innoHeim/Rsupport Screen Capture Codec decoder
[ffmpeg.git] / libavcodec / cabac.h
index 0993eb8..40eefed 100644 (file)
 #ifndef AVCODEC_CABAC_H
 #define AVCODEC_CABAC_H
 
+#include <stdint.h>
+
 #include "put_bits.h"
 
-//#undef NDEBUG
-#include <assert.h>
-#include "libavutil/x86_cpu.h"
+extern const uint8_t ff_h264_cabac_tables[512 + 4*2*64 + 4*64 + 63];
+#define H264_NORM_SHIFT_OFFSET 0
+#define H264_LPS_RANGE_OFFSET 512
+#define H264_MLPS_STATE_OFFSET 1024
+#define H264_LAST_COEFF_FLAG_OFFSET_8x8_OFFSET 1280
 
 #define CABAC_BITS 16
 #define CABAC_MASK ((1<<CABAC_BITS)-1)
 typedef struct CABACContext{
     int low;
     int range;
-    int outstanding_count;
-#ifdef STRICT_LIMITS
-    int symCount;
-#endif
     const uint8_t *bytestream_start;
     const uint8_t *bytestream;
     const uint8_t *bytestream_end;
-    PutBitContext pb;
 }CABACContext;
 
-extern uint8_t ff_h264_mlps_state[4*64];
-extern uint8_t ff_h264_lps_range[4*2*64];  ///< rangeTabLPS
-extern uint8_t ff_h264_mps_state[2*64];     ///< transIdxMPS
-extern uint8_t ff_h264_lps_state[2*64];     ///< transIdxLPS
-extern const uint8_t ff_h264_norm_shift[512];
-
-
-void ff_init_cabac_encoder(CABACContext *c, uint8_t *buf, int buf_size);
 void ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size);
-void ff_init_cabac_states(CABACContext *c);
-
-
-static inline void put_cabac_bit(CABACContext *c, int b){
-    put_bits(&c->pb, 1, b);
-    for(;c->outstanding_count; c->outstanding_count--){
-        put_bits(&c->pb, 1, 1-b);
-    }
-}
-
-static inline void renorm_cabac_encoder(CABACContext *c){
-    while(c->range < 0x100){
-        //FIXME optimize
-        if(c->low<0x100){
-            put_cabac_bit(c, 0);
-        }else if(c->low<0x200){
-            c->outstanding_count++;
-            c->low -= 0x100;
-        }else{
-            put_cabac_bit(c, 1);
-            c->low -= 0x200;
-        }
-
-        c->range+= c->range;
-        c->low += c->low;
-    }
-}
-
-#ifdef TEST
-static void put_cabac(CABACContext *c, uint8_t * const state, int bit){
-    int RangeLPS= ff_h264_lps_range[2*(c->range&0xC0) + *state];
-
-    if(bit == ((*state)&1)){
-        c->range -= RangeLPS;
-        *state= ff_h264_mps_state[*state];
-    }else{
-        c->low += c->range - RangeLPS;
-        c->range = RangeLPS;
-        *state= ff_h264_lps_state[*state];
-    }
-
-    renorm_cabac_encoder(c);
-
-#ifdef STRICT_LIMITS
-    c->symCount++;
-#endif
-}
-
-static void put_cabac_static(CABACContext *c, int RangeLPS, int bit){
-    assert(c->range > RangeLPS);
-
-    if(!bit){
-        c->range -= RangeLPS;
-    }else{
-        c->low += c->range - RangeLPS;
-        c->range = RangeLPS;
-    }
-
-    renorm_cabac_encoder(c);
-
-#ifdef STRICT_LIMITS
-    c->symCount++;
-#endif
-}
-
-/**
- * @param bit 0 -> write zero bit, !=0 write one bit
- */
-static void put_cabac_bypass(CABACContext *c, int bit){
-    c->low += c->low;
-
-    if(bit){
-        c->low += c->range;
-    }
-//FIXME optimize
-    if(c->low<0x200){
-        put_cabac_bit(c, 0);
-    }else if(c->low<0x400){
-        c->outstanding_count++;
-        c->low -= 0x200;
-    }else{
-        put_cabac_bit(c, 1);
-        c->low -= 0x400;
-    }
-
-#ifdef STRICT_LIMITS
-    c->symCount++;
-#endif
-}
-
-/**
- *
- * @return the number of bytes written
- */
-static int put_cabac_terminate(CABACContext *c, int bit){
-    c->range -= 2;
-
-    if(!bit){
-        renorm_cabac_encoder(c);
-    }else{
-        c->low += c->range;
-        c->range= 2;
-
-        renorm_cabac_encoder(c);
-
-        assert(c->low <= 0x1FF);
-        put_cabac_bit(c, c->low>>9);
-        put_bits(&c->pb, 2, ((c->low>>7)&3)|1);
-
-        flush_put_bits(&c->pb); //FIXME FIXME FIXME XXX wrong
-    }
-
-#ifdef STRICT_LIMITS
-    c->symCount++;
-#endif
-
-    return (put_bits_count(&c->pb)+7)>>3;
-}
-
-/**
- * put (truncated) unary binarization.
