stash/vendor/github.com/zencoder/go-dash/v3/mpd/pssh.go
2023-03-07 12:57:27 +11:00

41 lines
932 B
Go

package mpd
import (
"bytes"
"encoding/binary"
"fmt"
)
func MakePSSHBox(systemID, payload []byte) ([]byte, error) {
if len(systemID) != 16 {
return nil, fmt.Errorf("SystemID must be 16 bytes, was: %d", len(systemID))
}
psshBuf := &bytes.Buffer{}
size := uint32(12 + 16 + 4 + len(payload)) // 3 uint32s, systemID, "pssh" string and payload
if err := binary.Write(psshBuf, binary.BigEndian, size); err != nil {
return nil, err
}
if err := binary.Write(psshBuf, binary.BigEndian, []byte("pssh")); err != nil {
return nil, err
}
if err := binary.Write(psshBuf, binary.BigEndian, uint32(0)); err != nil {
return nil, err
}
if _, err := psshBuf.Write(systemID); err != nil {
return nil, err
}
if err := binary.Write(psshBuf, binary.BigEndian, uint32(len(payload))); err != nil {
return nil, err
}
if _, err := psshBuf.Write(payload); err != nil {
return nil, err
}
return psshBuf.Bytes(), nil
}