Implement Pepper PPB_VideoDecoder interface.

content/renderer/pepper/pepper_video_decoder_host.cc

Index: content/renderer/pepper/pepper_video_decoder_host.cc
diff --git a/content/renderer/pepper/pepper_video_decoder_host.cc b/content/renderer/pepper/pepper_video_decoder_host.cc
new file mode 100644
index 0000000000000000000000000000000000000000..aef2066262eed0cebd980bedd48c14393f4b04d0
--- /dev/null
+++ b/content/renderer/pepper/pepper_video_decoder_host.cc
@@ -0,0 +1,396 @@
+// Copyright (c) 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/renderer/pepper/pepper_video_decoder_host.h"
+
+#include "base/bind.h"
+#include "base/memory/shared_memory.h"
+#include "content/common/gpu/client/gpu_channel_host.h"
+#include "content/public/renderer/render_thread.h"
+#include "content/public/renderer/renderer_ppapi_host.h"
+#include "content/renderer/pepper/ppb_graphics_3d_impl.h"
+#include "content/renderer/render_thread_impl.h"
+#include "content/renderer/render_view_impl.h"
+#include "media/video/picture.h"
+#include "media/video/video_decode_accelerator.h"
+#include "ppapi/c/pp_completion_callback.h"
+#include "ppapi/c/pp_errors.h"
+#include "ppapi/host/dispatch_host_message.h"
+#include "ppapi/host/ppapi_host.h"
+#include "ppapi/proxy/ppapi_messages.h"
+#include "ppapi/thunk/enter.h"
+#include "ppapi/thunk/ppb_graphics_3d_api.h"
+
+using ppapi::proxy::SerializedHandle;
+using ppapi::thunk::EnterResourceNoLock;
+using ppapi::thunk::PPB_Graphics3D_API;
+
+namespace content {
+
+namespace {
+
+media::VideoCodecProfile PepperToMediaVideoProfile(PP_VideoProfile profile) {
+  switch (profile) {
+    case PP_VIDEOPROFILE_H264BASELINE:
+      return media::H264PROFILE_BASELINE;
+    case PP_VIDEOPROFILE_H264MAIN:
+      return media::H264PROFILE_MAIN;
+    case PP_VIDEOPROFILE_H264EXTENDED:
+      return media::H264PROFILE_EXTENDED;
+    case PP_VIDEOPROFILE_H264HIGH:
+      return media::H264PROFILE_HIGH;
+    case PP_VIDEOPROFILE_H264HIGH10PROFILE:
+      return media::H264PROFILE_HIGH10PROFILE;
+    case PP_VIDEOPROFILE_H264HIGH422PROFILE:
+      return media::H264PROFILE_HIGH422PROFILE;
+    case PP_VIDEOPROFILE_H264HIGH444PREDICTIVEPROFILE:
+      return media::H264PROFILE_HIGH444PREDICTIVEPROFILE;
+    case PP_VIDEOPROFILE_H264SCALABLEBASELINE:
+      return media::H264PROFILE_SCALABLEBASELINE;
+    case PP_VIDEOPROFILE_H264SCALABLEHIGH:
+      return media::H264PROFILE_SCALABLEHIGH;
+    case PP_VIDEOPROFILE_H264STEREOHIGH:
+      return media::H264PROFILE_STEREOHIGH;
+    case PP_VIDEOPROFILE_H264MULTIVIEWHIGH:
+      return media::H264PROFILE_MULTIVIEWHIGH;
+    case PP_VIDEOPROFILE_VP8MAIN:
+      return media::VP8PROFILE_MAIN;
+      // No default case, to catch unhandled PP_VideoProfile values.

[dmichael (off chromium), 2014/05/20 22:40:38]

I think the previous indent was right. Did clang-format do this? That might be
considered a bug...

You can probably force it to the right indent by adding a carriage return
before.

[bbudge, 2014/05/22 18:34:55]

I think I "fixed" this when I fixed the indent in OnResourceMessageReceived.
Fixed it back. Done.

+  }
+
+  return media::VIDEO_CODEC_PROFILE_UNKNOWN;
+}
+
+// These constants should be kept in sync with VideoDecoderResource.

