Merge branch 'yapingcat:main' into main

Author: timmattison

go-mp4/mp4demuxer.go

@@ -231,6 +231,10 @@ func (demuxer *MovDemuxer) ReadHead() ([]TrackInfo, error) {
             err = decodeTrunBox(demuxer, uint32(basebox.Size))
 		case mov_tag([4]byte{'s', 'e', 'n', 'c'}):
 			err = decodeSencBox(demuxer, uint32(basebox.Size))
+		case mov_tag([4]byte{'s', 'a', 'i', 'z'}):
+		 	err = decodeSaizBox(demuxer, uint32(basebox.Size))
+		case mov_tag([4]byte{'s', 'a', 'i', 'o'}):
+			err = decodeSaioBox(demuxer, uint32(basebox.Size))
 		case mov_tag([4]byte{'u', 'u', 'i', 'd'}):
 			_, err = demuxer.reader.Seek(int64(basebox.Size)-BasicBoxLen-16, io.SeekCurrent)
 		case mov_tag([4]byte{'s', 'g', 'p', 'd'}):

go-mp4/mp4track.go

@@ -131,6 +131,7 @@ type mp4track struct {
 	defaultConstantIV      []byte
 	defaultKID             [16]byte
 	lastSeig               *SeigSampleGroupEntry
+	lastSaiz 			   *SaizBox
 	subSamples             []sencEntry
 }
 

go-mp4/saio-box.go

@@ -0,0 +1,96 @@
+package mp4
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+)
+
+// SaioBox - Sample Auxiliary Information Offsets Box (saiz) (in stbl or traf box)
+type SaioBox struct {
+	Box                  *FullBox
+	AuxInfoType          string // Used for Common Encryption Scheme (4-bytes uint32 according to spec)
+	AuxInfoTypeParameter uint32
+	Offset               []int64
+}
+
+func (s *SaioBox) Decode(r io.Reader, size uint32) error {
+ 	if _, err := s.Box.Decode(r); err != nil {
+		return err
+	}
+	buf := make([]byte, size-12)
+	if _, err := io.ReadFull(r, buf); err != nil {
+		return err
+	}
+	var n int
+	flags := uint32(s.Box.Flags[0])<<16 | uint32(s.Box.Flags[1])<<8 | uint32(s.Box.Flags[2])
+	if flags&0x01 != 0 {
+		s.AuxInfoType = string(buf[n:n+4])
+		n += 4
+		s.AuxInfoTypeParameter = binary.BigEndian.Uint32(buf[n:])
+		n += 4
+	}
+	entryCount := binary.BigEndian.Uint32(buf[n:])
+	n += 4
+	if s.Box.Version == 0 {
+		for i := uint32(0); i < entryCount; i++ {
+			s.Offset = append(s.Offset, int64(binary.BigEndian.Uint32(buf[n:])))
+			n += 4
+		}
+	} else {
+		for i := uint32(0); i < entryCount; i++ {
+			s.Offset = append(s.Offset, int64(binary.BigEndian.Uint64(buf[n:])))
+			n += 8
+		}
+	}
+	return nil
+}
+
+func decodeSaioBox(demuxer *MovDemuxer, size uint32) error {
+	saio := SaioBox{Box: new(FullBox)}
+	err := saio.Decode(demuxer.reader, size)
+	if err != nil {
+		return err
+	}
+	if demuxer.currentTrack == nil {
+		return errors.New("current track is nil")
+	}
+	if len(saio.Offset) > 0 && len(demuxer.currentTrack.subSamples) == 0 {
+		var currentOffset int64
+		currentOffset, err = demuxer.reader.Seek(0, io.SeekCurrent)
+		if err != nil {
+			return err
+		}
+		demuxer.reader.Seek(demuxer.moofOffset+saio.Offset[0], io.SeekStart)
+		saiz := demuxer.currentTrack.lastSaiz
+		for i := uint32(0); i < saiz.SampleCount; i++ {
+			sampleSize := saiz.DefaultSampleInfoSize
+			if saiz.DefaultSampleInfoSize == 0 {
+				sampleSize = saiz.SampleInfo[i]
+			}
+			buf := make([]byte, sampleSize)
+			demuxer.reader.Read(buf)
+			var se sencEntry
+			se.iv = make([]byte, 16)
+			copy(se.iv, buf[:8])
+			if sampleSize == 8 {
+				demuxer.currentTrack.subSamples = append(demuxer.currentTrack.subSamples, se)
+				continue
+			}
+			n := 8
+			sampleCount := binary.BigEndian.Uint16(buf[n:])
+			n += 2
+
+			se.subSamples = make([]subSampleEntry, sampleCount)
+			for j := 0; j < int(sampleCount); j++ {
+				se.subSamples[j].bytesOfClearData = binary.BigEndian.Uint16(buf[n:])
+				n += 2
+				se.subSamples[j].bytesOfProtectedData = binary.BigEndian.Uint32(buf[n:])
+				n += 4
+			}
+			demuxer.currentTrack.subSamples = append(demuxer.currentTrack.subSamples, se)
+		}
+		demuxer.reader.Seek(currentOffset, io.SeekStart)
+	}
+ 	return nil
+}

go-mp4/saiz-box.go

@@ -0,0 +1,61 @@
+package mp4
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+)
+
+// SaizBox - Sample Auxiliary Information Sizes Box (saiz)  (in stbl or traf box)
+type SaizBox struct {
+	Box                  *FullBox
+	AuxInfoType           string // Used for Common Encryption Scheme (4-bytes uint32 according to spec)
+	AuxInfoTypeParameter  uint32
+	SampleCount           uint32
+	SampleInfo            []byte
+	DefaultSampleInfoSize uint8
+}
+
+func (s *SaizBox) Decode(r io.Reader, size uint32) error {
+	if _, err := s.Box.Decode(r); err != nil {
+		return err
+	}
+	buf := make([]byte, size-12)
+	if _, err := io.ReadFull(r, buf); err != nil {
+		return err
+	}
+	var n int
+	flags := uint32(s.Box.Flags[0])<<16 | uint32(s.Box.Flags[1])<<8 | uint32(s.Box.Flags[2])
+	if flags&0x01 != 0 {
+		s.AuxInfoType = string(buf[n:n+4])
+		n += 4
+		s.AuxInfoTypeParameter = binary.BigEndian.Uint32(buf[n:])
+		n += 4
+	}
+	s.DefaultSampleInfoSize = buf[n]
+	n += 1
+
+	s.SampleCount = binary.BigEndian.Uint32(buf[n:])
+	n += 4
+
+	if s.DefaultSampleInfoSize == 0 {
+		for i := 0; i < int(s.SampleCount); i++ {
+			s.SampleInfo = append(s.SampleInfo, buf[n])
+			n += 1
+		}
+	}
+	return nil
+}
+
+func decodeSaizBox(demuxer *MovDemuxer, size uint32) error {
+ 	saiz := SaizBox{Box: new(FullBox)}
+	err := saiz.Decode(demuxer.reader, size)
+	if err != nil {
+		return err
+	}
+	if demuxer.currentTrack == nil {
+		return errors.New("current track is nil")
+	}
+	demuxer.currentTrack.lastSaiz = &saiz
+	return nil
+}