func avcodec_decode_video(ctx *_CodecContext, frame *Frame, finished *int, packet *avPacket) int {
return int(C.avcodec_decode_video2(
ctx.ctx,
(*C.AVFrame)(unsafe.Pointer(frame.avframe)),
(*C.int)(unsafe.Pointer(finished)),
(*C.AVPacket)(unsafe.Pointer(packet))))
}
// @todo should be private
func (this *Packet) Decode(cc *CodecCtx) (*Frame, bool, int, error) {
var gotOutput int
var ret int = 0
if frames[cc.Type()] == nil {
frames[cc.Type()] = &Frame{avFrame: C.av_frame_alloc(), mediaType: cc.Type()}
}
switch cc.Type() {
case AVMEDIA_TYPE_AUDIO:
ret = int(C.avcodec_decode_audio4(cc.avCodecCtx, frames[AVMEDIA_TYPE_AUDIO].avFrame, (*C.int)(unsafe.Pointer(&gotOutput)), &this.avPacket))
if ret < 0 {
return nil, false, int(ret), errors.New(fmt.Sprintf("Unable to decode audio packet, averror: %s", AvError(int(ret))))
}
break
case AVMEDIA_TYPE_VIDEO:
ret = int(C.avcodec_decode_video2(cc.avCodecCtx, frames[AVMEDIA_TYPE_VIDEO].avFrame, (*C.int)(unsafe.Pointer(&gotOutput)), &this.avPacket))
if ret < 0 {
return nil, false, int(ret), errors.New(fmt.Sprintf("Unable to decode video packet, averror: %s", AvError(int(ret))))
}
break
default:
return nil, false, int(ret), errors.New(fmt.Sprintf("Unknown codec type: %v", cc.Type()))
}
return frames[cc.Type()], (gotOutput > 0), int(ret), nil
}
func (id *Capture) Read(frame *C.AVFrame) error {
if frame == (*C.AVFrame)(null) {
return fmt.Errorf("buffer error")
}
pkt := C.AVPacket{}
C.av_init_packet(&pkt)
defer C.av_free_packet(&pkt)
if C.av_read_frame(id.context, &pkt) < 0 {
return fmt.Errorf("read frame error")
}
if int(pkt.stream_index) != id.index {
return fmt.Errorf("not video frame")
}
got_frame := C.int(0)
if C.avcodec_decode_video2(id.codec, id.frame, &got_frame, &pkt) < 0 {
return fmt.Errorf("decode frame error")
}
if got_frame != 0 {
if C.sws_scale(id.sws, (**C.uint8_t)(&(id.frame.data[0])), &id.frame.linesize[0], 0, id.codec.height, &frame.data[0], &frame.linesize[0]) >= 0 {
return nil
}
return fmt.Errorf("scale error")
}
return fmt.Errorf("no frame out")
}
func avcodec_decode_video(cdcctx *C.AVCodecContext, frame *Frame, packet *C.AVPacket) (bool, error) {
var gotFrame C.int
if C.avcodec_decode_video2(cdcctx, &frame.avframe, &gotFrame, packet) < 0 {
return false, errors.New("error decoding video")
}
if gotFrame != 0 {
frame.PTS = int64(C.av_frame_get_best_effort_timestamp(&frame.avframe))
}
return gotFrame != 0, nil
}
func (g *Generator) NextFrame() (image.Image, int64, error) {
img := image.NewRGBA(image.Rect(0, 0, g.Width, g.Height))
frame := C.av_frame_alloc()
var pkt C.struct_AVPacket
var frameFinished C.int
for C.av_read_frame(g.avfContext, &pkt) == 0 {
if int(pkt.stream_index) != g.vStreamIndex {
C.av_free_packet(&pkt)
continue
}
if C.avcodec_decode_video2(g.avcContext, frame, &frameFinished, &pkt) <= 0 {
C.av_free_packet(&pkt)
return nil, 0, errors.New("can't decode frame")
}
C.av_free_packet(&pkt)
if frameFinished == 0 {
continue
}
ctx := C.sws_getContext(
C.int(g.Width),
C.int(g.Height),
g.avcContext.pix_fmt,
C.int(g.Width),
C.int(g.Height),
C.PIX_FMT_RGBA,
C.SWS_BICUBIC,
nil,
nil,
nil,
)
if ctx == nil {
return nil, 0, errors.New("can't allocate scaling context")
}
srcSlice := (**C.uint8_t)(&frame.data[0])
srcStride := (*C.int)(&frame.linesize[0])
dst := (**C.uint8_t)(unsafe.Pointer(&img.Pix))
dstStride := (*C.int)(unsafe.Pointer(&[1]int{img.Stride}))
C.sws_scale(
ctx,
srcSlice,
srcStride,
C.int(0),
g.avcContext.height,
dst,
dstStride,
)
break
}
timestamp := int64(C.av_frame_get_best_effort_timestamp(frame))
return img, timestamp, nil
}
// @todo should be private
func (this *Packet) Decode(cc *CodecCtx) (*Frame, bool, int, error) {
var gotOutput int
var ret int = 0
if frames[cc.Type()] == nil {
frames[cc.Type()] = &Frame{avFrame: C.av_frame_alloc(), mediaType: cc.Type()}
}
switch cc.Type() {
