media/filters/decoder_selector.cc

   1 // Copyright 2014 The Chromium Authors
   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/filters/decoder_selector.h"
   6
   7 #include <algorithm>
   8 #include <utility>
   9
  10 #include "base/feature_list.h"
  11 #include "base/functional/bind.h"
  12 #include "base/functional/callback_helpers.h"
  13 #include "base/location.h"
  14 #include "base/logging.h"
  15 #include "base/metrics/histogram_functions.h"
  16 #include "base/strings/stringprintf.h"
  17 #include "base/task/sequenced_task_runner.h"
  18 #include "base/trace_event/trace_event.h"
  19 #include "build/build_config.h"
  20 #include "build/chromeos_buildflags.h"
  21 #include "media/base/audio_decoder.h"
  22 #include "media/base/cdm_context.h"
  23 #include "media/base/demuxer_stream.h"
  24 #include "media/base/media_log.h"
  25 #include "media/base/media_switches.h"
  26 #include "media/base/video_decoder.h"
  27 #include "media/filters/decoder_stream_traits.h"
  28 #include "media/filters/decrypting_demuxer_stream.h"
  29
  30 namespace media {
  31
  32 namespace {
  33
  34 const char kSelectDecoderTrace[] = "DecoderSelector::SelectDecoder";
  35
  36 bool SkipDecoderForRTC(const AudioDecoderConfig& /*config*/,
  37                        const AudioDecoder& /*decoder*/) {
  38   return false;
  39 }
  40
  41 bool SkipDecoderForRTC(const VideoDecoderConfig& config,
  42                        const VideoDecoder& decoder) {
  43   // Skip non-platform decoders for rtc based on the feature flag.
  44   return config.is_rtc() && !decoder.IsPlatformDecoder() &&
  45          !base::FeatureList::IsEnabled(kExposeSwDecodersToWebRTC);
  46 }
  47
  48 template <typename ConfigT, typename DecoderT>
  49 DecoderPriority NormalDecoderPriority(const ConfigT& config,
  50                                       const DecoderT& decoder) {
  51   if (SkipDecoderForRTC(config, decoder))
  52     return DecoderPriority::kSkipped;
  53
  54   return DecoderPriority::kNormal;
  55 }
  56
  57 DecoderPriority ResolutionBasedDecoderPriority(const VideoDecoderConfig& config,
  58                                                const VideoDecoder& decoder) {
  59 #if BUILDFLAG(IS_ANDROID)
  60   constexpr auto kSoftwareDecoderHeightCutoff = 360;
  61 #elif BUILDFLAG(IS_CHROMEOS_ASH)
  62   constexpr auto kSoftwareDecoderHeightCutoff = 360;
  63 #else
  64   constexpr auto kSoftwareDecoderHeightCutoff = 720;
  65 #endif
  66
  67   if (SkipDecoderForRTC(config, decoder))
  68     return DecoderPriority::kSkipped;
  69
  70   // We only do a height check to err on the side of prioritizing platform
  71   // decoders.
  72   const auto at_or_above_software_cutoff =
  73       config.visible_rect().height() >= kSoftwareDecoderHeightCutoff;
  74
  75   // Platform decoders are deprioritized below the cutoff, and non-platform
  76   // decoders are deprioritized above it.
  77   return at_or_above_software_cutoff == decoder.IsPlatformDecoder()
  78              ? DecoderPriority::kNormal
  79              : DecoderPriority::kDeprioritized;
  80 }
  81
  82 DecoderPriority PreferNonPlatformDecoders(const VideoDecoderConfig& config,
  83                                           const VideoDecoder& decoder) {
  84   // Prefer software decoders over hardware decoders.  This is useful to force
  85   // software fallback for WebRTC, but still use hardware if there's no software
  86   // implementation to choose.