[dmichael (off chromium), 2014/05/20 22:40:38]

Your header currently includes video_decoder_resource.h with a comment about
constants. Maybe a header in ppapi/proxy called media_codec_constants.h would
make sense? (ppapi/shared_impl would also be OK)

[bbudge, 2014/05/22 18:34:55]

Added a .h file, ppapi/proxy/video_decoder_constants.h.

+// Maximum number of concurrent decodes which can be pending.
+const uint32_t kMaximumPendingDecodes = 8;
+// Maximum size of shared-memory buffers we allocate (4 MB). This should be
+// enough for even 4K video at reasonable compression levels.
+const uint32_t kMaximumBitstreamBufferSize = 4 << 20;
+
+}  // namespace
+
+PepperVideoDecoderHost::PendingDecode::PendingDecode(
+    uint32_t shm_id,
+    const ppapi::host::ReplyMessageContext& reply_context)
+    : shm_id(shm_id), reply_context(reply_context) {
+}
+
+PepperVideoDecoderHost::PendingDecode::~PendingDecode() {
+}
+
+PepperVideoDecoderHost::PepperVideoDecoderHost(RendererPpapiHost* host,
+                                               PP_Instance instance,
+                                               PP_Resource resource)
+    : ResourceHost(host->GetPpapiHost(), instance, resource),
+      renderer_ppapi_host_(host),
+      next_decode_id_(0),
+      initialized_(false) {
+}
+
+PepperVideoDecoderHost::~PepperVideoDecoderHost() {
+  if (decoder_) {
+    decoder_->Destroy();
+    // The decoder will delete itself.
+    ignore_result(decoder_.release());

[dmichael (off chromium), 2014/05/20 22:40:38]

Yuck. Seems like the destructor for that class ought to be protected or private
(not your problem).

Is it worth using scoped_ptr in this case? I'm not sure. It does make it more
self-documenting in a way, but it would be a bug for scoped_ptr to actually
delete it via the destructor.

You could make scoped_ptr use Destroy() by using a custom deleter. It would look
something like:
struct VideoDecodeAcceleratorDeleter {
  void operator()(VideoDecodeAccelerator* decoder) {
    decoder->Destroy();
  }
};
The header would have:
scoped_ptr<VideoDecodeAccelerator, VideoDecodeAcceleratorDeleter> decoder_;
}

Arguably the Deleter could live with VideoDecodeAccelerator, kind of like this:
https://code.google.com/p/chromium/codesearch#chromium/src/media/base/android...
...but it's up to you and Ami if you want to go there.

[bbudge, 2014/05/22 18:34:55]

I looked for existing usages of Destroy. Seems like the idiom is a bit nicer:

if (decoder_)
  decoder_.release()->Destroy();

https://code.google.com/p/chromium/codesearch#chromium/src/media/video/video_...

Is that better?

[dmichael (off chromium), 2014/05/23 22:44:47]

Sure...  being consistent makes sense.

I still think the way the Video..codeAccelerator classes are designed w.r.t.
destruction is confusing, so I threw together:
https://codereview.chromium.org/292183011/
...we'll see what Ami or somebody else on media thinks.

