/* GStreamer byte reader
*
* Copyright (C) 2008 Sebastian Dröge <sebastian.droege@collabora.co.uk>.
* Copyright (C) 2009,2014 Tim-Philipp Müller <tim centricular net>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#define GST_BYTE_READER_DISABLE_INLINES
#include "gstbytereader.h"
#include <string.h>
/**
* SECTION:gstbytereader
* @title: GstByteReader
* @short_description: Reads different integer, string and floating point
* types from a memory buffer
*
* #GstByteReader provides a byte reader that can read different integer and
* floating point types from a memory buffer. It provides functions for reading
* signed/unsigned, little/big endian integers of 8, 16, 24, 32 and 64 bits
* and functions for reading little/big endian floating points numbers of
* 32 and 64 bits. It also provides functions to read NUL-terminated strings
* in various character encodings.
*/
/**
* gst_byte_reader_new: (skip)
* @data: (in) (transfer none) (array length=size): data from which the
* #GstByteReader should read
* @size: Size of @data in bytes
*
* Create a new #GstByteReader instance, which will read from @data.
*
* Free-function: gst_byte_reader_free
*
* Returns: (transfer full): a new #GstByteReader instance
*/
GstByteReader *
gst_byte_reader_new (const guint8 * data, guint size)
{
GstByteReader *ret = g_slice_new0 (GstByteReader);
ret->data = data;
ret->size = size;
return ret;
}
/**
* gst_byte_reader_free:
* @reader: (in) (transfer full): a #GstByteReader instance
*
* Frees a #GstByteReader instance, which was previously allocated by
* gst_byte_reader_new().
*/
void
gst_byte_reader_free (GstByteReader * reader)
{
g_return_if_fail (reader != NULL);
g_slice_free (GstByteReader, reader);
}
/**
* gst_byte_reader_init:
* @reader: a #GstByteReader instance
* @data: (in) (transfer none) (array length=size): data from which
* the #GstByteReader should read
* @size: Size of @data in bytes
*
* Initializes a #GstByteReader instance to read from @data. This function
* can be called on already initialized instances.
*/
void
gst_byte_reader_init (GstByteReader * reader, const guint8 * data, guint size)
{
g_return_if_fail (reader != NULL);
reader->data = data;
reader->size = size;
reader->byte = 0;
}
/**
* gst_byte_reader_peek_sub_reader: (skip)
* @reader: an existing and initialized #GstByteReader instance
* @sub_reader: a #GstByteReader instance to initialize as sub-reader
* @size: size of @sub_reader in bytes
*
* Initializes a #GstByteReader sub-reader instance to contain @size bytes of
* data from the current position of @reader. This is useful to read chunked
* formats and make sure that one doesn't read beyond the size of the sub-chunk.
*
* Unlike gst_byte_reader_get_sub_reader(), this function does not modify the
* current position of @reader.
*
* Returns: FALSE on error or if @reader does not contain @size more bytes from
* the current position, and otherwise TRUE
*
* Since: 1.6
*/
gboolean
gst_byte_reader_peek_sub_reader (GstByteReader * reader,
GstByteReader * sub_reader, guint size)
{
return _gst_byte_reader_peek_sub_reader_inline (reader, sub_reader, size);
}
/**
* gst_byte_reader_get_sub_reader: (skip)
* @reader: an existing and initialized #GstByteReader instance
* @sub_reader: a #GstByteReader instance to initialize as sub-reader
* @size: size of @sub_reader in bytes
*
* Initializes a #GstByteReader sub-reader instance to contain @size bytes of
* data from the current position of @reader. This is useful to read chunked
* formats and make sure that one doesn't read beyond the size of the sub-chunk.
*
* Unlike gst_byte_reader_peek_sub_reader(), this function also modifies the
* position of @reader and moves it forward by @size bytes.
*
* Returns: FALSE on error or if @reader does not contain @size more bytes from
* the current position, and otherwise TRUE
*
* Since: 1.6
*/
gboolean
gst_byte_reader_get_sub_reader (GstByteReader * reader,
GstByteReader * sub_reader, guint size)
{
return _gst_byte_reader_get_sub_reader_inline (reader, sub_reader, size);
}
/**
* gst_byte_reader_set_pos:
* @reader: a #GstByteReader instance
* @pos: The new position in bytes
*
* Sets the new position of a #GstByteReader instance to @pos in bytes.
