Use optimal size alignment

The video was always constrained to use a size that is a multiple of 8.
This was sometimes not necessary (recent codecs only require a video
size that is a multiple of 2 or even 1) and sometimes insufficient (some
codecs require a size that is multiple of 16).

Use the size alignment required by the codec.

Fixes #4949 <https://github.com/Genymobile/scrcpy/issues/4949>
Fixes #6236 <https://github.com/Genymobile/scrcpy/issues/6236>
PR #6746 <https://github.com/Genymobile/scrcpy/pull/6746>

server/src/main/java/com/genymobile/scrcpy/Options.java

@@ -369,7 +369,7 @@ public class Options {
                     options.audioDup = Boolean.parseBoolean(value);
                     break;
                 case "max_size":
-                    options.maxSize = Integer.parseInt(value) & ~7; // multiple of 8
+                    options.maxSize = Integer.parseInt(value);
                     break;
                 case "video_bit_rate":
                     options.videoBitRate = Integer.parseInt(value);

server/src/main/java/com/genymobile/scrcpy/device/Size.java

@@ -31,7 +31,6 @@ public final class Size {
 
     public Size limit(int maxSize) {
         assert maxSize >= 0 : "Max size may not be negative";
-        assert maxSize % 8 == 0 : "Max size must be a multiple of 8";
 
         if (maxSize == 0) {
             // No limit
@@ -55,13 +54,14 @@ public final class Size {
     }
 
     /**
-     * Round both dimensions of this size to be a multiple of 8 (as required by many encoders).
+     * Round both dimensions of this size to be multiples of {@code alignment}.
      *
-     * @return The current size rounded.
+     * @param alignment the required alignment
+     * @return the current size rounded
      */
-    public Size round8() {
-        if (isMultipleOf8()) {
-            // Already a multiple of 8
+    public Size round(int alignment) {
+        if (isMultipleOf(alignment)) {
+            // Already aligned
             return this;
         }
 
@@ -69,8 +69,8 @@ public final class Size {
         int major = portrait ? height : width;
         int minor = portrait ? width : height;
 
-        major &= ~7; // round down to not exceed the initial size
-        minor = (minor + 4) & ~7; // round to the nearest to minimize aspect ratio distortion
+        major = major / alignment * alignment; // round down to not exceed the initial size
+        minor = (minor + (alignment / 2)) / alignment * alignment; // round to the nearest to minimize aspect ratio distortion
         if (minor > major) {
             minor = major;
         }
@@ -80,8 +80,8 @@ public final class Size {
         return new Size(w, h);
     }
 
-    public boolean isMultipleOf8() {
-        return (width & 7) == 0 && (height & 7) == 0;
+    public boolean isMultipleOf(int alignment) {
+        return width % alignment == 0 && height % alignment == 0;
     }
 
     public Rect toRect() {

server/src/main/java/com/genymobile/scrcpy/video/CameraCapture.java

@@ -149,7 +149,7 @@ public class CameraCapture extends SurfaceCapture {
         filter.addAngle(angle);
 
         transform = filter.getInverseTransform();
-        videoSize = filter.getOutputSize().limit(maxSize).round8();
+        videoSize = filter.getOutputSize().limit(maxSize).round(getAlignment());
     }
 
     private static String selectCamera(String explicitCameraId, CameraFacing cameraFacing) throws CameraAccessException, ConfigurationException {

server/src/main/java/com/genymobile/scrcpy/video/NewDisplayCapture.java

@@ -133,12 +133,13 @@ public class NewDisplayCapture extends SurfaceCapture {
         filter.addOrientation(displayRotation, captureOrientationLocked, captureOrientation);
         filter.addAngle(angle);
 
+        int alignment = getAlignment();
         Size filteredSize = filter.getOutputSize();
-        if (!filteredSize.isMultipleOf8() || (maxSize != 0 && filteredSize.getMax() > maxSize)) {
+        if (!filteredSize.isMultipleOf(alignment) || (maxSize != 0 && filteredSize.getMax() > maxSize)) {
             if (maxSize != 0) {
                 filteredSize = filteredSize.limit(maxSize);
             }
-            filteredSize = filteredSize.round8();
+            filteredSize = filteredSize.round(alignment);
             filter.addResize(filteredSize);
         }
 

server/src/main/java/com/genymobile/scrcpy/video/ScreenCapture.java

@@ -97,7 +97,7 @@ public class ScreenCapture extends SurfaceCapture {
         filter.addAngle(angle);
 
         transform = filter.getInverseTransform();
-        videoSize = filter.getOutputSize().limit(maxSize).round8();
+        videoSize = filter.getOutputSize().limit(maxSize).round(getAlignment());
     }
 
     @Override

server/src/main/java/com/genymobile/scrcpy/video/SurfaceCapture.java

@@ -17,6 +17,7 @@ public abstract class SurfaceCapture {
     }
 
     private CaptureListener listener;
+    private int alignment;
 
     /**
      * Notify the listener that the capture has been invalidated (for example, because its size changed, or due to a manual user request).
@@ -28,8 +29,9 @@ public abstract class SurfaceCapture {
     /**
      * Called once before the first capture starts.
      */
-    public final void init(CaptureListener listener) throws ConfigurationException, IOException {
+    public final void init(CaptureListener listener, int alignment) throws ConfigurationException, IOException {
         this.listener = listener;
+        this.alignment = alignment;
         init();
     }
 
@@ -86,4 +88,15 @@ public abstract class SurfaceCapture {
     public boolean isClosed() {
         return false;
     }
+
+    /**
+     * Return the video alignment
+     * <p>
+     * This a power-of-2 value that the video width and height must be multiples of.
+     *
+     * @return the video alignment
+     */
+    protected int getAlignment() {
+        return alignment;
+    }
 }

server/src/main/java/com/genymobile/scrcpy/video/SurfaceEncoder.java

@@ -65,9 +65,15 @@ public class SurfaceEncoder implements AsyncProcessor {
     private void streamCapture() throws IOException, ConfigurationException {
         Codec codec = streamer.getCodec();
         MediaCodec mediaCodec = createMediaCodec(codec, encoderName);
+
+        MediaCodecInfo.VideoCapabilities caps = mediaCodec.getCodecInfo().getCapabilitiesForType(codec.getMimeType())
+                .getVideoCapabilities();
+        int alignment = caps != null ? Math.max(caps.getWidthAlignment(), caps.getHeightAlignment()) : 8;
+        Ln.d("Video codec size alignment requirement: " + alignment + "px");
+
         MediaFormat format = createFormat(codec.getMimeType(), videoBitRate, maxFps, codecOptions);
 
-        capture.init(reset);
+        capture.init(reset, alignment);
 
         try {
             boolean alive;