Files
monibuca/plugin/mp4/pkg/box/vmhd.go
2024-09-12 18:23:36 +08:00

70 lines
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package box
import (
"encoding/binary"
"io"
)
// Box Types: vmhd, smhd, hmhd, nmhd
// Container: Media Information Box (minf)
// Mandatory: Yes
// Quantity: Exactly one specific media header shall be present
// aligned(8) class VideoMediaHeaderBox
// extends FullBox(vmhd, version = 0, 1) {
// template unsigned int(16) graphicsmode = 0; // copy, see below template
// unsigned int(16)[3] opcolor = {0, 0, 0};
// }
type VideoMediaHeaderBox struct {
Graphicsmode uint16
Opcolor [3]uint16
}
func NewVideoMediaHeaderBox() *VideoMediaHeaderBox {
return &VideoMediaHeaderBox{
Graphicsmode: 0,
Opcolor: [3]uint16{0, 0, 0},
}
}
func (vmhd *VideoMediaHeaderBox) Decode(r io.Reader) (offset int, err error) {
var fullbox FullBox
if _, err = fullbox.Decode(r); err != nil {
return 0, err
}
buf := make([]byte, 8)
if _, err = io.ReadFull(r, buf); err != nil {
return 0, err
}
offset = 0
vmhd.Graphicsmode = binary.BigEndian.Uint16(buf[offset:])
vmhd.Opcolor[0] = binary.BigEndian.Uint16(buf[offset+2:])
vmhd.Opcolor[1] = binary.BigEndian.Uint16(buf[offset+4:])
vmhd.Opcolor[2] = binary.BigEndian.Uint16(buf[offset+6:])
offset += 8
return
}
func (vmhd *VideoMediaHeaderBox) Encode() (int, []byte) {
fullbox := NewFullBox(TypeVMHD, 0)
fullbox.Box.Size = FullBoxLen + 8
fullbox.Flags[2] = 1
offset, buf := fullbox.Encode()
binary.BigEndian.PutUint16(buf[offset:], vmhd.Graphicsmode)
offset += 2
binary.BigEndian.PutUint16(buf[offset:], vmhd.Opcolor[0])
offset += 2
binary.BigEndian.PutUint16(buf[offset:], vmhd.Opcolor[1])
offset += 2
binary.BigEndian.PutUint16(buf[offset:], vmhd.Opcolor[2])
offset += 2
return offset, buf
}
func MakeVmhdBox() []byte {
vmhd := NewVideoMediaHeaderBox()
_, vmhdbox := vmhd.Encode()
return vmhdbox
}