Kill unused getbit_context->size_in_bits and add some doku.

[paraslash.git] / bitstream.h

diff --git a/bitstream.h b/bitstream.h
index 0a701d7c8636229f98b37f49dd16603a8b132a1b..07c65389081d9b4b979c5c556dc5e1a9d4ce75f1 100644 (file)
--- a/bitstream.h
+++ b/bitstream.h
@@ -14,19 +14,16 @@
                      (((const uint8_t*)(x))[2] <<  8) | \
                       ((const uint8_t*)(x))[3])
 
-# define NEG_SSR32(a,s) ((( int32_t)(a))>>(32-(s)))
-# define NEG_USR32(a,s) (((uint32_t)(a))>>(32-(s)))
+#define NEG_USR32(a,s) (((uint32_t)(a))>>(32-(s)))
 
-/**
- * Structure for bistream I/O.
- *
- * The buffer, buffer_end and size_in_bits fields must be present and are used
- * by every reader.
- */
+/** Structure for bistream I/O. */
 struct getbit_context {
-       const uint8_t *buffer, *buffer_end;
+       /* Start of the internal buffer. */
+       const uint8_t *buffer;
+       /* End of the internal buffer. */
+       const uint8_t *buffer_end;
+       /** Bit counter. */
        int index;
-       int size_in_bits;
 };
 
 #define VLC_TYPE int16_t
@@ -37,8 +34,6 @@ struct vlc {
        int table_size, table_allocated;
 };
 
-#define MIN_CACHE_BITS 25
-
 /** Load \a gb into local variables. */
 #define OPEN_READER(name, gb)\
        int name##_index= (gb)->index;\
@@ -50,8 +45,6 @@ struct vlc {
 
 /**
  * Refill the internal cache from the bitstream.
- *
- * After this call at least MIN_CACHE_BITS will be available.
  */
 #define UPDATE_CACHE(name, gb)\
        name##_cache= AV_RB32( ((const uint8_t *)(gb)->buffer) \
@@ -96,14 +89,8 @@ static inline int get_bits_count(struct getbit_context *s)
        return s->index;
 }
 
-static inline void skip_bits_long(struct getbit_context *s, int n)
-{
-       s->index += n;
-}
-
 /**
- * reads 1-17 bits.
- * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
+ * Read 1-17 bits.
  */
 static inline unsigned int get_bits(struct getbit_context *s, int n)
 {
@@ -118,9 +105,6 @@ static inline unsigned int get_bits(struct getbit_context *s, int n)
 
 /**
  * Show 1-17 bits.
- *
- * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2
- * reader can't.
  */
 static inline unsigned int show_bits(struct getbit_context *s, int n)
 {
@@ -128,7 +112,6 @@ static inline unsigned int show_bits(struct getbit_context *s, int n)
        OPEN_READER(re, s)
        UPDATE_CACHE(re, s)
        tmp = SHOW_UBITS(re, s, n);
-//    CLOSE_READER(re, s)
        return tmp;
 }
 
@@ -153,19 +136,6 @@ static inline unsigned int get_bits1(struct getbit_context *s)
        return result;
 }
 
-/**
- * reads 0-32 bits.
- */
-static inline unsigned int get_bits_long(struct getbit_context *s, int n)
-{
-       if (n <= 17)
-               return get_bits(s, n);
-       else {
-               int ret = get_bits(s, 16) << (n - 16);
-               return ret | get_bits(s, n - 16);
-       }
-}
-
 /**
  * Initialize a getbit_context structure.
  *
@@ -176,7 +146,7 @@ static inline unsigned int get_bits_long(struct getbit_context *s, int n)
  * \param bit_size The size of the buffer in bits.
  */
 static inline void init_get_bits(struct getbit_context *s,
-               const uint8_t * buffer, int bit_size)
+               const uint8_t *buffer, int bit_size)
 {
        int buffer_size = (bit_size + 7) >> 3;
        if (buffer_size < 0 || bit_size < 0) {
@@ -184,14 +154,12 @@ static inline void init_get_bits(struct getbit_context *s,
                buffer = NULL;
        }
        s->buffer = buffer;
-       s->size_in_bits = bit_size;
        s->buffer_end = buffer + buffer_size;
        s->index = 0;
 }
 
-int init_vlc(struct vlc *vlc, int nb_bits, int nb_codes,
-       const void *bits, int bits_wrap, int bits_size,
-       const void *codes, int codes_wrap, int codes_size);
+void init_vlc(struct vlc *vlc, int nb_bits, int nb_codes, const void *bits,
+               const void *codes, int codes_size);
 
 void free_vlc(struct vlc *vlc);