Add very special handling for the MJPG video format

diff --git a/config.properties.template b/config.properties.template
index 317ead1..ff75679 100644 (file)
--- a/config.properties.template
+++ b/config.properties.template
@@ -1,11 +1,15 @@
 jdk.home=/usr/lib/jvm/java-8-openjdk-amd64
 
 # Video info can be found with 'v4l2-ctl --get-fmt-video'
-# Supported formats: UYVY, YUYV, YVYU
+# Supported formats: UYVY, YUYV, YVYU, MJPG
+# When using MJPG, stream data via a named pipe and point video.device at the pipe:
+#   mkfifo cakelight-video-stream
+#   v4l2-ctl --stream-mmap --stream-to cakelight-video-stream
 video.format=UYVY
 video.width=720
 video.height=480
 video.bpp=2
+video.device=auto
 
 video.crop.left=27
 video.crop.right=29

diff --git a/src/kaka/cakelight/Configuration.java b/src/kaka/cakelight/Configuration.java
index 9975658..755586f 100644 (file)
--- a/src/kaka/cakelight/Configuration.java
+++ b/src/kaka/cakelight/Configuration.java
@@ -53,6 +53,7 @@ public class Configuration {
         public int height;
         public int bpp;
         public int format;
+        public boolean mjpg;
         public double saturation;
         public String device;
         public boolean deviceIsAutomatic;
@@ -72,6 +73,9 @@ public class Configuration {
                 case "YVYU":
                     format = Imgproc.COLOR_YUV2BGR_YVYU;
                     break;
+                case "MJPG":
+                    format = 0;
+                    mjpg = true;
                 default:
                     format = Imgproc.COLOR_YUV2BGR_UYVY;
             }

diff --git a/src/kaka/cakelight/FrameGrabber.java b/src/kaka/cakelight/FrameGrabber.java
index e654c91..5354ea6 100644 (file)
--- a/src/kaka/cakelight/FrameGrabber.java
+++ b/src/kaka/cakelight/FrameGrabber.java
@@ -1,5 +1,7 @@
 package kaka.cakelight;
 
+import javax.imageio.ImageIO;
+import java.awt.image.BufferedImage;
 import java.io.*;
 import java.util.Optional;
 
@@ -10,6 +12,7 @@ public class FrameGrabber implements Closeable {
     private File file;
     private int bytesPerFrame;
     private InputStream fileStream;
+    private final ByteArrayOutputStream bufferedBytes = new ByteArrayOutputStream();
 
     private FrameGrabber() {
     }
@@ -39,11 +42,26 @@ public class FrameGrabber implements Closeable {
      */
     public Optional<VideoFrame> grabFrame() {
         try {
-            byte[] data = new byte[bytesPerFrame];
-            int count = fileStream.read(data);
-            if (count != bytesPerFrame) {
-                log("Expected to read " + bytesPerFrame + " bytes per frame but read " + count);
+            byte[] data;
+            if (config.video.mjpg) {
+                byte[] jpgData = readStreamingJpgData();
+                if (jpgData == null) {
+                    return Optional.empty();
+                }
+                saveTemporaryJpgFile(jpgData);
+                byte[] bmpData = convertJpgFileToByteArray();
+                if (bmpData == null) {
+                    return Optional.empty();
+                }
+                data = bmpData;
+            } else {
+                data = new byte[bytesPerFrame];
+                int count = fileStream.read(data);
+                if (count != bytesPerFrame) {
+                    log("Expected to read " + bytesPerFrame + " bytes per frame but read " + count);
+                }
             }
+
             return Optional.of(VideoFrame.of(data, config));
         } catch (IOException e) {
             e.printStackTrace();
@@ -52,6 +70,62 @@ public class FrameGrabber implements Closeable {
         return Optional.empty();
     }
 
