diff --git a/libavcodec/cabac.c b/libavcodec/cabac.c index 9d56e23fc7..915c057114 100644 --- a/libavcodec/cabac.c +++ b/libavcodec/cabac.c @@ -69,6 +69,25 @@ const uint8_t ff_h264_lps_state[64]= { 36,36,37,37,37,38,38,63, }; +const uint8_t ff_h264_norm_shift[256]= { + 8,7,6,6,5,5,5,5,4,4,4,4,4,4,4,4, + 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, + 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, + 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, + 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, + 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, + 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, + 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, +}; + /** * * @param buf_size size of buf in bits @@ -95,10 +114,14 @@ void ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size){ c->bytestream= buf; c->bytestream_end= buf + buf_size; - c->low= *c->bytestream++; - c->low= (c->low<<9) + ((*c->bytestream++)<<1); - c->range= 0x1FE00; - c->bits_left= 7; +#if CABAC_BITS == 16 + c->low = (*c->bytestream++)<<18; + c->low+= (*c->bytestream++)<<10; +#else + c->low = (*c->bytestream++)<<10; +#endif + c->low+= ((*c->bytestream++)<<2) + 2; + c->range= 0x1FE<<(CABAC_BITS + 1); } void ff_init_cabac_states(CABACContext *c, uint8_t const (*lps_range)[4], @@ -107,8 +130,8 @@ void ff_init_cabac_states(CABACContext *c, uint8_t const (*lps_range)[4], for(i=0; ilps_range[2*i+0][j]= - c->lps_range[2*i+1][j]= lps_range[i][j]; + c->lps_range[2*i+0][j+4]= + c->lps_range[2*i+1][j+4]= lps_range[i][j]; } c->mps_state[2*i+0]= 2*mps_state[i]; diff --git a/libavcodec/cabac.h b/libavcodec/cabac.h index 21085b21e8..67fa3b988c 100644 --- a/libavcodec/cabac.h +++ b/libavcodec/cabac.h @@ -27,6 +27,9 @@ #undef NDEBUG #include +#define CABAC_BITS 8 +#define CABAC_MASK ((1<lps_range[*state][((c->range)>>6)&3]; + int RangeLPS= c->lps_range[*state][c->range>>6]; if(bit == ((*state)&1)){ c->range -= RangeLPS; @@ -249,63 +253,101 @@ static inline void put_cabac_ueg(CABACContext *c, uint8_t * state, int v, int ma } } +static void refill(CABACContext *c){ + if(c->bytestream < c->bytestream_end) +#if CABAC_BITS == 16 + c->low+= ((c->bytestream[0]<<9) + (c->bytestream[1])<<1); +#else + c->low+= c->bytestream[0]<<1; +#endif + c->low -= CABAC_MASK; + c->bytestream+= CABAC_BITS/8; +} + +static void refill2(CABACContext *c){ + int i, x; + + x= c->low ^ (c->low-1); + i= 8 - ff_h264_norm_shift[x>>(CABAC_BITS+1)]; + + x= -CABAC_MASK; + + if(c->bytestream < c->bytestream_end) +#if CABAC_BITS == 16 + x+= (c->bytestream[0]<<9) + (c->bytestream[1]<<1); +#else + x+= c->bytestream[0]<<1; +#endif + + c->low += x<bytestream+= CABAC_BITS/8; +} + + static inline void renorm_cabac_decoder(CABACContext *c){ - while(c->range < 0x10000){ + while(c->range < (0x200 << CABAC_BITS)){ c->range+= c->range; c->low+= c->low; - if(--c->bits_left == 0){ - if(c->bytestream < c->bytestream_end) - c->low+= *c->bytestream; - c->bytestream++; - c->bits_left= 8; - } + if(!(c->low & CABAC_MASK)) + refill(c); } } +static inline void renorm_cabac_decoder_once(CABACContext *c){ + int mask= (c->range - (0x200 << CABAC_BITS))>>31; + c->range+= c->range&mask; + c->low += c->low &mask; + if(!(c->low & CABAC_MASK)) + refill(c); +} + static inline int get_cabac(CABACContext *c, uint8_t * const state){ - int RangeLPS= c->lps_range[*state][((c->range)>>14)&3]<<8; - int bit; + int RangeLPS= c->lps_range[*state][c->range>>(CABAC_BITS+7)]<<(CABAC_BITS+1); + int bit, lps_mask; c->range -= RangeLPS; +#if 1 if(c->low < c->range){ bit= (*state)&1; *state= c->mps_state[*state]; + renorm_cabac_decoder_once(c); }else{ +// int shift= ff_h264_norm_shift[RangeLPS>>17]; bit= ((*state)&1)^1; c->low -= c->range; - c->range = RangeLPS; *state= c->lps_state[*state]; - } - renorm_cabac_decoder(c); - - return bit; -} - -static inline int get_cabac_static(CABACContext *c, int RangeLPS){ - int bit; - - c->range -= RangeLPS; - if(c->low < c->range){ - bit= 0; - }else{ - bit= 1; - c->low -= c->range; c->range = RangeLPS; + renorm_cabac_decoder(c); +/* c->range = RangeLPS<low <<= shift; + if(!(c->low & 0xFFFF)){ + refill2(c); + }*/ } - renorm_cabac_decoder(c); +#else + lps_mask= (c->range - c->low)>>31; + c->low -= c->range & lps_mask; + c->range += (RangeLPS - c->range) & lps_mask; + + bit= ((*state)^lps_mask)&1; + *state= c->mps_state[(*state) - (128&lps_mask)]; + + lps_mask= ff_h264_norm_shift[c->range>>(CABAC_BITS+2)]; + c->range<<= lps_mask; + c->low <<= lps_mask; + if(!(c->low & CABAC_MASK)) + refill2(c); +#endif + return bit; } static inline int get_cabac_bypass(CABACContext *c){ c->low += c->low; - if(--c->bits_left == 0){ - if(c->bytestream < c->bytestream_end) - c->low+= *c->bytestream; - c->bytestream++; - c->bits_left= 8; - } + if(!(c->low & CABAC_MASK)) + refill(c); if(c->low < c->range){ return 0; @@ -320,9 +362,9 @@ static inline int get_cabac_bypass(CABACContext *c){ * @return the number of bytes read or 0 if no end */ static inline int get_cabac_terminate(CABACContext *c){ - c->range -= 2<<8; + c->range -= 4<low < c->range){ - renorm_cabac_decoder(c); + renorm_cabac_decoder_once(c); return 0; }else{ return c->bytestream - c->bytestream_start;