case AVMEDIA_TYPE_AUDIO:
ret = int(C.avcodec_decode_audio4(cc.avCodecCtx, frames[AVMEDIA_TYPE_AUDIO].avFrame, (*C.int)(unsafe.Pointer(&gotOutput)), &this.avPacket))
if ret < 0 {
return nil, false, int(ret), errors.New(fmt.Sprintf("Unable to decode audio packet, averror: %s", AvError(int(ret))))
}
break
case AVMEDIA_TYPE_VIDEO:
ret = int(C.avcodec_decode_video2(cc.avCodecCtx, frames[AVMEDIA_TYPE_VIDEO].avFrame, (*C.int)(unsafe.Pointer(&gotOutput)), &this.avPacket))
if ret < 0 {
return nil, false, int(ret), errors.New(fmt.Sprintf("Unable to decode video packet, averror: %s", AvError(int(ret))))
}
break
default:
return nil, false, int(ret), errors.New(fmt.Sprintf("Unknown codec type: %v", cc.Type()))
}
defer func() {
if r := recover(); r != nil {
buf := make([]byte, 1<<16)
runtime.Stack(buf, false)
reason := fmt.Sprintf("%v: %s", r, buf)
fmt.Println("Runtime failure, reason -> %s", reason)
}
}()
return frames[cc.Type()], (gotOutput > 0), int(ret), nil
}
//Decode the video frame of size avpkt->size from avpkt->data into picture.
func (ctxt *Context) AvcodecDecodeVideo2(p *Frame, g *int, a *Packet) int {
return int(C.avcodec_decode_video2((*C.struct_AVCodecContext)(ctxt), (*C.struct_AVFrame)(p), (*C.int)(unsafe.Pointer(g)), (*C.struct_AVPacket)(a)))
}
func (c *Decoder) decodeVideo(p Packet) *Frame {
if !c.Valid {
//println("try to decode with an invalid Decoder")
return nil
}
//println("try to decode with a valid Decoder")
packet := new(C.AVPacket)
C.av_init_packet(packet)
defer C.av_free_packet(packet)
packet.pts = C.int64_t(p.Pts)
packet.dts = C.int64_t(p.Dts)
packet.size = C.int(p.Size)
//packet.data=&C.uint8_t(make([]byte, p.Size)[0])
//myBytes:=make([]byte,p.Size);
/*
var pb *byte
if(len(p.Data)>0){
//println("Data > 0")
pb=&p.Data[0]
}*/
packet.data = (*C.uint8_t)(unsafe.Pointer(&p.Data[0]))
// println(p.Data)
// println(pb)
// println(packet.data)
// packet.data=unsafe.Pointer(p.Data)
// for i:= 0; i < re.Size; i++ {
// re.Data[i] = data[i];
// }
packet.stream_index = C.int(p.Stream)
packet.flags = C.int(p.Flags)
packet.duration = C.int(p.Duration)
packet.pos = C.int64_t(p.Pos)
height := c.Ctx.height
width := c.Ctx.width
var frame *Frame = new(Frame)
numBytes := C.avpicture_get_size(0, width, height)
//_size = numBytes;
//_buffer := (*C.uint8_t) (C.av_malloc(C.uint(numBytes)));
if numBytes > 0 {
var buffer []byte = make([]byte, numBytes)
var pbuffer *byte = &buffer[0]
// C.memset((*C.uint8_t)(_buffer), 0, C.size_t(numBytes));
// Assign appropriate parts of buffer to image planes
//var picture * C.AVPicture=(*C.AVPicture)(unsafe.Pointer(frame))
//println(frame)
//println(picture)
//:=&frame
//854x480
C.avpicture_fill((*C.AVPicture)(unsafe.Pointer(frame)), (*C.uint8_t)(unsafe.Pointer(pbuffer)), 0, width, height)
}
//frameFinished:=C.int(0)
var frameFinished *C.int = new(C.int)
//bytes_decoded:=
C.avcodec_decode_video2(c.Ctx, (*C.AVFrame)(unsafe.Pointer(frame)), frameFinished, packet)
frame.pts = packet.pts
//frame.dts=packet.dts
/*
//C.avcodec_decode_video2(nil,nil,nil,nil)
header:=fmt.Sprintf("P5\n%d %d\n255\n",width,height)
file, err := os.Open("test.ppm", os.O_CREATE|os.O_TRUNC|os.O_RDWR, 0666)
if(err!=nil){
println("error while openning file")
}
file.WriteString(header)
linesize:=int(frame.linesize[0])
//println(linesize)
data:=make([]byte, width)
tmpdata:=(*(*[1<<30]byte)(unsafe.Pointer(frame.data[0])))[0:numBytes]
// for i:= 0; i < 1; i++ {
// data[i] = tmpdata[i];
// }
for i := 0; i < int(height); i++{
for a:= 0; a < int(width); a++ {
data[a] = tmpdata[(i*linesize)+a];
}
file.Write(data);
}
file.Close()*/
//ioutil.WriteFile("test.data", header,0755)
//println("bla fasel")
//println(bytes_decoded)
//println(*frameFinished)
return frame
}
// ImageWxH returns a screenshot at the ts milliseconds, scaled to the specified width and height.
