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lavc/get_bits: add a compat wrapper for the cached bitstream reader
Use that instead of the merged version.
This commit is contained in:
Anton Khirnov
parent
b6742259bf
commit
fcd557a2c2
@ -1,6 +1,5 @@
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/*
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* Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
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* Copyright (c) 2016 Alexandra Hájková
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*
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* This file is part of FFmpeg.
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*
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@ -58,12 +57,55 @@
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#define CACHED_BITSTREAM_READER 0
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#endif
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#if CACHED_BITSTREAM_READER
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// we always want the LE implementation, to provide get_bits_le()
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#define BITSTREAM_LE
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#ifndef BITSTREAM_READER_LE
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# define BITSTREAM_BE
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# define BITSTREAM_DEFAULT_BE
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#endif
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#include "bitstream.h"
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#undef BITSTREAM_LE
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#undef BITSTREAM_BE
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#undef BITSTREAM_DEFAULT_BE
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typedef BitstreamContext GetBitContext;
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#define get_bits_count bits_tell
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#define get_bits_left bits_left
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#define skip_bits_long bits_skip
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#define skip_bits bits_skip
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#define get_bits bits_read_nz
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#define get_bitsz bits_read
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#define get_bits_long bits_read
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#define get_bits1 bits_read_bit
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#define get_bits64 bits_read_64
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#define get_xbits bits_read_xbits
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#define get_sbits bits_read_signed
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#define get_sbits_long bits_read_signed
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#define show_bits bits_peek
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#define show_bits_long bits_peek
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#define init_get_bits bits_init
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#define init_get_bits8 bits_init8
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#define align_get_bits bits_align
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#define get_vlc2 bits_read_vlc
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#define init_get_bits8_le(s, buffer, byte_size) bits_init8_le((BitstreamContextLE*)s, buffer, byte_size)
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#define get_bits_le(s, n) bits_read_le((BitstreamContextLE*)s, n)
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#define show_bits1(s) bits_peek(s, 1)
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#define skip_bits1(s) bits_skip(s, 1)
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#define skip_1stop_8data_bits bits_skip_1stop_8data
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#else // CACHED_BITSTREAM_READER
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typedef struct GetBitContext {
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const uint8_t *buffer, *buffer_end;
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#if CACHED_BITSTREAM_READER
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uint64_t cache;
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unsigned bits_left;
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#endif
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int index;
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int size_in_bits;
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int size_in_bits_plus8;
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@ -120,16 +162,12 @@ static inline unsigned int show_bits(GetBitContext *s, int n);
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* For examples see get_bits, show_bits, skip_bits, get_vlc.
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*/
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#if CACHED_BITSTREAM_READER
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# define MIN_CACHE_BITS 64
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#elif defined LONG_BITSTREAM_READER
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#if defined LONG_BITSTREAM_READER
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# define MIN_CACHE_BITS 32
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#else
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# define MIN_CACHE_BITS 25
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#endif
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#if !CACHED_BITSTREAM_READER
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#define OPEN_READER_NOSIZE(name, gb) \
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unsigned int name ## _index = (gb)->index; \
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unsigned int av_unused name ## _cache
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@ -214,73 +252,12 @@ static inline unsigned int show_bits(GetBitContext *s, int n);
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#define GET_CACHE(name, gb) ((uint32_t) name ## _cache)
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#endif
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static inline int get_bits_count(const GetBitContext *s)
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{
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#if CACHED_BITSTREAM_READER
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return s->index - s->bits_left;
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#else
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return s->index;
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#endif
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}
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#if CACHED_BITSTREAM_READER
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static inline void refill_32(GetBitContext *s, int is_le)
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{
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#if !UNCHECKED_BITSTREAM_READER
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if (s->index >> 3 >= s->buffer_end - s->buffer)
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return;
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#endif
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if (is_le)
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s->cache = (uint64_t)AV_RL32(s->buffer + (s->index >> 3)) << s->bits_left | s->cache;
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else
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s->cache = s->cache | (uint64_t)AV_RB32(s->buffer + (s->index >> 3)) << (32 - s->bits_left);
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s->index += 32;
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s->bits_left += 32;
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}
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static inline void refill_64(GetBitContext *s, int is_le)
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{
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#if !UNCHECKED_BITSTREAM_READER
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if (s->index >> 3 >= s->buffer_end - s->buffer)
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return;
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#endif
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if (is_le)
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s->cache = AV_RL64(s->buffer + (s->index >> 3));
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else
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s->cache = AV_RB64(s->buffer + (s->index >> 3));
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s->index += 64;
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s->bits_left = 64;
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}
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static inline uint64_t get_val(GetBitContext *s, unsigned n, int is_le)
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{
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uint64_t ret;
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av_assert2(n>0 && n<=63);
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if (is_le) {
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ret = s->cache & ((UINT64_C(1) << n) - 1);
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s->cache >>= n;
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} else {
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ret = s->cache >> (64 - n);
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s->cache <<= n;
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}
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s->bits_left -= n;
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return ret;
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}
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static inline unsigned show_val(const GetBitContext *s, unsigned n)
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{
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#ifdef BITSTREAM_READER_LE
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return s->cache & ((UINT64_C(1) << n) - 1);
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#else
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return s->cache >> (64 - n);
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#endif
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}
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#endif
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/**
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* Skips the specified number of bits.
