/* 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 */