func (g *Generator) ImageWxH(ts int64, width, height int) (image.Image, error) {
img := image.NewRGBA(image.Rect(0, 0, width, height))
frame := C.av_frame_alloc()
defer C.av_frame_free(&frame)
frameNum := C.av_rescale(
C.int64_t(ts),
C.int64_t(g.streams[g.vStreamIndex].time_base.den),
C.int64_t(g.streams[g.vStreamIndex].time_base.num),
) / 1000
if C.avformat_seek_file(
g.avfContext,
C.int(g.vStreamIndex),
0,
frameNum,
frameNum,
C.AVSEEK_FLAG_FRAME,
) < 0 {
return nil, errors.New("can't seek to timestamp")
}
C.avcodec_flush_buffers(g.avcContext)
var pkt C.struct_AVPacket
var frameFinished C.int
for C.av_read_frame(g.avfContext, &pkt) == 0 {
if int(pkt.stream_index) != g.vStreamIndex {
C.av_free_packet(&pkt)
continue
}
if C.avcodec_decode_video2(g.avcContext, frame, &frameFinished, &pkt) <= 0 {
C.av_free_packet(&pkt)
return nil, errors.New("can't decode frame")
}
C.av_free_packet(&pkt)
if frameFinished == 0 || pkt.dts < frameNum {
continue
}
ctx := C.sws_getContext(
C.int(g.Width),
C.int(g.Height),
g.avcContext.pix_fmt,
C.int(width),
C.int(height),
C.PIX_FMT_RGBA,
C.SWS_BICUBIC,
nil,
nil,
nil,
)
if ctx == nil {
return nil, errors.New("can't allocate scaling context")
}
srcSlice := (**C.uint8_t)(&frame.data[0])
srcStride := (*C.int)(&frame.linesize[0])
dst := (**C.uint8_t)(unsafe.Pointer(&img.Pix))
dstStride := (*C.int)(unsafe.Pointer(&[1]int{img.Stride}))
C.sws_scale(
ctx,
srcSlice,
srcStride,
0,
g.avcContext.height,
dst,
dstStride,
)
break
}
return img, nil
}
func (self *Decoder) Start(videoStream, audioStream *C.AVStream,
scaleWidth, scaleHeight C.int) *Decoder {
self.running = true
self.duration = time.Duration(self.FormatContext.duration * C.AV_TIME_BASE / 1000)
vCodecCtx := videoStream.codec
aCodecCtx := audioStream.codec
self.durationPerSample = time.Second / time.Duration(aCodecCtx.sample_rate)
// frame pool
poolSize := 16
pool := make(chan *C.AVFrame, poolSize)
self.pool = pool
numBytes := C.size_t(C.avpicture_get_size(C.PIX_FMT_YUV420P, scaleWidth, scaleHeight))
for i := 0; i < poolSize; i++ {
frame := C.av_frame_alloc()
self.frames = append(self.frames, frame)
buffer := (*C.uint8_t)(unsafe.Pointer(C.av_malloc(numBytes)))
self.buffers = append(self.buffers, buffer)
C.avpicture_fill((*C.AVPicture)(unsafe.Pointer(frame)), buffer, C.PIX_FMT_YUV420P,
scaleWidth, scaleHeight)
pool <- frame
}
// decode
self.frameChan = make(chan *C.AVFrame, 512)
go func() {
runtime.LockOSThread()
// scale context
scaleContext := C.sws_getCachedContext(nil, vCodecCtx.width, vCodecCtx.height, vCodecCtx.pix_fmt,
scaleWidth, scaleHeight, C.PIX_FMT_YUV420P, C.SWS_LANCZOS, nil, nil, nil)
if scaleContext == nil {
log.Fatal("get scale context failed")
}
// resample context
resampleContext := C.swr_alloc_set_opts(nil,
C.AV_CH_LAYOUT_STEREO, C.AV_SAMPLE_FMT_FLT, aCodecCtx.sample_rate,
C.int64_t(aCodecCtx.channel_layout), aCodecCtx.sample_fmt, aCodecCtx.sample_rate,
0, nil)
if resampleContext == nil {
log.Fatal("get resample context failed")
}
C.swr_init(resampleContext)
var packet C.AVPacket
var frameFinished C.int
var pts int64
var packetTime time.Duration
vFrame := C.av_frame_alloc()
aFrame := C.av_frame_alloc()
videoIndex := videoStream.index
audioIndex := audioStream.index
resampleBuffer := (*C.uint8_t)(C.av_malloc(4096 * 8))
resampleBufferp := &resampleBuffer