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* @param n the number of bits to skip,
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@ -290,29 +267,13 @@ static inline unsigned show_val(const GetBitContext *s, unsigned n)
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*/
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static inline void skip_bits_long(GetBitContext *s, int n)
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{
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#if CACHED_BITSTREAM_READER
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skip_bits(s, n);
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#else
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#if UNCHECKED_BITSTREAM_READER
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s->index += n;
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#else
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s->index += av_clip(n, -s->index, s->size_in_bits_plus8 - s->index);
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#endif
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#endif
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}
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#if CACHED_BITSTREAM_READER
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static inline void skip_remaining(GetBitContext *s, unsigned n)
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{
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#ifdef BITSTREAM_READER_LE
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s->cache >>= n;
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#else
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s->cache <<= n;
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#endif
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s->bits_left -= n;
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}
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#endif
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/**
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* Read MPEG-1 dc-style VLC (sign bit + mantissa with no MSB).
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* if MSB not set it is negative
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@ -320,13 +281,6 @@ static inline void skip_remaining(GetBitContext *s, unsigned n)
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*/
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static inline int get_xbits(GetBitContext *s, int n)
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{
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#if CACHED_BITSTREAM_READER
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int32_t cache = show_bits(s, 32);
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int sign = ~cache >> 31;
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skip_remaining(s, n);
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return ((((uint32_t)(sign ^ cache)) >> (32 - n)) ^ sign) - sign;
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#else
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register int sign;
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register int32_t cache;
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OPEN_READER(re, s);
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@ -337,10 +291,8 @@ static inline int get_xbits(GetBitContext *s, int n)
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LAST_SKIP_BITS(re, s, n);
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CLOSE_READER(re, s);
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return (NEG_USR32(sign ^ cache, n) ^ sign) - sign;
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#endif
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}
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#if !CACHED_BITSTREAM_READER
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static inline int get_xbits_le(GetBitContext *s, int n)
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{
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register int sign;
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@ -354,22 +306,16 @@ static inline int get_xbits_le(GetBitContext *s, int n)
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CLOSE_READER(re, s);
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return (zero_extend(sign ^ cache, n) ^ sign) - sign;
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}
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#endif
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static inline int get_sbits(GetBitContext *s, int n)
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{
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register int tmp;
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#if CACHED_BITSTREAM_READER
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av_assert2(n>0 && n<=25);
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tmp = sign_extend(get_bits(s, n), n);
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#else
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OPEN_READER(re, s);
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av_assert2(n>0 && n<=25);
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UPDATE_CACHE(re, s);
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tmp = SHOW_SBITS(re, s, n);
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LAST_SKIP_BITS(re, s, n);
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CLOSE_READER(re, s);
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#endif
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return tmp;
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}
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@ -379,32 +325,12 @@ static inline int get_sbits(GetBitContext *s, int n)
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static inline unsigned int get_bits(GetBitContext *s, int n)
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{
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register unsigned int tmp;
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#if CACHED_BITSTREAM_READER
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av_assert2(n>0 && n<=32);
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if (n > s->bits_left) {
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#ifdef BITSTREAM_READER_LE
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refill_32(s, 1);
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#else
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refill_32(s, 0);
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#endif
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if (s->bits_left < 32)
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s->bits_left = n;
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}
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#ifdef BITSTREAM_READER_LE
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tmp = get_val(s, n, 1);
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#else
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tmp = get_val(s, n, 0);
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#endif
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#else
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OPEN_READER(re, s);
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av_assert2(n>0 && n<=25);
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UPDATE_CACHE(re, s);
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tmp = SHOW_UBITS(re, s, n);
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LAST_SKIP_BITS(re, s, n);
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CLOSE_READER(re, s);
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#endif
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av_assert2(tmp < UINT64_C(1) << n);
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return tmp;
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}
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@ -419,16 +345,6 @@ static av_always_inline int get_bitsz(GetBitContext *s, int n)
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static inline unsigned int get_bits_le(GetBitContext *s, int n)
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{
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#if CACHED_BITSTREAM_READER
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av_assert2(n>0 && n<=32);