  87   return decoder.IsPlatformDecoder() ? DecoderPriority::kDeprioritized
  88                                      : DecoderPriority::kNormal;
  89 }
  90
  91 DecoderPriority UnifiedDecoderPriority(const VideoDecoderConfig& config,
  92                                        const VideoDecoder& decoder) {
  93   if (config.is_rtc() ||
  94       base::FeatureList::IsEnabled(kResolutionBasedDecoderPriority)) {
  95     return ResolutionBasedDecoderPriority(config, decoder);
  96   } else {
  97     return NormalDecoderPriority(config, decoder);
  98   }
  99 }
 100
 101 template <typename ConfigT, typename DecoderT>
 102 DecoderPriority SkipNonPlatformDecoders(const ConfigT& config,
 103                                         const DecoderT& decoder) {
 104   if (SkipDecoderForRTC(config, decoder))
 105     return DecoderPriority::kSkipped;
 106
 107   return decoder.IsPlatformDecoder() ? DecoderPriority::kNormal
 108                                      : DecoderPriority::kSkipped;
 109 }
 110
 111 void SetDefaultDecoderPriorityCB(
 112     VideoDecoderSelector::DecoderPriorityCB* out,
 113     const DecoderStreamTraits<DemuxerStream::VIDEO>* traits) {
 114   if (base::FeatureList::IsEnabled(kForceHardwareVideoDecoders)) {
 115     *out = base::BindRepeating(
 116         SkipNonPlatformDecoders<VideoDecoderConfig, VideoDecoder>);
 117   } else if (traits->GetPreferNonPlatformDecoders()) {
 118     *out = base::BindRepeating(PreferNonPlatformDecoders);
 119   } else {
 120     *out = base::BindRepeating(UnifiedDecoderPriority);
 121   }
 122 }
 123
 124 void SetDefaultDecoderPriorityCB(
 125     AudioDecoderSelector::DecoderPriorityCB* out,
 126     const DecoderStreamTraits<DemuxerStream::AUDIO>*) {
 127   if (base::FeatureList::IsEnabled(kForceHardwareAudioDecoders)) {
 128     *out = base::BindRepeating(
 129         SkipNonPlatformDecoders<AudioDecoderConfig, AudioDecoder>);
 130   } else {
 131     // Platform audio decoders are not currently prioritized or deprioritized
 132     *out = base::BindRepeating(
 133         NormalDecoderPriority<AudioDecoderConfig, AudioDecoder>);
 134   }
 135 }
 136
 137 }  // namespace
 138
 139 template <DemuxerStream::Type StreamType>
 140 DecoderSelector<StreamType>::DecoderSelector(
 141     scoped_refptr<base::SequencedTaskRunner> task_runner,
 142     CreateDecodersCB create_decoders_cb,
 143     MediaLog* media_log)
 144     : task_runner_(std::move(task_runner)),
 145       create_decoders_cb_(std::move(create_decoders_cb)),
 146       media_log_(media_log) {
 147   DETACH_FROM_SEQUENCE(sequence_checker_);
 148 }
 149
 150 template <DemuxerStream::Type StreamType>
 151 DecoderSelector<StreamType>::~DecoderSelector() {
 152   DVLOG(2) << __func__;
 153   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 154   if (select_decoder_cb_)
 155     ReturnSelectionError(DecoderStatus::Codes::kFailed);
 156 }
 157
 158 template <DemuxerStream::Type StreamType>
 159 void DecoderSelector<StreamType>::Initialize(StreamTraits* traits,
 160                                              DemuxerStream* stream,
 161                                              CdmContext* cdm_context,
 162                                              WaitingCB waiting_cb) {
 163   DVLOG(2) << __func__;
 164   DCHECK(traits);
 165   DCHECK(stream);
 166
 167   traits_ = traits;
 168   stream_ = stream;
 169   cdm_context_ = cdm_context;
 170   waiting_cb_ = std::move(waiting_cb);
 171   // Only set this here if nobody has overridden it for tests.
 172   if (!decoder_priority_cb_)
 173     SetDefaultDecoderPriorityCB(&decoder_priority_cb_, traits_);
 174 }
 175
 176 template <DemuxerStream::Type StreamType>
 177 void DecoderSelector<StreamType>::SelectDecoderInternal(
 178     SelectDecoderCB select_decoder_cb,
 179     typename Decoder::OutputCB output_cb,
 180     bool needs_new_decoders) {
 181   DVLOG(2) << __func__;
 182   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 183   DCHECK(select_decoder_cb);
 184   DCHECK(!select_decoder_cb_);
 185   select_decoder_cb_ = std::move(select_decoder_cb);
 186   output_cb_ = std::move(output_cb);
 187   config_ = traits_->GetDecoderConfig(stream_);
 188
 189   TRACE_EVENT_ASYNC_BEGIN2("media", kSelectDecoderTrace, this, "type",
 190                            DemuxerStream::GetTypeName(StreamType), "config",
 191                            config_.AsHumanReadableString());
 192
 193   if (!config_.IsValidConfig()) {
 194     DLOG(ERROR) << "Invalid stream config";
 195     ReturnSelectionError(DecoderStatus::Codes::kUnsupportedConfig);
 196     return;
 197   }
 198
 199   if (needs_new_decoders) {
 200     decode_failure_reinit_cause_ = absl::nullopt;
 201     CreateDecoders();
 202   }
 203
 204   GetAndInitializeNextDecoder();
 205 }
 206
 207 template <DemuxerStream::Type StreamType>
 208 void DecoderSelector<StreamType>::BeginDecoderSelection(
 209     SelectDecoderCB select_decoder_cb,
 210     typename Decoder::OutputCB output_cb) {
 211   SelectDecoderInternal(std::move(select_decoder_cb), std::move(output_cb),
 212                         /*needs_new_decoders = */ true);
 213 }
 214
 215 template <DemuxerStream::Type StreamType>
 216 void DecoderSelector<StreamType>::ResumeDecoderSelection(
 217     SelectDecoderCB select_decoder_cb,
 218     typename Decoder::OutputCB output_cb,
 219     DecoderStatus&& reinit_cause) {
 220   DVLOG(2) << __func__;
 221   if (!decode_failure_reinit_cause_.has_value())
 222     decode_failure_reinit_cause_ = std::move(reinit_cause);
 223   SelectDecoderInternal(std::move(select_decoder_cb), std::move(output_cb),
 224                         /*needs_new_decoders = */ false);
 225 }
 226
 227 template <DemuxerStream::Type StreamType>
 228 void DecoderSelector<StreamType>::FinalizeDecoderSelection() {
 229   DVLOG(2) << __func__;
 230   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 231   DCHECK(!select_decoder_cb_);
 232
 233   // Discard any remaining decoder instances, they won't be used.