*
* Returns: %TRUE if the position could be set successfully, %FALSE
* otherwise.
*/
gboolean
gst_byte_reader_set_pos (GstByteReader * reader, guint pos)
{
g_return_val_if_fail (reader != NULL, FALSE);
if (pos > reader->size)
return FALSE;
reader->byte = pos;
return TRUE;
}
/**
* gst_byte_reader_get_pos:
* @reader: a #GstByteReader instance
*
* Returns the current position of a #GstByteReader instance in bytes.
*
* Returns: The current position of @reader in bytes.
*/
guint
gst_byte_reader_get_pos (const GstByteReader * reader)
{
return _gst_byte_reader_get_pos_inline (reader);
}
/**
* gst_byte_reader_get_remaining:
* @reader: a #GstByteReader instance
*
* Returns the remaining number of bytes of a #GstByteReader instance.
*
* Returns: The remaining number of bytes of @reader instance.
*/
guint
gst_byte_reader_get_remaining (const GstByteReader * reader)
{
return _gst_byte_reader_get_remaining_inline (reader);
}
/**
* gst_byte_reader_get_size:
* @reader: a #GstByteReader instance
*
* Returns the total number of bytes of a #GstByteReader instance.
*
* Returns: The total number of bytes of @reader instance.
*/
guint
gst_byte_reader_get_size (const GstByteReader * reader)
{
return _gst_byte_reader_get_size_inline (reader);
}
#define gst_byte_reader_get_remaining _gst_byte_reader_get_remaining_inline
#define gst_byte_reader_get_size _gst_byte_reader_get_size_inline
/**
* gst_byte_reader_skip:
* @reader: a #GstByteReader instance
* @nbytes: the number of bytes to skip
*
* Skips @nbytes bytes of the #GstByteReader instance.
*
* Returns: %TRUE if @nbytes bytes could be skipped, %FALSE otherwise.
*/
gboolean
gst_byte_reader_skip (GstByteReader * reader, guint nbytes)
{
return _gst_byte_reader_skip_inline (reader, nbytes);
}
/**
* gst_byte_reader_get_uint8:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint8 to store the result
*
* Read an unsigned 8 bit integer into @val and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_int8:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint8 to store the result
*
* Read a signed 8 bit integer into @val and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_uint8:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint8 to store the result
*
* Read an unsigned 8 bit integer into @val but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_int8:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint8 to store the result
*
* Read a signed 8 bit integer into @val but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_uint16_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint16 to store the result
*
* Read an unsigned 16 bit little endian integer into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_int16_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint16 to store the result
*
* Read a signed 16 bit little endian integer into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_uint16_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint16 to store the result
*
* Read an unsigned 16 bit little endian integer into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_int16_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint16 to store the result
*
* Read a signed 16 bit little endian integer into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_uint16_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint16 to store the result
*
* Read an unsigned 16 bit big endian integer into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_int16_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint16 to store the result
*
* Read a signed 16 bit big endian integer into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_uint16_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint16 to store the result
*
* Read an unsigned 16 bit big endian integer into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_int16_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint16 to store the result
*
* Read a signed 16 bit big endian integer into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_uint24_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint32 to store the result
*
* Read an unsigned 24 bit little endian integer into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_int24_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint32 to store the result
*
* Read a signed 24 bit little endian integer into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_uint24_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint32 to store the result
*
* Read an unsigned 24 bit little endian integer into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_int24_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint32 to store the result
*
* Read a signed 24 bit little endian integer into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_uint24_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint32 to store the result
*
* Read an unsigned 24 bit big endian integer into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_int24_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint32 to store the result
*
* Read a signed 24 bit big endian integer into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_uint24_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint32 to store the result
