put timestamp on frames

examples/video-stream/video_play.py

@@ -13,10 +13,9 @@
 
 try:
     import av
-    import cv2
 except ImportError:
     raise RuntimeError(
-        "av and opencv-python is required to run this example, install with `pip install av opencv-python`"
+        "av is required to run this example, install with `pip install av`"
     )
 
 # ensure LIVEKIT_URL, LIVEKIT_API_KEY, and LIVEKIT_API_SECRET are set
@@ -52,32 +51,18 @@ def __init__(self, media_file: Union[str, Path]) -> None:
             audio_sample_rate=audio_stream.sample_rate,
             audio_channels=audio_stream.channels,
         )
-        print(self._info)
 
     @property
     def info(self) -> MediaInfo:
         return self._info
 
-    async def stream_video(
-        self, av_sync: rtc.AVSynchronizer
-    ) -> AsyncIterable[tuple[rtc.VideoFrame, float]]:
+    async def stream_video(self) -> AsyncIterable[tuple[rtc.VideoFrame, float]]:
         """Streams video frames from the media file in an endless loop."""
         for i, av_frame in enumerate(self._video_container.decode(video=0)):
             # Convert video frame to RGBA
             frame = av_frame.to_rgb().to_ndarray()
             frame_rgba = np.ones((frame.shape[0], frame.shape[1], 4), dtype=np.uint8)
             frame_rgba[:, :, :3] = frame
-
-            # put fps and timestamps in the frame
-            frame_rgba = cv2.putText(
-                frame_rgba, f"{av_sync.actual_fps:.2f}fps", (10, 30), cv2.FONT_HERSHEY_SIMPLEX, 1, (0, 0, 255), 2
-            )
-
-            if i % 10 == 0:
-                print(
-                    f"decoded frame {i} ({av_frame.time:.3f}s), {av_sync.actual_fps:.2f}fps, "
-                    f"last video time: {av_sync.last_video_time:.3f}s, last audio time: {av_sync.last_audio_time:.3f}s"
-                )
             yield (
                 rtc.VideoFrame(
                     width=frame.shape[1],
@@ -190,7 +175,7 @@ async def _push_frames(
         while True:
             streamer.reset()
             video_task = asyncio.create_task(
-                _push_frames(streamer.stream_video(av_sync), av_sync)
+                _push_frames(streamer.stream_video(), av_sync)
             )
             audio_task = asyncio.create_task(
                 _push_frames(streamer.stream_audio(), av_sync)

livekit-rtc/livekit/rtc/synchronizer.py

@@ -8,6 +8,8 @@
 from .audio_frame import AudioFrame
 from .audio_source import AudioSource
 from .video_source import VideoSource
+import numpy as np
+import cv2
 
 logger = logging.getLogger(__name__)
 
@@ -84,8 +86,39 @@ async def wait_for_playout(self) -> None:
         await self._video_queue.join()
 
     async def _capture_video(self) -> None:
+        count = 0
         while not self._stopped:
             frame, timestamp = await self._video_queue.get()
+
+            # debug
+            frame_rgba = np.frombuffer(frame.data, dtype=np.uint8).reshape(
+                frame.height, frame.width, 4
+            )
+            frame_bgr = cv2.cvtColor(frame_rgba[:, :, :3], cv2.COLOR_RGBA2BGR)
+            frame_bgr = cv2.putText(
+                frame_bgr,
+                f"{self.actual_fps:.2f}fps, video time: {timestamp:.3f}s, audio time: {self.last_audio_time:.3f}s",
+                (10, 100),
+                cv2.FONT_HERSHEY_SIMPLEX,
+                1,
+                (0, 0, 255),
+                2,
+            )
+            frame_rgba = cv2.cvtColor(frame_bgr, cv2.COLOR_BGR2RGBA)
+            frame = VideoFrame(
+                width=frame.width,
+                height=frame.height,
+                type=frame.type,
+                data=frame_rgba.tobytes(),
+            )
+            count += 1
+            if count % 30 == 0:
+                print(
+                    f"{self.actual_fps:.2f}fps, last video time: {self.last_video_time:.3f}s, "
+                    f"last audio time: {self.last_audio_time:.3f}s"
+                )
+            # end debug
+
             async with self._fps_controller:
                 self._video_source.capture_frame(frame)
                 if timestamp is not None: