try gmf project

src/open_speed_data/video.go

@@ -0,0 +1,194 @@
+package main
+
+import (
+	"log"
+	"os"
+	"runtime/debug"
+	"strconv"
+	"bytes"
+	"image/png"
+
+	"github.com/3d0c/gmf"
+)
+
+type Video struct {
+	inputCtx *gmf.FmtCtx
+	srcVideoStream *gmf.Stream
+	Filename string
+	Duration float64
+	Frames int64
+	converter *Converter
+}
+
+func Open(srcFileName string) (*Video, error) {
+	v = &Video{
+		inputCtx: gmf.NewInputCtx(srcFileName),
+	}
+	var err error
+	v.srcVideoStream, err = v.inputCtx.GetBestStream(gmf.AVMEDIA_TYPE_VIDEO)
+	if err != nil {
+		v.inputCtx.CloseInputAndRelease()
+		return nil, err
+	}
+	v.Converter, err = Converter.Open(v.inputCtx)
+	if err != nil {
+		v.inputCtx.CloseInputAndRelease()
+		return nil, err
+	}
+	return v, nil
+}
+
+func (v *Video) Close() {
+	v.inputCtx.CloseInputAndRelease()
+}
+func (v *Video) Frame(n int) (*Image, error) {
+	// AVSEEK_FLAG_FRAME
+	// ist, err := this.GetStream(streamIndex)
+	// if err := this.SeekFile(ist, frameTs, frameTs, C.AVSEEK_FLAG_FRAME); err != nil {
+	// ist.CodecCtx().FlushBuffers()
+	for {
+		packet := v.inputCtxt.GetNextPacket()
+		if packet.StreamIndex() != v.srcVideoStream.Index() {
+			continue
+		}
+		if p != nil {
+			return nil, errors.New("nil packet")
+		}
+	}
+	return v.Converter.FrameToImage()
+}
+type Converter struct {
+	cc *gmf.CodecCtx
+	swsCtx *gmf.SwsCtx
+	destFrame *gmf.Frame
+}
+func (c *Converter) FrameToImage(srcFrame *gmf.Frame) (*Image, error) {
+	defer gmf.Release(srcFrame)
+	swsCtx.Scale(srcFrame, c.dstFrame)
+
+	p, ready, err := dstFrame.EncodeNewPacket(cc)
+	if err != nil {
+		return nil, err
+	}
+	if !ready {
+		return nil, errors.New("not ready")
+	}
+	return png.Decode(bytes.NewReader(p.Data()))
+}
+
+func (c *Converter) Close() {
+	gmf.Release(c.cc)
+	gmf.Release(c.swsCtx)
+	gmf.Release(c.destFrame)
+}
+
+func NewConverter(srcCtx *gmf.CodecCtx) (*Converter, error) {
+	codec, err := gmf.FindEncoder(gmf.AV_CODEC_ID_PNG)
+	if err != nil {
+		return nil, err
+	}
+
+	c = &Converter{
+		cc: gmf.NewCodecCtx(codec),
+	}
+
+	w, h := srcCtx.Width(), srcCtx.Height()
+
+	c.cc.SetPixFmt(gmf.AV_PIX_FMT_RGB24).SetWidth(w).SetHeight(h)
+
+	if codec.IsExperimental() {
+		c.cc.SetStrictCompliance(gmf.FF_COMPLIANCE_EXPERIMENTAL)
+	}
+
+	if err := cc.Open(nil); err != nil {
+		return nil, err
+	}
+
+	c.swsCtx = gmf.NewSwsCtx(srcCtx, cc, gmf.SWS_BICUBIC)
+
+	// convert to RGB, optionally resize could be here
+	c.dstFrame = gmf.NewFrame().
+		SetWidth(w).
+		SetHeight(h).
+		SetFormat(gmf.AV_PIX_FMT_RGB24)
+
+	if err := dstFrame.ImgAlloc(); err != nil {
+		return nil, err
+	}
+	return c, nil
+}
+
+
+func main() {
+	srcFileName := "tests-sample.mp4"
+
+	os.Mkdir("./tmp", 0755)
+
+	if len(os.Args) > 1 {
+		srcFileName = os.Args[1]
+	}
+
+
+	
+	log.Printf("TimeBase %#v", srcVideoStream.TimeBase())
+	log.Printf("Duration %#v", srcVideoStream.Duration())
+	log.Printf("NbFrames %#v", srcVideoStream.NbFrames())
+
+	codec, err := FindEncoder(AV_CODEC_ID_PNG)
+	if err != nil {
+		fatal(err)
+	}
+
+	cc := NewCodecCtx(codec)
+	defer Release(cc)
+
+	cc.SetPixFmt(AV_PIX_FMT_RGB24).SetWidth(srcVideoStream.CodecCtx().Width()).SetHeight(srcVideoStream.CodecCtx().Height())
+
+	if codec.IsExperimental() {
+		cc.SetStrictCompliance(FF_COMPLIANCE_EXPERIMENTAL)
+	}
+
+	if err := cc.Open(nil); err != nil {
+		fatal(err)
+	}
+
+	swsCtx := NewSwsCtx(srcVideoStream.CodecCtx(), cc, SWS_BICUBIC)
+	defer Release(swsCtx)
+
+	dstFrame := NewFrame().
+		SetWidth(srcVideoStream.CodecCtx().Width()).
+		SetHeight(srcVideoStream.CodecCtx().Height()).
+		SetFormat(AV_PIX_FMT_RGB24)
+	defer Release(dstFrame)
+
+	if err := dstFrame.ImgAlloc(); err != nil {
+		fatal(err)
+	}
+	
+	// AVSEEK_FLAG_FRAME
+	// ist, err := this.GetStream(streamIndex)
+	// if err := this.SeekFile(ist, frameTs, frameTs, C.AVSEEK_FLAG_FRAME); err != nil {
+	// ist.CodecCtx().FlushBuffers()
+
+	for packet := range inputCtx.GetNewPackets() {
+		if packet.StreamIndex() != srcVideoStream.Index() {
+			// skip non video streams
+			continue
+		}
+		ist := assert(inputCtx.GetStream(packet.StreamIndex())).(*Stream)
+
+		for frame := range packet.Frames(ist.CodecCtx()) {
+			// CloneNewFrame
+			swsCtx.Scale(frame, dstFrame)
+
+			if p, ready, _ := dstFrame.EncodeNewPacket(cc); ready {
+				writeFile(p.Data())
+				defer Release(p)
+			}
+		}
+		Release(packet)
+	}
+
+	Release(dstFrame)
+
+}