*
* Read an unsigned 24 bit big endian integer into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_int24_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint32 to store the result
*
* Read a signed 24 bit big endian integer into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_uint32_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint32 to store the result
*
* Read an unsigned 32 bit little endian integer into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_int32_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint32 to store the result
*
* Read a signed 32 bit little endian integer into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_uint32_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint32 to store the result
*
* Read an unsigned 32 bit little endian integer into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_int32_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint32 to store the result
*
* Read a signed 32 bit little endian integer into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_uint32_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint32 to store the result
*
* Read an unsigned 32 bit big endian integer into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_int32_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint32 to store the result
*
* Read a signed 32 bit big endian integer into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_uint32_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint32 to store the result
*
* Read an unsigned 32 bit big endian integer into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_int32_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint32 to store the result
*
* Read a signed 32 bit big endian integer into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_uint64_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint64 to store the result
*
* Read an unsigned 64 bit little endian integer into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_int64_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint64 to store the result
*
* Read a signed 64 bit little endian integer into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_uint64_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint64 to store the result
*
* Read an unsigned 64 bit little endian integer into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_int64_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint64 to store the result
*
* Read a signed 64 bit little endian integer into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_uint64_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint64 to store the result
*
* Read an unsigned 64 bit big endian integer into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_int64_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint64 to store the result
*
* Read a signed 64 bit big endian integer into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_uint64_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #guint64 to store the result
*
* Read an unsigned 64 bit big endian integer into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_int64_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gint64 to store the result
*
* Read a signed 64 bit big endian integer into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
#define GST_BYTE_READER_PEEK_GET(bits,type,name) \
gboolean \
gst_byte_reader_get_##name (GstByteReader * reader, type * val) \
{ \
return _gst_byte_reader_get_##name##_inline (reader, val); \
} \
\
gboolean \
gst_byte_reader_peek_##name (const GstByteReader * reader, type * val) \
{ \
return _gst_byte_reader_peek_##name##_inline (reader, val); \
}
/* *INDENT-OFF* */
GST_BYTE_READER_PEEK_GET(8,guint8,uint8)
GST_BYTE_READER_PEEK_GET(8,gint8,int8)
GST_BYTE_READER_PEEK_GET(16,guint16,uint16_le)
GST_BYTE_READER_PEEK_GET(16,guint16,uint16_be)
GST_BYTE_READER_PEEK_GET(16,gint16,int16_le)
GST_BYTE_READER_PEEK_GET(16,gint16,int16_be)
GST_BYTE_READER_PEEK_GET(24,guint32,uint24_le)
GST_BYTE_READER_PEEK_GET(24,guint32,uint24_be)
GST_BYTE_READER_PEEK_GET(24,gint32,int24_le)
GST_BYTE_READER_PEEK_GET(24,gint32,int24_be)
GST_BYTE_READER_PEEK_GET(32,guint32,uint32_le)
GST_BYTE_READER_PEEK_GET(32,guint32,uint32_be)
GST_BYTE_READER_PEEK_GET(32,gint32,int32_le)
GST_BYTE_READER_PEEK_GET(32,gint32,int32_be)
GST_BYTE_READER_PEEK_GET(64,guint64,uint64_le)
GST_BYTE_READER_PEEK_GET(64,guint64,uint64_be)
GST_BYTE_READER_PEEK_GET(64,gint64,int64_le)
GST_BYTE_READER_PEEK_GET(64,gint64,int64_be)
/**
* gst_byte_reader_get_float32_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gfloat to store the result
*
* Read a 32 bit little endian floating point value into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_float32_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gfloat to store the result
*
* Read a 32 bit little endian floating point value into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_float32_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gfloat to store the result
*
* Read a 32 bit big endian floating point value into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_float32_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gfloat to store the result
