Pepper: add video_encoder example

ppapi/examples/video_encode/video_encode.cc

Index: ppapi/examples/video_encode/video_encode.cc
diff --git a/ppapi/examples/video_encode/video_encode.cc b/ppapi/examples/video_encode/video_encode.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b648d18a1e324b093534e3c666438d4ae43e2921
--- /dev/null
+++ b/ppapi/examples/video_encode/video_encode.cc
@@ -0,0 +1,496 @@
+// Copyright (c) 2014 The Chromium Authors. All rights reserved.

[bbudge, 2015/02/18 23:43:22]

nit: remove (c) and 2015

[llandwerlin-old, 2015/02/19 16:04:13]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <math.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <iostream>
+#include <sstream>
+#include <vector>
+
+#include "ppapi/c/pp_errors.h"
+#include "ppapi/c/ppb_console.h"
+#include "ppapi/cpp/input_event.h"
+#include "ppapi/cpp/instance.h"
+#include "ppapi/cpp/media_stream_video_track.h"
+#include "ppapi/cpp/module.h"
+#include "ppapi/cpp/rect.h"
+#include "ppapi/cpp/var.h"
+#include "ppapi/cpp/var_array_buffer.h"
+#include "ppapi/cpp/var_dictionary.h"
+#include "ppapi/cpp/video_encoder.h"
+#include "ppapi/cpp/video_frame.h"
+#include "ppapi/utility/completion_callback_factory.h"
+
+// TODO(llandwerlin): turn on by default when we have software encode.
+// #define USE_VP8_INSTEAD_OF_H264
+
+// Use assert as a poor-man's CHECK, even in non-debug mode.
+// Since <assert.h> redefines assert on every inclusion (it doesn't use
+// include-guards), make sure this is the last file #include'd in this file.
+#undef NDEBUG
+#include <assert.h>
+
+namespace {
+
+std::string VideoProfileToString(PP_VideoProfile profile) {
+  switch (profile) {
+    case PP_VIDEOPROFILE_H264BASELINE:
+      return "h264baseline";
+    case PP_VIDEOPROFILE_H264MAIN:
+      return "h264main";
+    case PP_VIDEOPROFILE_H264EXTENDED:
+      return "h264extended";
+    case PP_VIDEOPROFILE_H264HIGH:
+      return "h264high";
+    case PP_VIDEOPROFILE_H264HIGH10PROFILE:
+      return "h264high10";
+    case PP_VIDEOPROFILE_H264HIGH422PROFILE:
+      return "h264high422";
+    case PP_VIDEOPROFILE_H264HIGH444PREDICTIVEPROFILE:
+      return "h264high444predictive";
+    case PP_VIDEOPROFILE_H264SCALABLEBASELINE:
+      return "h264scalablebaseline";
+    case PP_VIDEOPROFILE_H264SCALABLEHIGH:
+      return "h264scalablehigh";
+    case PP_VIDEOPROFILE_H264STEREOHIGH:
+      return "h264stereohigh";
+    case PP_VIDEOPROFILE_H264MULTIVIEWHIGH:
+      return "h264multiviewhigh";
+    case PP_VIDEOPROFILE_VP8_ANY:
+      return "vp8";
+    case PP_VIDEOPROFILE_VP9_ANY:
+      return "vp9";
+      // No default to catch unhandled profiles.

[bbudge, 2015/02/18 23:43:24]

nit: indent

[llandwerlin-old, 2015/02/19 16:04:13]

Done.

+  }
+  return "unknown";
+}
+
+std::string HardwareAccelerationToString(PP_HardwareAcceleration acceleration) {
+  switch (acceleration) {
+    case PP_HARDWAREACCELERATION_ONLY:
+      return "hardware";
+    case PP_HARDWAREACCELERATION_WITHFALLBACK:
+      return "hardware/software";
+    case PP_HARDWAREACCELERATION_NONE:
+      return "software";
+      // No default to catch unhandled accelerations.

[bbudge, 2015/02/18 23:43:24]

nit: indent

[llandwerlin-old, 2015/02/19 16:04:13]

Done.

