Add 4k HW decode override flag and support larger bitstream buffers in V4L2VDA.

media/filters/gpu_video_decoder.cc

 // Copyright (c) 2012 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/filters/gpu_video_decoder.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
+#include "base/command_line.h"
 #include "base/cpu.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/stl_util.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/task_runner_util.h"
 #include "gpu/command_buffer/common/mailbox_holder.h"
 #include "media/base/bind_to_current_loop.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/media_log.h"
+#include "media/base/media_switches.h"
 #include "media/base/pipeline.h"
 #include "media/base/pipeline_status.h"
 #include "media/base/video_decoder_config.h"
 #include "media/filters/gpu_video_accelerator_factories.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 
 namespace media {
 
 // Maximum number of concurrent VDA::Decode() operations GVD will maintain.
 // Higher values allow better pipelining in the GPU, but also require more
@@ skipping 84 matching lines @@
 }
 
 static bool IsCodedSizeSupported(const gfx::Size& coded_size) {
   // Only non-Windows, Ivy Bridge+ platforms can support more than 1920x1080.
   // We test against 1088 to account for 16x16 macroblocks.
   if (coded_size.width() <= 1920 && coded_size.height() <= 1088)
     return true;
 
   base::CPU cpu;
   bool hw_large_video_support =
-      (cpu.vendor_name() == "GenuineIntel") && cpu.model() >= 55;
+      CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kForce4kAcceleratedVideoDecode) ||
+      ((cpu.vendor_name() == "GenuineIntel") && cpu.model() >= 55);

[piman, 2014/05/15 17:02:27]

Is this in the renderer?

What would happen if the renderer submits large videos anyway? Think malicious
renderer.

[Pawel Osciak, 2014/05/16 03:53:01]

This gates whether a HW or SW decoder is used. It's called after parsing the
container with the values from the container to decide if we can instantiate a
HW decoder to decode given stream. If not, we use a SW one.

If you mean a malicious stream that has invalid header information in the
container, then if it doesn't fit in the buffers, we check for that and fail if
we can't fit in the buffers. Such a case doesn't really differ much from a
stream that has any other invalid metadata in it.

   bool os_large_video_support = true;
 #if defined(OS_WIN)
   os_large_video_support = false;
 #endif
   return os_large_video_support && hw_large_video_support;
 }
 
 // Report |status| to UMA and run |cb| with it.  This is super-specific to the
 // UMA stat reported because the UMA_HISTOGRAM_ENUMERATION API requires a
 // callsite to always be called with the same stat name (can't parameterize it).
@@ skipping 504 matching lines @@
     return;
   }
 }
 
 void GpuVideoDecoder::DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent()
     const {
   DCHECK(factories_->GetTaskRunner()->BelongsToCurrentThread());
 }
 
 }  // namespace media