/* 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 * @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 offset, 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 + offset); } } /* 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)) { guint ret = _scan_for_start_code (data, offset, size); if (G_UNLIKELY (value)) *value = (1 << 8) | data[ret + 3]; return ret; } /* 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: * <programlisting> * // 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 * </programlisting> */ 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: 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);