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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>
278 lines
6.8 KiB
C
278 lines
6.8 KiB
C
/*
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* gstbitwriter.c - bitstream writer
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*
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* Copyright (C) 2013 Intel Corporation
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public License
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* as published by the Free Software Foundation; either version 2.1
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* of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free
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* Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
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* Boston, MA 02110-1301 USA
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*/
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#define GST_BIT_WRITER_DISABLE_INLINES
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#include "gstbitwriter.h"
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/**
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* gst_bit_writer_init:
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* @bitwriter: a #GstBitWriter instance
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* @reserved_bits: reserved bits to allocate data
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*
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* Initializes a #GstBitWriter instance and allocate @reserved_bits
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* data inside.
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*
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* Cleanup function: gst_bit_writer_clear
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*/
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void
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gst_bit_writer_init (GstBitWriter * bitwriter, guint32 reserved_bits)
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{
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bitwriter->bit_size = 0;
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bitwriter->data = NULL;
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bitwriter->bit_capacity = 0;
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bitwriter->auto_grow = TRUE;
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if (reserved_bits)
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_gst_bit_writer_check_space (bitwriter, reserved_bits);
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}
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/**
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* gst_bit_writer_init_fill:
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* @bitwriter: a #GstBitWriter instance
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* @data: allocated data
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* @bits: size of allocated @data in bits
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*
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* Initializes a #GstBitWriter instance with alocated @data and @bit outside.
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*
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* Cleanup function: gst_bit_writer_clear
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*/
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void
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gst_bit_writer_init_fill (GstBitWriter * bitwriter, guint8 * data, guint bits)
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{
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bitwriter->bit_size = 0;
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bitwriter->data = data;
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bitwriter->bit_capacity = bits;
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bitwriter->auto_grow = FALSE;
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}
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/**
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* gst_bit_writer_clear:
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* @bitwriter: a #GstBitWriter instance
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* @free_data: flag to free #GstBitWriter allocated data
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*
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* Clear a #GstBitWriter instance and destroy allocated data inside
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* if @free_data is %TRUE.
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*/
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void
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gst_bit_writer_clear (GstBitWriter * bitwriter, gboolean free_data)
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{
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if (bitwriter->auto_grow && bitwriter->data && free_data)
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g_free (bitwriter->data);
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bitwriter->data = NULL;
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bitwriter->bit_size = 0;
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bitwriter->bit_capacity = 0;
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}
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/**
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* gst_bit_writer_new:
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* @bitwriter: a #GstBitWriter instance
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* @reserved_bits: reserved bits to allocate data
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*
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* Create a #GstBitWriter instance and allocate @reserved_bits data inside.
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*
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* Free-function: gst_bit_writer_free
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*
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* Returns: a new #GstBitWriter instance
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*/
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GstBitWriter *
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gst_bit_writer_new (guint32 reserved_bits)
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{
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GstBitWriter *ret = g_slice_new0 (GstBitWriter);
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gst_bit_writer_init (ret, reserved_bits);
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return ret;
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}
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/**
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* gst_bit_writer_new_fill:
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* @bitwriter: a #GstBitWriter instance
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* @data: allocated data
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* @bits: size of allocated @data in bits
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*
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* Create a #GstBitWriter instance with allocated @data and @bit outside.
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*
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* Free-function: gst_bit_writer_free
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*
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* Returns: a new #GstBitWriter instance
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*/
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GstBitWriter *
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gst_bit_writer_new_fill (guint8 * data, guint bits)
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{
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GstBitWriter *ret = g_slice_new0 (GstBitWriter);
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gst_bit_writer_init_fill (ret, data, bits);
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return ret;
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}
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/**
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* gst_bit_writer_free:
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* @bitwriter: a #GstBitWriter instance
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* @free_data: flag to free @data which is allocated inside
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*
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* Clear a #GstBitWriter instance and destroy allocated data inside if
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* @free_data is %TRUE
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*/
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void
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gst_bit_writer_free (GstBitWriter * writer, gboolean free_data)
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{
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g_return_if_fail (writer != NULL);
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gst_bit_writer_clear (writer, free_data);
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g_slice_free (GstBitWriter, writer);
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}
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/**
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* gst_bit_writer_get_size:
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* @bitwriter: a #GstBitWriter instance
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*
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* Get size of written @data
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*
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* Returns: size of bits written in @data
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*/
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guint
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gst_bit_writer_get_size (GstBitWriter * bitwriter)
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{
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return _gst_bit_writer_get_size_inline (bitwriter);
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}
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/**
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* gst_bit_writer_get_data:
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* @bitwriter: a #GstBitWriter instance
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*
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* Get written @data pointer
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*
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* Returns: @data pointer
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*/
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guint8 *
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gst_bit_writer_get_data (GstBitWriter * bitwriter)
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{
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return _gst_bit_writer_get_data_inline (bitwriter);
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}
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/**
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* gst_bit_writer_get_data:
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* @bitwriter: a #GstBitWriter instance
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* @pos: new position of data end
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*
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* Set the new postion of data end which should be the new size of @data.