+  }
+  return "unknown";
+}
+
+// This object is the global object representing this plugin library as long
+// as it is loaded.
+class MediaStreamVideoEncoderModule : public pp::Module {
+ public:
+  MediaStreamVideoEncoderModule() : pp::Module() {}
+  virtual ~MediaStreamVideoEncoderModule() {}
+
+  virtual pp::Instance* CreateInstance(PP_Instance instance);
+};
+
+class MediaStreamVideoEncoderInstance : public pp::Instance {
+ public:
+  MediaStreamVideoEncoderInstance(PP_Instance instance, pp::Module* module);
+  virtual ~MediaStreamVideoEncoderInstance();
+
+  // pp::Instance implementation.
+  virtual void DidChangeView(const pp::Rect& position,
+                             const pp::Rect& clip_ignored);
+  virtual void HandleMessage(const pp::Var& var_message);
+
+ private:
+  void ConfigureTrack();
+  void OnConfiguredTrack(int32_t result);
+  void ProbeEncoder();
+  void OnEncoderProbed(int32_t result,
+                       const std::vector<PP_VideoProfileDescription> profiles);
+  void InitializeEncoder();
+  void OnInitializedEncoder(int32_t result);
+  void ScheduleNextGetEncoderFrame();
+  void GetEncoderFrameTick(int32_t result);
+  void GetEncoderFrame();
+  void GetTrackFrame(const pp::VideoFrame& encoder_frame);
+  void OnGetTrackFrame(int32_t result,
+                       pp::VideoFrame track_frame,
+                       pp::VideoFrame encoder_frame);
+  void OnGetEncoderFrame(int32_t result, const pp::VideoFrame& frame);
+  int32_t CopyTrackFrameToEncoderFrame(pp::VideoFrame dest, pp::VideoFrame src);
+  void EncodeFrame(const pp::VideoFrame& frame);
+  void OnEncodeDone(int32_t result);
+  void OnGetBitstreamBuffer(int32_t result, PP_BitstreamBuffer buffer);
+  void StopEncode();
+
+  void LogError(int32_t error, const std::string& message);
+  void LogWarning(const std::string& message);
+  void Log(const std::string& message);
+
+  void PostDataMessage(const void* buffer, uint32_t size);
+  void PostSignalMessage(const char* name);
+
+  bool is_encoding_;
+
+  pp::VideoEncoder video_encoder_;
+  pp::MediaStreamVideoTrack video_track_;
+  pp::CompletionCallbackFactory<MediaStreamVideoEncoderInstance>
+      callback_factory_;
+
+  PP_VideoProfile video_profile_;
+  PP_VideoFrame_Format frame_format_;
+
+  pp::Size frame_size_;
+  pp::Size plugin_size_;
+  pp::Size encoder_size_;
+  uint32_t encoded_frames_;
+
+  pp::VideoFrame encoder_frame_;
+};
+
+MediaStreamVideoEncoderInstance::MediaStreamVideoEncoderInstance(
+    PP_Instance instance,
+    pp::Module* module)
+    : pp::Instance(instance),
+      is_encoding_(false),
+      callback_factory_(this),
+#if defined(USE_VP8_INSTEAD_OF_H264)
+      video_profile_(PP_VIDEOPROFILE_VP8_ANY),
+#else
+      video_profile_(PP_VIDEOPROFILE_H264MAIN),
+#endif
+      frame_format_(PP_VIDEOFRAME_FORMAT_I420),
+      encoded_frames_(0) {
+}
+
+MediaStreamVideoEncoderInstance::~MediaStreamVideoEncoderInstance() {
+}
+
+//

[bbudge, 2015/02/18 23:43:24]

nit: remove

[llandwerlin-old, 2015/02/19 16:04:13]

Done.

