src/media/filters/decoder_selector.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 "decoder_selector.h"
   6
   7 #include "base/bind.h"
   8 #include "base/callback_helpers.h"
   9 #include "base/logging.h"
  10 #include "base/single_thread_task_runner.h"
  11 #include "media/base/audio_decoder.h"
  12 #include "media/base/bind_to_current_loop.h"
  13 #include "media/base/demuxer_stream.h"
  14 #include "media/base/pipeline.h"
  15 #include "media/base/video_decoder.h"
  16 #include "media/filters/decoder_stream_traits.h"
  17 #include "media/filters/decrypting_audio_decoder.h"
  18 #include "media/filters/decrypting_demuxer_stream.h"
  19 #include "media/filters/decrypting_video_decoder.h"
  20
  21 namespace media {
  22
  23 static bool HasValidStreamConfig(DemuxerStream* stream) {
  24   switch (stream->type()) {
  25     case DemuxerStream::AUDIO:
  26       return stream->audio_decoder_config().IsValidConfig();
  27     case DemuxerStream::VIDEO:
  28       return stream->video_decoder_config().IsValidConfig();
  29     case DemuxerStream::UNKNOWN:
  30     case DemuxerStream::TEXT:
  31     case DemuxerStream::NUM_TYPES:
  32       NOTREACHED();
  33   }
  34   return false;
  35 }
  36
  37 static bool IsStreamEncrypted(DemuxerStream* stream) {
  38   switch (stream->type()) {
  39     case DemuxerStream::AUDIO:
  40       return stream->audio_decoder_config().is_encrypted();
  41     case DemuxerStream::VIDEO:
  42       return stream->video_decoder_config().is_encrypted();
  43     case DemuxerStream::UNKNOWN:
  44     case DemuxerStream::TEXT:
  45     case DemuxerStream::NUM_TYPES:
  46       NOTREACHED();
  47   }
  48   return false;
  49 }
  50
  51 template <DemuxerStream::Type StreamType>
  52 DecoderSelector<StreamType>::DecoderSelector(
  53     const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
  54     ScopedVector<Decoder> decoders,
  55     const SetDecryptorReadyCB& set_decryptor_ready_cb)
  56     : task_runner_(task_runner),
  57       decoders_(decoders.Pass()),
  58       set_decryptor_ready_cb_(set_decryptor_ready_cb),
  59       input_stream_(NULL),
  60       weak_ptr_factory_(this) {}
  61
  62 template <DemuxerStream::Type StreamType>
  63 DecoderSelector<StreamType>::~DecoderSelector() {
  64   DVLOG(2) << __FUNCTION__;
  65   DCHECK(select_decoder_cb_.is_null());
  66 }
  67
  68 template <DemuxerStream::Type StreamType>
  69 void DecoderSelector<StreamType>::SelectDecoder(
  70     DemuxerStream* stream,
  71     bool low_delay,
  72     const SelectDecoderCB& select_decoder_cb,
  73     const typename Decoder::OutputCB& output_cb) {
  74   DVLOG(2) << __FUNCTION__;
  75   DCHECK(task_runner_->BelongsToCurrentThread());
  76   DCHECK(stream);
  77
  78   // Make sure |select_decoder_cb| runs on a different execution stack.
  79   select_decoder_cb_ = BindToCurrentLoop(select_decoder_cb);
  80
  81   if (!HasValidStreamConfig(stream)) {
  82     DLOG(ERROR) << "Invalid stream config.";
  83     ReturnNullDecoder();
  84     return;
  85   }
  86
  87   input_stream_ = stream;
  88   low_delay_ = low_delay;
  89   output_cb_ = output_cb;
  90
  91   if (!IsStreamEncrypted(input_stream_)) {
  92     InitializeDecoder();
  93     return;
  94   }
  95
  96   // This could happen if Encrypted Media Extension (EME) is not enabled.
  97   if (set_decryptor_ready_cb_.is_null()) {
  98     ReturnNullDecoder();
  99     return;
 100   }
 101
 102   decoder_.reset(new typename StreamTraits::DecryptingDecoderType(
 103       task_runner_, set_decryptor_ready_cb_));
 104
 105   DecoderStreamTraits<StreamType>::Initialize(
 106       decoder_.get(),
 107       StreamTraits::GetDecoderConfig(*input_stream_),
 108       low_delay_,
 109       base::Bind(&DecoderSelector<StreamType>::DecryptingDecoderInitDone,
 110                  weak_ptr_factory_.GetWeakPtr()),
 111       output_cb_);
 112 }
 113
 114 template <DemuxerStream::Type StreamType>
 115 void DecoderSelector<StreamType>::Abort() {
 116   DVLOG(2) << __FUNCTION__;
 117   DCHECK(task_runner_->BelongsToCurrentThread());
 118
 119   // This could happen when SelectDecoder() was not called or when
 120   // |select_decoder_cb_| was already posted but not fired (e.g. in the
 121   // message loop queue).