*
* Read a 32 bit big endian floating point value into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_float64_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gdouble to store the result
*
* Read a 64 bit little endian floating point value into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_float64_le:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gdouble to store the result
*
* Read a 64 bit little endian floating point value into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_get_float64_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gdouble to store the result
*
* Read a 64 bit big endian floating point value into @val
* and update the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_float64_be:
* @reader: a #GstByteReader instance
* @val: (out): Pointer to a #gdouble to store the result
*
* Read a 64 bit big endian floating point value into @val
* but keep the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
GST_BYTE_READER_PEEK_GET(32,gfloat,float32_le)
GST_BYTE_READER_PEEK_GET(32,gfloat,float32_be)
GST_BYTE_READER_PEEK_GET(64,gdouble,float64_le)
GST_BYTE_READER_PEEK_GET(64,gdouble,float64_be)
/* *INDENT-ON* */
/**
* gst_byte_reader_get_data:
* @reader: a #GstByteReader instance
* @size: Size in bytes
* @val: (out) (transfer none) (array length=size): address of a
* #guint8 pointer variable in which to store the result
*
* Returns a constant pointer to the current data
* position if at least @size bytes are left and
* updates the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
gboolean
gst_byte_reader_get_data (GstByteReader * reader, guint size,
const guint8 ** val)
{
return _gst_byte_reader_get_data_inline (reader, size, val);
}
/**
* gst_byte_reader_peek_data:
* @reader: a #GstByteReader instance
* @size: Size in bytes
* @val: (out) (transfer none) (array length=size): address of a
* #guint8 pointer variable in which to store the result
*
* Returns a constant pointer to the current data
* position if at least @size bytes are left and
* keeps the current position.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
gboolean
gst_byte_reader_peek_data (const GstByteReader * reader, guint size,
const guint8 ** val)
{
return _gst_byte_reader_peek_data_inline (reader, size, val);
}
/**
* gst_byte_reader_dup_data:
* @reader: a #GstByteReader instance
* @size: Size in bytes
* @val: (out) (transfer full) (array length=size): address of a
* #guint8 pointer variable in which to store the result
*
* Free-function: g_free
*
* Returns a newly-allocated copy of the current data
* position if at least @size bytes are left and
* updates the current position. Free with g_free() when no longer needed.
*
* Returns: %TRUE if successful, %FALSE otherwise.
*/
gboolean
gst_byte_reader_dup_data (GstByteReader * reader, guint size, guint8 ** val)
{
return _gst_byte_reader_dup_data_inline (reader, size, val);
}
/* Special optimized scan for mask 0xffffff00 and pattern 0x00000100 */
static inline gint
_scan_for_start_code (const guint8 * data, guint size)
{
guint8 *pdata = (guint8 *) data;
guint8 *pend = (guint8 *) (data + size - 4);
while (pdata <= pend) {
if (pdata[2] > 1) {
pdata += 3;
} else if (pdata[1]) {
pdata += 2;
} else if (pdata[0] || pdata[2] != 1) {
pdata++;
} else {
return (pdata - data);
}
}
/* nothing found */
return -1;
}
static inline guint
_masked_scan_uint32_peek (const GstByteReader * reader,
guint32 mask, guint32 pattern, guint offset, guint size, guint32 * value)
{
const guint8 *data;
guint32 state;
guint i;
g_return_val_if_fail (size > 0, -1);
g_return_val_if_fail ((guint64) offset + size <= reader->size - reader->byte,
-1);
/* we can't find the pattern with less than 4 bytes */
if (G_UNLIKELY (size < 4))
return -1;
data = reader->data + reader->byte + offset;
/* Handle special case found in MPEG and H264 */
if ((pattern == 0x00000100) && (mask == 0xffffff00)) {
gint ret = _scan_for_start_code (data, size);
if (ret == -1)
return ret;
if (value != NULL)
*value = (1 << 8) | data[ret + 3];
return ret + offset;
}
/* set the state to something that does not match */
state = ~pattern;
/* now find data */
for (i = 0; i < size; i++) {
/* throw away one byte and move in the next byte */
state = ((state << 8) | data[i]);
if (G_UNLIKELY ((state & mask) == pattern)) {
/* we have a match but we need to have skipped at
* least 4 bytes to fill the state. */
if (G_LIKELY (i >= 3)) {
if (value)
*value = state;
return offset + i - 3;
}
}
}
/* nothing found */
return -1;
}
/**
* gst_byte_reader_masked_scan_uint32:
* @reader: a #GstByteReader
* @mask: mask to apply to data before matching against @pattern
* @pattern: pattern to match (after mask is applied)
* @offset: offset from which to start scanning, relative to the current
* position
* @size: number of bytes to scan from offset
*
* Scan for pattern @pattern with applied mask @mask in the byte reader data,
* starting from offset @offset relative to the current position.
*
* The bytes in @pattern and @mask are interpreted left-to-right, regardless
* of endianness. All four bytes of the pattern must be present in the
* byte reader data for it to match, even if the first or last bytes are masked
* out.
