* using const buffers for reading

[ffmpeg] / libavcodec / common.c

diff --git a/libavcodec/common.c b/libavcodec/common.c
index abfa19072f213022d3e3f2fe09127b390cc179f5..58d79a9a0a5e40e7305cb463f1ce47d52dd854ee 100644 (file)
--- a/libavcodec/common.c
+++ b/libavcodec/common.c
@@ -20,10 +20,28 @@
  */
 #include "avcodec.h"
 
+const uint8_t ff_sqrt_tab[128]={
+        0, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5,
+        5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+        8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+        9, 9, 9, 9,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,11,11,11,11,11,11,11
+};
+
+const uint8_t ff_log2_tab[256]={
+        0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
+        5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
+        6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
+        6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
+        7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+        7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+        7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+        7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
+};
+
 void init_put_bits(PutBitContext *s, 
-                   UINT8 *buffer, int buffer_size,
+                   uint8_t *buffer, int buffer_size,
                    void *opaque,
-                   void (*write_data)(void *, UINT8 *, int))
+                   void (*write_data)(void *, uint8_t *, int))
 {
     s->buf = buffer;
     s->buf_end = s->buf + buffer_size;
@@ -44,12 +62,12 @@ void init_put_bits(PutBitContext *s,
 }
 
 /* return the number of bits output */
-INT64 get_bit_count(PutBitContext *s)
+int64_t get_bit_count(PutBitContext *s)
 {
 #ifdef ALT_BITSTREAM_WRITER
     return s->data_out_size * 8 + s->index;
 #else
-    return (s->buf_ptr - s->buf + s->data_out_size) * 8 + 32 - (INT64)s->bit_left;
+    return (s->buf_ptr - s->buf + s->data_out_size) * 8 + 32 - (int64_t)s->bit_left;
 #endif
 }
 
@@ -80,33 +98,6 @@ void flush_put_bits(PutBitContext *s)
 #endif
 }
 
-/* pad the end of the output stream with zeros */
-#ifndef ALT_BITSTREAM_WRITER
-void jflush_put_bits(PutBitContext *s)
-{
-    unsigned int b;
-    s->bit_buf<<= s->bit_left;
-    s->bit_buf |= ~1U >> (32 - s->bit_left); /* set all the unused bits to one */
-
-    while (s->bit_left < 32) {
-        b = s->bit_buf >> 24;
-        *s->buf_ptr++ = b;
-        if (b == 0xff)
-            *s->buf_ptr++ = 0;
-        s->bit_buf<<=8;
-        s->bit_left+=8;
-    }
-    s->bit_left=32;
-    s->bit_buf=0;
-}
-#else
-void jflush_put_bits(PutBitContext *s)
-{
-    int num= (  - s->index) & 7;
-    jput_bits(s, num,0xFF>>(8-num));
-}
-#endif
-
 void put_string(PutBitContext * pbc, char *s)
 {
     while(*s){
@@ -119,10 +110,12 @@ void put_string(PutBitContext * pbc, char *s)
 /* bit input functions */
 
 void init_get_bits(GetBitContext *s,
-                   UINT8 *buffer, int buffer_size)
+                   const uint8_t *buffer, int bit_size)
 {
+    const int buffer_size= (bit_size+7)>>3;
+
     s->buffer= buffer;
-    s->size= buffer_size;
+    s->size_in_bits= bit_size;
     s->buffer_end= buffer + buffer_size;
 #ifdef ALT_BITSTREAM_READER
     s->index=0;
@@ -153,7 +146,7 @@ void align_get_bits(GetBitContext *s)
     if(n) skip_bits(s, n);
 }
 
-int check_marker(GetBitContext *s, char *msg)
+int check_marker(GetBitContext *s, const char *msg)
 {
     int bit= get_bits1(s);
     if(!bit) printf("Marker bit missing %s\n", msg);
@@ -167,16 +160,16 @@ int check_marker(GetBitContext *s, char *msg)
 
 #define GET_DATA(v, table, i, wrap, size) \
 {\
-    UINT8 *ptr = (UINT8 *)table + i * wrap;\
+    const uint8_t *ptr = (const uint8_t *)table + i * wrap;\
     switch(size) {\
     case 1:\
-        v = *(UINT8 *)ptr;\
+        v = *(const uint8_t *)ptr;\
         break;\
     case 2:\
-        v = *(UINT16 *)ptr;\
+        v = *(const uint16_t *)ptr;\
         break;\
     default:\
-        v = *(UINT32 *)ptr;\
+        v = *(const uint32_t *)ptr;\
         break;\
     }\
 }
@@ -189,8 +182,8 @@ static int alloc_table(VLC *vlc, int size)
     vlc->table_size += size;
     if (vlc->table_size > vlc->table_allocated) {
         vlc->table_allocated += (1 << vlc->bits);
-        vlc->table = realloc(vlc->table,
-                             sizeof(VLC_TYPE) * 2 * vlc->table_allocated);
+        vlc->table = av_realloc(vlc->table,
+                                sizeof(VLC_TYPE) * 2 * vlc->table_allocated);
         if (!vlc->table)
             return -1;
     }
@@ -201,10 +194,10 @@ static int build_table(VLC *vlc, int table_nb_bits,
                        int nb_codes,
                        const void *bits, int bits_wrap, int bits_size,
                        const void *codes, int codes_wrap, int codes_size,
-                       UINT32 code_prefix, int n_prefix)
+                       uint32_t code_prefix, int n_prefix)
 {
     int i, j, k, n, table_size, table_index, nb, n1, index;
-    UINT32 code;
+    uint32_t code;
     VLC_TYPE (*table)[2];
 
     table_size = 1 << table_nb_bits;
@@ -286,7 +279,7 @@ static int build_table(VLC *vlc, int table_nb_bits,
                 return -1;
             /* note: realloc has been done, so reload tables */
             table = &vlc->table[table_index];
-            table[i][0] = index - table_index; //code
+            table[i][0] = index; //code
         }
     }
     return table_index;
@@ -346,3 +339,29 @@ int ff_gcd(int a, int b){
     if(b) return ff_gcd(b, a%b);
     else  return a;
 }
+
+void ff_float2fraction(int *nom_arg, int *denom_arg, double f, int max){
+    double best_diff=1E10, diff;
+    int best_denom=1, best_nom=1;
+    int nom, denom, gcd;
+    
+    //brute force here, perhaps we should try continued fractions if we need large max ...
+    for(denom=1; denom<=max; denom++){
+        nom= (int)(f*denom + 0.5);
+        if(nom<=0 || nom>max) continue;
+        
+        diff= ABS( f - (double)nom / (double)denom );
+        if(diff < best_diff){
+            best_diff= diff;
+            best_nom= nom;
+            best_denom= denom;
+        }
+    }
+    
+    gcd= ff_gcd(best_nom, best_denom);
+    best_nom   /= gcd;
+    best_denom /= gcd;
+
+    *nom_arg= best_nom;
+    *denom_arg= best_denom;
+}