 122   if (select_decoder_cb_.is_null())
 123     return;
 124
 125   // We must be trying to initialize the |decoder_| or the
 126   // |decrypted_stream_|. Invalid all weak pointers so that all initialization
 127   // callbacks won't fire.
 128   weak_ptr_factory_.InvalidateWeakPtrs();
 129
 130   if (decoder_) {
 131     // |decrypted_stream_| is either NULL or already initialized. We don't
 132     // need to Stop() |decrypted_stream_| in either case.
 133     decoder_->Stop();
 134     ReturnNullDecoder();
 135     return;
 136   }
 137
 138   if (decrypted_stream_) {
 139     decrypted_stream_->Stop(
 140         base::Bind(&DecoderSelector<StreamType>::ReturnNullDecoder,
 141                    weak_ptr_factory_.GetWeakPtr()));
 142     return;
 143   }
 144
 145   NOTREACHED();
 146 }
 147
 148 template <DemuxerStream::Type StreamType>
 149 void DecoderSelector<StreamType>::DecryptingDecoderInitDone(
 150     PipelineStatus status) {
 151   DVLOG(2) << __FUNCTION__;
 152   DCHECK(task_runner_->BelongsToCurrentThread());
 153
 154   if (status == PIPELINE_OK) {
 155     base::ResetAndReturn(&select_decoder_cb_)
 156         .Run(decoder_.Pass(), scoped_ptr<DecryptingDemuxerStream>());
 157     return;
 158   }
 159
 160   decoder_.reset();
 161
 162   decrypted_stream_.reset(
 163       new DecryptingDemuxerStream(task_runner_, set_decryptor_ready_cb_));
 164
 165   decrypted_stream_->Initialize(
 166       input_stream_,
 167       base::Bind(&DecoderSelector<StreamType>::DecryptingDemuxerStreamInitDone,
 168                  weak_ptr_factory_.GetWeakPtr()));
 169 }
 170
 171 template <DemuxerStream::Type StreamType>
 172 void DecoderSelector<StreamType>::DecryptingDemuxerStreamInitDone(
 173     PipelineStatus status) {
 174   DVLOG(2) << __FUNCTION__;
 175   DCHECK(task_runner_->BelongsToCurrentThread());
 176
 177   if (status != PIPELINE_OK) {
 178     ReturnNullDecoder();
 179     return;
 180   }
 181
 182   DCHECK(!IsStreamEncrypted(decrypted_stream_.get()));
 183   input_stream_ = decrypted_stream_.get();
 184   InitializeDecoder();
 185 }
 186
 187 template <DemuxerStream::Type StreamType>
 188 void DecoderSelector<StreamType>::InitializeDecoder() {
 189   DVLOG(2) << __FUNCTION__;
 190   DCHECK(task_runner_->BelongsToCurrentThread());
 191   DCHECK(!decoder_);
 192
 193   if (decoders_.empty()) {
 194     ReturnNullDecoder();
 195     return;
 196   }
 197
 198   decoder_.reset(decoders_.front());
 199   decoders_.weak_erase(decoders_.begin());
 200
 201   DecoderStreamTraits<StreamType>::Initialize(
 202       decoder_.get(),
 203       StreamTraits::GetDecoderConfig(*input_stream_),
 204       low_delay_,
 205       base::Bind(&DecoderSelector<StreamType>::DecoderInitDone,
 206                  weak_ptr_factory_.GetWeakPtr()),
 207       output_cb_);
 208 }
 209
 210 template <DemuxerStream::Type StreamType>
 211 void DecoderSelector<StreamType>::DecoderInitDone(PipelineStatus status) {
 212   DVLOG(2) << __FUNCTION__;
 213   DCHECK(task_runner_->BelongsToCurrentThread());
 214
 215   if (status != PIPELINE_OK) {
 216     decoder_.reset();
 217     InitializeDecoder();
 218     return;
 219   }
 220
 221   base::ResetAndReturn(&select_decoder_cb_)
 222       .Run(decoder_.Pass(), decrypted_stream_.Pass());
 223 }
 224
 225 template <DemuxerStream::Type StreamType>
 226 void DecoderSelector<StreamType>::ReturnNullDecoder() {
 227   DVLOG(2) << __FUNCTION__;
 228   DCHECK(task_runner_->BelongsToCurrentThread());
 229   base::ResetAndReturn(&select_decoder_cb_)
 230       .Run(scoped_ptr<Decoder>(),
 231            scoped_ptr<DecryptingDemuxerStream>());
 232 }
 233
 234 // These forward declarations tell the compiler that we will use
 235 // DecoderSelector with these arguments, allowing us to keep these definitions
 236 // in our .cc without causing linker errors. This also means if anyone tries to
 237 // instantiate a DecoderSelector with anything but these two specializations
 238 // they'll most likely get linker errors.
 239 template class DecoderSelector<DemuxerStream::AUDIO>;
 240 template class DecoderSelector<DemuxerStream::VIDEO>;
 241
 242 }  // namespace media