diff --git a/libavcodec/rangecoder.c b/libavcodec/rangecoder.c index b0c9f21512..dd09e46f8b 100644 --- a/libavcodec/rangecoder.c +++ b/libavcodec/rangecoder.c @@ -37,73 +37,75 @@ #include "rangecoder.h" #include "bytestream.h" - -void ff_init_range_encoder(RangeCoder *c, uint8_t *buf, int buf_size){ - c->bytestream_start= - c->bytestream= buf; - c->bytestream_end= buf + buf_size; - - c->low= 0; - c->range= 0xFF00; - c->outstanding_count= 0; - c->outstanding_byte= -1; +void ff_init_range_encoder(RangeCoder *c, uint8_t *buf, int buf_size) +{ + c->bytestream_start = + c->bytestream = buf; + c->bytestream_end = buf + buf_size; + c->low = 0; + c->range = 0xFF00; + c->outstanding_count = 0; + c->outstanding_byte = -1; } -void ff_init_range_decoder(RangeCoder *c, const uint8_t *buf, int buf_size){ +void ff_init_range_decoder(RangeCoder *c, const uint8_t *buf, int buf_size) +{ /* cast to avoid compiler warning */ - ff_init_range_encoder(c, (uint8_t *) buf, buf_size); + ff_init_range_encoder(c, (uint8_t *)buf, buf_size); c->low = bytestream_get_be16(&c->bytestream); } -void ff_build_rac_states(RangeCoder *c, int factor, int max_p){ - const int64_t one= 1LL<<32; +void ff_build_rac_states(RangeCoder *c, int factor, int max_p) +{ + const int64_t one = 1LL << 32; int64_t p; int last_p8, p8, i; memset(c->zero_state, 0, sizeof(c->zero_state)); - memset(c-> one_state, 0, sizeof(c-> one_state)); - - last_p8= 0; - p= one/2; - for(i=0; i<128; i++){ - p8= (256*p + one/2) >> 32; //FIXME try without the one - if(p8 <= last_p8) p8= last_p8+1; - if(last_p8 && last_p8<256 && p8<=max_p) - c->one_state[last_p8]= p8; - - p+= ((one-p)*factor + one/2) >> 32; - last_p8= p8; + memset(c->one_state, 0, sizeof(c->one_state)); + + last_p8 = 0; + p = one / 2; + for (i = 0; i < 128; i++) { + p8 = (256 * p + one / 2) >> 32; // FIXME: try without the one + if (p8 <= last_p8) + p8 = last_p8 + 1; + if (last_p8 && last_p8 < 256 && p8 <= max_p) + c->one_state[last_p8] = p8; + + p += ((one - p) * factor + one / 2) >> 32; + last_p8 = p8; } - for(i=256-max_p; i<=max_p; i++){ - if(c->one_state[i]) + for (i = 256 - max_p; i <= max_p; i++) { + if (c->one_state[i]) continue; - p= (i*one + 128) >> 8; - p+= ((one-p)*factor + one/2) >> 32; - p8= (256*p + one/2) >> 32; //FIXME try without the one - if(p8 <= i) p8= i+1; - if(p8 > max_p) p8= max_p; - c->one_state[ i]= p8; + p = (i * one + 128) >> 8; + p += ((one - p) * factor + one / 2) >> 32; + p8 = (256 * p + one / 2) >> 32; // FIXME: try without the one + if (p8 <= i) + p8 = i + 1; + if (p8 > max_p) + p8 = max_p; + c->one_state[i] = p8; } - for(i=1; i<255; i++) - c->zero_state[i]= 256-c->one_state[256-i]; + for (i = 1; i < 255; i++) + c->zero_state[i] = 256 - c->one_state[256 - i]; } -/** - * - * @return the number of bytes written - */ -int ff_rac_terminate(RangeCoder *c){ - c->range=0xFF; - c->low +=0xFF; +/* Return the number of bytes written. */ +int ff_rac_terminate(RangeCoder *c) +{ + c->range = 0xFF; + c->low += 0xFF; renorm_encoder(c); - c->range=0xFF; + c->range = 0xFF; renorm_encoder(c); - assert(c->low == 0); + assert(c->low == 0); assert(c->range >= 0x100); return c->bytestream - c->bytestream_start; @@ -114,10 +116,11 @@ int ff_rac_terminate(RangeCoder *c){ #include "libavutil/lfg.h" -int main(void){ +int main(void) +{ RangeCoder c; - uint8_t b[9*SIZE]; - uint8_t r[9*SIZE]; + uint8_t b[9 * SIZE]; + uint8_t r[9 * SIZE]; int i; uint8_t state[10]; AVLFG prng; @@ -125,17 +128,16 @@ int main(void){ av_lfg_init(&prng, 1); ff_init_range_encoder(&c, b, SIZE); - ff_build_rac_states(&c, 0.05*(1LL<<32), 128+64+32+16); + ff_build_rac_states(&c, 0.05 * (1LL << 32), 128 + 64 + 32 + 16); memset(state, 128, sizeof(state)); - for(i=0; i #include + #include "libavutil/common.h" -typedef struct RangeCoder{ +typedef struct RangeCoder { int low; int range; int outstanding_count; int