MJPEG acceleration for video capture using VAAPI

content/browser/renderer_host/media/video_capture_device_client.cc

Index: content/browser/renderer_host/media/video_capture_device_client.cc
diff --git a/content/browser/renderer_host/media/video_capture_device_client.cc b/content/browser/renderer_host/media/video_capture_device_client.cc
index 3fdbca2279847bcc186e08b42b89eda43bfdd9b8..e6a34cf7f075f6bbe22c1779112af84f7ddd54cc 100644
--- a/content/browser/renderer_host/media/video_capture_device_client.cc
+++ b/content/browser/renderer_host/media/video_capture_device_client.cc
@@ -11,6 +11,7 @@
 #include "content/browser/gpu/browser_gpu_channel_host_factory.h"
 #include "content/browser/gpu/browser_gpu_memory_buffer_manager.h"
 #include "content/browser/gpu/gpu_data_manager_impl.h"
+#include "content/browser/renderer_host/gpu_jpeg_decoder.h"
 #include "content/browser/renderer_host/media/video_capture_buffer_pool.h"
 #include "content/browser/renderer_host/media/video_capture_controller.h"
 #include "content/common/gpu/client/context_provider_command_buffer.h"
@@ -120,6 +121,9 @@ class AutoReleaseBuffer : public media::VideoCaptureDevice::Client::Buffer {
   ClientBuffer AsClientBuffer() override {
     return buffer_handle_->AsClientBuffer();
   }
+  base::SharedMemoryHandle AsPlatformHandle() override {
+    return buffer_handle_->AsPlatformHandle();
+  }
 
  private:
   ~AutoReleaseBuffer() override { pool_->RelinquishProducerReservation(id_); }
@@ -197,9 +201,17 @@ VideoCaptureDeviceClient::VideoCaptureDeviceClient(
       capture_task_runner_(capture_task_runner),
       last_captured_pixel_format_(media::PIXEL_FORMAT_UNKNOWN) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  if (GpuJpegDecoder::Supported()) {
+    external_jpeg_decoder_.reset(new GpuJpegDecoder(
+        this,
+        base::Bind(
+            &VideoCaptureController::DoIncomingCapturedVideoFrameOnIOThread,
+            controller_)));
+  }
 }
 
-VideoCaptureDeviceClient::~VideoCaptureDeviceClient() {}
+VideoCaptureDeviceClient::~VideoCaptureDeviceClient() {
+}
 
 void VideoCaptureDeviceClient::OnIncomingCapturedData(
     const uint8* data,
@@ -213,11 +225,22 @@ void VideoCaptureDeviceClient::OnIncomingCapturedData(
     OnLog("Pixel format: " + media::VideoCaptureFormat::PixelFormatToString(
                                  frame_format.pixel_format));
     last_captured_pixel_format_ = frame_format.pixel_format;
+
+    if (frame_format.pixel_format == media::PIXEL_FORMAT_MJPEG &&
+        external_jpeg_decoder_)

[mcasas, 2015/05/07 00:59:03]

With this condition, we would be calling 
external_jpeg_decoder_->Initialize() on every 
incoming MJPEG frame, is that what we want?

[wuchengli, 2015/05/07 06:23:14]

Not every incoming frame. Only when format changes.

I also asked Kuang-che to clear |external_jpeg_decoder_| when initialization
fails. So it won't try to initialize again next time the format changes.

[kcwu, 2015/05/08 14:42:42]

This only happens when pixel_format becomes from non-MJPEG to MJPEG. Not every
frame.

[kcwu, 2015/05/08 14:42:42]

Acknowledged.

+      ignore_result(external_jpeg_decoder_->Initialize());

[wuchengli, 2015/05/04 14:14:41]

Why not set |external_jpeg_decoder_| to NULL if Initialize fails? GpuJpegDecoder
won't need |initialized_|.

[wuchengli, 2015/05/06 07:59:18]

As discussed, if Initialize fails, there will be no any callback. So it's safe
to clear |external_jpeg_decoder_| here.

[kcwu, 2015/05/08 14:42:42]

Done.

[kcwu, 2015/05/08 14:42:42]

Done.

   }
 
   if (!frame_format.IsValid())
     return;
 
+  if (frame_format.pixel_format == media::PIXEL_FORMAT_MJPEG &&
+      external_jpeg_decoder_) {

[mcasas, 2015/05/07 00:59:03]

nit: Merge all conditions in lines l.237-238.

[kcwu, 2015/05/08 14:42:42]

Acknowledged.
This is changed to no fallback.

+    if (external_jpeg_decoder_->DecodeCapturedData(data, length, frame_format,
+                                                   rotation, timestamp))
+      return;
+  }
+
   // |chopped_{width,height} and |new_unrotated_{width,height}| are the lowest
   // bit decomposition of {width, height}, grabbing the odd and even parts.
   const int chopped_width = frame_format.frame_size.width() & 1;