X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Fget_bits.h;h=64393bc9d9ead92dfd8c3797422a75bf44c0551e;hb=d2205d6543881f2e6fa18c8a354bbcf91a1235f7;hp=4aa5da86bb47d411c83d02127036f58d23137b56;hpb=e42bb0ee01706702b1d0f9a483dbc3013030c62d;p=ffmpeg diff --git a/libavcodec/get_bits.h b/libavcodec/get_bits.h index 4aa5da86bb4..64393bc9d9e 100644 --- a/libavcodec/get_bits.h +++ b/libavcodec/get_bits.h @@ -49,8 +49,6 @@ #define UNCHECKED_BITSTREAM_READER !CONFIG_SAFE_BITSTREAM_READER #endif -/* bit input */ -/* buffer, buffer_end and size_in_bits must be present and used by every reader */ typedef struct GetBitContext { const uint8_t *buffer, *buffer_end; int index; @@ -110,11 +108,8 @@ SKIP_CACHE(name, gb, num) SKIP_COUNTER(name, gb, num) will increment the internal bit counter (see SKIP_CACHE & SKIP_BITS) -LAST_SKIP_CACHE(name, gb, num) - will remove the next num bits from the cache if it is needed for UPDATE_CACHE otherwise it will do nothing - LAST_SKIP_BITS(name, gb, num) - is equivalent to LAST_SKIP_CACHE; SKIP_COUNTER + like SKIP_BITS, to be used if next call is UPDATE_CACHE or CLOSE_READER for examples see get_bits, show_bits, skip_bits, get_vlc */ @@ -125,13 +120,26 @@ for examples see get_bits, show_bits, skip_bits, get_vlc # define MIN_CACHE_BITS 25 #endif +#if UNCHECKED_BITSTREAM_READER #define OPEN_READER(name, gb) \ unsigned int name##_index = (gb)->index; \ unsigned int av_unused name##_cache = 0 +#define HAVE_BITS_REMAINING(name, gb) 1 +#else +#define OPEN_READER(name, gb) \ + unsigned int name##_index = (gb)->index; \ + unsigned int av_unused name##_cache = 0; \ + unsigned int av_unused name##_size_plus8 = \ + (gb)->size_in_bits_plus8 + +#define HAVE_BITS_REMAINING(name, gb) \ + name##_index < name##_size_plus8 +#endif + #define CLOSE_READER(name, gb) (gb)->index = name##_index -#ifdef ALT_BITSTREAM_READER_LE +#ifdef BITSTREAM_READER_LE # ifdef LONG_BITSTREAM_READER # define UPDATE_CACHE(name, gb) name##_cache = \ @@ -157,12 +165,11 @@ for examples see get_bits, show_bits, skip_bits, get_vlc #endif -// FIXME name? #if UNCHECKED_BITSTREAM_READER # define SKIP_COUNTER(name, gb, num) name##_index += (num) #else # define SKIP_COUNTER(name, gb, num) \ - name##_index = FFMIN((gb)->size_in_bits_plus8, name##_index + (num)) + name##_index = FFMIN(name##_size_plus8, name##_index + (num)) #endif #define SKIP_BITS(name, gb, num) do { \ @@ -171,9 +178,8 @@ for examples see get_bits, show_bits, skip_bits, get_vlc } while (0) #define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num) -#define LAST_SKIP_CACHE(name, gb, num) -#ifdef ALT_BITSTREAM_READER_LE +#ifdef BITSTREAM_READER_LE # define SHOW_UBITS(name, gb, num) zero_extend(name##_cache, num) # define SHOW_SBITS(name, gb, num) sign_extend(name##_cache, num) #else @@ -200,7 +206,6 @@ static inline void skip_bits_long(GetBitContext *s, int n){ * read mpeg1 dc style vlc (sign bit + mantisse with no MSB). * if MSB not set it is negative * @param n length in bits - * @author BERO */ static inline int get_xbits(GetBitContext *s, int n) { @@ -254,7 +259,6 @@ static inline unsigned int show_bits(GetBitContext *s, int n) static inline void skip_bits(GetBitContext *s, int n) { - //Note 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); @@ -265,7 +269,7 @@ static inline unsigned int get_bits1(GetBitContext *s) { unsigned int index = s->index; uint8_t result = s->buffer[index>>3]; -#ifdef ALT_BITSTREAM_READER_LE +#ifdef BITSTREAM_READER_LE result >>= index & 7; result &= 1; #else @@ -299,7 +303,7 @@ static inline unsigned int get_bits_long(GetBitContext *s, int n) if (n <= MIN_CACHE_BITS) return get_bits(s, n); else { -#ifdef ALT_BITSTREAM_READER_LE +#ifdef BITSTREAM_READER_LE int ret = get_bits(s, 16); return ret | (get_bits(s, n-16) << 16); #else @@ -344,9 +348,6 @@ static inline int check_marker(GetBitContext *s, const char *msg) * @param buffer bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE bytes larger than 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 - * - * While GetBitContext stores the buffer size, for performance reasons you are - * responsible for checking for the buffer end yourself (take advantage of the padding)! */ static inline void init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size) @@ -376,19 +377,19 @@ static inline void align_get_bits(GetBitContext *s) bits, bits_wrap, bits_size, \ codes, codes_wrap, codes_size, \ flags) \ - init_vlc_sparse(vlc, nb_bits, nb_codes, \ - bits, bits_wrap, bits_size, \ - codes, codes_wrap, codes_size, \ - NULL, 0, 0, flags) + ff_init_vlc_sparse(vlc, nb_bits, nb_codes, \ + bits, bits_wrap, bits_size, \ + codes, codes_wrap, codes_size, \ + NULL, 0, 0, flags) -int init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes, +int ff_init_vlc_sparse(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, const void *symbols, int symbols_wrap, int symbols_size, int flags); #define INIT_VLC_LE 2 #define INIT_VLC_USE_NEW_STATIC 4 -void free_vlc(VLC *vlc); +void ff_free_vlc(VLC *vlc); #define INIT_VLC_STATIC(vlc, bits, a,b,c,d,e,f,g, static_size) do { \ static VLC_TYPE table[static_size][2]; \ @@ -462,7 +463,7 @@ void free_vlc(VLC *vlc); /** - * Parse a vlc code, faster than get_vlc(). + * Parse a vlc code. * @param bits is the number of bits which will be read at once, must be * identical to nb_bits in init_vlc() * @param max_depth is the number of times bits bits must be read to completely