 234   decoders_.clear();
 235 }
 236
 237 template <DemuxerStream::Type StreamType>
 238 void DecoderSelector<StreamType>::PrependDecoder(
 239     std::unique_ptr<Decoder> decoder) {
 240   DVLOG(2) << __func__;
 241   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 242
 243   // Decoders inserted directly should be given priority over those returned by
 244   // |create_decoders_cb_|.
 245   decoders_.insert(decoders_.begin(), std::move(decoder));
 246   FilterAndSortAvailableDecoders();
 247 }
 248
 249 template <DemuxerStream::Type StreamType>
 250 void DecoderSelector<StreamType>::OverrideDecoderPriorityCBForTesting(
 251     DecoderPriorityCB decoder_priority_cb) {
 252   decoder_priority_cb_ = std::move(decoder_priority_cb);
 253 }
 254
 255 template <DemuxerStream::Type StreamType>
 256 void DecoderSelector<StreamType>::CreateDecoders() {
 257   // Post-insert decoders returned by `create_decoders_cb_`, so that
 258   // any decoders added via `PrependDecoder()` are not overwritten and retain
 259   // priority (even if they are ultimately de-ranked by
 260   // `FilterAndSortAvailableDecoders()`)
 261   auto new_decoders = create_decoders_cb_.Run();
 262   std::move(new_decoders.begin(), new_decoders.end(),
 263             std::inserter(decoders_, decoders_.end()));
 264   FilterAndSortAvailableDecoders();
 265 }
 266
 267 template <DemuxerStream::Type StreamType>
 268 void DecoderSelector<StreamType>::GetAndInitializeNextDecoder() {
 269   DVLOG(2) << __func__;
 270   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 271   DCHECK(!decoder_);
 272
 273   if (decoders_.empty()) {
 274     // Decoder selection failed. If the stream is encrypted, try again using
 275     // DecryptingDemuxerStream.
 276     if (config_.is_encrypted() && cdm_context_) {
 277       InitializeDecryptingDemuxerStream();
 278       return;
 279     }
 280
 281     if (decode_failure_reinit_cause_.has_value()) {
 282       ReturnSelectionError(std::move(*decode_failure_reinit_cause_));
 283     } else {
 284       ReturnSelectionError(DecoderStatus::Codes::kUnsupportedConfig);
 285     }
 286     return;
 287   }
 288
 289   // Initialize the first decoder on the list.
 290   decoder_ = std::move(decoders_.front());
 291   decoders_.erase(decoders_.begin());
 292   TRACE_EVENT_ASYNC_STEP_INTO0("media", kSelectDecoderTrace, this,
 293                                GetDecoderName(decoder_->GetDecoderType()));
 294
 295   DVLOG(2) << __func__ << ": initializing " << decoder_->GetDecoderType();
 296   const bool is_live = stream_->liveness() == StreamLiveness::kLive;
 297   traits_->InitializeDecoder(
 298       decoder_.get(), config_, is_live, cdm_context_,
 299       base::BindOnce(&DecoderSelector<StreamType>::OnDecoderInitializeDone,
 300                      weak_this_factory_.GetWeakPtr()),
 301       output_cb_, waiting_cb_);
 302 }
 303
 304 template <DemuxerStream::Type StreamType>
 305 void DecoderSelector<StreamType>::OnDecoderInitializeDone(
 306     DecoderStatus status) {
 307   DCHECK(decoder_);
 308   DVLOG(2) << __func__ << ": " << decoder_->GetDecoderType()
 309            << " success=" << static_cast<int>(status.code());
 310   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 311
 312   if (!status.is_ok()) {
 313     // Note: Don't track this decode status, as it is the result of decoder
 314     // selection (initialization) failure.
