Add offset support to BitstreamBuffer.

content/common/gpu/media/v4l2_video_decode_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 <dlfcn.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <linux/videodev2.h>
 #include <poll.h>
 #include <string.h>
 #include <sys/eventfd.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/macros.h"
-#include "base/memory/shared_memory.h"
 #include "base/message_loop/message_loop.h"
 #include "base/numerics/safe_conversions.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/trace_event/trace_event.h"
 #include "build/build_config.h"
+#include "content/common/gpu/media/shared_memory_region.h"
 #include "content/common/gpu/media/v4l2_video_decode_accelerator.h"
 #include "media/base/media_switches.h"
 #include "media/filters/h264_parser.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gl/scoped_binders.h"
 
 #define NOTIFY_ERROR(x)                        \
   do {                                         \
     LOG(ERROR) << "Setting error state:" << x; \
     SetErrorState(x);                          \
@@ skipping 24 matching lines @@
 
 // static
 const uint32_t V4L2VideoDecodeAccelerator::supported_input_fourccs_[] = {
     V4L2_PIX_FMT_H264, V4L2_PIX_FMT_VP8, V4L2_PIX_FMT_VP9,
 };
 
 struct V4L2VideoDecodeAccelerator::BitstreamBufferRef {
   BitstreamBufferRef(
       base::WeakPtr<Client>& client,
       scoped_refptr<base::SingleThreadTaskRunner>& client_task_runner,
-      base::SharedMemory* shm,
-      size_t size,
+      SharedMemoryRegion* shm,

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

scoped_ptr<SharedMemoryRegion> to have the compiler document that ownership is
transferred (similar for the other BitstreamBufferRef helpers)

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

Done.

       int32_t input_id);
   ~BitstreamBufferRef();
   const base::WeakPtr<Client> client;
   const scoped_refptr<base::SingleThreadTaskRunner> client_task_runner;
-  const scoped_ptr<base::SharedMemory> shm;
-  const size_t size;
+  const scoped_ptr<SharedMemoryRegion> shm;
   size_t bytes_used;
   const int32_t input_id;
 };
 
 struct V4L2VideoDecodeAccelerator::EGLSyncKHRRef {
   EGLSyncKHRRef(EGLDisplay egl_display, EGLSyncKHR egl_sync);
   ~EGLSyncKHRRef();
   EGLDisplay const egl_display;
   EGLSyncKHR egl_sync;
 };
 
 struct V4L2VideoDecodeAccelerator::PictureRecord {
   PictureRecord(bool cleared, const media::Picture& picture);
   ~PictureRecord();
   bool cleared;  // Whether the texture is cleared and safe to render from.
   media::Picture picture;  // The decoded picture.
 };
 
 V4L2VideoDecodeAccelerator::BitstreamBufferRef::BitstreamBufferRef(
     base::WeakPtr<Client>& client,
     scoped_refptr<base::SingleThreadTaskRunner>& client_task_runner,
-    base::SharedMemory* shm,
-    size_t size,
+    SharedMemoryRegion* shm,
     int32_t input_id)
     : client(client),
       client_task_runner(client_task_runner),
       shm(shm),
-      size(size),
       bytes_used(0),
       input_id(input_id) {}
 
 V4L2VideoDecodeAccelerator::BitstreamBufferRef::~BitstreamBufferRef() {
   if (input_id >= 0) {
     client_task_runner->PostTask(
         FROM_HERE,
         base::Bind(&Client::NotifyEndOfBitstreamBuffer, client, input_id));
   }
 }
@@ skipping 361 matching lines @@
 void V4L2VideoDecodeAccelerator::DecodeTask(
     const media::BitstreamBuffer& bitstream_buffer) {
   DVLOG(3) << "DecodeTask(): input_id=" << bitstream_buffer.id();
   DCHECK_EQ(decoder_thread_.message_loop(), base::MessageLoop::current());
   DCHECK_NE(decoder_state_, kUninitialized);
   TRACE_EVENT1("Video Decoder", "V4L2VDA::DecodeTask", "input_id",
                bitstream_buffer.id());
 
