Disable HW H264 decoder for Win7 & add enable flag

content/renderer/media/rtc_video_decoder.cc

 // Copyright 2013 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 "content/renderer/media/rtc_video_decoder.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/metrics/histogram.h"
 #include "base/numerics/safe_conversions.h"
 #include "base/stl_util.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/task_runner_util.h"
 #include "content/renderer/media/webrtc/webrtc_video_frame_adapter.h"
 #include "gpu/command_buffer/common/mailbox_holder.h"
 #include "media/base/bind_to_current_loop.h"
 #include "media/renderers/gpu_video_accelerator_factories.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/webrtc/base/bind.h"
 #include "third_party/webrtc/base/refcount.h"
 #include "third_party/webrtc/video_frame.h"
 
+#if defined(OS_WIN)
+#include "base/command_line.h"
+#include "base/win/windows_version.h"
+#include "content/public/common/content_switches.h"
+#endif  // defined(OS_WIN)
+
 namespace content {
 
 const int32_t RTCVideoDecoder::ID_LAST = 0x3FFFFFFF;
 const int32_t RTCVideoDecoder::ID_HALF = 0x20000000;
 const int32_t RTCVideoDecoder::ID_INVALID = -1;
 const uint32_t kNumVDAErrorsBeforeSWFallback = 50;
 
 // Maximum number of concurrent VDA::Decode() operations RVD will maintain.
 // Higher values allow better pipelining in the GPU, but also require more
 // resources.
@@ skipping 46 matching lines @@
                                       decode_buffers_.end());
   decode_buffers_.clear();
   ClearPendingBuffers();
 }
 
 // static
 std::unique_ptr<RTCVideoDecoder> RTCVideoDecoder::Create(
     webrtc::VideoCodecType type,
     media::GpuVideoAcceleratorFactories* factories) {
   std::unique_ptr<RTCVideoDecoder> decoder;
+// See https://bugs.chromium.org/p/webrtc/issues/detail?id=5717.
+#if defined(OS_WIN)
+  if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableWin7WebRtcHWH264Decoding) &&
+      type == webrtc::kVideoCodecH264 &&
+      base::win::GetVersion() == base::win::VERSION_WIN7) {
+    DLOG(ERROR) << "H264 HW decoding on Win7 is not supported.";
+    return decoder;
+  }
+#endif  // defined(OS_WIN)
   // Convert WebRTC codec type to media codec profile.
   media::VideoCodecProfile profile;
   switch (type) {
     case webrtc::kVideoCodecVP8:
       profile = media::VP8PROFILE_ANY;
       break;
     case webrtc::kVideoCodecH264:
       profile = media::H264PROFILE_MAIN;
       break;
     default:
@@ skipping 756 matching lines @@
 
 void RTCVideoDecoder::TryResetVDAErrorCounter_Locked() {
   lock_.AssertAcquired();
 
   if (vda_error_counter_ == 0)
     return;
   vda_error_counter_ = 0;
 }
 
 }  // namespace content