+    private byte[] readStreamingJpgData() throws IOException {
+        byte[] data;
+        byte[] batch = new byte[1024];
+        boolean lastByteIsXX = false;
+        loop:
+        while (true) {
+            int batchCount = fileStream.read(batch);
+            if (batchCount == -1) {
+                return null;
+            }
+            if (lastByteIsXX) {
+                if (batch[0] == (byte) 0xd8) {
+                    data = bufferedBytes.toByteArray();
+                    bufferedBytes.reset();
+                    bufferedBytes.write(0xff);
+                    bufferedBytes.write(batch, 0, batchCount);
+                    break;
+                }
+                bufferedBytes.write(0xff);
+            }
+            for (int i = 0; i < batchCount - 1; i++) {
+                if (batch[i] == (byte) 0xff && batch[i + 1] == (byte) 0xd8) { // start of jpeg
+                    if (i > 0) {
+                        bufferedBytes.write(batch, 0, i);
+                    }
+                    data = bufferedBytes.toByteArray();
+                    bufferedBytes.reset();
+                    bufferedBytes.write(batch, i, batchCount - i);
+                    break loop;
+                }
+            }
+            lastByteIsXX = batch[batchCount - 1] == (byte) 0xff;
+            bufferedBytes.write(batch, 0, batchCount - (lastByteIsXX ? 1 : 0));
+        }
+        return data;
+    }
+
+    private void saveTemporaryJpgFile(byte[] data) throws IOException {
+        try (FileOutputStream fos = new FileOutputStream("/tmp/cakelight-video-stream.jpg")) {
+            fos.write(data);
+        }
+    }
+
+    private byte[] convertJpgFileToByteArray() throws IOException {
+        BufferedImage image = ImageIO.read(new File("/tmp/cakelight-video-stream.jpg"));
+        if (image != null) { // will almost always be null the first time
+            try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
+                ImageIO.write(image, "bmp", baos);
+                baos.flush();
+                return baos.toByteArray();
+            }
+        } else {
+            return null;
+        }
+    }
+
     @Override
     public void close() throws IOException {
         fileStream.close();

diff --git a/src/kaka/cakelight/VideoFrame.java b/src/kaka/cakelight/VideoFrame.java
index a3353a5..fd055a9 100644 (file)
--- a/src/kaka/cakelight/VideoFrame.java
+++ b/src/kaka/cakelight/VideoFrame.java
@@ -1,5 +1,6 @@
 package kaka.cakelight;
 
+import org.opencv.core.Core;
 import org.opencv.core.CvType;
 import org.opencv.core.Mat;
 import org.opencv.core.Size;
@@ -23,10 +24,37 @@ public class VideoFrame {
     public static VideoFrame of(byte[] data, Configuration config) {
         VideoFrame frame = new VideoFrame(data);
         frame.config = config;
-        frame.convert();
+        if (config.video.mjpg) {
+            frame.convertJpg();
+        } else {
+            frame.convert();
+        }
         return frame;
     }
 
+    private void convertJpg() {
+        Mat src = new Mat(config.video.height, config.video.width, CvType.CV_8UC3); // 8-bit, unsigned, 3 channels
+        src.put(0, 0, data);
+//        save(src, "/home/kaka/test-src.data");
+
+        converted = new Mat();
+        Imgproc.cvtColor(src, converted, Imgproc.COLOR_BGR2RGB);
+
+        Core.flip(converted, converted, 0); // up-side down
+//        save(converted, "/home/kaka/test-converted.data");
+        int mysteriousPixelShift = 18;
+        converted = converted.submat( // crop mysterious pixel shift
+                0,
+                converted.rows(),
+                mysteriousPixelShift,
+                converted.cols() - mysteriousPixelShift
+        );
+//        save(converted, "/home/kaka/test-croppedAgain.data");
+        model4(converted, Imgproc.INTER_AREA);
+        src.release();
+        converted.release();
+    }
+
     private void convert() {
         /* TODO: how to do this?
         1) Resize to an image with the size of the number of leds and use config to define how many pixels deep into the screen to use.