feat: configurable JPEG/WebP streaming with bounded buffering

.github/workflows/debug-build.yml

@@ -34,6 +34,18 @@ jobs:
       - name: Build and verify Debug
         run: ./gradlew --no-daemon :shared:testDebugUnitTest :common:testDebugUnitTest :common:assembleDebugAndroidTest :mobile:lintDebug :mobile:assembleDebug
 
+      - name: Upload failed unit test reports
+        if: failure()
+        uses: actions/upload-artifact@v4
+        with:
+          name: wheelplay-unit-test-results
+          path: |
+            shared/build/reports/tests/
+            shared/build/test-results/
+            common/build/reports/tests/
+            common/build/test-results/
+          if-no-files-found: warn
+
       - name: Upload browser runtime test APK
         uses: actions/upload-artifact@v4
         with:

README.md

@@ -9,7 +9,7 @@ Install the app on an Android device and open the displayed address in your car'
 ## Features
 
 - **Browser display and touch control**: CarPlay streaming, touch input, and fullscreen display.
-- **Selectable streaming modes**: Choose WebRTC video passthrough (H.264 / HEVC) or JPEG compatibility mode in settings. If passthrough fails, video automatically falls back to JPEG while audio and touch keep their existing routes.
+- **Selectable streaming modes**: Choose WebRTC video passthrough (H.264 / HEVC) or image compatibility mode in settings, with JPEG / WebP format and image quality from 1 to 100. Image streaming retains JPEG compatibility fallback and overlaps up to two frames while audio and touch keep their existing routes.
 - **Optional browser audio**: After pairing, the browser can play CarPlay audio. The browser microphone can provide CarPlay voice input through a trusted HTTPS page; Android handles audio and microphone input by default.
 - **Easy pairing**: Scan the QR code or enter a code once. Remembered browsers restore pairing automatically and retain a launch button for selecting options before streaming.
 - **iPhone connection management**: USB and wireless connections, connection status, and session management.

README.zh-CN.md

@@ -9,7 +9,7 @@ WheelPlay 是一款 Android 局域网 CarPlay 服务端应用，可将 iPhone 
 ## 功能
 
 - **浏览器显示与触控**：支持 CarPlay 画面串流、触摸操作和全屏显示。
-- **可选串流技术**：设置中可选 WebRTC 视频直通（H.264 / HEVC）或 JPEG 兼容模式。直通失败自动回退 JPEG，音频与触控保持原有路径。
+- **可选串流技术**：设置中可选 WebRTC 视频直通（H.264 / HEVC）或图片兼容模式，并调整 JPEG / WebP 格式和 1–100 的图片质量。图片串流保留 JPEG 兼容回退，最多两帧并行传输，音频与触控保持原有路径。详见[图片串流与多缓冲](docs/IMAGE_STREAM.md)。
 - **可选浏览器音频**：配对后可改由浏览器播放 CarPlay 音频；浏览器麦克风可通过可信 HTTPS 页面接入 CarPlay 语音输入，默认仍由 Android 处理。
 - **便捷配对**：首次扫描车机网页二维码或输入配对码，之后自动恢复已记住的浏览器配对；启动前仍可选择网页选项。
 - **iPhone 连接管理**：支持 USB 与无线连接，查看连接状态并管理会话。

common/src/androidTest/java/com/shilapi/xcertplay/web/WebRuntimeTest.kt

@@ -16,9 +16,37 @@ import java.util.concurrent.LinkedBlockingQueue
 
 @RunWith(AndroidJUnit4::class)
 class WebRuntimeTest {
+    @Test fun staticFrameIsReencodedWhenImageFormatOrQualityChanges() {
+        val frames = LinkedBlockingQueue<Triple<ByteArray, ImageFormat, Int>>()
+        val preferred = java.util.concurrent.atomic.AtomicReference(ImageFormat.JPEG)
+        val quality = java.util.concurrent.atomic.AtomicInteger(75)
+        val output = OffscreenVideoOutput(320, 180, { true }, { ImageEncodingOptions(preferred.get(), quality.get()) }) { bytes, format, value ->
+            frames.offer(Triple(bytes, format, value))
+        }
+        try {
+            val canvas = output.surface.lockCanvas(null); canvas.drawColor(Color.RED)
+            output.surface.unlockCanvasAndPost(canvas)
+            assertEquals(ImageFormat.JPEG, frames.poll(5, TimeUnit.SECONDS)?.second)
+            preferred.set(ImageFormat.WEBP)
+            val webp = requireNotNull(frames.poll(5, TimeUnit.SECONDS))
+            assertEquals(ImageFormat.WEBP, webp.second)
+            assertEquals("RIFF", webp.first.copyOfRange(0, 4).toString(Charsets.US_ASCII))
+            assertEquals("WEBP", webp.first.copyOfRange(8, 12).toString(Charsets.US_ASCII))
+            val bitmap = BitmapFactory.decodeByteArray(webp.first, 0, webp.first.size)
+            assertEquals(320, bitmap.width); assertTrue(Color.red(bitmap.getPixel(160, 90)) > 200); bitmap.recycle()
+            quality.set(40)
+            val refreshed = requireNotNull(frames.poll(5, TimeUnit.SECONDS))
+            assertEquals(ImageFormat.WEBP, refreshed.second); assertEquals(40, refreshed.third)
+            preferred.set(ImageFormat.JPEG)
+            val jpeg = requireNotNull(frames.poll(5, TimeUnit.SECONDS))
+            assertEquals(ImageFormat.JPEG, jpeg.second); assertEquals(40, jpeg.third)
+            assertNull("Static format changes must not start continuous encoding", frames.poll(400, TimeUnit.MILLISECONDS))
+        } finally { output.close() }
+    }
+
     @Test fun offscreenThrottlePublishesFinalFrameWithoutAnotherArrival() {
         val frames = LinkedBlockingQueue<ByteArray>()
-        val output = OffscreenVideoOutput(320, 180, { true }) { frames.offer(it) }
+        val output = OffscreenVideoOutput(320, 180, { true }) { bytes, _, _ -> frames.offer(bytes) }
         try {
             fun paint(color: Int) {
                 val canvas = output.surface.lockCanvas(null)
@@ -42,7 +70,7 @@ class WebRuntimeTest {
     @Test fun offscreenSurfaceProducesUprightJpegWithoutActivity() {
         val ready = CountDownLatch(1)
         var jpeg: ByteArray? = null
-        val output = OffscreenVideoOutput(320, 180, { true }) { jpeg = it; ready.countDown() }
+        val output = OffscreenVideoOutput(320, 180, { true }) { bytes, _, _ -> jpeg = bytes; ready.countDown() }
         try {
             val canvas = output.surface.lockCanvas(null)
             val paint = Paint()