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-rw-r--r--libavcodec/put_bits.h172
1 files changed, 150 insertions, 22 deletions
diff --git a/libavcodec/put_bits.h b/libavcodec/put_bits.h
index 17666fac48..1ceb1cc766 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 */
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-14 21:26:19 +0000