X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=bitstream.h;h=553dd04a0737b0c0cac9c845be8a460a13a64ffd;hp=df2c0b8bbb912ead15c5c6a9b4a2e019155f872d;hb=1301313c2eb8a9ce0ba8ce22062d1f87fc419aa2;hpb=a7722850be9f23daf1e095bc9527ba24faa9719b diff --git a/bitstream.h b/bitstream.h index df2c0b8b..553dd04a 100644 --- a/bitstream.h +++ b/bitstream.h @@ -47,7 +47,7 @@ struct vlc { * Refill the internal cache from the bitstream. */ #define UPDATE_CACHE(name, gb)\ - name##_cache= AV_RB32( ((const uint8_t *)(gb)->buffer) \ + name##_cache= AV_RB32( ((gb)->buffer) \ + (name##_index >> 3) ) << (name##_index & 0x07);\ /** @@ -61,25 +61,11 @@ struct vlc { /** * Increment the internal bit counter. * - * \sa SKIP_CACHE, SKIP_BITS. + * \sa SKIP_CACHE. */ #define SKIP_COUNTER(name, gb, num)\ name##_index += (num);\ -/** - * Skip over the next num bits. - * - * This is equivalent to SKIP_CACHE; SKIP_COUNTER. - */ -#define SKIP_BITS(name, gb, num)\ - {\ - SKIP_CACHE(name, gb, num)\ - SKIP_COUNTER(name, gb, num)\ - }\ - -/** This is equivalent to SKIP_LAST_CACHE; SKIP_COUNTER. */ -#define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num) - /** Return the next num bits. */ #define SHOW_UBITS(name, gb, num)\ NEG_USR32(name##_cache, num) @@ -98,18 +84,14 @@ static inline unsigned int get_bits(struct getbit_context *s, int n) OPEN_READER(re, s) UPDATE_CACHE(re, s) tmp = SHOW_UBITS(re, s, n); - LAST_SKIP_BITS(re, s, n) + SKIP_COUNTER(re, s, n) CLOSE_READER(re, s) return tmp; } static inline void skip_bits(struct getbit_context *s, int n) { - /* gcc seems to optimize this to s->index+=n for the ALT_READER :)) */ - OPEN_READER(re, s) - UPDATE_CACHE(re, s) - LAST_SKIP_BITS(re, s, n) - CLOSE_READER(re, s) + s->index += n; } static inline unsigned int get_bits1(struct getbit_context *s) @@ -131,18 +113,13 @@ static inline unsigned int get_bits1(struct getbit_context *s) * bytes larger then the actual read bits * because some optimized bitstream * readers read 32 or 64 bit at once and could read over the end. * - * \param bit_size The size of the buffer in bits. + * \param bit_size The size of the buffer in bytes. */ static inline void init_get_bits(struct getbit_context *s, - const uint8_t *buffer, int bit_size) + const uint8_t *buffer, int size) { - int buffer_size = (bit_size + 7) >> 3; - if (buffer_size < 0 || bit_size < 0) { - buffer_size = bit_size = 0; - buffer = NULL; - } s->buffer = buffer; - s->buffer_end = buffer + buffer_size; + s->buffer_end = buffer + size; s->index = 0; } @@ -171,14 +148,14 @@ static inline int get_vlc(struct getbit_context *gb, VLC_TYPE(*table)[2], code = table[idx][0]; n = table[idx][1]; if (max_depth > 1 && n < 0) { - LAST_SKIP_BITS(re, gb, bits) + SKIP_COUNTER(re, gb, bits) UPDATE_CACHE(re, gb) nb_bits = -n; idx = SHOW_UBITS(re, gb, nb_bits) + code; code = table[idx][0]; n = table[idx][1]; if (max_depth > 2 && n < 0) { - LAST_SKIP_BITS(re, gb, nb_bits) + SKIP_COUNTER(re, gb, nb_bits) UPDATE_CACHE(re, gb) nb_bits = -n; idx = SHOW_UBITS(re, gb, nb_bits) + code; @@ -186,7 +163,8 @@ static inline int get_vlc(struct getbit_context *gb, VLC_TYPE(*table)[2], n = table[idx][1]; } } - SKIP_BITS(re, gb, n) + SKIP_CACHE(re, gb, n) + SKIP_COUNTER(re, gb, n) CLOSE_READER(re, gb) return code; }