From b275500706ac3a20ac59bdb6ee080dc32f3254cf Mon Sep 17 00:00:00 2001 From: Stefano Sabatini Date: Sun, 12 Apr 2009 08:35:26 +0000 Subject: Split bitstream.h, put the bitstream writer stuff in the new file put_bits.h. Originally committed as revision 18461 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/put_bits.h | 311 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 311 insertions(+) create mode 100644 libavcodec/put_bits.h (limited to 'libavcodec/put_bits.h') diff --git a/libavcodec/put_bits.h b/libavcodec/put_bits.h new file mode 100644 index 0000000000..3bddd44ac0 --- /dev/null +++ b/libavcodec/put_bits.h @@ -0,0 +1,311 @@ +/* + * copyright (c) 2004 Michael Niedermayer + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file libavcodec/put_bits.h + * bitstream writer API + */ + +#ifndef AVCODEC_PUT_BITS_H +#define AVCODEC_PUT_BITS_H + +#include +#include +#include +#include "libavutil/bswap.h" +#include "libavutil/common.h" +#include "libavutil/intreadwrite.h" +#include "libavutil/log.h" +#include "mathops.h" + +//#define ALT_BITSTREAM_WRITER +//#define ALIGNED_BITSTREAM_WRITER + +/* buf and buf_end must be present and used by every alternative writer. */ +typedef struct PutBitContext { +#ifdef ALT_BITSTREAM_WRITER + uint8_t *buf, *buf_end; + int index; +#else + uint32_t bit_buf; + int bit_left; + uint8_t *buf, *buf_ptr, *buf_end; +#endif + int size_in_bits; +} PutBitContext; + +/** + * Initializes the PutBitContext \p s. + * + * @param buffer the buffer where to put bits + * @param buffer_size the size in bytes of \p buffer + */ +static inline void init_put_bits(PutBitContext *s, uint8_t *buffer, int buffer_size) +{ + if(buffer_size < 0) { + buffer_size = 0; + buffer = NULL; + } + + s->size_in_bits= 8*buffer_size; + s->buf = buffer; + s->buf_end = s->buf + buffer_size; +#ifdef ALT_BITSTREAM_WRITER + s->index=0; + ((uint32_t*)(s->buf))[0]=0; +// memset(buffer, 0, buffer_size); +#else + s->buf_ptr = s->buf; + s->bit_left=32; + s->bit_buf=0; +#endif +} + +/** + * Returns the total number of bits written to the bitstream. + */ +static inline int put_bits_count(PutBitContext *s) +{ +#ifdef ALT_BITSTREAM_WRITER + return s->index; +#else + return (s->buf_ptr - s->buf) * 8 + 32 - s->bit_left; +#endif +} + +/** + * Pads the end of the output stream with zeros. + */ +static inline void flush_put_bits(PutBitContext *s) +{ +#ifdef ALT_BITSTREAM_WRITER + align_put_bits(s); +#else +#ifndef BITSTREAM_WRITER_LE + s->bit_buf<<= s->bit_left; +#endif + while (s->bit_left < 32) { + /* XXX: should test end of buffer */ +#ifdef BITSTREAM_WRITER_LE + *s->buf_ptr++=s->bit_buf; + s->bit_buf>>=8; +#else + *s->buf_ptr++=s->bit_buf >> 24; + s->bit_buf<<=8; +#endif + s->bit_left+=8; + } + s->bit_left=32; + s->bit_buf=0; +#endif +} + +/** + * Pads the bitstream with zeros up to the next byte boundary. + */ +void align_put_bits(PutBitContext *s); + +/** + * Puts the string \p s in the bitstream. + * + * @param terminate_string 0-terminates the written string if value is 1 + */ +void ff_put_string(PutBitContext * pbc, const char *s, int terminate_string); + +/** + * Copies the content of \p src to the bitstream. + * + * @param length the number of bits of \p src to copy + */ +void ff_copy_bits(PutBitContext *pb, const uint8_t *src, int length); + +static inline void put_bits(PutBitContext *s, int n, unsigned int value) +#ifndef ALT_BITSTREAM_WRITER +{ + unsigned int bit_buf; + int bit_left; + + // printf("put_bits=%d %x\n", n, value); + assert(n == 32 || value < (1U << n)); + + bit_buf = s->bit_buf; + bit_left = s->bit_left; + + // printf("n=%d