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if (n > s->bits_left) {
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refill_32(s, 1);
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if (s->bits_left < 32)
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s->bits_left = n;
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}
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return get_val(s, n, 1);
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#else
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register int tmp;
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OPEN_READER(re, s);
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av_assert2(n>0 && n<=25);
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@ -437,7 +353,6 @@ static inline unsigned int get_bits_le(GetBitContext *s, int n)
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LAST_SKIP_BITS(re, s, n);
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CLOSE_READER(re, s);
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return tmp;
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#endif
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}
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/**
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@ -446,71 +361,22 @@ static inline unsigned int get_bits_le(GetBitContext *s, int n)
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static inline unsigned int show_bits(GetBitContext *s, int n)
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{
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register unsigned int tmp;
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#if CACHED_BITSTREAM_READER
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if (n > s->bits_left)
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#ifdef BITSTREAM_READER_LE
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refill_32(s, 1);
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#else
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refill_32(s, 0);
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#endif
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tmp = show_val(s, n);
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#else
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OPEN_READER_NOSIZE(re, s);
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av_assert2(n>0 && n<=25);
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UPDATE_CACHE(re, s);
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tmp = SHOW_UBITS(re, s, n);
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#endif
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return tmp;
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}
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static inline void skip_bits(GetBitContext *s, int n)
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{
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#if CACHED_BITSTREAM_READER
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if (n < s->bits_left)
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skip_remaining(s, n);
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else {
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n -= s->bits_left;
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s->cache = 0;
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s->bits_left = 0;
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if (n >= 64) {
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unsigned skip = (n / 8) * 8;
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n -= skip;
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s->index += skip;
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}
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#ifdef BITSTREAM_READER_LE
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refill_64(s, 1);
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#else
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refill_64(s, 0);
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#endif
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if (n)
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skip_remaining(s, n);
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}
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#else
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OPEN_READER(re, s);
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LAST_SKIP_BITS(re, s, n);
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CLOSE_READER(re, s);
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#endif
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}
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static inline unsigned int get_bits1(GetBitContext *s)
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{
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#if CACHED_BITSTREAM_READER
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if (!s->bits_left)
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#ifdef BITSTREAM_READER_LE
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refill_64(s, 1);
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#else
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refill_64(s, 0);
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#endif
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#ifdef BITSTREAM_READER_LE
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return get_val(s, 1, 1);
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#else
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return get_val(s, 1, 0);
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#endif
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#else
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unsigned int index = s->index;
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uint8_t result = s->buffer[index >> 3];
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#ifdef BITSTREAM_READER_LE
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@ -527,7 +393,6 @@ static inline unsigned int get_bits1(GetBitContext *s)
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s->index = index;
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return result;
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#endif
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}
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static inline unsigned int show_bits1(GetBitContext *s)
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@ -548,10 +413,6 @@ static inline unsigned int get_bits_long(GetBitContext *s, int n)
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av_assert2(n>=0 && n<=32);
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if (!n) {
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return 0;
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#if CACHED_BITSTREAM_READER
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}
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return get_bits(s, n);
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#else
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} else if (n <= MIN_CACHE_BITS) {
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return get_bits(s, n);
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} else {
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@ -563,7 +424,6 @@ static inline unsigned int get_bits_long(GetBitContext *s, int n)
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return ret | get_bits(s, n - 16);
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#endif
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}
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#endif
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}
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/**
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@ -621,8 +481,17 @@ static inline unsigned int show_bits_long(GetBitContext *s, int n)
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}
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}
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static inline int init_get_bits_xe(GetBitContext *s, const uint8_t *buffer,
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int bit_size, int is_le)
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/**
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* Initialize GetBitContext.