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*
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* Returns: %TRUE if successful, %FALSE otherwise
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*/
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gboolean
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gst_bit_writer_set_pos (GstBitWriter * bitwriter, guint pos)
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{
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return _gst_bit_writer_set_pos_inline (bitwriter, pos);
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}
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/**
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* gst_bit_writer_put_bits_uint8:
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* @bitwriter: a #GstBitWriter instance
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* @value: value of #guint8 to write
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* @nbits: number of bits to write
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*
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* Write @nbits bits of @value to #GstBitWriter.
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*
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* Returns: %TRUE if successful, %FALSE otherwise.
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*/
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/**
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* gst_bit_writer_put_bits_uint16:
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* @bitwriter: a #GstBitWriter instance
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* @value: value of #guint16 to write
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* @nbits: number of bits to write
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*
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* Write @nbits bits of @value to #GstBitWriter.
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*
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* Returns: %TRUE if successful, %FALSE otherwise.
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*/
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/**
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* gst_bit_writer_put_bits_uint32:
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* @bitwriter: a #GstBitWriter instance
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* @value: value of #guint32 to write
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* @nbits: number of bits to write
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*
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* Write @nbits bits of @value to #GstBitWriter.
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*
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* Returns: %TRUE if successful, %FALSE otherwise.
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*/
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/**
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* gst_bit_writer_put_bits_uint64:
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* @bitwriter: a #GstBitWriter instance
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* @value: value of #guint64 to write
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* @nbits: number of bits to write
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*
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* Write @nbits bits of @value to #GstBitWriter.
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*
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* Returns: %TRUE if successful, %FALSE otherwise.
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*/
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#define GST_BIT_WRITER_WRITE_BITS(bits) \
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gboolean \
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gst_bit_writer_put_bits_uint##bits (GstBitWriter *bitwriter, guint##bits value, guint nbits) \
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{ \
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return _gst_bit_writer_put_bits_uint##bits##_inline (bitwriter, value, nbits); \
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}
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GST_BIT_WRITER_WRITE_BITS (8)
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GST_BIT_WRITER_WRITE_BITS (16)
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GST_BIT_WRITER_WRITE_BITS (32)
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GST_BIT_WRITER_WRITE_BITS (64)
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#undef GST_BIT_WRITER_WRITE_BITS
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/**
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* gst_bit_writer_put_bytes:
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* @bitwriter: a #GstBitWriter instance
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* @data: pointer of data to write
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* @nbytes: number of bytes to write
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*
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* Write @nbytes bytes of @data to #GstBitWriter.
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*
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* Returns: %TRUE if successful, %FALSE otherwise.
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*/
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gboolean
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gst_bit_writer_put_bytes (GstBitWriter * bitwriter,
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const guint8 * data, guint nbytes)
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{
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return _gst_bit_writer_put_bytes_inline (bitwriter, data, nbytes);
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}
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/**
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* gst_bit_writer_align_bytes:
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* @bitwriter: a #GstBitWriter instance
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* @trailing_bit: trailing bits of last byte, 0 or 1
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*
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* Write trailing bit to align last byte of @data. @trailing_bit can
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* only be 1 or 0.
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*
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* Returns: %TRUE if successful, %FALSE otherwise.
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*/
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gboolean
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gst_bit_writer_align_bytes (GstBitWriter * bitwriter, guint8 trailing_bit)
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{
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return _gst_bit_writer_align_bytes_inline (bitwriter, trailing_bit);
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}
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