188,124,252, + 2,130,66,194,34,162,98,226,18,146,82,210,50,178,114,242, + 10,138,74,202,42,170,106,234,26,154,90,218,58,186,122,250, + 6,134,70,198,38,166,102,230,22,150,86,214,54,182,118,246, + 14,142,78,206,46,174,110,238,30,158,94,222,62,190,126,254, + 1,129,65,193,33,161,97,225,17,145,81,209,49,177,113,241, + 9,137,73,201,41,169,105,233,25,153,89,217,57,185,121,249, + 5,133,69,197,37,165,101,229,21,149,85,213,53,181,117,245, + 13,141,77,205,45,173,109,237,29,157,93,221,61,189,125,253, + 3,131,67,195,35,163,99,227,19,147,83,211,51,179,115,243, + 11,139,75,203,43,171,107,235,27,155,91,219,59,187,123,251, + 7,135,71,199,39,167,103,231,23,151,87,215,55,183,119,247, + 15,143,79,207,47,175,111,239,31,159,95,223,63,191,127,255 +}; +#endif + +#ifdef ERROR_RESILIENCE + +/* Modified bit reading functions for HCR */ + +typedef struct +{ + /* bit input */ + uint32_t bufa; + uint32_t bufb; + int8_t len; +} bits_t; + + +static INLINE uint32_t showbits_hcr(bits_t *ld, uint8_t bits) +{ + if (bits == 0) return 0; + if (ld->len <= 32) + { + /* huffman_spectral_data_2 needs to read more than may be available, bits maybe + > ld->len, deliver 0 than */ + if (ld->len >= bits) + return ((ld->bufa >> (ld->len - bits)) & (0xFFFFFFFF >> (32 - bits))); + else + return ((ld->bufa << (bits - ld->len)) & (0xFFFFFFFF >> (32 - bits))); + } else { + if ((ld->len - bits) < 32) + { + return ( (ld->bufb & (0xFFFFFFFF >> (64 - ld->len))) << (bits - ld->len + 32)) | + (ld->bufa >> (ld->len - bits)); + } else { + return ((ld->bufb >> (ld->len - bits - 32)) & (0xFFFFFFFF >> (32 - bits))); + } + } +} + +/* return 1 if position is outside of buffer, 0 otherwise */ +static INLINE int8_t flushbits_hcr( bits_t *ld, uint8_t bits) +{ + ld->len -= bits; + + if (ld->len <0) + { + ld->len = 0; + return 1; + } else { + return 0; + } +} + +static INLINE int8_t getbits_hcr(bits_t *ld, uint8_t n, uint32_t *result) +{ + *result = showbits_hcr(ld, n); + return flushbits_hcr(ld, n); +} + +static INLINE int8_t get1bit_hcr(bits_t *ld, uint8_t *result) +{ + uint32_t res; + int8_t ret; + + ret = getbits_hcr(ld, 1, &res); + *result = (int8_t)(res & 1); + return ret; +} + +#endif + #ifdef __cplusplus } |