   scoped_ptr<BitstreamBufferRef> bitstream_record(new BitstreamBufferRef(
       io_client_, io_task_runner_,
-      new base::SharedMemory(bitstream_buffer.handle(), true),
-      bitstream_buffer.size(), bitstream_buffer.id()));
-  if (!bitstream_record->shm->Map(bitstream_buffer.size())) {
+      new SharedMemoryRegion(bitstream_buffer, true), bitstream_buffer.id()));
+  if (!bitstream_record->shm->Map()) {
     LOG(ERROR) << "Decode(): could not map bitstream_buffer";
     NOTIFY_ERROR(UNREADABLE_INPUT);
     return;
   }
   DVLOG(3) << "DecodeTask(): mapped at=" << bitstream_record->shm->memory();
 
   if (decoder_state_ == kResetting || decoder_flushing_) {
     // In the case that we're resetting or flushing, we need to delay decoding
     // the BitstreamBuffers that come after the Reset() or Flush() call.  When
     // we're here, we know that this DecodeTask() was scheduled by a Decode()
@@ skipping 38 matching lines @@
     }
     linked_ptr<BitstreamBufferRef>& buffer_ref = decoder_input_queue_.front();
     if (decoder_delay_bitstream_buffer_id_ == buffer_ref->input_id) {
       // We're asked to delay decoding on this and subsequent buffers.
       return;
     }
 
     // Setup to use the next buffer.
     decoder_current_bitstream_buffer_.reset(buffer_ref.release());
     decoder_input_queue_.pop();
-    DVLOG(3) << "DecodeBufferTask(): reading input_id="
-             << decoder_current_bitstream_buffer_->input_id
-             << ", addr=" << (decoder_current_bitstream_buffer_->shm ?
-                              decoder_current_bitstream_buffer_->shm->memory() :
-                              NULL)
-             << ", size=" << decoder_current_bitstream_buffer_->size;
+    const auto& shm = decoder_current_bitstream_buffer_->shm;
+    if (shm) {
+      DVLOG(3) << "DecodeBufferTask(): reading input_id="
+               << decoder_current_bitstream_buffer_->input_id
+               << ", addr=" << shm->memory() << ", size=" << shm->size();
+    } else {
+      DCHECK_EQ(decoder_current_bitstream_buffer_->input_id, kFlushBufferId);
+      DVLOG(3) << "DecodeBufferTask(): reading input_id=kFlushBufferId";
+    }
   }
   bool schedule_task = false;
-  const size_t size = decoder_current_bitstream_buffer_->size;
   size_t decoded_size = 0;
-  if (size == 0) {
-    const int32_t input_id = decoder_current_bitstream_buffer_->input_id;
-    if (input_id >= 0) {
-      // This is a buffer queued from the client that has zero size.  Skip.
+  const auto& shm = decoder_current_bitstream_buffer_->shm;
+  if (!shm) {
+    // This is a dummy buffer, queued to flush the pipe.  Flush.
+    DCHECK_EQ(decoder_current_bitstream_buffer_->input_id, kFlushBufferId);
+    // Enqueue a buffer guaranteed to be empty.  To do that, we flush the
+    // current input, enqueue no data to the next frame, then flush that down.
+    schedule_task = true;
+    if (decoder_current_input_buffer_ != -1 &&
+        input_buffer_map_[decoder_current_input_buffer_].input_id !=
+            kFlushBufferId)
+      schedule_task = FlushInputFrame();
+
+    if (schedule_task && AppendToInputFrame(NULL, 0) && FlushInputFrame()) {
+      DVLOG(2) << "DecodeBufferTask(): enqueued flush buffer";
+      decoder_partial_frame_pending_ = false;
       schedule_task = true;
     } else {
-      // This is a buffer of zero size, queued to flush the pipe.  Flush.
-      DCHECK_EQ(decoder_current_bitstream_buffer_->shm.get(),
-                static_cast<base::SharedMemory*>(NULL));
-      // Enqueue a buffer guaranteed to be empty.  To do that, we flush the
-      // current input, enqueue no data to the next frame, then flush that down.
-      schedule_task = true;
-      if (decoder_current_input_buffer_ != -1 &&
-          input_buffer_map_[decoder_current_input_buffer_].input_id !=
-              kFlushBufferId)
-        schedule_task = FlushInputFrame();
-
-      if (schedule_task && AppendToInputFrame(NULL, 0) && FlushInputFrame()) {
-        DVLOG(2) << "DecodeBufferTask(): enqueued flush buffer";
-        decoder_partial_frame_pending_ = false;
-        schedule_task = true;
-      } else {
-        // If we failed to enqueue the empty buffer (due to pipeline
-        // backpressure), don't advance the bitstream buffer queue, and don't
-        // schedule the next task.  This bitstream buffer queue entry will get
-        // reprocessed when the pipeline frees up.
-        schedule_task = false;
-      }
+      // If we failed to enqueue the empty buffer (due to pipeline
+      // backpressure), don't advance the bitstream buffer queue, and don't
+      // schedule the next task.  This bitstream buffer queue entry will get
+      // reprocessed when the pipeline frees up.
+      schedule_task = false;
     }
+  } else if (shm->size() == 0) {
+    // This is a buffer queued from the client that has zero size.  Skip.
+    schedule_task = true;
   } else {
     // This is a buffer queued from the client, with actual contents.  Decode.
     const uint8_t* const data =
-        reinterpret_cast<const uint8_t*>(
-            decoder_current_bitstream_buffer_->shm->memory()) +
+        reinterpret_cast<const uint8_t*>(shm->memory()) +
         decoder_current_bitstream_buffer_->bytes_used;
     const size_t data_size =
-        decoder_current_bitstream_buffer_->size -
-        decoder_current_bitstream_buffer_->bytes_used;
+        shm->size() - decoder_current_bitstream_buffer_->bytes_used;
     if (!AdvanceFrameFragment(data, data_size, &decoded_size)) {
       NOTIFY_ERROR(UNREADABLE_INPUT);
       return;
     }
     // AdvanceFrameFragment should not return a size larger than the buffer
     // size, even on invalid data.
     CHECK_LE(decoded_size, data_size);
 