+  }
+}
+
+int32_t PepperVideoDecoderHost::OnResourceMessageReceived(
+    const IPC::Message& msg,
+    ppapi::host::HostMessageContext* context) {
+  PPAPI_BEGIN_MESSAGE_MAP(PepperVideoDecoderHost, msg)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_VideoDecoder_Initialize,
+                                      OnHostMsgInitialize)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_VideoDecoder_GetShm,
+                                      OnHostMsgGetShm)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_VideoDecoder_AssignTextures,
+                                      OnHostMsgAssignTextures)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_VideoDecoder_Decode,
+                                      OnHostMsgDecode)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_VideoDecoder_RecyclePicture,
+                                      OnHostMsgRecyclePicture)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(PpapiHostMsg_VideoDecoder_Flush,
+                                        OnHostMsgFlush)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(PpapiHostMsg_VideoDecoder_Reset,
+                                        OnHostMsgReset)
+  PPAPI_END_MESSAGE_MAP()
+  return PP_ERROR_FAILED;
+}
+
+int32_t PepperVideoDecoderHost::OnHostMsgInitialize(
+    ppapi::host::HostMessageContext* context,
+    const ppapi::HostResource& graphics_context,
+    PP_VideoProfile profile,
+    bool allow_software_fallback) {
+  if (initialized_)
+    return PP_ERROR_FAILED;
+
+  EnterResourceNoLock<PPB_Graphics3D_API> enter_graphics(
+      graphics_context.host_resource(), true);
+  if (enter_graphics.failed())
+    return PP_ERROR_FAILED;
+  graphics3d_ = static_cast<PPB_Graphics3D_Impl*>(enter_graphics.object());
+
+  int command_buffer_route_id = graphics3d_->GetCommandBufferRouteId();
+  if (!command_buffer_route_id)
+    return PP_ERROR_FAILED;
+
+  media::VideoCodecProfile media_profile = PepperToMediaVideoProfile(profile);
+
+  // This is not synchronous, but subsequent IPC messages will be buffered, so
+  // it is okay to immediately send IPC messages through the returned channel.
+  GpuChannelHost* channel = graphics3d_->channel();
+  DCHECK(channel);
+
+  if (channel) {
+    decoder_ = channel->CreateVideoDecoder(command_buffer_route_id);
+    if (decoder_ && decoder_->Initialize(media_profile, this)) {
+      initialized_ = true;
+      return PP_OK;
+    }
+    decoder_.reset();
+  }
+
+  // TODO(bbudge) Implement software fallback.
+  return PP_ERROR_NOTSUPPORTED;
+}
+
+int32_t PepperVideoDecoderHost::OnHostMsgGetShm(
+    ppapi::host::HostMessageContext* context,
+    uint32_t size,
+    uint32_t pending_shm_id) {
+  if (!initialized_)
+    return PP_ERROR_FAILED;
+  if (size > kMaximumBitstreamBufferSize)
+    return PP_ERROR_FAILED;
+  if (pending_shm_id >= kMaximumPendingDecodes)
+    return PP_ERROR_FAILED;
+  // The shm_id must be inside or at the end of shm_buffers_.
+  if (pending_shm_id > shm_buffers_.size())
+    return PP_ERROR_FAILED;
+
+  // Is this is a request to reallocate (grow) a buffer?
+  if (pending_shm_id < shm_buffers_.size()) {
+    // Reject an attempt to reallocate a busy shm buffer.
+    if (shm_buffer_busy_[pending_shm_id])

[dmichael (off chromium), 2014/05/20 22:40:38]

Could you instead just say:
if (pending_decodes_.count(pending_shm_id))
and get rid of shm_buffer_busy_?

...or maybe more idiomatic in Chromium:
if (ContainsKey(pending_decodes_, pending_shm_id))

(https://code.google.com/p/chromium/codesearch#chromium/src/base/stl_util.h&l=195)

[bbudge, 2014/05/22 18:34:55]

It requires iterating through the map. The key here is decode number, not
shm_id.

+      return PP_ERROR_FAILED;
+    // The buffer isn't in use. Delete it early to make allocation of a new,
+    // larger one more likely to succeed. Delete it manually since ScopedVector
+    // doesn't do the right thing.

[dmichael (off chromium), 2014/05/20 22:40:38]

nit: maybe better to say "won't delete the existing element if we just assign
it" or something for clarity.

[bbudge, 2014/05/22 18:34:55]

Done.

+    delete shm_buffers_[pending_shm_id];
+    shm_buffers_[pending_shm_id] = NULL;
+  }
+
+  content::RenderThread* render_thread = content::RenderThread::Get();
+  scoped_ptr<base::SharedMemory> shm(
+      render_thread->HostAllocateSharedMemoryBuffer(size).Pass());
+  if (!shm)
+    return PP_ERROR_FAILED;
+  if (!shm->Map(size))
+    return PP_ERROR_FAILED;
+
+  base::SharedMemoryHandle shm_handle = shm->handle();
+  if (pending_shm_id == shm_buffers_.size()) {
+    shm_buffers_.push_back(shm.release());
+    shm_buffer_busy_.push_back(0);
+  } else {
+    // Fill in the new resized buffer.
+    shm_buffers_[pending_shm_id] = shm.release();
+  }
+
+#if defined(OS_WIN)
+  base::PlatformFile platform_file = shm_handle;
+#elif defined(OS_POSIX)
+  base::PlatformFile platform_file = shm_handle.fd;
+#else
+#error Not implemented.
+#endif
+  SerializedHandle handle(
+      renderer_ppapi_host_->ShareHandleWithRemote(platform_file, false), size);
+  ppapi::host::ReplyMessageContext reply_context =
+      context->MakeReplyMessageContext();
+  reply_context.params.AppendHandle(handle);
+  host()->SendReply(reply_context,
+                    PpapiPluginMsg_VideoDecoder_GetShmReply(size));
+  return PP_OK_COMPLETIONPENDING;
+}
+
+int32_t PepperVideoDecoderHost::OnHostMsgAssignTextures(
+    ppapi::host::HostMessageContext* context,
+    const PP_Size& size,
+    const std::vector<uint32_t>& texture_ids) {
+  if (!initialized_)
+    return PP_ERROR_FAILED;
+  DCHECK(decoder_);
+
+  std::vector<media::PictureBuffer> picture_buffers;
+  for (uint32 i = 0; i < texture_ids.size(); i++) {
+    media::PictureBuffer buffer(
+        texture_ids[i],  // Use the texture_id to identify the buffer.
+        gfx::Size(size.width, size.height),
+        texture_ids[i]);
+    picture_buffers.push_back(buffer);
+  }
+  decoder_->AssignPictureBuffers(picture_buffers);
+  return PP_OK;
+}
+
+int32_t PepperVideoDecoderHost::OnHostMsgDecode(
+    ppapi::host::HostMessageContext* context,
+    uint32_t shm_id,
+    uint32_t size) {
+  if (!initialized_)
+    return PP_ERROR_FAILED;
+  DCHECK(decoder_);
+  // |shm_id| is just an index into shm_buffers_. Make sure it's in range.
+  if (static_cast<size_t>(shm_id) >= shm_buffers_.size())
+    return PP_ERROR_FAILED;
+  // Reject an attempt to pass a busy buffer to the decoder again.
+  if (shm_buffer_busy_[shm_id])

[dmichael (off chromium), 2014/05/20 22:40:38]

same as above, I think you could just look in the PendingDecode map?

[bbudge, 2014/05/22 18:34:55]

See comments above.

