Adds keyframe API

pkg/mp4/helpers.go

@@ -0,0 +1,47 @@
+package mp4
+
+import (
+	"errors"
+	"io"
+)
+
+type MemoryWriter struct {
+	buf []byte
+	pos int
+}
+
+func (m *MemoryWriter) Write(p []byte) (n int, err error) {
+	minCap := m.pos + len(p)
+	if minCap > cap(m.buf) { // Make sure buf has enough capacity:
+		buf2 := make([]byte, len(m.buf), minCap+len(p)) // add some extra
+		copy(buf2, m.buf)
+		m.buf = buf2
+	}
+	if minCap > len(m.buf) {
+		m.buf = m.buf[:minCap]
+	}
+	copy(m.buf[m.pos:], p)
+	m.pos += len(p)
+	return len(p), nil
+}
+
+func (m *MemoryWriter) Seek(offset int64, whence int) (int64, error) {
+	newPos, offs := 0, int(offset)
+	switch whence {
+	case io.SeekStart:
+		newPos = offs
+	case io.SeekCurrent:
+		newPos = m.pos + offs
+	case io.SeekEnd:
+		newPos = len(m.buf) + offs
+	}
+	if newPos < 0 {
+		return 0, errors.New("negative result pos")
+	}
+	m.pos = newPos
+	return int64(newPos), nil
+}
+
+func (m *MemoryWriter) Bytes() []byte {
+	return m.buf
+}

pkg/mp4/muxer.go

@@ -0,0 +1,37 @@
+package mp4
+
+import (
+	"github.com/deepch/vdk/av"
+	"github.com/deepch/vdk/codec/h264parser"
+	"github.com/deepch/vdk/format/mp4"
+	"time"
+)
+
+func MarshalMP4(sps, pps, frame []byte) []byte {
+	writer := &MemoryWriter{}
+	muxer := mp4.NewMuxer(writer)
+
+	stream, err := h264parser.NewCodecDataFromSPSAndPPS(sps, pps)
+	if err != nil {
+		panic(err)
+	}
+
+	if err = muxer.WriteHeader([]av.CodecData{stream}); err != nil {
+		panic(err)
+	}
+
+	pkt := av.Packet{
+		CompositionTime: time.Millisecond,
+		IsKeyFrame:      true,
+		Duration:        time.Second,
+		Data:            frame,
+	}
+	if err = muxer.WritePacket(pkt); err != nil {
+		panic(err)
+	}
+	if err = muxer.WriteTrailer(); err != nil {
+		panic(err)
+	}
+
+	return writer.buf
+}