Remove media::VideoFrame from media::VideoCaptureDevice::Client interface

content/browser/renderer_host/media/video_capture_buffer_pool.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/browser/renderer_host/media/video_capture_buffer_pool.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 24 matching lines @@
   if (!buffer) {
     NOTREACHED() << "Invalid buffer_id.";
     return base::SharedMemory::NULLHandle();
   }
   base::SharedMemoryHandle remote_handle;
   buffer->shared_memory.ShareToProcess(process_handle, &remote_handle);
   *memory_size = buffer->shared_memory.requested_size();
   return remote_handle;
 }
 
+bool VideoCaptureBufferPool::GetBufferInfo(int buffer_id,
+                                           void** memory,
+                                           size_t* size) {
+  base::AutoLock lock(lock_);
+
+  Buffer* buffer = GetBuffer(buffer_id);
+  if (!buffer) {
+    NOTREACHED() << "Invalid buffer_id.";
+    return false;
+  }
+
+  DCHECK(buffer->held_by_producer);
+  *memory = buffer->shared_memory.memory();
+  *size = buffer->shared_memory.mapped_size();
+  return true;
+}
+
 int VideoCaptureBufferPool::ReserveForProducer(size_t size,
                                                int* buffer_id_to_drop) {
   base::AutoLock lock(lock_);
   return ReserveForProducerInternal(size, buffer_id_to_drop);
 }
 
 void VideoCaptureBufferPool::RelinquishProducerReservation(int buffer_id) {
   base::AutoLock lock(lock_);
   Buffer* buffer = GetBuffer(buffer_id);
   if (!buffer) {
@@ skipping 28 matching lines @@
   Buffer* buffer = GetBuffer(buffer_id);
   if (!buffer) {
     NOTREACHED() << "Invalid buffer_id.";
     return;
   }
   DCHECK_GE(buffer->consumer_hold_count, num_clients);
 
   buffer->consumer_hold_count -= num_clients;
 }
 
-int VideoCaptureBufferPool::RecognizeReservedBuffer(
-    base::SharedMemoryHandle maybe_belongs_to_pool) {
-  base::AutoLock lock(lock_);
-  for (BufferMap::iterator it = buffers_.begin(); it != buffers_.end(); it++) {
-    if (it->second->shared_memory.handle() == maybe_belongs_to_pool) {
-      DCHECK(it->second->held_by_producer);
-      return it->first;
-    }
-  }
-  return kInvalidId;  // Buffer is not from our pool.
-}
-
-scoped_refptr<media::VideoFrame> VideoCaptureBufferPool::ReserveI420VideoFrame(
-    const gfx::Size& size,
-    int rotation,
-    int* buffer_id_to_drop) {
-  base::AutoLock lock(lock_);
-
-  size_t frame_bytes =
-      media::VideoFrame::AllocationSize(media::VideoFrame::I420, size);
-
-  int buffer_id = ReserveForProducerInternal(frame_bytes, buffer_id_to_drop);
-  if (buffer_id == kInvalidId)
-    return NULL;
-
-  base::Closure disposal_handler = base::Bind(
-      &VideoCaptureBufferPool::RelinquishProducerReservation,
-      this,
-      buffer_id);
-
-  Buffer* buffer = GetBuffer(buffer_id);
-  // Wrap the buffer in a VideoFrame container.
-  scoped_refptr<media::VideoFrame> frame =
-      media::VideoFrame::WrapExternalSharedMemory(
-          media::VideoFrame::I420,
-          size,
-          gfx::Rect(size),
-          size,
-          static_cast<uint8*>(buffer->shared_memory.memory()),
-          frame_bytes,
-          buffer->shared_memory.handle(),
-          base::TimeDelta(),
-          disposal_handler);
-
-  if (buffer->rotation != rotation) {
-    // TODO(jiayl): Generalize the |rotation| mechanism.
-    media::FillYUV(frame.get(), 0, 128, 128);
-    buffer->rotation = rotation;
-  }
-
-  return frame;
-}
-
 VideoCaptureBufferPool::Buffer::Buffer()
-    : rotation(0),
-      held_by_producer(false),
-      consumer_hold_count(0) {}
+    : held_by_producer(false), consumer_hold_count(0) {}
 
 int VideoCaptureBufferPool::ReserveForProducerInternal(size_t size,
                                                        int* buffer_id_to_drop) {
   lock_.AssertAcquired();
 