self.Timer = NewTimer()
// decode
for self.running {
// seek
if self.seekTarget > 0 {
if C.av_seek_frame(self.FormatContext, -1,
C.int64_t(float64(self.seekNext)/float64(time.Second)*float64(C.AV_TIME_BASE)),
C.AVSEEK_FLAG_BACKWARD) < 0 {
log.Fatal("seek error")
}
for _, codecCtx := range self.openedCodecs {
C.avcodec_flush_buffers(codecCtx)
}
p("frame seek done\n")
}
read_packet:
// read packet
C.av_free_packet(&packet)
if C.av_read_frame(self.FormatContext, &packet) < 0 { // read packet
log.Fatal("read frame error") //TODO stop gracefully
}
// get packet time
if packet.dts != C.AV_NOPTS_VALUE {
pts = int64(packet.dts)
} else {
pts = 0
}
if packet.stream_index == videoIndex {
packetTime = time.Duration(float64(pts) * float64(C.av_q2d(videoStream.time_base)) * float64(time.Second))
} else if packet.stream_index == audioIndex {
packetTime = time.Duration(float64(pts) * float64(C.av_q2d(audioStream.time_base)) * float64(time.Second))
} else { // ignore packet
goto read_packet
}
p("packet time %v at timer time %v\n", packetTime, self.Timer.Now())
// check seek
if self.seekTarget > 0 && packetTime > 0 { // if packet time cannot determined, skip
if packetTime < self.seekTarget { // seek again
self.seekNext += self.seekStep
p("seek again %v\n", self.seekNext)
} else { // seek ok
p("seek ok\n")
self.seekTarget = 0
self.Timer.Jump(packetTime - self.Timer.Now())
}
}
// decode
if packet.stream_index == videoIndex { // decode video
if C.avcodec_decode_video2(vCodecCtx, vFrame, &frameFinished, &packet) < 0 {
continue // bad packet
}
if frameFinished <= 0 {
goto read_packet // frame not complete
}
bufFrame := <-pool // get frame buffer
C.sws_scale(scaleContext, // scale
&vFrame.data[0], &vFrame.linesize[0], 0, vCodecCtx.height,
&bufFrame.data[0], &bufFrame.linesize[0])
bufFrame.pts = C.int64_t(packetTime) // set packet time
self.frameChan <- bufFrame // push to queue
p("video frame %v\n", packetTime)
} else if packet.stream_index == audioIndex { // decode audio
decode_audio_packet:
l := C.avcodec_decode_audio4(aCodecCtx, aFrame, &frameFinished, &packet)
if l < 0 {
continue // bad packet
}
if frameFinished <= 0 {
goto read_packet // frame not complete
}
if frameFinished > 0 { // frame finished
n := C.swr_convert(resampleContext, resampleBufferp, 4096,
aFrame.extended_data, aFrame.nb_samples)
if n != aFrame.nb_samples {
log.Fatal("audio resample failed")
}
self.audioFrames <- &AudioFrame{
time: packetTime,
data: C.GoBytes(unsafe.Pointer(resampleBuffer), n*8),
}
}
if l != packet.size { // multiple frame packet
packet.size -= l
packet.data = (*C.uint8_t)(unsafe.Pointer(uintptr(unsafe.Pointer(packet.data)) + uintptr(l)))
goto decode_audio_packet
}
p("audio frame %v\n", packetTime)
} else { // other stream
goto read_packet
}
}
}()
// sync video
go func() {
maxDelta := (time.Second / time.Duration(C.av_q2d(videoStream.r_frame_rate)/10))
for frame := range self.frameChan {
delta := time.Duration(frame.pts) - self.Timer.Now()
p("video frame %v, delta %v, max delta %v\n", time.Duration(frame.pts), delta, maxDelta)
if delta > 0 {
if delta > maxDelta {
self.Timer.Jump(delta)
print("timer jumped\n")
} else {
time.Sleep(delta)
}
} else if delta < 0 { // drop frame
self.RecycleFrame(frame)
continue
}
self.timedFrames <- frame
}
}()
return self
}