Improve documentation and minor clean up

app/src/main/java/com/homesoft/muxer/FragmentServer.java

@@ -10,6 +10,10 @@
 
 import kotlin.NotImplementedError;
 
+/**
+ * Mp4 Fragment Server
+ * Holds the stream header(ftyp+moov) and the latest movie fragment (moof)
+ */
 public class FragmentServer implements GatheringByteChannel {
     private static final String TAG = FragmentServer.class.getSimpleName();
 
@@ -22,6 +26,14 @@ public long write(ByteBuffer[] srcs, int offset, int length) {
         throw new NotImplementedError();
     }
 
+    /**
+     * This is a little hacky, the FragmentedMp4Writer always writes data in chunks
+     * The first chuck is the ftyp+moov and all subsequent chunks are moof.
+     * @param srcs
+     *         The buffers from which bytes are to be retrieved
+     *
+     * @return the number of bytes written
+     */
     @Override
     public long write(ByteBuffer[] srcs) throws ClosedChannelException {
         if (!isOpen()) {
@@ -72,7 +84,7 @@ public synchronized void close() {
     }
 
     /**
-     * Return the common MP4 header (FTYP + MOOV)
+     * Return the common MP4 header (ftyp + moov)
      */
     public synchronized ByteBuffer getHeader() throws ClosedChannelException, InterruptedException {
         if (header == null) {

app/src/main/java/com/homesoft/muxer/MainActivity.java

@@ -30,9 +30,8 @@
     private static final String TAG = MainActivity.class.getSimpleName();
     private AutoFixSurfaceView surfaceView;
 
-    private Button stream;
-
     private TextView url;
+    private TextView clients;
 
     private CameraViewModel cameraViewModel;
 
@@ -53,46 +52,28 @@ protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         cameraViewModel = new ViewModelProvider.AndroidViewModelFactory(getApplication()).create(CameraViewModel.class);
-        stream = findViewById(R.id.stream);
-        stream.setOnClickListener((v)-> {
-            InetSocketAddress inetSocketAddress;
-            if (cameraViewModel.stateData.getValue() == CameraViewModel.State.STOPPED) {
-                cameraViewModel.startStream();
+        url = findViewById(R.id.url);
+        clients = findViewById(R.id.clients);
+
+        cameraViewModel.inetSocketAddressData.observe(this, inetSocketAddress -> {
+            final String text;
+            if (inetSocketAddress == null) {
+                text = getString(R.string.noWiFi);
             } else {
-                cameraViewModel.stopStream();
-                inetSocketAddress = null;
+                text = "http://" + inetSocketAddress.getAddress().getHostAddress() + ":" + inetSocketAddress.getPort();
             }
+            url.setText(text);
         });
-        cameraViewModel.stateData.observe(this, state -> {
+
+        cameraViewModel.connectionData.observe(this, connections -> {
             final String text;
-            final int urlVisibility;
-            final boolean enabled = switch (state) {
-                case STREAMING -> {
-                    text = "Stop";
-                    urlVisibility = View.VISIBLE;
-                    yield true;
-                }
-                case STOPPING -> {
-                    text = "Stopping";
-                    urlVisibility = View.INVISIBLE;
-                    yield false;
-                }
-                case STOPPED -> {
-                    text = "Start";
-                    urlVisibility = View.INVISIBLE;
-                    yield true;
-                }
-                default -> throw new IllegalArgumentException();
-            };
-            stream.setText(text);
-            stream.setEnabled(enabled);
-            InetSocketAddress inetSocketAddress = cameraViewModel.getInetSocketAddress();
-            if (inetSocketAddress != null) {
-                url.setText("http://" + inetSocketAddress.getAddress().getHostAddress() + ":" + inetSocketAddress.getPort());
+            if (connections < 0) {
+                text = getString(R.string.idle);
+            } else {
+                text = connections.toString();
             }
-            url.setVisibility(urlVisibility);
+            clients.setText(text);
         });
-        url = findViewById(R.id.url);
         surfaceView = findViewById(R.id.surfaceView);
         surfaceView.getHolder().addCallback(this);
     }

app/src/main/java/com/homesoft/muxer/Remuxer.java

@@ -7,13 +7,15 @@
 import android.media.MediaFormat;
 import android.media.MediaParser;
 import android.net.Uri;
+import android.os.Build;
 import android.os.ParcelFileDescriptor;
 import android.provider.MediaStore;
 import android.util.Log;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.OptIn;
+import androidx.annotation.RequiresApi;
 import androidx.media3.common.Format;
 import androidx.media3.common.MimeTypes;
 import androidx.media3.common.util.UnstableApi;
@@ -28,6 +30,7 @@
 import java.util.HashMap;
 import java.util.List;
 
+@RequiresApi(Build.VERSION_CODES.R)
 public class Remuxer implements MediaParser.OutputConsumer, Runnable {
     private static final int MAX_B_FRAMES = 4;
     private static final String TAG = Remuxer.class.getSimpleName();
@@ -86,43 +89,9 @@ public void onTrackCountFound(int numberOfTracks) {
 