-  // Look for a buffer that's allocated, big enough, and not in use.
+  // Look for a buffer that's allocated, big enough, and not in use. Track the
+  // largest one that's not big enough, in case we have to reallocate a buffer.
   *buffer_id_to_drop = kInvalidId;
+  size_t realloc_size = 0;
+  BufferMap::iterator realloc = buffers_.end();
   for (BufferMap::iterator it = buffers_.begin(); it != buffers_.end(); it++) {

[wjia(left Chromium), 2013/11/19 01:47:35]

nit: ++it

[sheu, 2013/11/19 20:28:17]

Done.

     Buffer* buffer = it->second;
     if (!buffer->consumer_hold_count && !buffer->held_by_producer) {
       if (buffer->shared_memory.requested_size() >= size) {
         // Existing buffer is big enough. Reuse it.
         buffer->held_by_producer = true;
         return it->first;
       }
+      if (buffer->shared_memory.requested_size() > realloc_size) {
+        realloc_size = buffer->shared_memory.requested_size();
+        realloc = it;

[wjia(left Chromium), 2013/11/19 01:47:35]

OOC, what's the reason to reallocate the largest one? 

It seems VideoCaptureBufferPool doesn't downsize buffer when the requested size
is smaller than the existing buffer size. Any concern about holding unnecessary
memory?

[sheu, 2013/11/19 20:28:17]

VideoCaptureBufferPool doesn't downsize until it has run out of buffers.  At
that point I think it makes sense to downsize, starting with the largest one so
we get the biggest reduction in memory usage.

+      }
     }
   }
 
-  // Look for a buffer that's not in use, that we can reallocate.
-  for (BufferMap::iterator it = buffers_.begin(); it != buffers_.end(); it++) {
-    Buffer* buffer = it->second;
-    if (!buffer->consumer_hold_count && !buffer->held_by_producer) {
-      // Existing buffer is too small. Free it so we can allocate a new one
-      // after the loop.
-      *buffer_id_to_drop = it->first;
-      buffers_.erase(it);
-      delete buffer;
-      break;
+  // Preferentially grow the pool by creating a new buffer. If we're at maximum
+  // size, then reallocate by deleting an existing one instead.
+  if (buffers_.size() == static_cast<size_t>(count_)) {
+    if (realloc == buffers_.end()) {
+      // We're out of space, and can't find an unused buffer to reallocate.
+      return kInvalidId;
     }
+    *buffer_id_to_drop = realloc->first;
+    delete realloc->second;
+    buffers_.erase(realloc);
   }
 
-  // If possible, grow the pool by creating a new buffer.
-  if (static_cast<int>(buffers_.size()) < count_) {
-    int buffer_id = next_buffer_id_++;
-    scoped_ptr<Buffer> buffer(new Buffer());
+  // Create the new buffer.
+  int buffer_id = next_buffer_id_++;
+  scoped_ptr<Buffer> buffer(new Buffer());
+  if (size) {
+    // |size| can be 0 for buffers that do not require memory backing.
     if (!buffer->shared_memory.CreateAndMapAnonymous(size))
       return kInvalidId;
-    buffer->held_by_producer = true;
-    buffers_[buffer_id] = buffer.release();
-    return buffer_id;
   }
-
-  // The pool is at its size limit, and all buffers are in use.
-  return kInvalidId;
+  buffer->held_by_producer = true;
+  buffers_[buffer_id] = buffer.release();
+  return buffer_id;
 }
 
 VideoCaptureBufferPool::Buffer* VideoCaptureBufferPool::GetBuffer(
     int buffer_id) {
   BufferMap::iterator it = buffers_.find(buffer_id);
   if (it == buffers_.end())
     return NULL;
   return it->second;
 }
 
 }  // namespace content