src/media/cast/receiver/video_decoder.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "media/cast/receiver/video_decoder.h"
   6
   7 #include "base/bind.h"
   8 #include "base/bind_helpers.h"
   9 #include "base/json/json_reader.h"
  10 #include "base/location.h"
  11 #include "base/logging.h"
  12 #include "base/values.h"
  13 #include "media/base/video_util.h"
  14 #include "media/cast/cast_defines.h"
  15 #include "media/cast/cast_environment.h"
  16 // VPX_CODEC_DISABLE_COMPAT excludes parts of the libvpx API that provide
  17 // backwards compatibility for legacy applications using the library.
  18 #define VPX_CODEC_DISABLE_COMPAT 1
  19 #include "third_party/libvpx/source/libvpx/vpx/vp8dx.h"
  20 #include "third_party/libvpx/source/libvpx/vpx/vpx_decoder.h"
  21 #include "ui/gfx/size.h"
  22
  23 namespace media {
  24 namespace cast {
  25
  26 // Base class that handles the common problem of detecting dropped frames, and
  27 // then invoking the Decode() method implemented by the subclasses to convert
  28 // the encoded payload data into a usable video frame.
  29 class VideoDecoder::ImplBase
  30     : public base::RefCountedThreadSafe<VideoDecoder::ImplBase> {
  31  public:
  32   ImplBase(const scoped_refptr<CastEnvironment>& cast_environment,
  33            Codec codec)
  34       : cast_environment_(cast_environment),
  35         codec_(codec),
  36         cast_initialization_status_(STATUS_VIDEO_UNINITIALIZED),
  37         seen_first_frame_(false) {}
  38
  39   CastInitializationStatus InitializationResult() const {
  40     return cast_initialization_status_;
  41   }
  42
  43   void DecodeFrame(scoped_ptr<EncodedFrame> encoded_frame,
  44                    const DecodeFrameCallback& callback) {
  45     DCHECK_EQ(cast_initialization_status_, STATUS_VIDEO_INITIALIZED);
  46
  47     COMPILE_ASSERT(sizeof(encoded_frame->frame_id) == sizeof(last_frame_id_),
  48                    size_of_frame_id_types_do_not_match);
  49     bool is_continuous = true;
  50     if (seen_first_frame_) {
  51       const uint32 frames_ahead = encoded_frame->frame_id - last_frame_id_;
  52       if (frames_ahead > 1) {
  53         RecoverBecauseFramesWereDropped();
  54         is_continuous = false;
  55       }
  56     } else {
  57       seen_first_frame_ = true;
  58     }
  59     last_frame_id_ = encoded_frame->frame_id;
  60
  61     const scoped_refptr<VideoFrame> decoded_frame = Decode(
  62         encoded_frame->mutable_bytes(),
  63         static_cast<int>(encoded_frame->data.size()));
  64     cast_environment_->PostTask(
  65         CastEnvironment::MAIN,
  66         FROM_HERE,
  67         base::Bind(callback, decoded_frame, is_continuous));
  68   }
  69
  70  protected:
  71   friend class base::RefCountedThreadSafe<ImplBase>;
  72   virtual ~ImplBase() {}
  73
  74   virtual void RecoverBecauseFramesWereDropped() {}
  75
  76   // Note: Implementation of Decode() is allowed to mutate |data|.
  77   virtual scoped_refptr<VideoFrame> Decode(uint8* data, int len) = 0;
  78
  79   const scoped_refptr<CastEnvironment> cast_environment_;
  80   const Codec codec_;
  81
  82   // Subclass' ctor is expected to set this to STATUS_VIDEO_INITIALIZED.
  83   CastInitializationStatus cast_initialization_status_;
  84
  85  private:
  86   bool seen_first_frame_;
  87   uint32 last_frame_id_;
  88
  89   DISALLOW_COPY_AND_ASSIGN(ImplBase);
  90 };
  91
  92 class VideoDecoder::Vp8Impl : public VideoDecoder::ImplBase {
  93  public:
  94   explicit Vp8Impl(const scoped_refptr<CastEnvironment>& cast_environment)
  95       : ImplBase(cast_environment, CODEC_VIDEO_VP8) {
  96     if (ImplBase::cast_initialization_status_ != STATUS_VIDEO_UNINITIALIZED)
  97       return;
  98
  99     vpx_codec_dec_cfg_t cfg = {0};
 100     // TODO(miu): Revisit this for typical multi-core desktop use case.  This
 101     // feels like it should be 4 or 8.
 102     cfg.threads = 1;
 103
 104     DCHECK(vpx_codec_get_caps(vpx_codec_vp8_dx()) & VPX_CODEC_CAP_POSTPROC);
 105     if (vpx_codec_dec_init(&context_,
 106                            vpx_codec_vp8_dx(),
 107                            &cfg,
 108                            VPX_CODEC_USE_POSTPROC) != VPX_CODEC_OK) {
 109       ImplBase::cast_initialization_status_ =
 110           STATUS_INVALID_VIDEO_CONFIGURATION;
 111       return;
 112     }
 113     ImplBase::cast_initialization_status_ = STATUS_VIDEO_INITIALIZED;
 114   }
 115
 116  private:
 117   virtual ~Vp8Impl() {
 118     if (ImplBase::cast_initialization_status_ == STATUS_VIDEO_INITIALIZED)
 119       CHECK_EQ(VPX_CODEC_OK, vpx_codec_destroy(&context_));
 120   }
 121
 122   virtual scoped_refptr<VideoFrame> Decode(uint8* data, int len) OVERRIDE {
 123     if (len <= 0 || vpx_codec_decode(&context_,
 124                                      data,
 125                                      static_cast<unsigned int>(len),
 126                                      NULL,
 127                                      0) != VPX_CODEC_OK) {
 128       return NULL;
 129     }
 130
 131     vpx_codec_iter_t iter = NULL;
 132     vpx_image_t* const image = vpx_codec_get_frame(&context_, &iter);
 133     if (!image)
 134       return NULL;
 135     if (image->fmt != VPX_IMG_FMT_I420 && image->fmt != VPX_IMG_FMT_YV12) {
 136       NOTREACHED();
 137       return NULL;
 138     }
 139     DCHECK(vpx_codec_get_frame(&context_, &iter) == NULL)
 140         << "Should have only decoded exactly one frame.";
 141
 142     const gfx::Size frame_size(image->d_w, image->d_h);
 143     // Note: Timestamp for the VideoFrame will be set in VideoReceiver.