*
* It is an error to call this function without making sure that there is
* enough data (offset+size bytes) in the byte reader.
*
* Returns: offset of the first match, or -1 if no match was found.
*
* Example:
* |[
* // Assume the reader contains 0x00 0x01 0x02 ... 0xfe 0xff
*
* gst_byte_reader_masked_scan_uint32 (reader, 0xffffffff, 0x00010203, 0, 256);
* // -> returns 0
* gst_byte_reader_masked_scan_uint32 (reader, 0xffffffff, 0x00010203, 1, 255);
* // -> returns -1
* gst_byte_reader_masked_scan_uint32 (reader, 0xffffffff, 0x01020304, 1, 255);
* // -> returns 1
* gst_byte_reader_masked_scan_uint32 (reader, 0xffff, 0x0001, 0, 256);
* // -> returns -1
* gst_byte_reader_masked_scan_uint32 (reader, 0xffff, 0x0203, 0, 256);
* // -> returns 0
* gst_byte_reader_masked_scan_uint32 (reader, 0xffff0000, 0x02030000, 0, 256);
* // -> returns 2
* gst_byte_reader_masked_scan_uint32 (reader, 0xffff0000, 0x02030000, 0, 4);
* // -> returns -1
* ]|
*/
guint
gst_byte_reader_masked_scan_uint32 (const GstByteReader * reader, guint32 mask,
guint32 pattern, guint offset, guint size)
{
return _masked_scan_uint32_peek (reader, mask, pattern, offset, size, NULL);
}
/**
* gst_byte_reader_masked_scan_uint32_peek:
* @reader: a #GstByteReader
* @mask: mask to apply to data before matching against @pattern
* @pattern: pattern to match (after mask is applied)
* @offset: offset from which to start scanning, relative to the current
* position
* @size: number of bytes to scan from offset
* @value: (out): pointer to uint32 to return matching data
*
* Scan for pattern @pattern with applied mask @mask in the byte reader data,
* starting from offset @offset relative to the current position.
*
* The bytes in @pattern and @mask are interpreted left-to-right, regardless
* of endianness. All four bytes of the pattern must be present in the
* byte reader data for it to match, even if the first or last bytes are masked
* out.
*
* It is an error to call this function without making sure that there is
* enough data (offset+size bytes) in the byte reader.
*
* Returns: offset of the first match, or -1 if no match was found.
*
* Since: 1.6
*/
guint
gst_byte_reader_masked_scan_uint32_peek (const GstByteReader * reader,
guint32 mask, guint32 pattern, guint offset, guint size, guint32 * value)
{
return _masked_scan_uint32_peek (reader, mask, pattern, offset, size, value);
}
#define GST_BYTE_READER_SCAN_STRING(bits) \
static guint \
gst_byte_reader_scan_string_utf##bits (const GstByteReader * reader) \
{ \
guint len, off, max_len; \
\
max_len = (reader->size - reader->byte) / sizeof (guint##bits); \
\
/* need at least a single NUL terminator */ \
if (max_len < 1) \
return 0; \
\
len = 0; \
off = reader->byte; \
/* endianness does not matter if we are looking for a NUL terminator */ \
while (GST_READ_UINT##bits##_LE (&reader->data[off]) != 0) { \
++len; \
off += sizeof (guint##bits); \
/* have we reached the end without finding a NUL terminator? */ \
if (len == max_len) \
return 0; \
} \
/* return size in bytes including the NUL terminator (hence the +1) */ \
return (len + 1) * sizeof (guint##bits); \
}
#define GST_READ_UINT8_LE GST_READ_UINT8
GST_BYTE_READER_SCAN_STRING (8);
#undef GST_READ_UINT8_LE
GST_BYTE_READER_SCAN_STRING (16);
GST_BYTE_READER_SCAN_STRING (32);
#define GST_BYTE_READER_SKIP_STRING(bits) \
gboolean \
gst_byte_reader_skip_string_utf##bits (GstByteReader * reader) \
{ \
guint size; /* size in bytes including the terminator */ \
\
g_return_val_if_fail (reader != NULL, FALSE); \
\
size = gst_byte_reader_scan_string_utf##bits (reader); \
reader->byte += size; \
return (size > 0); \
}
/**
* gst_byte_reader_skip_string:
* @reader: a #GstByteReader instance
*
* Skips a NUL-terminated string in the #GstByteReader instance, advancing
* the current position to the byte after the string. This will work for
* any NUL-terminated string with a character width of 8 bits, so ASCII,
* UTF-8, ISO-8859-N etc.