     }
 
-    private static void appendByteBuffer(ByteBuffer csd, List<byte[]> list) {
-        if (csd != null) {
-            byte[] buffer = new byte[csd.limit()];
-            csd.rewind();
-            csd.get(buffer);
-            list.add(buffer);
-        }
-    }
-
-    @OptIn(markerClass = UnstableApi.class)
-    public static Format getFormat(MediaFormat mediaFormat) {
-        final String mimeType = mediaFormat.getString(MediaFormat.KEY_MIME);
-        final Format.Builder builder = new Format.Builder().setSampleMimeType(mimeType);
-        if (mimeType.startsWith(MimeTypes.BASE_TYPE_VIDEO)) {
-            builder.setWidth(mediaFormat.getInteger(MediaFormat.KEY_WIDTH))
-                    .setHeight(mediaFormat.getInteger(MediaFormat.KEY_HEIGHT));
-            if (mediaFormat.containsKey(MediaFormat.KEY_ROTATION)) {
-                builder.setRotationDegrees(mediaFormat.getInteger(MediaFormat.KEY_ROTATION));
-            }
-        } else if (mimeType.startsWith(MimeTypes.BASE_TYPE_AUDIO)) {
-            builder.setChannelCount(mediaFormat.getInteger(MediaFormat.KEY_CHANNEL_COUNT))
-                    .setSampleRate(mediaFormat.getInteger(MediaFormat.KEY_SAMPLE_RATE));
-        } else {
-            Log.d(TAG, "Unknown mimeType: " + mimeType + " " + mediaFormat);
-        }
-        final ArrayList<byte[]> csdList = new ArrayList<>(2);
-        ByteBuffer csd0 = mediaFormat.getByteBuffer("csd-0");
-        appendByteBuffer(csd0, csdList);
-        ByteBuffer csd1 = mediaFormat.getByteBuffer("csd-1");
-        appendByteBuffer(csd1, csdList);
-        builder.setInitializationData(csdList);
-        return builder.build();
-    }
-
     @OptIn(markerClass = UnstableApi.class) @Override
     public void onTrackDataFound(int trackIndex, @NonNull MediaParser.TrackData trackData) {
-        final Format format = getFormat(trackData.mediaFormat);
+        final Format format = CameraViewModel.getFormat(trackData.mediaFormat);
         mMp4Muxer.setOrientation(format.rotationDegrees);
 
         final Mp4Muxer.TrackToken trackToken = mMp4Muxer.addTrack(trackIndex, format);
@@ -196,4 +165,15 @@ public void onSampleCompleted(int trackIndex, long timeMicros, int flags, int si
             }
         }
     }
+
+    private static Uri getUri(Context context, Uri collection, String fileName, String mimeType)
+            throws UnsupportedOperationException {
+        ContentResolver resolver = context.getContentResolver();
+
+        ContentValues newMediaValues = new ContentValues();
+        newMediaValues.put(MediaStore.MediaColumns.DISPLAY_NAME, fileName);
+        newMediaValues.put(MediaStore.MediaColumns.MIME_TYPE, mimeType);
+
+        return resolver.insert(collection, newMediaValues);
+    }
 }

app/src/main/res/layout-land/activity_main.xml

@@ -11,27 +11,28 @@
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toTopOf="parent"
         app:layout_constraintBottom_toBottomOf="parent" />
-    <Button
-        android:id="@+id/stream"
+
+    <TextView
+        android:id="@+id/url"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:text="Stream"
-        android:layout_marginStart="16dp"
+        android:text="@string/noWiFi"
         app:layout_constraintTop_toTopOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintBottom_toTopOf="@id/url"
         app:layout_constraintStart_toEndOf="@+id/surfaceView"
         app:layout_constraintVertical_chainStyle="packed"
+        app:layout_constraintBottom_toTopOf="@id/clients"
         />
 
     <TextView
-        android:id="@+id/url"
-        android:visibility="invisible"
+        android:id="@+id/clients"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:text="Text"
-        app:layout_constraintBottom_toBottomOf="parent"
+        android:text="@string/idle"
+        android:layout_marginTop="8dp"
+        app:layout_constraintTop_toBottomOf="@+id/url"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toEndOf="@+id/surfaceView"
-        app:layout_constraintTop_toBottomOf="@+id/stream" />
+        app:layout_constraintBottom_toBottomOf="parent"
+        />
 </androidx.constraintlayout.widget.ConstraintLayout>

app/src/main/res/layout/activity_main.xml

@@ -16,28 +16,30 @@
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toTopOf="parent" />
 
-    <Button
-        android:id="@+id/stream"
+    <TextView
+        android:id="@+id/url"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:text="Stream"
+        android:text="@string/noWiFi"
         app:layout_constraintTop_toBottomOf="@+id/surfaceView"
-        app:layout_constraintBottom_toTopOf="@id/url"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintVertical_chainStyle="packed"
-        />
+        app:layout_constraintBottom_toTopOf="@id/clients"
+         />
 
     <TextView
-        android:id="@+id/url"
+        android:id="@+id/clients"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:visibility="invisible"
-        android:text="Text"
-        app:layout_constraintBottom_toBottomOf="parent"
+        android:text="@string/idle"
+        android:layout_marginTop="8dp"
+        app:layout_constraintTop_toBottomOf="@+id/url"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toBottomOf="@+id/stream" />
+        app:layout_constraintBottom_toBottomOf="parent"
+        />
+
 
 
 </androidx.constraintlayout.widget.ConstraintLayout>

app/src/main/res/values/strings.xml

@@ -1,3 +1,5 @@
 <resources>
     <string name="app_name">Muxer</string>
+    <string name="noWiFi">No WiFi</string>
+    <string name="idle">Idle</string>
 </resources>

lib-muxer/src/main/java/androidx/media3/muxer/Mp4Muxer.java

@@ -65,7 +65,6 @@
  *       file may still have some partial data.
  * </ul>
  */
-@UnstableApi
 public final class Mp4Muxer {
   /** A token representing an added track. */
   public interface TrackToken {}