+//
+//
+
+void MediaStreamVideoEncoderInstance::DidChangeView(
+    const pp::Rect& position,
+    const pp::Rect& clip_ignored) {
+  plugin_size_ = position.size();
+}
+
+void MediaStreamVideoEncoderInstance::ConfigureTrack() {
+  if (encoder_size_.IsEmpty())
+    frame_size_ = plugin_size_;
+  else
+    frame_size_ = encoder_size_;
+
+  int32_t attrib_list[] = {PP_MEDIASTREAMVIDEOTRACK_ATTRIB_FORMAT,
+                           frame_format_,
+                           PP_MEDIASTREAMVIDEOTRACK_ATTRIB_WIDTH,
+                           frame_size_.width(),
+                           PP_MEDIASTREAMVIDEOTRACK_ATTRIB_HEIGHT,
+                           frame_size_.height(),
+                           PP_MEDIASTREAMVIDEOTRACK_ATTRIB_NONE};
+
+  pp::VarDictionary dict;
+  dict.Set(pp::Var("status"), pp::Var("configuring video track"));
+  dict.Set(pp::Var("width"), pp::Var(frame_size_.width()));
+  dict.Set(pp::Var("height"), pp::Var(frame_size_.height()));
+  PostMessage(dict);
+
+  video_track_.Configure(
+      attrib_list, callback_factory_.NewCallback(
+                       &MediaStreamVideoEncoderInstance::OnConfiguredTrack));
+}
+
+void MediaStreamVideoEncoderInstance::OnConfiguredTrack(int32_t result) {
+  if (result != PP_OK) {
+    LogError(result, "Cannot configure track");
+    return;
+  }
+
+  if (is_encoding_)
+    GetEncoderFrame();
+  else
+    ProbeEncoder();
+}
+
+void MediaStreamVideoEncoderInstance::ProbeEncoder() {
+  video_encoder_ = pp::VideoEncoder(this);
+  video_encoder_.GetSupportedProfiles(callback_factory_.NewCallbackWithOutput(
+      &MediaStreamVideoEncoderInstance::OnEncoderProbed));
+}
+
+void MediaStreamVideoEncoderInstance::OnEncoderProbed(
+    int32_t result,
+    const std::vector<PP_VideoProfileDescription> profiles) {
+  bool has_required_profile = false;
+
+  Log("Available profiles:");
+  for (const PP_VideoProfileDescription& profile : profiles) {
+    std::ostringstream oss;
+    oss << " profile=" << VideoProfileToString(profile.profile)
+        << " max_resolution=" << profile.max_resolution.width << "x"
+        << profile.max_resolution.height
+        << " max_framerate=" << profile.max_framerate_numerator << "/"
+        << profile.max_framerate_denominator << " acceleration="
+        << HardwareAccelerationToString(profile.acceleration);
+    Log(oss.str());
+
+    has_required_profile |= profile.profile == video_profile_;
+  }
+
+  if (!has_required_profile) {
+    std::ostringstream oss;
+    oss << "Cannot find required video profile: ";
+    oss << VideoProfileToString(video_profile_);
+    LogError(PP_ERROR_FAILED, oss.str());
+    return;
+  }
+
+  InitializeEncoder();
+}
+
+void MediaStreamVideoEncoderInstance::InitializeEncoder() {
+  video_encoder_ = pp::VideoEncoder(this);
+
+  pp::VarDictionary dict;
+  dict.Set(pp::Var("status"), pp::Var("initializing encoder"));
+  dict.Set(pp::Var("width"), pp::Var(encoder_size_.width()));
+  dict.Set(pp::Var("height"), pp::Var(encoder_size_.height()));
+  PostMessage(dict);
+
+  int32_t error = video_encoder_.Initialize(
+      frame_format_, frame_size_, video_profile_, 2000000,
+      PP_HARDWAREACCELERATION_WITHFALLBACK,
+      callback_factory_.NewCallback(
+          &MediaStreamVideoEncoderInstance::OnInitializedEncoder));
+  if (error != PP_OK_COMPLETIONPENDING) {
+    LogError(error, "Cannot initialize encoder");
+    return;
+  }
+}
+
+void MediaStreamVideoEncoderInstance::OnInitializedEncoder(int32_t result) {
+  if (result != PP_OK) {
+    LogError(result, "Encoder initialization failed");
+    return;
+  }
+
+  is_encoding_ = true;
+
+  if (video_encoder_.GetFrameCodedSize(&encoder_size_) != PP_OK) {
+    LogError(result, "Cannot get encoder coded frame size");
+    return;
+  }
+
+  pp::VarDictionary dict;
+  dict.Set(pp::Var("status"), pp::Var("encoder initialized"));
+  dict.Set(pp::Var("width"), pp::Var(encoder_size_.width()));
+  dict.Set(pp::Var("height"), pp::Var(encoder_size_.height()));
+  PostMessage(dict);
+
+  video_encoder_.GetBitstreamBuffer(callback_factory_.NewCallbackWithOutput(
+      &MediaStreamVideoEncoderInstance::OnGetBitstreamBuffer));
+
+  if (encoder_size_ != frame_size_)
+    ConfigureTrack();
+  else
+    GetEncoderFrame();
+}
+
+void MediaStreamVideoEncoderInstance::ScheduleNextGetEncoderFrame() {
+  pp::Module::Get()->core()->CallOnMainThread(
+      1000 / 30, callback_factory_.NewCallback(
+                     &MediaStreamVideoEncoderInstance::GetEncoderFrameTick),
+      0);
+}