+    return PP_ERROR_FAILED;
+
+  if (flush_reply_context_.is_valid() || reset_reply_context_.is_valid())
+    return PP_ERROR_FAILED;
+
+  uint32_t uid = next_decode_id_++;
+  pending_decodes_.insert(std::make_pair(
+      uid, PendingDecode(shm_id, context->MakeReplyMessageContext())));
+
+  shm_buffer_busy_[shm_id] = true;
+  decoder_->Decode(media::BitstreamBuffer(
+      uid, shm_buffers_[shm_id]->handle(), size));
+
+  return PP_OK_COMPLETIONPENDING;
+}
+
+int32_t PepperVideoDecoderHost::OnHostMsgRecyclePicture(
+    ppapi::host::HostMessageContext* context,
+    uint32_t texture_id) {
+  if (!initialized_)
+    return PP_ERROR_FAILED;
+  DCHECK(decoder_);
+  if (reset_reply_context_.is_valid())
+    return PP_ERROR_FAILED;
+
+  decoder_->ReusePictureBuffer(texture_id);
+
+  return PP_OK;
+}
+
+int32_t PepperVideoDecoderHost::OnHostMsgFlush(
+    ppapi::host::HostMessageContext* context) {
+  if (!initialized_)
+    return PP_ERROR_FAILED;
+  DCHECK(decoder_);
+  if (flush_reply_context_.is_valid() || reset_reply_context_.is_valid())
+    return PP_ERROR_FAILED;
+
+  flush_reply_context_ = context->MakeReplyMessageContext();
+  decoder_->Flush();
+
+  return PP_OK_COMPLETIONPENDING;
+}
+
+int32_t PepperVideoDecoderHost::OnHostMsgReset(
+    ppapi::host::HostMessageContext* context) {
+  if (!initialized_)
+    return PP_ERROR_FAILED;
+  DCHECK(decoder_);
+  if (flush_reply_context_.is_valid() || reset_reply_context_.is_valid())
+    return PP_ERROR_FAILED;
+
+  reset_reply_context_ = context->MakeReplyMessageContext();
+  decoder_->Reset();
+
+  return PP_OK_COMPLETIONPENDING;
+}
+
+void PepperVideoDecoderHost::ProvidePictureBuffers(
+    uint32 requested_num_of_buffers,
+    const gfx::Size& dimensions,
+    uint32 texture_target) {
+  RequestTextures(requested_num_of_buffers, dimensions, texture_target);
+}
+
+void PepperVideoDecoderHost::RequestTextures(uint32 requested_num_of_buffers,
+                                             const gfx::Size& dimensions,
+                                             uint32 texture_target) {
+  DCHECK(RenderThreadImpl::current());
+  host()->SendUnsolicitedReply(
+      pp_resource(),
+      PpapiPluginMsg_VideoDecoder_RequestTextures(
+          requested_num_of_buffers,
+          PP_MakeSize(dimensions.width(), dimensions.height()),
+          texture_target));
+}
+
+void PepperVideoDecoderHost::PictureReady(const media::Picture& picture) {
+  DCHECK(RenderThreadImpl::current());
+  host()->SendUnsolicitedReply(
+      pp_resource(),
+      PpapiPluginMsg_VideoDecoder_PictureReady(picture.bitstream_buffer_id(),
+                                               picture.picture_buffer_id()));
+}
+
+void PepperVideoDecoderHost::DismissPictureBuffer(int32 picture_buffer_id) {
+  DCHECK(RenderThreadImpl::current());
+  host()->SendUnsolicitedReply(
+      pp_resource(),
+      PpapiPluginMsg_VideoDecoder_DismissPicture(picture_buffer_id));
+}
+
+void PepperVideoDecoderHost::NotifyError(
+    media::VideoDecodeAccelerator::Error error) {
+  DCHECK(RenderThreadImpl::current());
+  int32_t pp_error = PP_ERROR_FAILED;
+  switch (error) {
+    case media::VideoDecodeAccelerator::UNREADABLE_INPUT:
+      pp_error = PP_ERROR_MALFORMED_INPUT;
+      break;
+    case media::VideoDecodeAccelerator::ILLEGAL_STATE:
+    case media::VideoDecodeAccelerator::INVALID_ARGUMENT:
+    case media::VideoDecodeAccelerator::PLATFORM_FAILURE:
+      pp_error = PP_ERROR_RESOURCE_FAILED;
+      break;
+    default:
+      NOTREACHED();
+      break;
+  }
+  host()->SendUnsolicitedReply(
+      pp_resource(), PpapiPluginMsg_VideoDecoder_NotifyError(pp_error));
+}
+
+void PepperVideoDecoderHost::NotifyResetDone() {
+  DCHECK(RenderThreadImpl::current());
+  host()->SendReply(reset_reply_context_,
+                    PpapiPluginMsg_VideoDecoder_ResetReply());
+  reset_reply_context_ = ppapi::host::ReplyMessageContext();
+}
+
+void PepperVideoDecoderHost::NotifyEndOfBitstreamBuffer(
+    int32 bitstream_buffer_id) {
+  DCHECK(RenderThreadImpl::current());
+  uint32_t uid = static_cast<uint32_t>(bitstream_buffer_id);

[dmichael (off chromium), 2014/05/20 22:40:38]

If the decode API forces you to use int32, you might just want to bite the
bullet and use int32 also. I think the conversion from unsigned to signed on
line 263 is implementation defined if the value is too large to fit in int32.
Probably does the right thing, but it's hard to say with optimizers these days.

OTOH, at 60Hz, I think it will take over 2 years to reach that case, so maybe
who cares.

[bbudge, 2014/05/22 18:34:55]

Changed uid type to int32.

+  PendingDecodeMap::iterator it = pending_decodes_.find(uid);
+  if (it == pending_decodes_.end()) {
+    NOTREACHED();
+    return;
+  }
+  const PendingDecode& pending_decode = it->second;
+  host()->SendReply(
+      pending_decode.reply_context,
+      PpapiPluginMsg_VideoDecoder_DecodeReply(pending_decode.shm_id));
+  shm_buffer_busy_[pending_decode.shm_id] = false;
+  pending_decodes_.erase(it);
+}
+
+void PepperVideoDecoderHost::NotifyFlushDone() {
+  DCHECK(RenderThreadImpl::current());
+  host()->SendReply(flush_reply_context_,
+                    PpapiPluginMsg_VideoDecoder_FlushReply());
+  flush_reply_context_ = ppapi::host::ReplyMessageContext();
+}
+
+}  // namespace content