/
prft.go
111 lines (99 loc) · 2.63 KB
/
prft.go
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package mp4
import (
"io"
"github.com/Eyevinn/mp4ff/bits"
)
// PrftBox - Producer Reference Box (prft)
//
// Contained in File before moof box
type PrftBox struct {
Version byte
Flags uint32
ReferenceTrackID uint32
NTPTimestamp uint64
MediaTime uint64
}
// CreatePrftBox creates a new PrftBox.
func CreatePrftBox(version byte, refTrackID uint32, ntp, mediatime uint64) *PrftBox {
return &PrftBox{
Version: version,
Flags: 0,
ReferenceTrackID: refTrackID,
NTPTimestamp: ntp,
MediaTime: mediatime,
}
}
// DecodePrft - box-specific decode
func DecodePrft(hdr BoxHeader, startPos uint64, r io.Reader) (Box, error) {
data, err := readBoxBody(r, hdr)
if err != nil {
return nil, err
}
sr := bits.NewFixedSliceReader(data)
return DecodePrftSR(hdr, startPos, sr)
}
// DecodePrftSR - box-specific decode
func DecodePrftSR(hdr BoxHeader, startPos uint64, sr bits.SliceReader) (Box, error) {
versionAndFlags := sr.ReadUint32()
version := byte(versionAndFlags >> 24)
flags := versionAndFlags & flagsMask
refTrackID := sr.ReadUint32()
ntp := sr.ReadUint64()
var mediatime uint64
if version == 0 {
mediatime = uint64(sr.ReadUint32())
} else {
mediatime = sr.ReadUint64()
}
p := PrftBox{
Version: version,
Flags: flags,
ReferenceTrackID: refTrackID,
NTPTimestamp: ntp,
MediaTime: mediatime,
}
return &p, sr.AccError()
}
// Type - return box type
func (b *PrftBox) Type() string {
return "prft"
}
// Size - return calculated size
func (b *PrftBox) Size() uint64 {
return uint64(boxHeaderSize + 20 + 4*int(b.Version))
}
// Encode - write box to w
func (b *PrftBox) Encode(w io.Writer) error {
sw := bits.NewFixedSliceWriter(int(b.Size()))
err := b.EncodeSW(sw)
if err != nil {
return err
}
_, err = w.Write(sw.Bytes())
return err
}
// EncodeSW - box-specific encode to slicewriter
func (b *PrftBox) EncodeSW(sw bits.SliceWriter) error {
err := EncodeHeaderSW(b, sw)
if err != nil {
return err
}
versionAndFlags := (uint32(b.Version) << 24) + b.Flags
sw.WriteUint32(versionAndFlags)
sw.WriteUint32(b.ReferenceTrackID)
sw.WriteUint64(b.NTPTimestamp)
if b.Version == 0 {
sw.WriteUint32(uint32(b.MediaTime))
} else {
sw.WriteUint64(b.MediaTime)
}
return sw.AccError()
}
// Info - write box-specific information
func (b *PrftBox) Info(w io.Writer, specificBoxLevels, indent, indentStep string) error {
bd := newInfoDumper(w, indent, b, int(b.Version), b.Flags)
bd.write(" - referenceTrackID: %d", b.ReferenceTrackID)
bd.write(" - ntpTimestamp: %d", b.NTPTimestamp)
bd.write(" - mediaTime: %d", b.MediaTime)
return bd.err
}