gstreamer/libs/gst/base/gstbitwriter.c
2019-10-06 11:12:11 -04:00

444 lines
11 KiB
C

/*
* gstbitwriter.c - bitstream writer
*
* Copyright (C) 2013 Intel Corporation
* Copyright (C) 2018 Igalia, S.L.
*
* 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
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#define GST_BIT_WRITER_DISABLE_INLINES
#include "gstbitwriter.h"
/**
* SECTION:gstbitwriter
* @title: GstBitWriter
* @short_description: Writes any number of bits into a memory buffer
*
* #GstBitWriter provides a bit writer that can write any number of
* bits into a memory buffer. It provides functions for writing any
* number of bits into 8, 16, 32 and 64 bit variables.
*/
/**
* gst_bit_writer_new: (skip)
*
* Creates a new, empty #GstBitWriter instance.
*
* Free-function: gst_bit_writer_free
*
* Returns: (transfer full): a new, empty #GstByteWriter instance
**/
GstBitWriter *
gst_bit_writer_new (void)
{
GstBitWriter *ret = g_slice_new0 (GstBitWriter);
ret->owned = TRUE;
ret->auto_grow = TRUE;
return ret;
}
/**
* gst_bit_writer_new_with_size: (skip)
* @size: Initial size of data in bytes
* @fixed: If %TRUE the data can't be reallocated
*
* Creates a #GstBitWriter instance with the given initial data size.
*
* Free-function: gst_bit_writer_free
*
* Returns: (transfer full): a new #GstBitWriter instance
*/
GstBitWriter *
gst_bit_writer_new_with_size (guint size, gboolean fixed)
{
GstBitWriter *ret = g_slice_new0 (GstBitWriter);
gst_bit_writer_init_with_size (ret, size, fixed);
return ret;
}
/**
* gst_bit_writer_new_with_data: (skip)
* @data: Memory area for writing
* @size: Size of @data in bytes
* @initialized: if %TRUE the complete data can be read from the beginning
*
* Creates a new #GstBitWriter instance with the given memory area. If
* @initialized is %TRUE it is possible to read @size bits from the
* #GstBitWriter from the beginning.
*
* Free-function: gst_bit_writer_free
*
* Returns: (transfer full): a new #GstBitWriter instance
*/
GstBitWriter *
gst_bit_writer_new_with_data (guint8 * data, guint size, gboolean initialized)
{
GstBitWriter *ret = g_slice_new0 (GstBitWriter);
gst_bit_writer_init_with_data (ret, data, size, initialized);
return ret;
}
/**
* gst_bit_writer_init: (skip)
* @bitwriter: #GstBitWriter instance
*
* Initializes @bitwriter to an empty instance.
**/
void
gst_bit_writer_init (GstBitWriter * bitwriter)
{
g_return_if_fail (bitwriter != NULL);
memset (bitwriter, 0, sizeof (GstBitWriter));
bitwriter->owned = TRUE;
bitwriter->auto_grow = TRUE;
}
/**
* gst_bit_writer_init_with_size: (skip)
* @bitwriter: #GstBitWriter instance
* @size: the size on bytes to allocate for data
* @fixed: If %TRUE the data can't be reallocated
*
* Initializes a #GstBitWriter instance and allocates the given data
* @size.
*/
void
gst_bit_writer_init_with_size (GstBitWriter * bitwriter, guint size,
gboolean fixed)
{
g_return_if_fail (bitwriter != NULL);
gst_bit_writer_init (bitwriter);
_gst_bit_writer_check_remaining (bitwriter, size << 3);
bitwriter->auto_grow = !fixed;
}
/**
* gst_bit_writer_init_with_data: (skip)
* @bitwriter: #GstBitWriter instance
* @data: (array length=size) (transfer none): Memory area for writing
* @size: Size of @data in bytes
* @initialized: If %TRUE the complete data can be read from the beginning
*
* Initializes @bitwriter with the given memory area @data. IF
* @initialized is %TRUE it is possible to read @size bits from the
* #GstBitWriter from the beginning.
