mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-11-13 21:01:14 +00:00
99947d0592
GstBitWriter provides a bit writer that can write any number of bits to a pre-allocated memory buffer. Helper functions are also provided to write any number of bits from 8, 16, 32 and 64 bit variables. Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
361 lines
10 KiB
C
361 lines
10 KiB
C
/*
|
|
* gstbitwriter.h - bitstream writer
|
|
*
|
|
* Copyright (C) 2013 Intel Corporation
|
|
*
|
|
* This library 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.
|
|
*
|
|
* This library 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 this library; if not, write to the Free
|
|
* Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
|
|
* Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#ifndef GST_BIT_WRITER_H
|
|
#define GST_BIT_WRITER_H
|
|
|
|
#include <gst/gst.h>
|
|
#include <string.h>
|
|
|
|
G_BEGIN_DECLS
|
|
|
|
#define GST_BIT_WRITER_DATA(writer) ((writer)->data)
|
|
#define GST_BIT_WRITER_BIT_SIZE(writer) ((writer)->bit_size)
|
|
#define GST_BIT_WRITER(writer) ((GstBitWriter *) (writer))
|
|
|
|
typedef struct _GstBitWriter GstBitWriter;
|
|
|
|
/**
|
|
* GstBitWriter:
|
|
* @data: Allocated @data for bit writer to write
|
|
* @bit_size: Size of written @data in bits
|
|
*
|
|
* Private:
|
|
* @bit_capacity: Capacity of the allocated @data
|
|
* @auto_grow: @data space can auto grow
|
|
*
|
|
* A bit writer instance.
|
|
*/
|
|
struct _GstBitWriter
|
|
{
|
|
guint8 *data;
|
|
guint bit_size;
|
|
|
|
/*< private >*/
|
|
guint bit_capacity;
|
|
gboolean auto_grow;
|
|
gpointer _gst_reserved[GST_PADDING];
|
|
};
|
|
|
|
GstBitWriter *
|
|
gst_bit_writer_new (guint32 reserved_bits) G_GNUC_MALLOC;
|
|
|
|
GstBitWriter *
|
|
gst_bit_writer_new_fill (guint8 * data, guint bits) G_GNUC_MALLOC;
|
|
|
|
void
|
|
gst_bit_writer_free (GstBitWriter * writer, gboolean free_data);
|
|
|
|
void
|
|
gst_bit_writer_init (GstBitWriter * bitwriter, guint32 reserved_bits);
|
|
|
|
void
|
|
gst_bit_writer_init_fill (GstBitWriter * bitwriter, guint8 * data, guint bits);
|
|
|
|
void
|
|
gst_bit_writer_clear (GstBitWriter * bitwriter, gboolean free_data);
|
|
|
|
guint
|
|
gst_bit_writer_get_size (GstBitWriter * bitwriter);
|
|
|
|
guint8 *
|
|
gst_bit_writer_get_data (GstBitWriter * bitwriter);
|
|
|
|
gboolean
|
|
gst_bit_writer_set_pos (GstBitWriter * bitwriter, guint pos);
|
|
|
|
guint
|
|
gst_bit_writer_get_space (GstBitWriter * bitwriter);
|
|
|
|
gboolean
|
|
gst_bit_writer_put_bits_uint8 (GstBitWriter * bitwriter,
|
|
guint8 value, guint nbits);
|
|
|
|
gboolean
|
|
gst_bit_writer_put_bits_uint16 (GstBitWriter * bitwriter,
|
|
guint16 value, guint nbits);
|
|
|
|
gboolean
|
|
gst_bit_writer_put_bits_uint32 (GstBitWriter * bitwriter,
|
|
guint32 value, guint nbits);
|
|
|
|
gboolean
|
|