*
* This function will fail if no NUL-terminator was found in in the data.
*
* Returns: %TRUE if a string could be skipped, %FALSE otherwise.
*/
/**
* gst_byte_reader_skip_string_utf8:
* @reader: a #GstByteReader instance
*
* Skips a NUL-terminated string in the #GstByteReader instance, advancing
* the current position to the byte after the string. This will work for
* any NUL-terminated string with a character width of 8 bits, so ASCII,
* UTF-8, ISO-8859-N etc. No input checking for valid UTF-8 is done.
*
* This function will fail if no NUL-terminator was found in in the data.
*
* Returns: %TRUE if a string could be skipped, %FALSE otherwise.
*/
GST_BYTE_READER_SKIP_STRING (8);
/**
* gst_byte_reader_skip_string_utf16:
* @reader: a #GstByteReader instance
*
* Skips a NUL-terminated UTF-16 string in the #GstByteReader instance,
* advancing the current position to the byte after the string.
*
* No input checking for valid UTF-16 is done.
*
* This function will fail if no NUL-terminator was found in in the data.
*
* Returns: %TRUE if a string could be skipped, %FALSE otherwise.
*/
GST_BYTE_READER_SKIP_STRING (16);
/**
* gst_byte_reader_skip_string_utf32:
* @reader: a #GstByteReader instance
*
* Skips a NUL-terminated UTF-32 string in the #GstByteReader instance,
* advancing the current position to the byte after the string.
*
* No input checking for valid UTF-32 is done.
*
* This function will fail if no NUL-terminator was found in in the data.
*
* Returns: %TRUE if a string could be skipped, %FALSE otherwise.
*/
GST_BYTE_READER_SKIP_STRING (32);
/**
* gst_byte_reader_peek_string:
* @reader: a #GstByteReader instance
* @str: (out) (transfer none) (array zero-terminated=1): address of a
* #gchar pointer variable in which to store the result
*
* Returns a constant pointer to the current data position if there is
* a NUL-terminated string in the data (this could be just a NUL terminator).
* The current position will be maintained. This will work for any
* NUL-terminated string with a character width of 8 bits, so ASCII,
* UTF-8, ISO-8859-N etc.
*
* This function will fail if no NUL-terminator was found in in the data.
*
* Returns: %TRUE if a string could be skipped, %FALSE otherwise.
*/
/**
* gst_byte_reader_peek_string_utf8:
* @reader: a #GstByteReader instance
* @str: (out) (transfer none) (array zero-terminated=1): address of a
* #gchar pointer variable in which to store the result
*
* Returns a constant pointer to the current data position if there is
* a NUL-terminated string in the data (this could be just a NUL terminator).
* The current position will be maintained. This will work for any
* NUL-terminated string with a character width of 8 bits, so ASCII,
* UTF-8, ISO-8859-N etc.
*
* No input checking for valid UTF-8 is done.
*
* This function will fail if no NUL-terminator was found in in the data.
*
* Returns: %TRUE if a string could be skipped, %FALSE otherwise.
*/
gboolean
gst_byte_reader_peek_string_utf8 (const GstByteReader * reader,
const gchar ** str)
{
g_return_val_if_fail (reader != NULL, FALSE);
g_return_val_if_fail (str != NULL, FALSE);
if (gst_byte_reader_scan_string_utf8 (reader) > 0) {
*str = (const gchar *) (reader->data + reader->byte);
} else {
*str = NULL;
}
return (*str != NULL);
}
/**
* gst_byte_reader_get_string_utf8:
* @reader: a #GstByteReader instance
* @str: (out) (transfer none) (array zero-terminated=1): address of a
* #gchar pointer variable in which to store the result
*
* Returns a constant pointer to the current data position if there is
* a NUL-terminated string in the data (this could be just a NUL terminator),
* advancing the current position to the byte after the string. This will work
* for any NUL-terminated string with a character width of 8 bits, so ASCII,
* UTF-8, ISO-8859-N etc.
