Get the one frame from the stream

[sttyru]

Hello!

Thank you for awesome library!

I have a trivial question, maybe. I want to write very easy monitoring tool for IP-cameras (above 50 devices). The main criteria of avalability of devices is an ability of getting an image. I mean that I need more than simple check by ICMP or TCP/UDP. In this case I want to fetch (programmly) of the frame and checking that this image is non-empty, e.g. Can I do that using of your library? I found sources of RTSP-client software but I don't know how fetch the frame.

[thenrich]

@sttyru I do something like this:

• Create a video decoder with the video stream decoder, err := ffmpeg.NewVideoDecoder(vstream)
• Run the decoder setup decoder.Setup()
• Read a packet with pkt, err := demuxer.ReadPacket()
• Decode the packet to a frame frame, err := decoder.Decode(pkt.Data)
• Free the memory after the function ends

  if err != nil {
  return err
  }
  defer frame.Free()

• Now you can access the image with frame.Image

  
  func encodeImg(img image.Image) bytes.Buffer {
  var b bytes.Buffer
  jpeg.Encode(&b, img, nil)
      return b
  }

jpegImg := encodeImg(frame.Image)

[sttyru]

@thenrich, very thank you!

[niklaskorz]

As this issue is still open, I have one question: Does a packet only contain a single frame? If not, why does the video decoder only return one frame for a whole packet instead of, e.g., a channel or array of frames?