gst_bit_writer_put_bits_uint64 (GstBitWriter * bitwriter,
|
|
guint64 value, guint nbits);
|
|
|
|
gboolean
|
|
gst_bit_writer_put_bytes (GstBitWriter * bitwriter, const guint8 * data,
|
|
guint nbytes);
|
|
|
|
gboolean
|
|
gst_bit_writer_align_bytes (GstBitWriter * bitwriter, guint8 trailing_bit);
|
|
|
|
static const guint8 _gst_bit_writer_bit_filling_mask[9] = {
|
|
0x00, 0x01, 0x03, 0x07,
|
|
0x0F, 0x1F, 0x3F, 0x7F,
|
|
0xFF
|
|
};
|
|
|
|
/* Aligned to 256 bytes */
|
|
#define __GST_BITS_WRITER_ALIGNMENT_MASK 2047
|
|
#define __GST_BITS_WRITER_ALIGNED(bitsize) \
|
|
(((bitsize) + __GST_BITS_WRITER_ALIGNMENT_MASK)&(~__GST_BITS_WRITER_ALIGNMENT_MASK))
|
|
|
|
static inline gboolean
|
|
_gst_bit_writer_check_space (GstBitWriter * bitwriter, guint32 bits)
|
|
{
|
|
guint32 new_bit_size = bits + bitwriter->bit_size;
|
|
guint32 clear_pos;
|
|
|
|
g_assert (bitwriter->bit_size <= bitwriter->bit_capacity);
|
|
if (new_bit_size <= bitwriter->bit_capacity)
|
|
return TRUE;
|
|
|
|
if (!bitwriter->auto_grow)
|
|
return FALSE;
|
|
|
|
/* auto grow space */
|
|
new_bit_size = __GST_BITS_WRITER_ALIGNED (new_bit_size);
|
|
g_assert (new_bit_size
|
|
&& ((new_bit_size & __GST_BITS_WRITER_ALIGNMENT_MASK) == 0));
|
|
clear_pos = ((bitwriter->bit_size + 7) >> 3);
|
|
bitwriter->data = g_realloc (bitwriter->data, (new_bit_size >> 3));
|
|
memset (bitwriter->data + clear_pos, 0, (new_bit_size >> 3) - clear_pos);
|
|
bitwriter->bit_capacity = new_bit_size;
|
|
return TRUE;
|
|
}
|
|
|
|
#undef __GST_BITS_WRITER_ALIGNMENT_MASK
|
|
#undef __GST_BITS_WRITER_ALIGNED
|
|
|
|
#define __GST_BIT_WRITER_WRITE_BITS_UNCHECKED(bits) \
|
|
static inline void \
|
|
gst_bit_writer_put_bits_uint##bits##_unchecked( \
|
|
GstBitWriter *bitwriter, \
|
|
guint##bits value, \
|
|
guint nbits \
|
|
) \
|
|
{ \
|
|
guint byte_pos, bit_offset; \
|
|
guint8 *cur_byte; \
|
|
guint fill_bits; \
|
|
\
|
|
byte_pos = (bitwriter->bit_size >> 3); \
|
|
bit_offset = (bitwriter->bit_size & 0x07); \
|
|
cur_byte = bitwriter->data + byte_pos; \
|
|
g_assert (nbits <= bits); \
|
|
g_assert( bit_offset < 8 && \
|
|
bitwriter->bit_size <= bitwriter->bit_capacity); \
|
|
\
|
|
while (nbits) { \
|
|
fill_bits = ((8 - bit_offset) < nbits ? (8 - bit_offset) : nbits); \
|
|
nbits -= fill_bits; \
|
|
bitwriter->bit_size += fill_bits; \
|
|
\
|
|
*cur_byte |= (((value >> nbits) & _gst_bit_writer_bit_filling_mask[fill_bits]) \
|
|
<< (8 - bit_offset - fill_bits)); \
|
|
++cur_byte; \
|
|
bit_offset = 0; \
|
|
} \
|
|
g_assert(cur_byte <= \
|
|
(bitwriter->data + (bitwriter->bit_capacity >> 3))); \
|
|
}
|
|
|
|
__GST_BIT_WRITER_WRITE_BITS_UNCHECKED (8)
|
|
__GST_BIT_WRITER_WRITE_BITS_UNCHECKED (16)
|
|
__GST_BIT_WRITER_WRITE_BITS_UNCHECKED (32)
|
|
__GST_BIT_WRITER_WRITE_BITS_UNCHECKED (64)
|
|
#undef __GST_BIT_WRITER_WRITE_BITS_UNCHECKED
|
|
|
|
static inline guint
|
|
