Add offset support to BitstreamBuffer.

content/common/gpu/media/android_video_decode_accelerator.cc

 // Copyright (c) 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/common/gpu/media/android_video_decode_accelerator.h"
 
 #include <stddef.h>
 
 #include "base/android/build_info.h"
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/trace_event/trace_event.h"
 #include "content/common/gpu/gpu_channel.h"
 #include "content/common/gpu/media/android_copying_backing_strategy.h"
 #include "content/common/gpu/media/android_deferred_rendering_backing_strategy.h"
+#include "content/common/gpu/media/shared_memory_region.h"
 #include "content/public/common/content_switches.h"
 #include "gpu/command_buffer/service/gles2_cmd_decoder.h"
 #include "gpu/command_buffer/service/gpu_switches.h"
 #include "gpu/command_buffer/service/mailbox_manager.h"
 #include "media/base/android/media_codec_util.h"
 #include "media/base/bind_to_current_loop.h"
 #include "media/base/bitstream_buffer.h"
 #include "media/base/limits.h"
 #include "media/base/media.h"
 #include "media/base/media_switches.h"
@@ skipping 341 matching lines @@
     pending_bitstream_buffers_.pop();
     TRACE_COUNTER1("media", "AVDA::PendingBitstreamBufferCount",
                    pending_bitstream_buffers_.size());
 
     DCHECK_NE(state_, ERROR);
     state_ = WAITING_FOR_EOS;
     media_codec_->QueueEOS(input_buf_index);
     return true;
   }
 
-  scoped_ptr<base::SharedMemory> shm;
+  scoped_ptr<SharedMemoryRegion> shm;
 
   if (pending_input_buf_index_ != -1) {
     // The buffer is already dequeued from MediaCodec, filled with data and
     // bitstream_buffer.handle() is closed.
-    shm.reset(new base::SharedMemory());
+    shm.reset(new SharedMemoryRegion(base::SharedMemoryHandle(), 0, 0, false));

[dcheng, 2016/03/01 01:48:43]

Maybe just shm.reset() and null check when initializing |memory| below? Then I
think you won't need the overloaded constructor.

const uint8_t* memory = shm ? static_cast<const uint8_t*>(shm->memory()) :
nullptr;

[Owen Lin, 2016/03/02 02:50:53]

Thanks.

   } else {
-    shm.reset(new base::SharedMemory(bitstream_buffer.handle(), true));
+    shm.reset(new SharedMemoryRegion(bitstream_buffer, true));
 
-    if (!shm->Map(bitstream_buffer.size())) {
-      POST_ERROR(UNREADABLE_INPUT, "Failed to SharedMemory::Map()");
+    if (!shm->Map()) {
+      POST_ERROR(UNREADABLE_INPUT, "Failed to SharedMemoryRegion::Map()");
       return false;
     }
   }
 
   const base::TimeDelta presentation_timestamp =
       bitstream_buffer.presentation_timestamp();
   DCHECK(presentation_timestamp != media::kNoTimestamp())
       << "Bitstream buffers must have valid presentation timestamps";
 
   // There may already be a bitstream buffer with this timestamp, e.g., VP9 alt
@@ skipping 647 matching lines @@
     capabilities.flags = media::VideoDecodeAccelerator::Capabilities::
                              NEEDS_ALL_PICTURE_BUFFERS_TO_DECODE |
                          media::VideoDecodeAccelerator::Capabilities::
                              SUPPORTS_EXTERNAL_OUTPUT_SURFACE;
   }
 
   return capabilities;
 }
 
 }  // namespace content