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* @param buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes
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* larger than the actual read bits because some optimized bitstream
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* readers read 32 or 64 bit at once and could read over the end
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* @param bit_size the size of the buffer in bits
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* @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow.
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*/
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static inline int init_get_bits(GetBitContext *s, const uint8_t *buffer,
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int bit_size)
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{
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int buffer_size;
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int ret = 0;
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@ -641,33 +510,9 @@ static inline int init_get_bits_xe(GetBitContext *s, const uint8_t *buffer,
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s->buffer_end = buffer + buffer_size;
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s->index = 0;
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#if CACHED_BITSTREAM_READER
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s->cache = 0;
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s->bits_left = 0;
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refill_64(s, is_le);
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#endif
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return ret;
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}
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/**
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* Initialize GetBitContext.
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* @param buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes
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* larger than the actual read bits because some optimized bitstream
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* readers read 32 or 64 bit at once and could read over the end
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* @param bit_size the size of the buffer in bits
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* @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow.
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*/
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static inline int init_get_bits(GetBitContext *s, const uint8_t *buffer,
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int bit_size)
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{
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#ifdef BITSTREAM_READER_LE
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return init_get_bits_xe(s, buffer, bit_size, 1);
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#else
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return init_get_bits_xe(s, buffer, bit_size, 0);
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#endif
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}
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/**
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* Initialize GetBitContext.
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* @param buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes
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@ -689,7 +534,7 @@ static inline int init_get_bits8_le(GetBitContext *s, const uint8_t *buffer,
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{
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if (byte_size > INT_MAX / 8 || byte_size < 0)
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byte_size = -1;
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return init_get_bits_xe(s, buffer, byte_size * 8, 1);
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return init_get_bits(s, buffer, byte_size * 8);
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}
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static inline const uint8_t *align_get_bits(GetBitContext *s)
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@ -774,19 +619,6 @@ static inline const uint8_t *align_get_bits(GetBitContext *s)
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SKIP_BITS(name, gb, n); \
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} while (0)
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/* Return the LUT element for the given bitstream configuration. */
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static inline int set_idx(GetBitContext *s, int code, int *n, int *nb_bits,
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const VLCElem *table)
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{
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unsigned idx;
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*nb_bits = -*n;
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idx = show_bits(s, *nb_bits) + code;
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*n = table[idx].len;
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return table[idx].sym;
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}
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/**
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* Parse a vlc code.
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* @param bits is the number of bits which will be read at once, must be
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@ -799,24 +631,6 @@ static inline int set_idx(GetBitContext *s, int code, int *n, int *nb_bits,
|
||||
static av_always_inline int get_vlc2(GetBitContext *s, const VLCElem *table,
|
||||
int bits, int max_depth)
|
||||
{
|
||||
#if CACHED_BITSTREAM_READER
|
||||
int nb_bits;
|
||||
unsigned idx = show_bits(s, bits);
|
||||
int code = table[idx].sym;
|
||||
int n = table[idx].len;
|
||||
|
||||
if (max_depth > 1 && n < 0) {
|
||||
skip_remaining(s, bits);
|
||||
code = set_idx(s, code, &n, &nb_bits, table);
|
||||
if (max_depth > 2 && n < 0) {
|
||||
skip_remaining(s, nb_bits);
|
||||
code = set_idx(s, code, &n, &nb_bits, table);
|
||||
}
|
||||
}
|
||||
skip_remaining(s, n);
|
||||
|
||||
return code;
|
||||
#else
|
||||
int code;
|
||||
|
||||
OPEN_READER(re, s);
|
||||
@ -827,7 +641,6 @@ static av_always_inline int get_vlc2(GetBitContext *s, const VLCElem *table,
|
||||
CLOSE_READER(re, s);
|
||||
|
||||
return code;
|
||||
#endif
|
||||
}
|
||||
|
||||
static inline int decode012(GetBitContext *gb)
|
||||
@ -867,4 +680,6 @@ static inline int skip_1stop_8data_bits(GetBitContext *gb)
|
||||
return 0;
|
||||
}
|
||||
|
||||
#endif // CACHED_BITSTREAM_READER
|
||||
|
||||
#endif /* AVCODEC_GET_BITS_H */
|
||||
|
||||
Loading…
Reference in New Issue
Block a user