*/
void
gst_bit_writer_init_with_data (GstBitWriter * bitwriter, guint8 * data,
guint size, gboolean initialized)
{
g_return_if_fail (bitwriter != NULL);
gst_bit_writer_init (bitwriter);
bitwriter->data = data;
bitwriter->bit_capacity = size * 8;
bitwriter->bit_size = (initialized) ? size << 3 : 0;
bitwriter->auto_grow = FALSE;
bitwriter->owned = FALSE;
}
/**
* gst_bit_writer_reset:
* @bitwriter: #GstBitWriter instance
*
* Resets @bitwriter and frees the data if it's owned by @bitwriter.
*/
void
gst_bit_writer_reset (GstBitWriter * bitwriter)
{
g_return_if_fail (bitwriter != NULL);
if (bitwriter->owned)
g_free (bitwriter->data);
memset (bitwriter, 0, sizeof (GstBitWriter));
}
/**
* gst_bit_writer_reset_and_get_data:
* @bitwriter: a #GstBitWriter instance
*
* Resets @bitwriter and returns the current data.
*
* Free-function: g_free
*
* Returns: (array) (transfer full): the current data. g_free() after
* usage.
**/
guint8 *
gst_bit_writer_reset_and_get_data (GstBitWriter * bitwriter)
{
guint8 *data;
g_return_val_if_fail (bitwriter != NULL, NULL);
data = bitwriter->data;
if (bitwriter->owned)
data = g_memdup (data, bitwriter->bit_size >> 3);
gst_bit_writer_reset (bitwriter);
return data;
}
/**
* gst_bit_writer_reset_and_get_buffer:
* @bitwriter: a #GstBitWriter instance
*
* Resets @bitwriter and returns the current data as #GstBuffer.
*
* Free-function: gst_buffer_unref
*
* Returns: (transfer full): a new allocated #GstBuffer wrapping the
* current data. gst_buffer_unref() after usage.
**/
GstBuffer *
gst_bit_writer_reset_and_get_buffer (GstBitWriter * bitwriter)
{
GstBuffer *buffer;
gpointer data;
gsize size;
g_return_val_if_fail (bitwriter != NULL, NULL);
size = bitwriter->bit_size >> 3;
data = gst_bit_writer_reset_and_get_data (bitwriter);
/* we cannot rely on buffers allocated externally, thus let's dup
* the data */
if (data && !bitwriter->owned)
data = g_memdup (data, size);
buffer = gst_buffer_new ();
if (data != NULL) {
gst_buffer_append_memory (buffer,
gst_memory_new_wrapped (0, data, size, 0, size, data, g_free));
}
return buffer;
}
/**
* gst_bit_writer_free:
* @bitwriter: (in) (transfer full): #GstBitWriter instance
*
* Frees @bitwriter and the allocated data inside.
*/
void
gst_bit_writer_free (GstBitWriter * bitwriter)
{
g_return_if_fail (bitwriter != NULL);
gst_bit_writer_reset (bitwriter);
g_slice_free (GstBitWriter, bitwriter);
}
/**
* gst_bit_writer_free_and_get_data:
* @bitwriter: (in) (transfer full): #GstBitWriter instance
*
* Frees @bitwriter without destroying the internal data, which is
* returned.
*
* Free-function: g_free
*
* Returns: (array) (transfer full): the current data. g_free() after
* usage.
**/
guint8 *
gst_bit_writer_free_and_get_data (GstBitWriter * bitwriter)
{
guint8 *data;
g_return_val_if_fail (bitwriter != NULL, NULL);
data = gst_bit_writer_reset_and_get_data (bitwriter);
g_slice_free (GstBitWriter, bitwriter);
return data;
}
/**
* gst_bit_writer_free_and_get_buffer:
* @bitwriter: (in) (transfer full): #GstBitWriter instance
*
* Frees @bitwriter without destroying the internal data, which is
* returned as #GstBuffer.
*
* Free-function: gst_buffer_unref
*
* Returns: (transfer full): a new allocated #GstBuffer wrapping the
* data inside. gst_buffer_unref() after usage.