gst_bit_writer_get_size_unchecked (GstBitWriter * bitwriter)
|
|
{
|
|
return GST_BIT_WRITER_BIT_SIZE (bitwriter);
|
|
}
|
|
|
|
static inline guint8 *
|
|
gst_bit_writer_get_data_unchecked (GstBitWriter * bitwriter)
|
|
{
|
|
return GST_BIT_WRITER_DATA (bitwriter);
|
|
}
|
|
|
|
static inline gboolean
|
|
gst_bit_writer_set_pos_unchecked (GstBitWriter * bitwriter, guint pos)
|
|
{
|
|
GST_BIT_WRITER_BIT_SIZE (bitwriter) = pos;
|
|
return TRUE;
|
|
}
|
|
|
|
static inline guint
|
|
gst_bit_writer_get_space_unchecked (GstBitWriter * bitwriter)
|
|
{
|
|
return bitwriter->bit_capacity - bitwriter->bit_size;
|
|
}
|
|
|
|
static inline void
|
|
gst_bit_writer_put_bytes_unchecked (GstBitWriter * bitwriter,
|
|
const guint8 * data, guint nbytes)
|
|
{
|
|
if ((bitwriter->bit_size & 0x07) == 0) {
|
|
memcpy (&bitwriter->data[bitwriter->bit_size >> 3], data, nbytes);
|
|
bitwriter->bit_size += (nbytes << 3);
|
|
} else {
|
|
g_assert (0);
|
|
while (nbytes) {
|
|
gst_bit_writer_put_bits_uint8_unchecked (bitwriter, *data, 8);
|
|
--nbytes;
|
|
++data;
|
|
}
|
|
}
|
|
}
|
|
|
|
static inline void
|
|
gst_bit_writer_align_bytes_unchecked (GstBitWriter * bitwriter,
|
|
guint8 trailing_bit)
|
|
{
|
|
guint32 bit_offset, bit_left;
|
|
guint8 value = 0;
|
|
|
|
bit_offset = (bitwriter->bit_size & 0x07);
|
|
if (!bit_offset)
|
|
return;
|
|
|
|
bit_left = 8 - bit_offset;
|
|
if (trailing_bit)
|
|
value = _gst_bit_writer_bit_filling_mask[bit_left];
|
|
return gst_bit_writer_put_bits_uint8_unchecked (bitwriter, value, bit_left);
|
|
}
|
|
|
|
#define __GST_BIT_WRITER_WRITE_BITS_INLINE(bits) \
|
|
static inline gboolean \
|
|
_gst_bit_writer_put_bits_uint##bits##_inline( \
|
|
GstBitWriter *bitwriter, \
|
|
guint##bits value, \
|
|
guint nbits \
|
|
) \
|
|
{ \
|
|
g_return_val_if_fail(bitwriter != NULL, FALSE); \
|
|
g_return_val_if_fail(nbits != 0, FALSE); \
|
|
g_return_val_if_fail(nbits <= bits, FALSE); \
|
|
\
|
|
if (!_gst_bit_writer_check_space(bitwriter, nbits)) \
|
|
return FALSE; \
|
|
gst_bit_writer_put_bits_uint##bits##_unchecked(bitwriter, value, nbits); \
|
|
return TRUE; \
|
|
}
|
|
|
|
__GST_BIT_WRITER_WRITE_BITS_INLINE (8)
|
|
__GST_BIT_WRITER_WRITE_BITS_INLINE (16)
|
|
__GST_BIT_WRITER_WRITE_BITS_INLINE (32)
|
|
__GST_BIT_WRITER_WRITE_BITS_INLINE (64)
|
|
#undef __GST_BIT_WRITER_WRITE_BITS_INLINE
|
|
|
|
static inline guint
|
|
_gst_bit_writer_get_size_inline (GstBitWriter * bitwriter)
|
|
{
|
|
g_return_val_if_fail (bitwriter != NULL, 0);
|
|
|
|
return gst_bit_writer_get_size_unchecked (bitwriter);
|
|
}
|
|
|
|
static inline guint8 *
|
|
_gst_bit_writer_get_data_inline (GstBitWriter * bitwriter)
|
|
{
|
|
g_return_val_if_fail (bitwriter != NULL, NULL);
|
|
|
|
return gst_bit_writer_get_data_unchecked (bitwriter);
|
|
}
|
|
|
|
static inline gboolean
|
|
_gst_bit_writer_set_pos_inline (GstBitWriter * bitwriter, guint pos)
