commit 42033b4a433d890c47a50e5f9a87a928ee614068
author mallinath@webrtc.org <mallinath@webrtc.org@4adac7df-926f-26a2-2b94-8c16560cd09d> Wed Aug 01 06:31:34 2012
committer mallinath@webrtc.org <mallinath@webrtc.org@4adac7df-926f-26a2-2b94-8c16560cd09d> Wed Aug 01 06:31:34 2012
tree ea48b568e8fbbdfee2bea756dabb394095cdd24a
parent d7a71d0719251db2a31b71a9d6e9fef4f60ba778

This change will allow us to set proper frame rate for the camera on Linux. Earlier we were setting based on the resolution irrespective of input frame rate.
Review URL: https://webrtc-codereview.appspot.com/692006

git-svn-id: http://webrtc.googlecode.com/svn/trunk@2545 4adac7df-926f-26a2-2b94-8c16560cd09d

src/modules/video_capture/main/source/Linux/video_capture_linux.cc

diff --git a/src/modules/video_capture/main/source/Linux/video_capture_linux.cc b/src/modules/video_capture/main/source/Linux/video_capture_linux.cc
index 2c690e9..d3033b6 100644
--- a/src/modules/video_capture/main/source/Linux/video_capture_linux.cc
+++ b/src/modules/video_capture/main/source/Linux/video_capture_linux.cc
@@ -122,7 +122,7 @@
 }
 
 WebRtc_Word32 VideoCaptureModuleV4L2::StartCapture(
-                                        const VideoCaptureCapability& capability)
+    const VideoCaptureCapability& capability)
 {
     if (_captureStarted)
     {
@@ -212,11 +212,43 @@
     _currentWidth = video_fmt.fmt.pix.width;
     _currentHeight = video_fmt.fmt.pix.height;
     _captureDelay = 120;
-    // No way of knowing frame rate, make a guess.
-    if(_currentWidth >= 800 && _captureVideoType != kVideoMJPEG)
-      _currentFrameRate = 15;
-    else
-      _currentFrameRate = 30;
+
+    // Trying to set frame rate, before check driver capability.
+    bool driver_framerate_support = true;
+    struct v4l2_streamparm streamparms;
+    memset(&streamparms, 0, sizeof(streamparms));
+    streamparms.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+    if (ioctl(_deviceFd, VIDIOC_G_PARM, &streamparms) < 0) {
+        WEBRTC_TRACE(webrtc::kTraceError, webrtc::kTraceVideoCapture, _id,
+                   "error in VIDIOC_G_PARM errno = %d", errno);
+        driver_framerate_support = false;
+      // continue
+    } else {
+      // check the capability flag is set to V4L2_CAP_TIMEPERFRAME.
+      if (streamparms.parm.capture.capability == V4L2_CAP_TIMEPERFRAME) {
+        // driver supports the feature. Set required framerate.
+        memset(&streamparms, 0, sizeof(streamparms));
+        streamparms.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+        streamparms.parm.capture.timeperframe.numerator = 1;
+        streamparms.parm.capture.timeperframe.denominator = capability.maxFPS;
+        if (ioctl(_deviceFd, VIDIOC_S_PARM, &streamparms) < 0) {
+          WEBRTC_TRACE(webrtc::kTraceError, webrtc::kTraceVideoCapture, _id,
+                   "Failed to set the framerate. errno=%d", errno);
+          driver_framerate_support = false;
+        } else {
+          _currentFrameRate = capability.maxFPS;
+        }
+      }
+    }
+    // If driver doesn't support framerate control, need to hardcode.
+    // Hardcoding the value based on the frame size.
+    if (!driver_framerate_support) {
+      if(_currentWidth >= 800 && _captureVideoType != kVideoMJPEG) {
+        _currentFrameRate = 15;
+      } else {
+        _currentFrameRate = 30;
+      }
+    }
 
     if (!AllocateVideoBuffers())
     {