     switch (decoder_state_) {
       case kInitialized:
       case kAfterReset:
         schedule_task = DecodeBufferInitial(data, decoded_size, &decoded_size);
         break;
       case kDecoding:
         schedule_task = DecodeBufferContinue(data, decoded_size);
         break;
       default:
         NOTIFY_ERROR(ILLEGAL_STATE);
         return;
     }
   }
   if (decoder_state_ == kError) {
     // Failed during decode.
     return;
   }
 
   if (schedule_task) {
     decoder_current_bitstream_buffer_->bytes_used += decoded_size;
-    if (decoder_current_bitstream_buffer_->bytes_used ==
-        decoder_current_bitstream_buffer_->size) {
+    if ((shm ? shm->size() : 0) ==
+        decoder_current_bitstream_buffer_->bytes_used) {
       // Our current bitstream buffer is done; return it.
       int32_t input_id = decoder_current_bitstream_buffer_->input_id;
       DVLOG(3) << "DecodeBufferTask(): finished input_id=" << input_id;
       // BitstreamBufferRef destructor calls NotifyEndOfBitstreamBuffer().
       decoder_current_bitstream_buffer_.reset();
     }
     ScheduleDecodeBufferTaskIfNeeded();
   }
 }
 
@@ skipping 635 matching lines @@
     DVLOG(2) << "FlushTask(): early out: kError state";
     return;
   }
 
   // We don't support stacked flushing.
   DCHECK(!decoder_flushing_);
 
   // Queue up an empty buffer -- this triggers the flush.
   decoder_input_queue_.push(
       linked_ptr<BitstreamBufferRef>(new BitstreamBufferRef(
-          io_client_, io_task_runner_, NULL, 0, kFlushBufferId)));
+          io_client_, io_task_runner_, nullptr, kFlushBufferId)));
   decoder_flushing_ = true;
   SendPictureReady();  // Send all pending PictureReady.
 
   ScheduleDecodeBufferTaskIfNeeded();
 }
 
 void V4L2VideoDecodeAccelerator::NotifyFlushDoneIfNeeded() {
   if (!decoder_flushing_)
     return;
 
@@ skipping 743 matching lines @@
 
 void V4L2VideoDecodeAccelerator::PictureCleared() {
   DVLOG(3) << "PictureCleared(). clearing count=" << picture_clearing_count_;
   DCHECK_EQ(decoder_thread_.message_loop(), base::MessageLoop::current());
   DCHECK_GT(picture_clearing_count_, 0);
   picture_clearing_count_--;
   SendPictureReady();
 }
 
 }  // namespace content