62 lines
1.7 KiB
Go
62 lines
1.7 KiB
Go
// Copyright 2024 Martin Riedl
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package gomp4
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import "encoding/binary"
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const (
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boxSizeLength uint32 = 4
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boxTypeLength uint32 = 4
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boxTypeParentFile = "__file"
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)
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// Box is an abstract box struct
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type Box struct {
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FilePosition uint64
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HeaderSize uint32
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}
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// FullBox is an abstract box type extending base box
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type FullBox struct {
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*Box
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Version uint8
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Flag []byte
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flagUInt32 uint32
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}
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// newFullBox parses based on 4 bytes data the version number (first byte) and the flags (bytes 2 - 4)
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func newFullBox(box *Box, data []byte) *FullBox {
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fullBox := &FullBox{Box: box, Version: data[0], Flag: data[1:4]}
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// build uint32 for flags (used for easier matching)
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flag4Bytes := append(make([]byte, 1), fullBox.Flag...)
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fullBox.flagUInt32 = binary.BigEndian.Uint32(flag4Bytes)
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// extend header size
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fullBox.HeaderSize = fullBox.HeaderSize + 4
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return fullBox
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}
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type BoxDefinition struct {
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Type string
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ParentTypes []string
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Parser BoxDefinitionParser
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}
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type BoxDefinitionParser func(parser *Parser, filePosition uint64, headerSize uint32, content []byte) (any, error)
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var BoxDefinitions []BoxDefinition
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