mirror of
https://github.com/langhuihui/monibuca.git
synced 2025-12-24 13:48:04 +08:00
73 lines
1.8 KiB
Go
73 lines
1.8 KiB
Go
package box
|
||
|
||
import (
|
||
"encoding/binary"
|
||
"io"
|
||
)
|
||
|
||
// aligned(8) class CompositionOffsetBox extends FullBox(‘ctts’, version = 0, 0) {
|
||
// unsigned int(32) entry_count;
|
||
// int i;
|
||
// if (version==0) {
|
||
// for (i=0; i < entry_count; i++) {
|
||
// unsigned int(32) sample_count;
|
||
// unsigned int(32) sample_offset;
|
||
// }
|
||
// }
|
||
// else if (version == 1) {
|
||
// for (i=0; i < entry_count; i++) {
|
||
// unsigned int(32) sample_count;
|
||
// signed int(32) sample_offset;
|
||
// }
|
||
// }
|
||
// }
|
||
|
||
type CompositionOffsetBox []CTTSEntry
|
||
|
||
func (ctts CompositionOffsetBox) Size() uint64 {
|
||
return FullBoxLen + 4 + 8*uint64(len(ctts))
|
||
}
|
||
|
||
func (ctts *CompositionOffsetBox) Decode(r io.Reader) (offset int, err error) {
|
||
var fullbox FullBox
|
||
if _, err = fullbox.Decode(r); err != nil {
|
||
return
|
||
}
|
||
entryCountBuf := make([]byte, 4)
|
||
if _, err = io.ReadFull(r, entryCountBuf); err != nil {
|
||
return
|
||
}
|
||
offset = 8
|
||
l := binary.BigEndian.Uint32(entryCountBuf)
|
||
*ctts = make([]CTTSEntry, l)
|
||
|
||
buf := make([]byte, l*8)
|
||
if _, err = io.ReadFull(r, buf); err != nil {
|
||
return
|
||
}
|
||
idx := 0
|
||
for i := 0; i < int(l); i++ {
|
||
(*ctts)[i].SampleCount = binary.BigEndian.Uint32(buf[idx:])
|
||
idx += 4
|
||
(*ctts)[i].SampleOffset = binary.BigEndian.Uint32(buf[idx:])
|
||
idx += 4
|
||
}
|
||
offset += idx
|
||
return
|
||
}
|
||
|
||
func (ctts CompositionOffsetBox) Encode() (int, []byte) {
|
||
fullbox := NewFullBox(TypeCTTS, 0)
|
||
fullbox.Box.Size = ctts.Size()
|
||
offset, buf := fullbox.Encode()
|
||
binary.BigEndian.PutUint32(buf[offset:], uint32(len(ctts)))
|
||
offset += 4
|
||
for _, entry := range ctts {
|
||
binary.BigEndian.PutUint32(buf[offset:], entry.SampleCount)
|
||
offset += 4
|
||
binary.BigEndian.PutUint32(buf[offset:], entry.SampleOffset)
|
||
offset += 4
|
||
}
|
||
return offset, buf
|
||
}
|