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• Streaming through FFMpeg stdout

  30 juin 2014, par SandyEmerald

  I need to stream my generating images using ffmpeg througth stdout. Is it possible ? If yes, could you give me some ffmpeg examples like commands or general conceptions ?

  The final task is to create streaming video server through RTP, so i could connect to it via VLC or other client. And i need to do it without using diskspace - only through streams.

  Now i have Qt program which generates images. I know that i can give them to stdout using QDataStream.

• How to use FFMPEG to send image via RTMP using ProcessBuilder

  13 mai 2022, par ljnoah

  I have a callback function that gives me frames as bytes type to which I would like to pass as FFMPEG parameter to write them to a rtmp URL. but I don't really have any experience with ffmpeg, thus far I was not able to find an example on how to do it. Basically, I would like to know can I use use the bytes array that is FrameData that holds the images I am getting and write to ffmpeg as a parameter to be sent via streaming to a server using ProcessBuilder.

  


   private byte[] FrameData = new byte[384 * 288 * 4];
    private final IFrameCallback mIFrameCallback = new IFrameCallback() {
          @Override
          public void onFrame(final ByteBuffer frameData) {
              frameData.clear();
              frameData.get(FrameData, 0, frameData.capacity());
              ProcessBuilder pb = new ProcessBuilder(ffmpeg ,  "-y",  "-f", "rawvideo",  "vcodec", "rawvideo",  "-pix_fmt", "bgr24",
                    "-r", "25",
                    "-i", "-",
                    "-c:v", "libx264",
                    "-pix_fmt", "yuv420p",
                    "-preset", "ultrafast",
                    "-f", "flv",
                    "rtmp://192.168.0.13:1935/live/test");
              }
            Log.e(TAG, "mIFrameCallback: onFrame------");
            try {
                pb.inheritIO().start().waitFor();
            } catch (InterruptedException | IOException e) {
                e.printStackTrace();
            }
      };


  


  This callback gives me the frames from my camera on the fly and writes it to FrameData, which I can compress to a bitmap if needed. The current attempt isn't working as I have no idea how to pass my byte array as a parameter to ffmpeg to be streamed via rtmp as above to push my frames from the camera that are stored FrameData byte buffer via RTMP/RTSP to my server IP. I would use a similar approach in python like this :

  


   import subprocess
    fps = 25
    width = 224
    height = 224
    command = ['ffmpeg',  '-y',  '-f', 'rawvideo',  '-vcodec', 'rawvideo',  '-pix_fmt', 'bgr24',
               '-s', "{}x{}".format(width, height),
               '-r', str(fps),
               '-i', '-',
               '-c:v', 'libx264',
               '-pix_fmt', 'yuv420p',
               '-preset', 'ultrafast',
               '-f', 'flv',
               'rtmp://192.168.0.13:1935/live/test']
    p = subprocess.Popen(command, stdin=subprocess.PIPE)
    while(True):
        frame = np.random.randint([255], size=(224, 224, 3))
        frame = frame.astype(np.uint8)
        p.stdin.write(frame.tobytes())


  


  I really don't understand how to write my byte arrays to the ffmpeg as I would in this Python example above.
What I tried doing was this :

  


   private byte[] FrameData = new byte[384 * 288 * 4];
    String ffmpeg = Loader.load(org.bytedeco.ffmpeg.ffmpeg.class);
    private final IFrameCallback mIFrameCallback = new IFrameCallback() {
        @RequiresApi(api = Build.VERSION_CODES.O)
        @Override
        public void onFrame(final ByteBuffer frameData) {
            frameData.clear();
            frameData.get(FrameData, 0, frameData.capacity());
            ProcessBuilder pb = new ProcessBuilder(ffmpeg ,  "-y",  "-f", "rawvideo",  "vcodec", "rawvideo",  "-pix_fmt", "bgr24",
                    "-r", "25",
                    "-i", "-",
                    "-c:v", "libx264",
                    "-pix_fmt", "yuv420p",
                    "-preset", "ultrafast",
                    "-f", "flv",
                    "rtmp://192.168.0.13:1935/live/test");
        try {

            Log.e(TAG, "mIFrameCallback: onFrame------");
            pb.redirectInput();
            pb.redirectError();
            Log.e(TAG, "frame data check 1");
            Process p = pb.start();
            Log.e(TAG, "frame data check 2");
            p.getOutputStream().write(FrameData);
            Log.e(TAG, "frame data check 3");
        } catch (IOException e) {
            e.printStackTrace();
        }
        }
    };


  


  Unfortunately, no results whatsoever. It appears that the try/catch block is not executed, I am not even sure if this is the right way to send bytes via RTMP stream

  


  Edit : I have fixed the indicated issue with the ProcessBuilder being called twice and logged the calls made inside the code, it only calls up to : Log.e(TAG, "frame data check 1"); Although, I am still not sure if that's the write way to write an array of bytes to ffmpeg for rtmp streaming.

  


• How video editor show real time preview of videos ? [closed]

  3 juin 2024, par SWIK

  I am trying to create a simple video editor that combine two video by layering one over another, i can easily do it with ffmpeg, but I am not sure how can I make a preview of it before making final video ? How video editor display preview without building them ? I am looking towards create a react application.