Send bytes_used of v4l2 captured frame when video capture

media/video/capture/linux/v4l2_capture_delegate_multi_plane.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/video/capture/linux/v4l2_capture_delegate_multi_plane.h"
 
 #include <sys/mman.h>
 
 namespace media {
 
@@ skipping 39 matching lines @@
   buffer->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
   buffer->length = v4l2_planes_.size();
 
   static const struct v4l2_plane empty_plane = {};
   std::fill(v4l2_planes_.begin(), v4l2_planes_.end(), empty_plane);
   buffer->m.planes = v4l2_planes_.data();
 }
 
 void V4L2CaptureDelegateMultiPlane::SendBuffer(
     const scoped_refptr<BufferTracker>& buffer_tracker,
-    const v4l2_format& format) const {
+    const v4l2_format& format,
+    size_t /*bytes_used*/) const {

[wuchengli, 2015/05/19 04:05:54]

From the v4l2 documentation, bytesused is ignored for multiplanar. So this value
doesn't make sense for 4L2CaptureDelegateMultiPlane. I think you can add
V4L2CaptureDelegate::BufferTracker::GetBytesused(size_t plane) and
V4L2CaptureDelegate::BufferTracker::Plane::bytesused. You won't need to add
|bytes_used| to SendBuffer.

http://linuxtv.org/downloads/v4l-dvb-apis/buffer.html

[wuchengli, 2015/05/19 04:18:51]

Kuang-che told me bytesused is different for every frame and BufferTracker is
initialized only once. So how about passing a |bytesused| array to SendBuffer()
in V4L2CaptureDelegate::DoCapture()? 
__u32 bytesused[VIDEO_MAX_PLANES];
if (video_fmt_.type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
  bytesused[0] = buffer.bytesused;
else
  for (i = 0; i < video_fmt_.pix_mp.num_planes; i++)
    bytesused[i] = buffer.m.planes[i].bytesused;

[Pawel Osciak, 2015/05/20 07:29:02]

Personally I liked the idea to add this to BufferTracker. What do you think
about adding a plane_payload[] array to BufferTracker and a setter/getter
SetPlanePayload()/GetPlanePayload()?

[kcwu, 2015/05/20 12:14:52]

Done.

   DCHECK_EQ(capture_format().pixel_format, PIXEL_FORMAT_I420);
   const size_t y_stride = format.fmt.pix_mp.plane_fmt[0].bytesperline;
   const size_t u_stride = format.fmt.pix_mp.plane_fmt[1].bytesperline;
   const size_t v_stride = format.fmt.pix_mp.plane_fmt[2].bytesperline;
   DCHECK_GE(y_stride, 1u * capture_format().frame_size.width());
   DCHECK_GE(u_stride, 1u * capture_format().frame_size.width() / 2);
   DCHECK_GE(v_stride, 1u * capture_format().frame_size.width() / 2);
   client()->OnIncomingCapturedYuvData(buffer_tracker->GetPlaneStart(0),
                                       buffer_tracker->GetPlaneStart(1),
                                       buffer_tracker->GetPlaneStart(2),
@@ skipping 19 matching lines @@
       return false;
     }
     AddMmapedPlane(static_cast<uint8_t*>(start), buffer.m.planes[p].length);
     DVLOG(3) << "Mmap()ed plane #" << p << " of " << buffer.m.planes[p].length
              << "B";
   }
   return true;
 }
 
 }  // namespace media