func (m *Muxer) writeAudioFrame(frame *C.AVFrame) bool {
for C.av_audio_fifo_size(m.fifo) < 1024 { // generate & store in fifo
C.fill_audio_frame(frame, m.audioStream.stream.codec)
frame_size := frame.nb_samples
if C.av_audio_fifo_realloc(m.fifo, C.av_audio_fifo_size(m.fifo)+frame_size) < 0 {
return false
}
if C.av_audio_fifo_write(m.fifo, (*unsafe.Pointer)(unsafe.Pointer(&frame.data[0])), frame_size) < frame_size {
return false
}
}
got_packet := C.int(0)
for C.av_audio_fifo_size(m.fifo) >= 1024 { // read & encode & write
frame_size := C.min(C.av_audio_fifo_size(m.fifo), m.audioStream.stream.codec.frame_size)
output_frame := C.alloc_audio_frame(m.audioStream.stream.codec)
if C.av_audio_fifo_read(m.fifo, (*unsafe.Pointer)(unsafe.Pointer(&output_frame.data[0])), frame_size) < frame_size {
C.av_frame_free(&output_frame)
return false
}
pkt := C.AVPacket{}
C.av_init_packet(&pkt)
output_frame.pts = C.int64_t(m.audioStream.ts)
m.audioStream.ts += int(m.audioStream.stream.codec.frame_size)
if C.avcodec_encode_audio2(m.audioStream.stream.codec, &pkt, frame, &got_packet) < 0 {
C.av_free_packet(&pkt)
return false
}
if got_packet == 0 {
continue
}
C.av_packet_rescale_ts(&pkt, m.audioStream.stream.codec.time_base, m.audioStream.stream.time_base)
pkt.stream_index = m.audioStream.stream.index
if C.av_interleaved_write_frame(m.context, &pkt) < 0 {
return false
}
}
return true
}
func (m *Muxer) routine() {
vFrame := C.alloc_video_frame(m.videoStream.stream.codec)
if vFrame == (*C.AVFrame)(null) {
m.done <- true
return
}
aFrame := C.alloc_audio_frame(m.audioStream.stream.codec)
if aFrame == (*C.AVFrame)(null) {
m.done <- true
return
}
for m.loop {
if C.av_compare_ts(C.int64_t(m.videoStream.ts), m.videoStream.stream.codec.time_base,
C.int64_t(m.audioStream.ts), m.audioStream.stream.codec.time_base) <= 0 {
m.writeVideoFrame(vFrame)
} else {
m.writeAudioFrame(aFrame)
}
time.Sleep(time.Millisecond * 30)
}
if vFrame != (*C.AVFrame)(null) {
C.av_frame_free(&vFrame)
}
if aFrame != (*C.AVFrame)(null) {
C.av_frame_free(&aFrame)
}
m.done <- true
}
func (self *Decoder) Close() {
C.avformat_close_input(&self.FormatContext)
for _, stream := range self.Streams {
C.avcodec_close(stream.codec)
}
for _, frame := range self.frames {
C.av_frame_free(&frame)
}
for _, buffer := range self.buffers {
C.av_free(unsafe.Pointer(buffer))
}
close(self.frameChan)
self.running = false
}
func (f *Frame) Free() {
if f.CAVFrame != nil {
defer C.av_frame_free(&f.CAVFrame)
f.CAVFrame = nil
}
}
func (this *Frame) Free() {
C.av_frame_free(&this.avFrame)
}
func (id *Capture) Close() {
C.av_frame_free(&(id.frame))
C.avcodec_close(id.codec)
C.avformat_close_input(&(id.context))
C.sws_freeContext(id.sws)
}
// 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
}
//void av_frame_free (AVFrame **frame)
//Free the frame and any dynamically allocated objects in it, e.g.
func Av_frame_free(f *AVFrame) {
C.av_frame_free((**C.struct_AVFrame)(unsafe.Pointer(f)))
}