diff options
Diffstat (limited to 'libavcodec/put_bits.h')
-rw-r--r-- | libavcodec/put_bits.h | 172 |
1 files changed, 150 insertions, 22 deletions
diff --git a/libavcodec/put_bits.h b/libavcodec/put_bits.h index 17666fa..1ceb1cc 100644 --- a/libavcodec/put_bits.h +++ b/libavcodec/put_bits.h @@ -1,20 +1,20 @@ /* * copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at> * - * This file is part of Libav. + * This file is part of FFmpeg. * - * Libav is free software; you can redistribute it and/or + * 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. * - * Libav is distributed in the hope that it will be useful, + * 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 Libav; if not, write to the Free Software + * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ @@ -28,9 +28,9 @@ #include <stdint.h> #include <stddef.h> -#include <assert.h> #include "libavutil/intreadwrite.h" +#include "libavutil/avassert.h" typedef struct PutBitContext { uint32_t bit_buf; @@ -62,6 +62,24 @@ static inline void init_put_bits(PutBitContext *s, uint8_t *buffer, } /** + * Rebase the bit writer onto a reallocated buffer. + * + * @param buffer the buffer where to put bits + * @param buffer_size the size in bytes of buffer, + * must be larger than the previous size + */ +static inline void rebase_put_bits(PutBitContext *s, uint8_t *buffer, + int buffer_size) +{ + av_assert0(8*buffer_size > s->size_in_bits); + + s->buf_end = buffer + buffer_size; + s->buf_ptr = buffer + (s->buf_ptr - s->buf); + s->buf = buffer; + s->size_in_bits = 8 * buffer_size; +} + +/** * @return the total number of bits written to the bitstream. */ static inline int put_bits_count(PutBitContext *s) @@ -87,7 +105,7 @@ static inline void flush_put_bits(PutBitContext *s) s->bit_buf <<= s->bit_left; #endif while (s->bit_left < 32) { - /* XXX: should test end of buffer */ + av_assert0(s->buf_ptr < s->buf_end); #ifdef BITSTREAM_WRITER_LE *s->buf_ptr++ = s->bit_buf; s->bit_buf >>= 8; @@ -101,6 +119,18 @@ static inline void flush_put_bits(PutBitContext *s) s->bit_buf = 0; } +static inline void flush_put_bits_le(PutBitContext *s) +{ + while (s->bit_left < 32) { + av_assert0(s->buf_ptr < s->buf_end); + *s->buf_ptr++ = s->bit_buf; + s->bit_buf >>= 8; + s->bit_left += 8; + } + s->bit_left = 32; + s->bit_buf = 0; +} + #ifdef BITSTREAM_WRITER_LE #define avpriv_align_put_bits align_put_bits_unsupported_here #define avpriv_put_string ff_put_string_unsupported_here @@ -136,7 +166,7 @@ static inline void put_bits(PutBitContext *s, int n, unsigned int value) unsigned int bit_buf; int bit_left; - assert(n <= 31 && value < (1U << n)); + av_assert2(n <= 31 && value < (1U << n)); bit_buf = s->bit_buf; bit_left = s->bit_left; @@ -145,9 +175,14 @@ static inline void put_bits(PutBitContext *s, int n, unsigned int value) #ifdef BITSTREAM_WRITER_LE bit_buf |= value << (32 - bit_left); if (n >= bit_left) { - AV_WL32(s->buf_ptr, bit_buf); - s->buf_ptr += 4; - bit_buf = (bit_left == 32) ? 0 : value >> bit_left; + if (3 < s->buf_end - s->buf_ptr) { + AV_WL32(s->buf_ptr, bit_buf); + s->buf_ptr += 4; + } else { + av_log(NULL, AV_LOG_ERROR, "Internal error, put_bits buffer too small\n"); + av_assert2(0); + } + bit_buf = value >> bit_left; bit_left += 32; } bit_left -= n; @@ -158,8 +193,13 @@ static inline void put_bits(PutBitContext *s, int n, unsigned int value) } else { bit_buf <<= bit_left; bit_buf |= value >> (n - bit_left); - AV_WB32(s->buf_ptr, bit_buf); - s->buf_ptr += 4; + if (3 < s->buf_end - s->buf_ptr) { + AV_WB32(s->buf_ptr, bit_buf); + s->buf_ptr += 4; + } else { + av_log(NULL, AV_LOG_ERROR, "Internal error, put_bits buffer too small\n"); + av_assert2(0); + } bit_left += 32 - n; bit_buf = value; } @@ -169,11 +209,39 @@ static inline void put_bits(PutBitContext *s, int n, unsigned int value) s->bit_left = bit_left; } +static inline void put_bits_le(PutBitContext *s, int n, unsigned int value) +{ + unsigned int bit_buf; + int bit_left; + + av_assert2(n <= 31 && value < (1U << n)); + + bit_buf = s->bit_buf; + bit_left = s->bit_left; + + bit_buf |= value << (32 - bit_left); + if (n >= bit_left) { + if (3 < s->buf_end - s->buf_ptr) { + AV_WL32(s->buf_ptr, bit_buf); + s->buf_ptr += 4; + } else { + av_log(NULL, AV_LOG_ERROR, "Internal error, put_bits buffer too small\n"); + av_assert2(0); + } + bit_buf = value >> bit_left; + bit_left += 32; + } + bit_left -= n; + + s->bit_buf = bit_buf; + s->bit_left = bit_left; +} + static inline void put_sbits(PutBitContext *pb, int n, int32_t value) { - assert(n >= 0 && n <= 31); + av_assert2(n >= 0 && n <= 31); - put_bits(pb, n, value & ((1 << n) - 1)); + put_bits(pb, n, av_mod_uintp2(value, n)); } /** @@ -181,15 +249,72 @@ static inline void put_sbits(PutBitContext *pb, int n, int32_t value) */ static void av_unused put_bits32(PutBitContext *s, uint32_t value) { - int lo = value & 0xffff; - int hi = value >> 16; + unsigned int bit_buf; + int bit_left; + + bit_buf = s->bit_buf; + bit_left = s->bit_left; + #ifdef BITSTREAM_WRITER_LE - put_bits(s, 16, lo); - put_bits(s, 16, hi); + bit_buf |= value << (32 - bit_left); + if (3 < s->buf_end - s->buf_ptr) { + AV_WL32(s->buf_ptr, bit_buf); + s->buf_ptr += 4; + } else { + av_log(NULL, AV_LOG_ERROR, "Internal error, put_bits buffer too small\n"); + av_assert2(0); + } + bit_buf = (uint64_t)value >> bit_left; #else - put_bits(s, 16, hi); - put_bits(s, 16, lo); + bit_buf = (uint64_t)bit_buf << bit_left; + bit_buf |= value >> (32 - bit_left); + if (3 < s->buf_end - s->buf_ptr) { + AV_WB32(s->buf_ptr, bit_buf); + s->buf_ptr += 4; + } else { + av_log(NULL, AV_LOG_ERROR, "Internal error, put_bits buffer too small\n"); + av_assert2(0); + } + bit_buf = value; #endif + + s->bit_buf = bit_buf; + s->bit_left = bit_left; +} + +/** + * Write up to 64 bits into a bitstream. + */ +static inline void put_bits64(PutBitContext *s, int n, uint64_t value) +{ + av_assert2((n == 64) || (n < 64 && value < (UINT64_C(1) << n))); + + if (n < 32) + put_bits(s, n, value); + else if (n == 32) + put_bits32(s, value); + else if (n < 64) { + uint32_t lo = value & 0xffffffff; + uint32_t hi = value >> 32; +#ifdef BITSTREAM_WRITER_LE + put_bits32(s, lo); + put_bits(s, n - 32, hi); +#else + put_bits(s, n - 32, hi); + put_bits32(s, lo); +#endif + } else { + uint32_t lo = value & 0xffffffff; + uint32_t hi = value >> 32; +#ifdef BITSTREAM_WRITER_LE + put_bits32(s, lo); + put_bits32(s, hi); +#else + put_bits32(s, hi); + put_bits32(s, lo); +#endif + + } } /** @@ -207,8 +332,9 @@ static inline uint8_t *put_bits_ptr(PutBitContext *s) */ static inline void skip_put_bytes(PutBitContext *s, int n) { - assert((put_bits_count(s) & 7) == 0); - assert(s->bit_left == 32); + av_assert2((put_bits_count(s) & 7) == 0); + av_assert2(s->bit_left == 32); + av_assert0(n <= s->buf_end - s->buf_ptr); s->buf_ptr += n; } @@ -231,7 +357,9 @@ static inline void skip_put_bits(PutBitContext *s, int n) */ static inline void set_put_bits_buffer_size(PutBitContext *s, int size) { + av_assert0(size <= INT_MAX/8 - 32); s->buf_end = s->buf + size; + s->size_in_bits = 8*size; } #endif /* AVCODEC_PUT_BITS_H */ |