Bug Fix: Logitech C930 On Linux Results In Freezing Video [M55]

media/capture/video/linux/v4l2_capture_delegate.cc

Index: media/capture/video/linux/v4l2_capture_delegate.cc
diff --git a/media/capture/video/linux/v4l2_capture_delegate.cc b/media/capture/video/linux/v4l2_capture_delegate.cc
index aecebccdde8abefdf15175505500ff8d3247e8a0..9adeed35926aff42f4fdcfba19c5ba1ad035b00c 100644
--- a/media/capture/video/linux/v4l2_capture_delegate.cc
+++ b/media/capture/video/linux/v4l2_capture_delegate.cc
@@ -563,12 +563,18 @@ void V4L2CaptureDelegate::DoCapture() {
     const scoped_refptr<BufferTracker>& buffer_tracker =
         buffer_tracker_pool_[buffer.index];
 
-    base::TimeDelta timestamp =
-        base::TimeDelta::FromSeconds(buffer.timestamp.tv_sec) +
-        base::TimeDelta::FromMicroseconds(buffer.timestamp.tv_usec);
-    client_->OnIncomingCapturedData(
-        buffer_tracker->start(), buffer_tracker->payload_size(),
-        capture_format_, rotation_, base::TimeTicks::Now(), timestamp);
+    // There's a wide-spread issue where the kernel does not report accurate,
+    // monotonically-increasing timestamps in the v4l2_buffer::timestamp
+    // field (goo.gl/Nlfamz).
+    // Until this issue is fixed, just use the reference clock as a source of
+    // media timestamps.
+    const base::TimeTicks now = base::TimeTicks::Now();
+    if (first_ref_time_.is_null())
+      first_ref_time_ = now;
+    const base::TimeDelta timestamp = now - first_ref_time_;
+    client_->OnIncomingCapturedData(buffer_tracker->start(),
+                                    buffer_tracker->payload_size(),
+                                    capture_format_, rotation_, now, timestamp);
 
     while (!take_photo_callbacks_.empty()) {
       VideoCaptureDevice::TakePhotoCallback cb =