- */
-static void put_cabac_u(CABACContext *c, uint8_t * state, int v, int max, int max_index, int truncated){
-    int i;
-
-    assert(v <= max);
-
-#if 1
-    for(i=0; i<v; i++){
-        put_cabac(c, state, 1);
-        if(i < max_index) state++;
-    }
-    if(truncated==0 || v<max)
-        put_cabac(c, state, 0);
-#else
-    if(v <= max_index){
-        for(i=0; i<v; i++){
-            put_cabac(c, state+i, 1);
-        }
-        if(truncated==0 || v<max)
-            put_cabac(c, state+i, 0);
-    }else{
-        for(i=0; i<=max_index; i++){
-            put_cabac(c, state+i, 1);
-        }
-        for(; i<v; i++){
-            put_cabac(c, state+max_index, 1);
-        }
-        if(truncated==0 || v<max)
-            put_cabac(c, state+max_index, 0);
-    }
-#endif
-}
-
-/**
- * put unary exp golomb k-th order binarization.
- */
-static void put_cabac_ueg(CABACContext *c, uint8_t * state, int v, int max, int is_signed, int k, int max_index){
-    int i;
-
-    if(v==0)
-        put_cabac(c, state, 0);
-    else{
-        const int sign= v < 0;
-
-        if(is_signed) v= FFABS(v);
-
-        if(v<max){
-            for(i=0; i<v; i++){
-                put_cabac(c, state, 1);
-                if(i < max_index) state++;
-            }
-
-            put_cabac(c, state, 0);
-        }else{
-            int m= 1<<k;
-
-            for(i=0; i<max; i++){
-                put_cabac(c, state, 1);
-                if(i < max_index) state++;
-            }
-
-            v -= max;
-            while(v >= m){ //FIXME optimize
-                put_cabac_bypass(c, 1);
-                v-= m;
-                m+= m;
-            }
-            put_cabac_bypass(c, 0);
-            while(m>>=1){
-                put_cabac_bypass(c, v&m);
-            }
-        }
-
-        if(is_signed)
-            put_cabac_bypass(c, sign);
-    }
-}
-#endif /* TEST */
-
-static void refill(CABACContext *c){
-#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;
-}
-
-#if ! ( ARCH_X86 && HAVE_7REGS && HAVE_EBX_AVAILABLE && !defined(BROKEN_RELOCATIONS) )
-static void refill2(CABACContext *c){
-    int i, x;
-
-    x= c->low ^ (c->low-1);
-    i= 7 - ff_h264_norm_shift[x>>(CABAC_BITS-1)];
-
-    x= -CABAC_MASK;
-
-#if CABAC_BITS == 16
-        x+= (c->bytestream[0]<<9) + (c->bytestream[1]<<1);
-#else
-        x+= c->bytestream[0]<<1;
-#endif
-
-    c->low += x<<i;
-    c->bytestream+= CABAC_BITS/8;
-}
-#endif
-
-static inline void renorm_cabac_decoder(CABACContext *c){
-    while(c->range < 0x100){
-        c->range+= c->range;
-        c->low+= c->low;
-        if(!(c->low & CABAC_MASK))
-            refill(c);
-    }
-}
-
-static inline void renorm_cabac_decoder_once(CABACContext *c){
-    int shift= (uint32_t)(c->range - 0x100)>>31;
-    c->range<<= shift;
-    c->low  <<= shift;
-    if(!(c->low & CABAC_MASK))
-        refill(c);
-}
-
-static av_always_inline int get_cabac_inline(CABACContext *c, uint8_t * const state){
-    //FIXME gcc generates duplicate load/stores for c->low and c->range
-#define LOW          "0"
-#define RANGE        "4"
-#if ARCH_X86_64
-#define BYTESTART   "16"
-#define BYTE        "24"
-#define BYTEEND     "32"
-#else
-#define BYTESTART   "12"
-#define BYTE        "16"
-#define BYTEEND     "20"
-#endif
-#if ARCH_X86 && HAVE_7REGS && HAVE_EBX_AVAILABLE && !defined(BROKEN_RELOCATIONS)
-    int bit;
-
-#if HAVE_FAST_CMOV
-#define BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
-        "mov    "tmp"       , %%ecx                                     \n\t"\
-        "shl    $17         , "tmp"                                     \n\t"\
-        "cmp    "low"       , "tmp"                                     \n\t"\
-        "cmova  %%ecx       , "range"                                   \n\t"\
-        "sbb    %%ecx       , %%ecx                                     \n\t"\
-        "and    %%ecx       , "tmp"                                     \n\t"\
-        "sub    "tmp"       , "low"                                     \n\t"\
-        "xor    %%ecx       , "ret"                                     \n\t"
-#else /* HAVE_FAST_CMOV */
-#define BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
-        "mov    "tmp"       , %%ecx                                     \n\t"\
-        "shl    $17         , "tmp"                                     \n\t"\
-        "sub    "low"       , "tmp"                                     \n\t"\
-        "sar    $31         , "tmp"                                     \n\t" /*lps_mask*/\
-        "sub    %%ecx       , "range"                                   \n\t" /*RangeLPS - range*/\
-        "and    "tmp"       , "range"                                   \n\t" /*(RangeLPS - range)&lps_mask*/\
-        "add    %%ecx       , "range"                                   \n\t" /*new range*/\
-        "shl    $17         , %%ecx                                     \n\t"\
-        "and    "tmp"       , %%ecx                                     \n\t"\
-        "sub    %%ecx       , "low"                                     \n\t"\
-        "xor    "tmp"       , "ret"                                     \n\t"
-#endif /* HAVE_FAST_CMOV */
-
-
-#define BRANCHLESS_GET_CABAC(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
-        "movzbl "statep"    , "ret"                                     \n\t"\
-        "mov    "range"     , "tmp"                                     \n\t"\
-        "and    $0xC0       , "range"                                   \n\t"\
-        "movzbl "MANGLE(ff_h264_lps_range)"("ret", "range", 2), "range" \n\t"\
-        "sub    "range"     , "tmp"                                     \n\t"\
-        BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
-        "movzbl " MANGLE(ff_h264_norm_shift) "("range"), %%ecx          \n\t"\
-        "shl    %%cl        , "range"                                   \n\t"\
-        "movzbl "MANGLE(ff_h264_mlps_state)"+128("ret"), "tmp"          \n\t"\
-        "mov    "tmpbyte"   , "statep"                                  \n\t"\
-        "shl    %%cl        , "low"                                     \n\t"\
-        "test   "lowword"   , "lowword"                                 \n\t"\
-        " jnz   1f                                                      \n\t"\
-        "mov "BYTE"("cabac"), %%"REG_c"                                 \n\t"\
-        "movzwl (%%"REG_c")     , "tmp"                                 \n\t"\
-        "bswap  "tmp"                                                   \n\t"\
-        "shr    $15         , "tmp"                                     \n\t"\
-        "sub    $0xFFFF     , "tmp"                                     \n\t"\
-        "add    $2          , %%"REG_c"                                 \n\t"\
-        "mov    %%"REG_c"   , "BYTE    "("cabac")                       \n\t"\
-        "lea    -1("low")   , %%ecx                                     \n\t"\
-        "xor    "low"       , %%ecx                                     \n\t"\
-        "shr    $15         , %%ecx                                     \n\t"\
-        "movzbl " MANGLE(ff_h264_norm_shift) "(%%ecx), %%ecx            \n\t"\
-        "neg    %%ecx                                                   \n\t"\
-        "add    $7          , %%ecx                                     \n\t"\
-        "shl    %%cl        , "tmp"                                     \n\t"\
-        "add    "tmp"       , "low"                                     \n\t"\
-        "1:                                                             \n\t"
-
-    __asm__ volatile(
-        "movl "RANGE    "(%2), %%esi            \n\t"
-        "movl "LOW      "(%2), %%ebx            \n\t"
-        BRANCHLESS_GET_CABAC("%0", "%2", "(%1)", "%%ebx", "%%bx", "%%esi", "%%edx", "%%dl")
-        "movl %%esi, "RANGE    "(%2)            \n\t"
-        "movl %%ebx, "LOW      "(%2)            \n\t"
-
-        :"=&a"(bit)
-        :"r"(state), "r"(c)
-        : "%"REG_c, "%ebx", "%edx", "%esi", "memory"
-    );
-    bit&=1;
-#else /* ARCH_X86 && HAVE_7REGS && HAVE_EBX_AVAILABLE && !defined(BROKEN_RELOCATIONS) */
-    int s = *state;
-    int RangeLPS= ff_h264_lps_range[2*(c->range&0xC0) + s];
-    int bit, lps_mask;
-
-    c->range -= RangeLPS;
-    lps_mask= ((c->range<<(CABAC_BITS+1)) - c->low)>>31;
-
-    c->low -= (c->range<<(CABAC_BITS+1)) & lps_mask;
