Add --angle

Add an option to rotate the video content by a custom angle.

app/data/bash-completion/scrcpy

@@ -2,6 +2,7 @@ _scrcpy() {
     local cur prev words cword
     local opts="
         --always-on-top
+        --angle
         --audio-bit-rate=
         --audio-buffer=
         --audio-codec=

app/data/zsh-completion/_scrcpy

@@ -9,6 +9,7 @@ local arguments
 
 arguments=(
     '--always-on-top[Make scrcpy window always on top \(above other windows\)]'
+    '--angle=[Rotate the video content by a custom angle, in degrees]'
     '--audio-bit-rate=[Encode the audio at the given bit-rate]'
     '--audio-buffer=[Configure the audio buffering delay (in milliseconds)]'
     '--audio-codec=[Select the audio codec]:codec:(opus aac flac raw)'

app/scrcpy.1

@@ -19,6 +19,10 @@ provides display and control of Android devices connected on USB (or over TCP/IP
 .B \-\-always\-on\-top
 Make scrcpy window always on top (above other windows).
 
+.TP
+.BI "\-\-angle " degrees
+Rotate the video content by a custom angle, in degrees counter-clockwise.
+
 .TP
 .BI "\-\-audio\-bit\-rate " value
 Encode the audio at the given bit rate, expressed in bits/s. Unit suffixes are supported: '\fBK\fR' (x1000) and '\fBM\fR' (x1000000).

app/src/cli.c

@@ -108,6 +108,7 @@ enum {
     OPT_START_APP,
     OPT_SCREEN_OFF_TIMEOUT,
     OPT_CAPTURE_ORIENTATION,
+    OPT_ANGLE,
 };
 
 struct sc_option {
@@ -149,6 +150,13 @@ static const struct sc_option options[] = {
         .longopt = "always-on-top",
         .text = "Make scrcpy window always on top (above other windows).",
     },
+    {
+        .longopt_id = OPT_ANGLE,
+        .longopt = "angle",
+        .argdesc = "degrees",
+        .text = "Rotate the video content by a custom angle, in degrees "
+                "counter-clockwise.",
+    },
     {
         .longopt_id = OPT_AUDIO_BIT_RATE,
         .longopt = "audio-bit-rate",
@@ -2691,6 +2699,9 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
                     return false;
                 }
                 break;
+            case OPT_ANGLE:
+                opts->angle = optarg;
+                break;
             default:
                 // getopt prints the error message on stderr
                 return false;

app/src/options.c

@@ -107,6 +107,7 @@ const struct scrcpy_options scrcpy_options_default = {
     .audio_dup = false,
     .new_display = NULL,
     .start_app = NULL,
+    .angle = NULL,
 };
 
 enum sc_orientation

app/src/options.h

@@ -247,6 +247,7 @@ struct scrcpy_options {
     uint32_t video_bit_rate;
     uint32_t audio_bit_rate;
     const char *max_fps; // float to be parsed by the server
+    const char *angle; // float to be parsed by the server
     enum sc_orientation capture_orientation;
     enum sc_orientation_lock capture_orientation_lock;
     enum sc_orientation display_orientation;

app/src/scrcpy.c

@@ -428,6 +428,7 @@ scrcpy(struct scrcpy_options *options) {
         .video_bit_rate = options->video_bit_rate,
         .audio_bit_rate = options->audio_bit_rate,
         .max_fps = options->max_fps,
+        .angle = options->angle,
         .screen_off_timeout = options->screen_off_timeout,
         .capture_orientation = options->capture_orientation,
         .capture_orientation_lock = options->capture_orientation_lock,

app/src/server.c

@@ -274,6 +274,10 @@ execute_server(struct sc_server *server,
         VALIDATE_STRING(params->max_fps);
         ADD_PARAM("max_fps=%s", params->max_fps);
     }
+    if (params->angle) {
+        VALIDATE_STRING(params->angle);
+        ADD_PARAM("angle=%s", params->angle);
+    }
     if (params->capture_orientation_lock != SC_ORIENTATION_UNLOCKED
             || params->capture_orientation != SC_ORIENTATION_0) {
         if (params->capture_orientation_lock == SC_ORIENTATION_LOCKED_INITIAL) {

app/src/server.h

@@ -45,6 +45,7 @@ struct sc_server_params {
     uint32_t video_bit_rate;
     uint32_t audio_bit_rate;
     const char *max_fps; // float to be parsed by the server
+    const char *angle; // float to be parsed by the server
     sc_tick screen_off_timeout;
     enum sc_orientation capture_orientation;
     enum sc_orientation_lock capture_orientation_lock;

doc/video.md

@@ -158,6 +158,17 @@ to the MP4 or MKV target file. Flipping is not supported, so only the 4 first
 values are allowed when recording.
 
 
+## Angle
+
+To rotate the video content by a custom angle (in degrees, counter-clockwise):
+
+```
+scrcpy --angle=23
+```
+
+The center of rotation is the center of the visible area (after cropping).
+
+
 ## Crop
 
 The device screen may be cropped to mirror only part of the screen.

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

@@ -34,6 +34,7 @@ public class Options {
     private int videoBitRate = 8000000;
     private int audioBitRate = 128000;
     private float maxFps;
+    private float angle;
     private boolean tunnelForward;
     private Rect crop;
     private boolean control = true;
@@ -127,6 +128,10 @@ public class Options {
         return maxFps;
     }
 
+    public float getAngle() {
+        return angle;
+    }
+
     public boolean isTunnelForward() {
         return tunnelForward;
     }
@@ -349,6 +354,9 @@ public class Options {
                 case "max_fps":
                     options.maxFps = parseFloat("max_fps", value);
                     break;
+                case "angle":
+                    options.angle = parseFloat("angle", value);
+                    break;
                 case "tunnel_forward":
                     options.tunnelForward = Boolean.parseBoolean(value);
                     break;

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

@@ -38,6 +38,7 @@ public class ScreenCapture extends DisplayCapture {
     private final Rect crop;
     private Orientation.Lock captureOrientationLock;
     private Orientation captureOrientation;
+    private float angle;
 
     private DisplayInfo displayInfo;
     private Size videoSize;
@@ -68,6 +69,7 @@ public class ScreenCapture extends DisplayCapture {
         this.captureOrientation = options.getCaptureOrientation();
         assert captureOrientationLock != null;
         assert captureOrientation != null;
+        this.angle = options.getAngle();
     }
 
     @Override
@@ -126,6 +128,7 @@ public class ScreenCapture extends DisplayCapture {
 
         boolean locked = captureOrientationLock != Orientation.Lock.Unlocked;
         filter.addOrientation(displayInfo.getRotation(), locked, captureOrientation);
+        filter.addAngle(angle);
 
         transform = filter.getInverseTransform();
         videoSize = filter.getOutputSize().limit(maxSize).round8();

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

@@ -89,4 +89,11 @@ public class VideoFilter {
         }
         addOrientation(captureOrientation);
     }
+
+    public void addAngle(double ccwAngle) {
+        if (ccwAngle == 0) {
+            return;
+        }
+        transform = AffineMatrix.rotate(ccwAngle).withAspectRatio(size).fromCenter().multiply(transform);
+    }
 }