value=%x cnt=%d buf=%x\n", n, value, bit_cnt, bit_buf); + /* XXX: optimize */ +#ifdef BITSTREAM_WRITER_LE + bit_buf |= value << (32 - bit_left); + if (n >= bit_left) { +#if !HAVE_FAST_UNALIGNED + if (3 & (intptr_t) s->buf_ptr) { + AV_WL32(s->buf_ptr, bit_buf); + } else +#endif + *(uint32_t *)s->buf_ptr = le2me_32(bit_buf); + s->buf_ptr+=4; + bit_buf = (bit_left==32)?0:value >> bit_left; + bit_left+=32; + } + bit_left-=n; +#else + if (n < bit_left) { + bit_buf = (bit_buf<> (n - bit_left); +#if !HAVE_FAST_UNALIGNED + if (3 & (intptr_t) s->buf_ptr) { + AV_WB32(s->buf_ptr, bit_buf); + } else +#endif + *(uint32_t *)s->buf_ptr = be2me_32(bit_buf); + //printf("bitbuf = %08x\n", bit_buf); + s->buf_ptr+=4; + bit_left+=32 - n; + bit_buf = value; + } +#endif + + s->bit_buf = bit_buf; + s->bit_left = bit_left; +} +#else /* ALT_BITSTREAM_WRITER defined */ +{ +# ifdef ALIGNED_BITSTREAM_WRITER +# if ARCH_X86 + __asm__ volatile( + "movl %0, %%ecx \n\t" + "xorl %%eax, %%eax \n\t" + "shrdl %%cl, %1, %%eax \n\t" + "shrl %%cl, %1 \n\t" + "movl %0, %%ecx \n\t" + "shrl $3, %%ecx \n\t" + "andl $0xFFFFFFFC, %%ecx \n\t" + "bswapl %1 \n\t" + "orl %1, (%2, %%ecx) \n\t" + "bswapl %%eax \n\t" + "addl %3, %0 \n\t" + "movl %%eax, 4(%2, %%ecx) \n\t" + : "=&r" (s->index), "=&r" (value) + : "r" (s->buf), "r" (n), "0" (s->index), "1" (value<<(-n)) + : "%eax", "%ecx" + ); +# else + int index= s->index; + uint32_t *ptr= ((uint32_t *)s->buf)+(index>>5); + + value<<= 32-n; + + ptr[0] |= be2me_32(value>>(index&31)); + ptr[1] = be2me_32(value<<(32-(index&31))); +//if(n>24) printf("%d %d\n", n, value); + index+= n; + s->index= index; +# endif +# else //ALIGNED_BITSTREAM_WRITER +# if ARCH_X86 + __asm__ volatile( + "movl $7, %%ecx \n\t" + "andl %0, %%ecx \n\t" + "addl %3, %%ecx \n\t" + "negl %%ecx \n\t" + "shll %%cl, %1 \n\t" + "bswapl %1 \n\t" + "movl %0, %%ecx \n\t" + "shrl $3, %%ecx \n\t" + "orl %1, (%%ecx, %2) \n\t" + "addl %3, %0 \n\t" + "movl $0, 4(%%ecx, %2) \n\t" + : "=&r" (s->index), "=&r" (value) + : "r" (s->buf), "r" (n), "0" (s->index), "1" (value) + : "%ecx" + ); +# else + int index= s->index; + uint32_t *ptr= (uint32_t*)(((uint8_t *)s->buf)+(index>>3)); + + ptr[0] |= be2me_32(value<<(32-n-(index&7) )); + ptr[1] = 0; +//if(n>24) printf("%d %d\n", n, value); + index+= n; + s->index= index; +# endif +# endif //!ALIGNED_BITSTREAM_WRITER +} +#endif + +static inline void put_sbits(PutBitContext *pb, int bits, int32_t val) +{ + assert(bits >= 0 && bits <= 31); + + put_bits(pb, bits, val & ((1<buf + (s->index>>3); +#else + return s->buf_ptr; +#endif +} + +/** + * Skips the given number of bytes. + * PutBitContext must be flushed & aligned to a byte boundary before calling this. + */ +static inline void skip_put_bytes(PutBitContext *s, int n){ + assert((put_bits_count(s)&7)==0); +#ifdef ALT_BITSTREAM_WRITER + FIXME may need some cleaning of the buffer + s->index += n<<3; +#else + assert(s->bit_left==32); + s->buf_ptr += n; +#endif +} + +/** + * Skips the given number of bits. + * Must only be used if the actual values in the bitstream do not matter. + * If \p n is 0 the behavior is undefined. + */ +static inline void skip_put_bits(PutBitContext *s, int n){ +#ifdef ALT_BITSTREAM_WRITER + s->index += n; +#else + s->bit_left -= n; + s->buf_ptr-= s->bit_left>>5; + s->bit_left &= 31; +#endif +} + +/** + * Changes the end of the buffer. + * + * @param size the new size in bytes of the buffer where to put bits + */ +static inline void set_put_bits_buffer_size(PutBitContext *s, int size){ + s->buf_end= s->buf + size; +} + +#endif /* AVCODEC_PUT_BITS_H */ -- cgit v1.2.3