// Copyright 2024 Martin Riedl // // 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. package gomp4 // TrackBox track box struct // // 8.3.1 Track Box // Box Type: ‘trak’ // Container: Movie Box (‘moov’) // Mandatory: Yes // Quantity: One or more // // This is a container box for a single track of a presentation. A presentation consists of one or more tracks. // Each track is independent of the other tracks in the presentation and carries its own temporal and // spatial information. Each track will contain its associated Media Box. // // Tracks are used for two purposes: (a) to contain media data (media tracks) and (b) to contain // packetization information for streaming protocols (hint tracks). // // There shall be at least one media track within an ISO file, and all the media tracks that contributed to // the hint tracks shall remain in the file, even if the media data within them is not referenced by the hint // tracks; after deleting all hint tracks, the entire un‐hinted presentation shall remain. type TrackBox struct { *Box ChildBoxes []interface{} } // ParseTrackBox creates a new track box struct based on bytes func ParseTrackBox(filePosition uint64, headerSize uint32, content []byte) (*TrackBox, error) { box := &TrackBox{Box: &Box{filePosition, headerSize}} // parse child boxes var err error box.ChildBoxes, err = box.parseChildBoxes(filePosition, content) return box, err }