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/geometry/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         operational_status_(STATUS_UNINITIALIZED),
  37         seen_first_frame_(false) {}
  38
  39   OperationalStatus InitializationResult() const {
  40     return operational_status_;
  41   }
  42
  43   void DecodeFrame(scoped_ptr<EncodedFrame> encoded_frame,
  44                    const DecodeFrameCallback& callback) {
  45     DCHECK_EQ(operational_status_, STATUS_INITIALIZED);
  46
  47     static_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_INITIALIZED.
  83   OperationalStatus operational_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::operational_status_ != STATUS_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::operational_status_ = STATUS_INVALID_CONFIGURATION;
 110       return;
 111     }
 112     ImplBase::operational_status_ = STATUS_INITIALIZED;
 113   }
 114
 115  private:
 116   ~Vp8Impl() final {
 117     if (ImplBase::operational_status_ == STATUS_INITIALIZED)
 118       CHECK_EQ(VPX_CODEC_OK, vpx_codec_destroy(&context_));
 119   }
 120
 121   scoped_refptr<VideoFrame> Decode(uint8* data, int len) final {
 122     if (len <= 0 || vpx_codec_decode(&context_,
 123                                      data,
 124                                      static_cast<unsigned int>(len),
 125                                      NULL,
 126                                      0) != VPX_CODEC_OK) {
 127       return NULL;
 128     }
 129
 130     vpx_codec_iter_t iter = NULL;
 131     vpx_image_t* const image = vpx_codec_get_frame(&context_, &iter);
 132     if (!image)
 133       return NULL;
 134     if (image->fmt != VPX_IMG_FMT_I420 && image->fmt != VPX_IMG_FMT_YV12) {
 135       NOTREACHED();
 136       return NULL;
 137     }
 138     DCHECK(vpx_codec_get_frame(&context_, &iter) == NULL)
 139         << "Should have only decoded exactly one frame.";
 140
 141     const gfx::Size frame_size(image->d_w, image->d_h);
 142     // Note: Timestamp for the VideoFrame will be set in VideoReceiver.
 143     const scoped_refptr<VideoFrame> decoded_frame = VideoFrame::CreateFrame(
 144         PIXEL_FORMAT_YV12, frame_size, gfx::Rect(frame_size), frame_size,
 145         base::TimeDelta());
 146     CopyYPlane(image->planes[VPX_PLANE_Y],
 147                image->stride[VPX_PLANE_Y],
 148                image->d_h,
 149                decoded_frame.get());
 150     CopyUPlane(image->planes[VPX_PLANE_U],
 151                image->stride[VPX_PLANE_U],
 152                (image->d_h + 1) / 2,
 153                decoded_frame.get());
 154     CopyVPlane(image->planes[VPX_PLANE_V],
 155                image->stride[VPX_PLANE_V],
 156                (image->d_h + 1) / 2,
 157                decoded_frame.get());
 158     return decoded_frame;
 159   }
 160
 161   // VPX decoder context (i.e., an instantiation).
 162   vpx_codec_ctx_t context_;
 163
 164   DISALLOW_COPY_AND_ASSIGN(Vp8Impl);
 165 };
 166
 167 #ifndef OFFICIAL_BUILD
 168 // A fake video decoder that always output 2x2 black frames.
 169 class VideoDecoder::FakeImpl : public VideoDecoder::ImplBase {
 170  public:
 171   explicit FakeImpl(const scoped_refptr<CastEnvironment>& cast_environment)
 172       : ImplBase(cast_environment, CODEC_VIDEO_FAKE),
 173         last_decoded_id_(-1) {
 174     if (ImplBase::operational_status_ != STATUS_UNINITIALIZED)
 175       return;
 176     ImplBase::operational_status_ = STATUS_INITIALIZED;
 177   }
 178
 179  private:
 180   ~FakeImpl() final {}
 181
 182   scoped_refptr<VideoFrame> Decode(uint8* data, int len) final {
 183     // Make sure this is a JSON string.
 184     if (!len || data[0] != '{')
 185       return NULL;
 186     base::JSONReader reader;
 187     scoped_ptr<base::Value> values(
 188         reader.Read(base::StringPiece(reinterpret_cast<char*>(data), len)));
 189     if (!values)
 190       return NULL;
 191     base::DictionaryValue* dict = NULL;
 192     values->GetAsDictionary(&dict);
 193
 194     bool key = false;
 195     int id = 0;
 196     int ref = 0;
 197     dict->GetBoolean("key", &key);
 198     dict->GetInteger("id", &id);
 199     dict->GetInteger("ref", &ref);
 200     DCHECK(id == last_decoded_id_ + 1);
 201     last_decoded_id_ = id;
 202     return media::VideoFrame::CreateBlackFrame(gfx::Size(2, 2));
 203   }
 204
 205   int last_decoded_id_;
 206
 207   DISALLOW_COPY_AND_ASSIGN(FakeImpl);
 208 };
 209 #endif
 210
 211 VideoDecoder::VideoDecoder(
 212     const scoped_refptr<CastEnvironment>& cast_environment,
 213     Codec codec)
 214     : cast_environment_(cast_environment) {
 215   switch (codec) {
 216 #ifndef OFFICIAL_BUILD
 217     case CODEC_VIDEO_FAKE:
 218       impl_ = new FakeImpl(cast_environment);
 219       break;
 220 #endif
 221     case CODEC_VIDEO_VP8:
 222       impl_ = new Vp8Impl(cast_environment);
 223       break;
 224     case CODEC_VIDEO_H264:
 225       // TODO(miu): Need implementation.
 226       NOTIMPLEMENTED();
 227       break;
 228     default:
 229       NOTREACHED() << "Unknown or unspecified codec.";
 230       break;
 231   }
 232 }
 233
 234 VideoDecoder::~VideoDecoder() {}
 235
 236 OperationalStatus VideoDecoder::InitializationResult() const {
 237   if (impl_.get())
 238     return impl_->InitializationResult();
 239   return STATUS_UNSUPPORTED_CODEC;
 240 }
 241
 242 void VideoDecoder::DecodeFrame(
 243     scoped_ptr<EncodedFrame> encoded_frame,
 244     const DecodeFrameCallback& callback) {
 245   DCHECK(encoded_frame.get());
 246   DCHECK(!callback.is_null());
 247   if (!impl_.get() || impl_->InitializationResult() != STATUS_INITIALIZED) {
 248     callback.Run(make_scoped_refptr<VideoFrame>(NULL), false);
 249     return;
 250   }
 251   cast_environment_->PostTask(CastEnvironment::VIDEO,
 252                               FROM_HERE,
 253                               base::Bind(&VideoDecoder::ImplBase::DecodeFrame,
 254                                          impl_,
 255                                          base::Passed(&encoded_frame),
 256                                          callback));
 257 }
 258
 259 }  // namespace cast
 260 }  // namespace media