*
* No input checking for valid UTF-8 is done.
*
* This function will fail if no NUL-terminator was found in in the data.
*
* Returns: %TRUE if a string could be found, %FALSE otherwise.
*/
gboolean
gst_byte_reader_get_string_utf8 (GstByteReader * reader, const gchar ** str)
{
guint size; /* size in bytes including the terminator */
g_return_val_if_fail (reader != NULL, FALSE);
g_return_val_if_fail (str != NULL, FALSE);
size = gst_byte_reader_scan_string_utf8 (reader);
if (size == 0) {
*str = NULL;
return FALSE;
}
*str = (const gchar *) (reader->data + reader->byte);
reader->byte += size;
return TRUE;
}
#define GST_BYTE_READER_DUP_STRING(bits,type) \
gboolean \
gst_byte_reader_dup_string_utf##bits (GstByteReader * reader, type ** str) \
{ \
guint size; /* size in bytes including the terminator */ \
\
g_return_val_if_fail (reader != NULL, FALSE); \
g_return_val_if_fail (str != NULL, FALSE); \
\
size = gst_byte_reader_scan_string_utf##bits (reader); \
if (size == 0) { \
*str = NULL; \
return FALSE; \
} \
*str = g_memdup (reader->data + reader->byte, size); \
reader->byte += size; \
return TRUE; \
}
/**
* gst_byte_reader_dup_string_utf8:
* @reader: a #GstByteReader instance
* @str: (out) (transfer full) (array zero-terminated=1): address of a
* #gchar pointer variable in which to store the result
*
* Free-function: g_free
*
* FIXME:Reads (copies) a NUL-terminated string in the #GstByteReader instance,
* advancing the current position to the byte after the string. This will work
* for any NUL-terminated string with a character width of 8 bits, so ASCII,
* UTF-8, ISO-8859-N etc. No input checking for valid UTF-8 is done.
*
* This function will fail if no NUL-terminator was found in in the data.
*
* Returns: %TRUE if a string could be read into @str, %FALSE otherwise. The
* string put into @str must be freed with g_free() when no longer needed.
*/
GST_BYTE_READER_DUP_STRING (8, gchar);
/**
* gst_byte_reader_dup_string_utf16:
* @reader: a #GstByteReader instance
* @str: (out) (transfer full) (array zero-terminated=1): address of a
* #guint16 pointer variable in which to store the result
*
* Free-function: g_free
*
* Returns a newly-allocated copy of the current data position if there is
* a NUL-terminated UTF-16 string in the data (this could be an empty string
* as well), and advances the current position.
*
* No input checking for valid UTF-16 is done. This function is endianness
* agnostic - you should not assume the UTF-16 characters are in host
* endianness.
*
* This function will fail if no NUL-terminator was found in in the data.
*
* Note: there is no peek or get variant of this function to ensure correct
* byte alignment of the UTF-16 string.
*
* Returns: %TRUE if a string could be read, %FALSE otherwise. The
* string put into @str must be freed with g_free() when no longer needed.
*/
GST_BYTE_READER_DUP_STRING (16, guint16);
/**
* gst_byte_reader_dup_string_utf32:
* @reader: a #GstByteReader instance
* @str: (out) (transfer full) (array zero-terminated=1): address of a
* #guint32 pointer variable in which to store the result
*
* Free-function: g_free
*
* Returns a newly-allocated copy of the current data position if there is
* a NUL-terminated UTF-32 string in the data (this could be an empty string
* as well), and advances the current position.
*
* No input checking for valid UTF-32 is done. This function is endianness
* agnostic - you should not assume the UTF-32 characters are in host
* endianness.
*
* This function will fail if no NUL-terminator was found in in the data.
*
* Note: there is no peek or get variant of this function to ensure correct
* byte alignment of the UTF-32 string.
*
* Returns: %TRUE if a string could be read, %FALSE otherwise. The
* string put into @str must be freed with g_free() when no longer needed.
*/
GST_BYTE_READER_DUP_STRING (32, guint32);