[bbudge, 2015/02/18 23:43:24]

I don't understand why you need to schedule getting a frame from the encoder.
Why not make an initial GetVideoFrame request just before you request your first
bitstream buffer (in OnInitializedEncoder above) and then request an additional
one each time you send a frame to the Encoder? You would need to be able to
store one frame from the video track and the encoder, and copy the frame when
you had received both. Or am I missing something?

[llandwerlin-old, 2015/02/19 00:22:25]

There isn't much point to encode as fast at possible. This can lead to
generating more frames than what is actually needed. That's why there is this
30fps scheduling.

[bbudge, 2015/02/19 21:54:38]

How does it work if the video track is running faster, say 60 fps. Do we drop
frames?

[llandwerlin-old, 2015/02/27 14:19:44]

In the case of MediaStreamVideoTrack, it will actually drop frames for us : 

https://code.google.com/p/chromium/codesearch#chromium/src/content/renderer/p...

I updated the example to extract frame as quick as possible and only encode the
latest one.

+
+void MediaStreamVideoEncoderInstance::GetEncoderFrameTick(int32_t result) {
+  if (is_encoding_)
+    GetEncoderFrame();
+}
+
+void MediaStreamVideoEncoderInstance::GetEncoderFrame() {
+  video_encoder_.GetVideoFrame(callback_factory_.NewCallbackWithOutput(
+      &MediaStreamVideoEncoderInstance::OnGetEncoderFrame));
+}
+
+void MediaStreamVideoEncoderInstance::OnGetEncoderFrame(
+    int32_t result,
+    const pp::VideoFrame& frame) {
+  if (result == PP_ERROR_ABORTED)
+    return;
+  if (result != PP_OK) {
+    LogError(result, "Cannot get video frame from video encoder");
+    return;
+  }
+
+  GetTrackFrame(frame);
+}
+
+void MediaStreamVideoEncoderInstance::GetTrackFrame(
+    const pp::VideoFrame& encoder_frame) {
+  video_track_.GetFrame(callback_factory_.NewCallbackWithOutput(
+      &MediaStreamVideoEncoderInstance::OnGetTrackFrame, encoder_frame));
+}
+
+void MediaStreamVideoEncoderInstance::OnGetTrackFrame(
+    int32_t result,
+    pp::VideoFrame track_frame,
+    pp::VideoFrame encoder_frame) {
+  if (result == PP_ERROR_ABORTED)
+    return;
+  if (result != PP_OK) {
+    LogError(result, "Cannot get video frame from video track");
+    return;
+  }
+
+  track_frame.GetSize(&frame_size_);
+
+  if (frame_size_ != encoder_size_) {
+    video_track_.RecycleFrame(track_frame);
+    LogError(PP_ERROR_FAILED, "MediaStreamVideoTrack frame size incorrect");
+    return;
+  }
+
+  if (CopyTrackFrameToEncoderFrame(encoder_frame, track_frame) == PP_OK) {
+    EncodeFrame(encoder_frame);
+    ScheduleNextGetEncoderFrame();
+  }
+  video_track_.RecycleFrame(track_frame);
+}
+
+int32_t MediaStreamVideoEncoderInstance::CopyTrackFrameToEncoderFrame(
+    pp::VideoFrame dest,
+    pp::VideoFrame src) {
+  if (dest.GetDataBufferSize() < src.GetDataBufferSize()) {
+    std::ostringstream oss;
+    oss << "Incorrect destination video frame buffer size : "
+        << dest.GetDataBufferSize() << " < " << src.GetDataBufferSize();
+    LogError(PP_ERROR_FAILED, oss.str());
+    return PP_ERROR_FAILED;
+  }
+
+  memcpy(dest.GetDataBuffer(), src.GetDataBuffer(), src.GetDataBufferSize());
+  return PP_OK;
+}
+
+void MediaStreamVideoEncoderInstance::EncodeFrame(const pp::VideoFrame& frame) {
+  video_encoder_.Encode(frame, PP_FALSE,
+                        callback_factory_.NewCallback(
+                            &MediaStreamVideoEncoderInstance::OnEncodeDone));