-    c->range += (RangeLPS - c->range) & lps_mask;
-
-    s^=lps_mask;
-    *state= (ff_h264_mlps_state+128)[s];
-    bit= s&1;
-
-    lps_mask= ff_h264_norm_shift[c->range];
-    c->range<<= lps_mask;
-    c->low  <<= lps_mask;
-    if(!(c->low & CABAC_MASK))
-        refill2(c);
-#endif /* ARCH_X86 && HAVE_7REGS && HAVE_EBX_AVAILABLE && !defined(BROKEN_RELOCATIONS) */
-    return bit;
-}
-
-static int av_noinline av_unused get_cabac_noinline(CABACContext *c, uint8_t * const state){
-    return get_cabac_inline(c,state);
-}
-
-static int av_unused get_cabac(CABACContext *c, uint8_t * const state){
-    return get_cabac_inline(c,state);
-}
-
-static int av_unused get_cabac_bypass(CABACContext *c){
-    int range;
-    c->low += c->low;
-
-    if(!(c->low & CABAC_MASK))
-        refill(c);
-
-    range= c->range<<(CABAC_BITS+1);
-    if(c->low < range){
-        return 0;
-    }else{
-        c->low -= range;
-        return 1;
-    }
-}
-
-
-static av_always_inline int get_cabac_bypass_sign(CABACContext *c, int val){
-#if ARCH_X86 && HAVE_EBX_AVAILABLE
-    __asm__ volatile(
-        "movl "RANGE    "(%1), %%ebx            \n\t"
-        "movl "LOW      "(%1), %%eax            \n\t"
-        "shl $17, %%ebx                         \n\t"
-        "add %%eax, %%eax                       \n\t"
-        "sub %%ebx, %%eax                       \n\t"
-        "cltd                                   \n\t"
-        "and %%edx, %%ebx                       \n\t"
-        "add %%ebx, %%eax                       \n\t"
-        "xor %%edx, %%ecx                       \n\t"
-        "sub %%edx, %%ecx                       \n\t"
-        "test %%ax, %%ax                        \n\t"
-        " jnz 1f                                \n\t"
-        "mov  "BYTE     "(%1), %%"REG_b"        \n\t"
-        "subl $0xFFFF, %%eax                    \n\t"
-        "movzwl (%%"REG_b"), %%edx              \n\t"
-        "bswap %%edx                            \n\t"
-        "shrl $15, %%edx                        \n\t"
-        "add  $2, %%"REG_b"                     \n\t"
-        "addl %%edx, %%eax                      \n\t"
-        "mov  %%"REG_b", "BYTE     "(%1)        \n\t"
-        "1:                                     \n\t"
-        "movl %%eax, "LOW      "(%1)            \n\t"
-
-        :"+c"(val)
-        :"r"(c)
-        : "%eax", "%"REG_b, "%edx", "memory"
-    );
-    return val;
-#else
-    int range, mask;
-    c->low += c->low;
-
-    if(!(c->low & CABAC_MASK))
-        refill(c);
-
-    range= c->range<<(CABAC_BITS+1);
-    c->low -= range;
-    mask= c->low >> 31;
-    range &= mask;
-    c->low += range;
-    return (val^mask)-mask;
-#endif
-}
-
-/**
- *
- * @return the number of bytes read or 0 if no end
- */
-static int av_unused get_cabac_terminate(CABACContext *c){
-    c->range -= 2;
-    if(c->low < c->range<<(CABAC_BITS+1)){
-        renorm_cabac_decoder_once(c);
-        return 0;
-    }else{
-        return c->bytestream - c->bytestream_start;
-    }
-}
-
-#if 0
-/**
- * Get (truncated) unary binarization.
- */
-static int get_cabac_u(CABACContext *c, uint8_t * state, int max, int max_index, int truncated){
-    int i;
-
-    for(i=0; i<max; i++){
-        if(get_cabac(c, state)==0)
-            return i;
-
-        if(i< max_index) state++;
-    }
-
-    return truncated ? max : -1;
-}
-
-/**
- * get unary exp golomb k-th order binarization.
- */
-static int get_cabac_ueg(CABACContext *c, uint8_t * state, int max, int is_signed, int k, int max_index){
-    int i, v;
-    int m= 1<<k;
-
-    if(get_cabac(c, state)==0)
-        return 0;
-
-    if(0 < max_index) state++;
-
-    for(i=1; i<max; i++){
-        if(get_cabac(c, state)==0){
-            if(is_signed && get_cabac_bypass(c)){
-                return -i;
-            }else
-                return i;
-        }
-
-        if(i < max_index) state++;
-    }
-
-    while(get_cabac_bypass(c)){
-        i+= m;
-        m+= m;
-    }
-
-    v=0;
-    while(m>>=1){
-        v+= v + get_cabac_bypass(c);
-    }
-    i += v;
-
-    if(is_signed && get_cabac_bypass(c)){
-        return -i;
-    }else
-        return i;
-}
-#endif /* 0 */
 
 #endif /* AVCODEC_CABAC_H */