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/* GStreamer QuickTime atom parser
* Copyright (C) 2009 Tim-Philipp Müller <tim centricular net>
* Copyright (C) <2009> STEricsson <benjamin.gaignard@stericsson.com>
*
* 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.
*/
#ifndef QT_ATOM_PARSER_H
#define QT_ATOM_PARSER_H
#include <gst/base/gstbytereader.h>
/* our inlined version of GstByteReader */
static inline gboolean
qt_atom_parser_has_remaining (GstByteReader * parser, guint64 bytes_needed)
{
return G_LIKELY (parser->size >= bytes_needed) &&
G_LIKELY ((parser->size - bytes_needed) >= parser->byte);
}
static inline gboolean
qt_atom_parser_has_chunks (GstByteReader * parser, guint32 n_chunks,
guint32 chunk_size)
{
/* assumption: n_chunks and chunk_size are 32-bit, we cast to 64-bit here
* to avoid overflows, to handle e.g. (guint32)-1 * size correctly */
return qt_atom_parser_has_remaining (parser, (guint64) n_chunks * chunk_size);
}
static inline gboolean
qt_atom_parser_peek_sub (GstByteReader * parser, guint offset, guint size,
GstByteReader * sub)
{
*sub = *parser;
if (G_UNLIKELY (!gst_byte_reader_skip (sub, offset)))
return FALSE;
return (gst_byte_reader_get_remaining (sub) >= size);
}
static inline gboolean
qt_atom_parser_skipn_and_get_uint32 (GstByteReader * parser,
guint bytes_to_skip, guint32 * val)
{
if (G_UNLIKELY (gst_byte_reader_get_remaining (parser) < (bytes_to_skip + 4)))
return FALSE;
gst_byte_reader_skip_unchecked (parser, bytes_to_skip);
*val = gst_byte_reader_get_uint32_be_unchecked (parser);
return TRUE;
}
/* off_size must be either 4 or 8 */
static inline gboolean
qt_atom_parser_get_offset (GstByteReader * parser, guint off_size,
guint64 * val)
{
if (G_UNLIKELY (gst_byte_reader_get_remaining (parser) < off_size))
return FALSE;
if (off_size == sizeof (guint64)) {
*val = gst_byte_reader_get_uint64_be_unchecked (parser);
} else {
*val = gst_byte_reader_get_uint32_be_unchecked (parser);
}
return TRUE;
}
/* off_size must be either 4 or 8 */
static inline guint64
qt_atom_parser_get_offset_unchecked (GstByteReader * parser, guint off_size)
{
if (off_size == sizeof (guint64)) {
return gst_byte_reader_get_uint64_be_unchecked (parser);
} else {
return gst_byte_reader_get_uint32_be_unchecked (parser);
}
}
/* size must be from 1 to 4 */
static inline guint32
qt_atom_parser_get_uint_with_size_unchecked (GstByteReader * parser,
guint size)
{
switch (size) {
case 1:
return gst_byte_reader_get_uint8_unchecked (parser);
case 2:
return gst_byte_reader_get_uint16_be_unchecked (parser);
case 3:
return gst_byte_reader_get_uint24_be_unchecked (parser);
case 4:
return gst_byte_reader_get_uint32_be_unchecked (parser);
default:
g_assert_not_reached ();
gst_byte_reader_skip_unchecked (parser, size);
break;
}
return 0;
}
static inline gboolean
qt_atom_parser_get_fourcc (GstByteReader * parser, guint32 * fourcc)
{
guint32 f_be;
if (G_UNLIKELY (gst_byte_reader_get_remaining (parser) < 4))
return FALSE;
f_be = gst_byte_reader_get_uint32_be_unchecked (parser);
*fourcc = GUINT32_SWAP_LE_BE (f_be);
return TRUE;
}
static inline guint32
qt_atom_parser_get_fourcc_unchecked (GstByteReader * parser)
{
guint32 fourcc;
fourcc = gst_byte_reader_get_uint32_be_unchecked (parser);
return GUINT32_SWAP_LE_BE (fourcc);
}
#endif /* QT_ATOM_PARSER_H */
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