outstanding_byte; uint8_t zero_state[256]; - uint8_t one_state[256]; + uint8_t one_state[256]; uint8_t *bytestream_start; uint8_t *bytestream; uint8_t *bytestream_end; -}RangeCoder; +} RangeCoder; void ff_init_range_encoder(RangeCoder *c, uint8_t *buf, int buf_size); void ff_init_range_decoder(RangeCoder *c, const uint8_t *buf, int buf_size); int ff_rac_terminate(RangeCoder *c); void ff_build_rac_states(RangeCoder *c, int factor, int max_p); -static inline void renorm_encoder(RangeCoder *c){ - //FIXME optimize - while(c->range < 0x100){ - if(c->outstanding_byte < 0){ - c->outstanding_byte= c->low>>8; - }else if(c->low <= 0xFF00){ +static inline void renorm_encoder(RangeCoder *c) +{ + // FIXME: optimize + while (c->range < 0x100) { + if (c->outstanding_byte < 0) { + c->outstanding_byte = c->low >> 8; + } else if (c->low <= 0xFF00) { *c->bytestream++ = c->outstanding_byte; - for(;c->outstanding_count; c->outstanding_count--) + for (; c->outstanding_count; c->outstanding_count--) *c->bytestream++ = 0xFF; - c->outstanding_byte= c->low>>8; - }else if(c->low >= 0x10000){ + c->outstanding_byte = c->low >> 8; + } else if (c->low >= 0x10000) { *c->bytestream++ = c->outstanding_byte + 1; - for(;c->outstanding_count; c->outstanding_count--) + for (; c->outstanding_count; c->outstanding_count--) *c->bytestream++ = 0x00; - c->outstanding_byte= (c->low>>8) & 0xFF; - }else{ + c->outstanding_byte = (c->low >> 8) & 0xFF; + } else { c->outstanding_count++; } - c->low = (c->low & 0xFF)<<8; + c->low = (c->low & 0xFF) << 8; c->range <<= 8; } } -static inline int get_rac_count(RangeCoder *c){ - int x= c->bytestream - c->bytestream_start + c->outstanding_count; - if(c->outstanding_byte >= 0) +static inline int get_rac_count(RangeCoder *c) +{ + int x = c->bytestream - c->bytestream_start + c->outstanding_count; + if (c->outstanding_byte >= 0) x++; - return 8*x - av_log2(c->range); + return 8 * x - av_log2(c->range); } -static inline void put_rac(RangeCoder *c, uint8_t * const state, int bit){ - int range1= (c->range * (*state)) >> 8; +static inline void put_rac(RangeCoder *c, uint8_t *const state, int bit) +{ + int range1 = (c->range * (*state)) >> 8; assert(*state); assert(range1 < c->range); assert(range1 > 0); - if(!bit){ + if (!bit) { c->range -= range1; - *state= c->zero_state[*state]; - }else{ - c->low += c->range - range1; + *state = c->zero_state[*state]; + } else { + c->low += c->range - range1; c->range = range1; - *state= c->one_state[*state]; + *state = c->one_state[*state]; } renorm_encoder(c); } -static inline void refill(RangeCoder *c){ - if(c->range < 0x100){ +static inline void refill(RangeCoder *c) +{ + if (c->range < 0x100) { c->range <<= 8; - c->low <<= 8; - if(c->bytestream < c->bytestream_end) - c->low+= c->bytestream[0]; + c->low <<= 8; + if (c->bytestream < c->bytestream_end) + c->low += c->bytestream[0]; c->bytestream++; } } -static inline int get_rac(RangeCoder *c, uint8_t * const state){ - int range1= (c->range * (*state)) >> 8; +static inline int get_rac(RangeCoder *c, uint8_t *const state) +{ + int range1 = (c->range * (*state)) >> 8; int av_unused one_mask; c->range -= range1; #if 1 - if(c->low < c->range){ - *state= c->zero_state[*state]; + if (c->low < c->range) { + *state = c->zero_state[*state]; refill(c); return 0; - }else{ - c->low -= c->range; - *state= c->one_state[*state]; + } else { + c->low -= c->range; + *state = c->one_state[*state]; c->range = range1; refill(c); return 1; } #else - one_mask= (c->range - c->low-1)>>31; + one_mask = (c->range - c->low - 1) >> 31; - c->low -= c->range & one_mask; + c->low -= c->range & one_mask; c->range += (range1 - c->range) & one_mask; - *state= c->zero_state[(*state) + (256&one_mask)]; + *state = c->zero_state[(*state) + (256 & one_mask)]; refill(c); - return one_mask&1; + return one_mask & 1; #endif }