**/
GstBuffer *
gst_bit_writer_free_and_get_buffer (GstBitWriter * bitwriter)
{
GstBuffer *buffer;
g_return_val_if_fail (bitwriter != NULL, NULL);
buffer = gst_bit_writer_reset_and_get_buffer (bitwriter);
g_slice_free (GstBitWriter, bitwriter);
return buffer;
}
/**
* gst_bit_writer_get_size:
* @bitwriter: a #GstBitWriter instance
*
* Get size of written @data
*
* Returns: size of bits written in @data
*/
guint
gst_bit_writer_get_size (const GstBitWriter * bitwriter)
{
return _gst_bit_writer_get_size_inline (bitwriter);
}
/**
* gst_bit_writer_get_data:
* @bitwriter: a #GstBitWriter instance
*
* Get written data pointer
*
* Returns: data pointer
*/
guint8 *
gst_bit_writer_get_data (const GstBitWriter * bitwriter)
{
return _gst_bit_writer_get_data_inline (bitwriter);
}
/**
* gst_bit_writer_get_pos:
* @bitwriter: a #GstBitWriter instance
* @pos: The new position in bits
*
* Set the new position of data end which should be the new size of @data.
*
* Returns: %TRUE if successful, %FALSE otherwise
*/
gboolean
gst_bit_writer_set_pos (GstBitWriter * bitwriter, guint pos)
{
return _gst_bit_writer_set_pos_inline (bitwriter, pos);
}
/**
* gst_bit_writer_put_bits_uint8:
* @bitwriter: a #GstBitWriter instance
* @value: value of #guint8 to write
* @nbits: number of bits to write
*
* Write @nbits bits of @value to #GstBitWriter.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_bit_writer_put_bits_uint16:
* @bitwriter: a #GstBitWriter instance
* @value: value of #guint16 to write
* @nbits: number of bits to write
*
* Write @nbits bits of @value to #GstBitWriter.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_bit_writer_put_bits_uint32:
* @bitwriter: a #GstBitWriter instance
* @value: value of #guint32 to write
* @nbits: number of bits to write
*
* Write @nbits bits of @value to #GstBitWriter.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_bit_writer_put_bits_uint64:
* @bitwriter: a #GstBitWriter instance
* @value: value of #guint64 to write
* @nbits: number of bits to write
*
* Write @nbits bits of @value to #GstBitWriter.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/* *INDENT-OFF* */
#define GST_BIT_WRITER_WRITE_BITS(bits) \
gboolean \
gst_bit_writer_put_bits_uint##bits (GstBitWriter *bitwriter, guint##bits value, guint nbits) \
{ \
return _gst_bit_writer_put_bits_uint##bits##_inline (bitwriter, value, nbits); \
}
GST_BIT_WRITER_WRITE_BITS (8)
GST_BIT_WRITER_WRITE_BITS (16)
GST_BIT_WRITER_WRITE_BITS (32)
GST_BIT_WRITER_WRITE_BITS (64)
#undef GST_BIT_WRITER_WRITE_BITS
/* *INDENT-ON* */
/**
* gst_bit_writer_put_bytes:
* @bitwriter: a #GstBitWriter instance
* @data: pointer of data to write
* @nbytes: number of bytes to write
*
* Write @nbytes bytes of @data to #GstBitWriter.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
gboolean
gst_bit_writer_put_bytes (GstBitWriter * bitwriter, const guint8 * data,
guint nbytes)
{
return _gst_bit_writer_put_bytes_inline (bitwriter, data, nbytes);
}
/**
* gst_bit_writer_align_bytes:
* @bitwriter: a #GstBitWriter instance
* @trailing_bit: trailing bits of last byte, 0 or 1
*
* Write trailing bit to align last byte of @data. @trailing_bit can
* only be 1 or 0.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
gboolean
gst_bit_writer_align_bytes (GstBitWriter * bitwriter, guint8 trailing_bit)
{
return _gst_bit_writer_align_bytes_inline (bitwriter, trailing_bit);
}