vlc_bits: Differentiate between writable bits stream and read only.

[vlc] / include / vlc_bits.h

diff --git a/include/vlc_bits.h b/include/vlc_bits.h
index 778493cb3f7f7e46a8ae967b500300b52b77f846..774d9558059189e3e5877025b07cfdbeee1bf2f9 100644 (file)
--- a/include/vlc_bits.h
+++ b/include/vlc_bits.h
@@ -30,15 +30,25 @@
  */
 
 typedef struct bs_s
+{
+    const uint8_t *p_start;
+    const uint8_t *p;
+    const uint8_t *p_end;
+
+    unsigned     i_left;    /* i_count number of available bits */
+} bs_t;
+
+typedef struct bs_writable_s
 {
     uint8_t *p_start;
     uint8_t *p;
     uint8_t *p_end;
+    
+    unsigned     i_left;    /* i_count number of available bits */
+} bsw_t;
 
-    int     i_left;    /* i_count number of available bits */
-} bs_t;
 
-static inline void bs_init( bs_t *s, void *p_data, int i_data )
+static inline void bs_init( bs_t *s, const void *p_data, unsigned i_data )
 {
     s->p_start = p_data;
     s->p       = p_data;
@@ -141,25 +151,67 @@ static inline void bs_skip( bs_t *s, int i_count )
     }
 }
 
-static inline void bs_write( bs_t *s, int i_count, uint32_t i_bits )
+/*
+ * Writable bits stream
+ */
+static inline void bsw_init_writable( bsw_t *s, void *p_data, unsigned i_data )
+{
+    s->p_start = p_data;
+    s->p       = p_data;
+    s->p_end   = s->p + i_data;
+    s->i_left  = 8;
+}
+
+static inline bs_t * bs_from_writable( bsw_t *s )
+{
+    return (bs_t *)s;
+}
+
+static inline void bsw_skip( bsw_t *s, int count )
+{
+    return bs_skip(bs_from_writable(s), count);
+}
+
+static inline uint32_t bsw_show( bsw_t *s, int count )
+{
+    return bs_show(bs_from_writable(s), count);
+}
+
+static inline uint32_t bsw_read1( bsw_t *s )
+{
+    return bs_read1(bs_from_writable(s));
+}
+
+static inline uint32_t bsw_read( bsw_t *s, int count )
+{
+    return bs_read(bs_from_writable(s), count);
+}
+
+static inline int bsw_pos( bsw_t *s )
+{
+    return bs_pos(bs_from_writable(s));
+}
+
+static inline int bsw_eof( bsw_t *s )
+{
+    return bs_eof(bs_from_writable(s));
+}
+
+
+static inline void bsw_write( bsw_t *s, int i_count, uint32_t i_bits )
 {
     while( i_count > 0 )
     {
         if( s->p >= s->p_end )
-        {
             break;
-        }
 
         i_count--;
 
         if( ( i_bits >> i_count )&0x01 )
-        {
             *s->p |= 1 << ( s->i_left - 1 );
-        }
         else
-        {
             *s->p &= ~( 1 << ( s->i_left - 1 ) );
-        }
+
         s->i_left--;
         if( s->i_left == 0 )
         {
@@ -169,7 +221,7 @@ static inline void bs_write( bs_t *s, int i_count, uint32_t i_bits )
     }
 }
 
-static inline void bs_align( bs_t *s )
+static inline void bsw_align( bsw_t *s )
 {
     if( s->i_left != 8 )
     {
@@ -178,20 +230,16 @@ static inline void bs_align( bs_t *s )
     }
 }
 
-static inline void bs_align_0( bs_t *s )
+static inline void bsw_align_0( bsw_t *s )
 {
     if( s->i_left != 8 )
-    {
-        bs_write( s, s->i_left, 0 );
-    }
+        bsw_write( s, s->i_left, 0 );
 }
 
-static inline void bs_align_1( bs_t *s )
+static inline void bsw_align_1( bsw_t *s )
 {
     while( s->i_left != 8 )
-    {
-        bs_write( s, 1, 1 );
-    }
+        bsw_write( s, 1, 1 );
 }
 
 #endif