VAVEA: Turn VAAPI encoder flag into a kill switch.

content/common/gpu/media/vaapi_video_encode_accelerator.cc

 // Copyright 2014 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/common/gpu/media/vaapi_video_encode_accelerator.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/command_line.h"
+#include "base/cpu.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/metrics/histogram.h"
 #include "base/numerics/safe_conversions.h"
 #include "content/common/gpu/media/h264_dpb.h"
 #include "content/public/common/content_switches.h"
 #include "media/base/bind_to_current_loop.h"
 #include "third_party/libva/va/va_enc_h264.h"
 
 #define DVLOGF(level) DVLOG(level) << __FUNCTION__ << "(): "
 
@@ skipping 82 matching lines @@
   const int32 id;
   const scoped_ptr<base::SharedMemory> shm;
   const size_t size;
 };
 
 // static
 std::vector<media::VideoEncodeAccelerator::SupportedProfile>
 VaapiVideoEncodeAccelerator::GetSupportedProfiles() {
   std::vector<SupportedProfile> profiles;
 
+  base::CPU cpu;
   const CommandLine* cmd_line = CommandLine::ForCurrentProcess();
-  if (!cmd_line->HasSwitch(switches::kEnableVaapiAcceleratedVideoEncode))
+  bool encode_enabled =
+      (!cmd_line->HasSwitch(switches::kDisableVaapiAcceleratedVideoEncode) &&
+       (cpu.vendor_name() == "GenuineIntel") && (cpu.model() == 55));

[piman, 2014/07/07 17:57:47]

You said this was used in the renderer? Does this correctly work with the
sandbox? base::CPU needs to access files.

I'm not excited about pegging the encoder to the CPU type.

Why not keeping the enable flag and pass it from the board definition on the
Chrome OS side?

[Pawel Osciak, 2014/07/08 05:32:42]

Yes, this is in renderer. PreSandboxStartup()
(https://code.google.com/p/chromium/codesearch#chromium/src/chrome/app/chrome_...)
prepopulates /proc/cpuinfo.
Me neither of course, but there is a bug in the driver that says it's available
even if it's not. I'm waiting for a fix from Intel, so this should hopefully be
temporary.
We have quite a few boards that support this and this way feels to me like a
better idea rather than manually curating a board list in command line builder. 

+
+  if (!encode_enabled)
     return profiles;
 
   SupportedProfile profile;
   profile.profile = media::H264PROFILE_MAIN;
   profile.max_resolution.SetSize(1920, 1088);
   profile.max_framerate.numerator = kDefaultFramerate;
   profile.max_framerate.denominator = 1;
   profiles.push_back(profile);
 
   // This is actually only constrained (see crbug.com/345569).
@@ skipping 928 matching lines @@
 }
 
 VaapiVideoEncodeAccelerator::EncodeJob::EncodeJob()
     : coded_buffer(VA_INVALID_ID), keyframe(false) {
 }
 
 VaapiVideoEncodeAccelerator::EncodeJob::~EncodeJob() {
 }
 
 }  // namespace content