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Diffstat (limited to 'media/libstagefright/webm/EbmlUtil.h')
-rw-r--r-- | media/libstagefright/webm/EbmlUtil.h | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/media/libstagefright/webm/EbmlUtil.h b/media/libstagefright/webm/EbmlUtil.h new file mode 100644 index 0000000..eb9c37c --- /dev/null +++ b/media/libstagefright/webm/EbmlUtil.h @@ -0,0 +1,50 @@ +/* + * Copyright (C) 2014 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef EBMLUTIL_H_ +#define EBMLUTIL_H_ + +#include <stdint.h> + +namespace webm { + +// Encode the id and/or size of an EBML element bytes by setting a leading length descriptor bit: +// +// 1xxxxxxx - 1-byte values +// 01xxxxxx xxxxxxxx - +// 001xxxxx xxxxxxxx xxxxxxxx - +// 0001xxxx xxxxxxxx xxxxxxxx xxxxxxxx - ... +// 00001xxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx - +// 000001xx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx - +// 0000001x xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx - +// 00000001 xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx - 8-byte values +// +// This function uses the least the number of bytes possible. +uint64_t encodeUnsigned(uint64_t u); + +// Like above but pads the input value with leading zeros up to the specified width. The length +// descriptor is calculated based on width. +uint64_t encodeUnsigned(uint64_t u, int width); + +// Serialize an EBML coded id or size in big-endian order. +int serializeCodedUnsigned(uint64_t u, uint8_t* bary); + +// Calculate the length of an EBML coded id or size from its length descriptor. +int sizeOf(uint64_t u); + +} + +#endif /* EBMLUTIL_H_ */ |