+}
+
+void MediaStreamVideoEncoderInstance::OnEncodeDone(int32_t result) {
+  if (result != PP_OK)
+    LogError(result, "Encode failed");
+}
+
+void MediaStreamVideoEncoderInstance::OnGetBitstreamBuffer(
+    int32_t result,
+    PP_BitstreamBuffer buffer) {
+  if (result == PP_ERROR_ABORTED)
+    return;
+  if (result != PP_OK) {
+    LogError(result, "Cannot get bitstream buffer");
+    return;
+  }
+
+  encoded_frames_++;
+  PostDataMessage(buffer.buffer, buffer.size);
+  video_encoder_.RecycleBitstreamBuffer(buffer);
+
+  video_encoder_.GetBitstreamBuffer(callback_factory_.NewCallbackWithOutput(
+      &MediaStreamVideoEncoderInstance::OnGetBitstreamBuffer));
+}
+
+void MediaStreamVideoEncoderInstance::StopEncode() {
+  video_encoder_.Close();
+  video_track_.Close();
+  is_encoding_ = false;
+  encoded_frames_ = 0;
+}
+
+//
+
+void MediaStreamVideoEncoderInstance::HandleMessage(
+    const pp::Var& var_message) {
+  if (!var_message.is_dictionary()) {
+    LogToConsole(PP_LOGLEVEL_ERROR, pp::Var("Invalid message!"));
+    return;
+  }
+
+  pp::VarDictionary var_dictionary_message(var_message);
+  std::string command = var_dictionary_message.Get("command").AsString();
+
+  if (command == "start") {
+    pp::Var var_track = var_dictionary_message.Get("track");
+    if (!var_track.is_resource()) {
+      LogToConsole(PP_LOGLEVEL_ERROR, pp::Var("Given track is not a resource"));
+      return;
+    }
+    pp::Resource resource_track = var_track.AsResource();
+    video_track_ = pp::MediaStreamVideoTrack(resource_track);
+    video_encoder_ = pp::VideoEncoder();
+    ConfigureTrack();
+  } else if (command == "stop") {
+    StopEncode();
+    PostSignalMessage("stopped");
+  } else {
+    LogToConsole(PP_LOGLEVEL_ERROR, pp::Var("Invalid command!"));
+  }
+}
+
+void MediaStreamVideoEncoderInstance::PostDataMessage(const void* buffer,
+                                                      uint32_t size) {
+  pp::VarDictionary dictionary;
+
+  dictionary.Set(pp::Var("name"), pp::Var("data"));
+
+  pp::VarArrayBuffer array_buffer(size);
+  void* data_ptr = array_buffer.Map();
+  memcpy(data_ptr, buffer, size);
+  array_buffer.Unmap();
+  dictionary.Set(pp::Var("data"), array_buffer);
+
+  PostMessage(dictionary);
+}
+
+void MediaStreamVideoEncoderInstance::PostSignalMessage(const char* name) {
+  pp::VarDictionary dictionary;
+  dictionary.Set(pp::Var("name"), pp::Var(name));
+
+  PostMessage(dictionary);
+}
+
+void MediaStreamVideoEncoderInstance::LogError(int32_t error,
+                                               const std::string& message) {
+  std::string msg("Error: ");
+  msg.append(pp::Var(error).DebugString());
+  msg.append(" : ");
+  msg.append(message);
+  LogToConsole(PP_LOGLEVEL_ERROR, pp::Var(msg));
+}
+
+void MediaStreamVideoEncoderInstance::LogWarning(const std::string& message) {
+  std::string msg("Warning: ");
+  msg.append(message);
+  LogToConsole(PP_LOGLEVEL_WARNING, pp::Var(msg));
+}
+
+void MediaStreamVideoEncoderInstance::Log(const std::string& message) {
+  LogToConsole(PP_LOGLEVEL_LOG, pp::Var(message));
+}
+
+pp::Instance* MediaStreamVideoEncoderModule::CreateInstance(
+    PP_Instance instance) {
+  return new MediaStreamVideoEncoderInstance(instance, this);
+}
+
+}  // anonymous namespace
+
+namespace pp {
+// Factory function for your specialization of the Module object.
+Module* CreateModule() {
+  return new MediaStreamVideoEncoderModule();
+}
+}  // namespace pp