|
|
{
|
|
g_return_val_if_fail (bitwriter != NULL, FALSE);
|
|
g_return_val_if_fail (pos <= bitwriter->bit_capacity, FALSE);
|
|
|
|
return gst_bit_writer_set_pos_unchecked (bitwriter, pos);
|
|
}
|
|
|
|
static inline guint
|
|
_gst_bit_writer_get_space_inline (GstBitWriter * bitwriter)
|
|
{
|
|
g_return_val_if_fail (bitwriter != NULL, 0);
|
|
g_return_val_if_fail (bitwriter->bit_size < bitwriter->bit_capacity, 0);
|
|
|
|
return gst_bit_writer_get_space_unchecked (bitwriter);
|
|
}
|
|
|
|
static inline gboolean
|
|
_gst_bit_writer_put_bytes_inline (GstBitWriter * bitwriter,
|
|
const guint8 * data, guint nbytes)
|
|
{
|
|
g_return_val_if_fail (bitwriter != NULL, FALSE);
|
|
g_return_val_if_fail (data != NULL, FALSE);
|
|
g_return_val_if_fail (nbytes, FALSE);
|
|
|
|
if (!_gst_bit_writer_check_space (bitwriter, nbytes * 8))
|
|
return FALSE;
|
|
|
|
gst_bit_writer_put_bytes_unchecked (bitwriter, data, nbytes);
|
|
return TRUE;
|
|
}
|
|
|
|
static inline gboolean
|
|
_gst_bit_writer_align_bytes_inline (GstBitWriter * bitwriter,
|
|
guint8 trailing_bit)
|
|
{
|
|
g_return_val_if_fail (bitwriter != NULL, FALSE);
|
|
g_return_val_if_fail ((trailing_bit == 0 || trailing_bit == 1), FALSE);
|
|
g_return_val_if_fail (((bitwriter->bit_size + 7) & (~7)) <=
|
|
bitwriter->bit_capacity, FALSE);
|
|
|
|
gst_bit_writer_align_bytes_unchecked (bitwriter, trailing_bit);
|
|
return TRUE;
|
|
}
|
|
|
|
#ifndef GST_BIT_WRITER_DISABLE_INLINES
|
|
#define gst_bit_writer_get_size(bitwriter) \
|
|
_gst_bit_writer_get_size_inline(bitwriter)
|
|
#define gst_bit_writer_get_data(bitwriter) \
|
|
_gst_bit_writer_get_data_inline(bitwriter)
|
|
#define gst_bit_writer_set_pos(bitwriter, pos) \
|
|
G_LIKELY (_gst_bit_writer_set_pos_inline (bitwriter, pos))
|
|
#define gst_bit_writer_get_space(bitwriter) \
|
|
_gst_bit_writer_get_space_inline(bitwriter)
|
|
|
|
#define gst_bit_writer_put_bits_uint8(bitwriter, value, nbits) \
|
|
G_LIKELY (_gst_bit_writer_put_bits_uint8_inline (bitwriter, value, nbits))
|
|
#define gst_bit_writer_put_bits_uint16(bitwriter, value, nbits) \
|
|
G_LIKELY (_gst_bit_writer_put_bits_uint16_inline (bitwriter, value, nbits))
|
|
#define gst_bit_writer_put_bits_uint32(bitwriter, value, nbits) \
|
|
G_LIKELY (_gst_bit_writer_put_bits_uint32_inline (bitwriter, value, nbits))
|
|
#define gst_bit_writer_put_bits_uint64(bitwriter, value, nbits) \
|
|
G_LIKELY (_gst_bit_writer_put_bits_uint64_inline (bitwriter, value, nbits))
|
|
|
|
#define gst_bit_writer_put_bytes(bitwriter, data, nbytes) \
|
|
G_LIKELY (_gst_bit_writer_put_bytes_inline (bitwriter, data, nbytes))
|
|
|
|
#define gst_bit_writer_align_bytes(bitwriter, trailing_bit) \
|
|
G_LIKELY (_gst_bit_writer_align_bytes_inline(bitwriter, trailing_bit))
|
|
#endif
|
|
|
|
G_END_DECLS
|
|
|
|
#endif /* GST_BIT_WRITER_H */
|