 144     const scoped_refptr<VideoFrame> decoded_frame =
 145         VideoFrame::CreateFrame(VideoFrame::YV12,
 146                                 frame_size,
 147                                 gfx::Rect(frame_size),
 148                                 frame_size,
 149                                 base::TimeDelta());
 150     CopyYPlane(image->planes[VPX_PLANE_Y],
 151                image->stride[VPX_PLANE_Y],
 152                image->d_h,
 153                decoded_frame.get());
 154     CopyUPlane(image->planes[VPX_PLANE_U],
 155                image->stride[VPX_PLANE_U],
 156                (image->d_h + 1) / 2,
 157                decoded_frame.get());
 158     CopyVPlane(image->planes[VPX_PLANE_V],
 159                image->stride[VPX_PLANE_V],
 160                (image->d_h + 1) / 2,
 161                decoded_frame.get());
 162     return decoded_frame;
 163   }
 164
 165   // VPX decoder context (i.e., an instantiation).
 166   vpx_codec_ctx_t context_;
 167
 168   DISALLOW_COPY_AND_ASSIGN(Vp8Impl);
 169 };
 170
 171 #ifndef OFFICIAL_BUILD
 172 // A fake video decoder that always output 2x2 black frames.
 173 class VideoDecoder::FakeImpl : public VideoDecoder::ImplBase {
 174  public:
 175   explicit FakeImpl(const scoped_refptr<CastEnvironment>& cast_environment)
 176       : ImplBase(cast_environment, CODEC_VIDEO_FAKE),
 177         last_decoded_id_(-1) {
 178     if (ImplBase::cast_initialization_status_ != STATUS_VIDEO_UNINITIALIZED)
 179       return;
 180     ImplBase::cast_initialization_status_ = STATUS_VIDEO_INITIALIZED;
 181   }
 182
 183  private:
 184   virtual ~FakeImpl() {}
 185
 186   virtual scoped_refptr<VideoFrame> Decode(uint8* data, int len) OVERRIDE {
 187     // Make sure this is a JSON string.
 188     if (!len || data[0] != '{')
 189       return NULL;
 190     base::JSONReader reader;
 191     scoped_ptr<base::Value> values(
 192         reader.Read(base::StringPiece(reinterpret_cast<char*>(data), len)));
 193     if (!values)
 194       return NULL;
 195     base::DictionaryValue* dict = NULL;
 196     values->GetAsDictionary(&dict);
 197
 198     bool key = false;
 199     int id = 0;
 200     int ref = 0;
 201     dict->GetBoolean("key", &key);
 202     dict->GetInteger("id", &id);
 203     dict->GetInteger("ref", &ref);
 204     DCHECK(id == last_decoded_id_ + 1);
 205     last_decoded_id_ = id;
 206     return media::VideoFrame::CreateBlackFrame(gfx::Size(2, 2));
 207   }
 208
 209   int last_decoded_id_;
 210
 211   DISALLOW_COPY_AND_ASSIGN(FakeImpl);
 212 };
 213 #endif
 214
 215 VideoDecoder::VideoDecoder(
 216     const scoped_refptr<CastEnvironment>& cast_environment,
 217     Codec codec)
 218     : cast_environment_(cast_environment) {
 219   switch (codec) {
 220 #ifndef OFFICIAL_BUILD
 221     case CODEC_VIDEO_FAKE:
 222       impl_ = new FakeImpl(cast_environment);
 223       break;
 224 #endif
 225     case CODEC_VIDEO_VP8:
 226       impl_ = new Vp8Impl(cast_environment);
 227       break;
 228     case CODEC_VIDEO_H264:
 229       // TODO(miu): Need implementation.
 230       NOTIMPLEMENTED();
 231       break;
 232     default:
 233       NOTREACHED() << "Unknown or unspecified codec.";
 234       break;
 235   }
 236 }
 237
 238 VideoDecoder::~VideoDecoder() {}
 239
 240 CastInitializationStatus VideoDecoder::InitializationResult() const {
 241   if (impl_.get())
 242     return impl_->InitializationResult();
 243   return STATUS_UNSUPPORTED_VIDEO_CODEC;
 244 }
 245
 246 void VideoDecoder::DecodeFrame(
 247     scoped_ptr<EncodedFrame> encoded_frame,
 248     const DecodeFrameCallback& callback) {
 249   DCHECK(encoded_frame.get());
 250   DCHECK(!callback.is_null());
 251   if (!impl_.get() ||
 252       impl_->InitializationResult() != STATUS_VIDEO_INITIALIZED) {
 253     callback.Run(make_scoped_refptr<VideoFrame>(NULL), false);
 254     return;
 255   }
 256   cast_environment_->PostTask(CastEnvironment::VIDEO,
 257                               FROM_HERE,
 258                               base::Bind(&VideoDecoder::ImplBase::DecodeFrame,
 259                                          impl_,
 260                                          base::Passed(&encoded_frame),
 261                                          callback));
 262 }
 263
 264 }  // namespace cast
 265 }  // namespace media