 315     MEDIA_LOG(INFO, media_log_)
 316         << "Cannot select " << decoder_->GetDecoderType() << " for "
 317         << DemuxerStream::GetTypeName(StreamType) << " decoding";
 318
 319     // Try the next decoder on the list.
 320     decoder_ = nullptr;
 321     GetAndInitializeNextDecoder();
 322     return;
 323   }
 324
 325   RunSelectDecoderCB(std::move(decoder_));
 326 }
 327
 328 template <DemuxerStream::Type StreamType>
 329 void DecoderSelector<StreamType>::ReturnSelectionError(DecoderStatus error) {
 330   DVLOG(1) << __func__ << ": No decoder selected";
 331   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 332   DCHECK(!error.is_ok());
 333
 334   decrypting_demuxer_stream_.reset();
 335   decoders_.clear();
 336   RunSelectDecoderCB(std::move(error));
 337 }
 338
 339 template <DemuxerStream::Type StreamType>
 340 void DecoderSelector<StreamType>::InitializeDecryptingDemuxerStream() {
 341   DCHECK(decoders_.empty());
 342   DCHECK(config_.is_encrypted());
 343   DCHECK(cdm_context_);
 344   TRACE_EVENT_ASYNC_STEP_INTO0("media", kSelectDecoderTrace, this,
 345                                "DecryptingDemuxerStream");
 346
 347   decrypting_demuxer_stream_ = std::make_unique<DecryptingDemuxerStream>(
 348       task_runner_, media_log_, waiting_cb_);
 349
 350   decrypting_demuxer_stream_->Initialize(
 351       stream_, cdm_context_,
 352       base::BindOnce(
 353           &DecoderSelector<StreamType>::OnDecryptingDemuxerStreamInitializeDone,
 354           weak_this_factory_.GetWeakPtr()));
 355 }
 356
 357 template <DemuxerStream::Type StreamType>
 358 void DecoderSelector<StreamType>::OnDecryptingDemuxerStreamInitializeDone(
 359     PipelineStatus status) {
 360   DVLOG(2) << __func__ << ": status=" << status;
 361   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 362
 363   if (status != PIPELINE_OK) {
 364     // Since we already tried every potential decoder without DDS, give up.
 365     ReturnSelectionError(
 366         {DecoderStatus::Codes::kUnsupportedEncryptionMode, std::move(status)});
 367     return;
 368   }
 369
 370   // Once DDS is enabled, there is no going back.
 371   // TODO(sandersd): Support transitions from encrypted to unencrypted.
 372   stream_ = decrypting_demuxer_stream_.get();
 373   cdm_context_ = nullptr;
 374
 375   // We'll use the decrypted config from now on.
 376   config_ = traits_->GetDecoderConfig(stream_);
 377   DCHECK(!config_.is_encrypted());
 378
 379   // Try decoder selection again now that DDS is being used.
 380   CreateDecoders();
 381   GetAndInitializeNextDecoder();
 382 }
 383
 384 template <DemuxerStream::Type StreamType>
 385 void DecoderSelector<StreamType>::RunSelectDecoderCB(
 386     DecoderOrError decoder_or_error) {
 387   DCHECK(select_decoder_cb_);
 388   TRACE_EVENT_ASYNC_END2(
 389       "media", kSelectDecoderTrace, this, "type",
 390       DemuxerStream::GetTypeName(StreamType), "decoder",
 391       base::StringPrintf(
 392           "%s (%s)",
 393           decoder_or_error.has_value()
 394               ? GetDecoderName(decoder_or_error->GetDecoderType()).c_str()
 395               : "null",
 396           decrypting_demuxer_stream_ ? "encrypted" : "unencrypted"));
 397
 398   task_runner_->PostTask(
 399       FROM_HERE,
 400       base::BindOnce(std::move(select_decoder_cb_), std::move(decoder_or_error),
 401                      std::move(decrypting_demuxer_stream_)));
 402 }
 403
 404 template <DemuxerStream::Type StreamType>
 405 void DecoderSelector<StreamType>::FilterAndSortAvailableDecoders() {
 406   std::vector<std::unique_ptr<Decoder>> decoders = std::move(decoders_);
 407   std::vector<std::unique_ptr<Decoder>> deprioritized_decoders;
 408   DCHECK(decoder_priority_cb_);
 409
 410   for (auto& decoder : decoders) {
 411     // Skip the decoder if this decoder doesn't support encryption for a
 412     // decrypting config
 413     if (config_.is_encrypted() && !decoder->SupportsDecryption())
 414       continue;
 415
 416     // Run the predicate on this decoder.
 417     switch (decoder_priority_cb_.Run(config_, *decoder)) {
 418       case DecoderPriority::kSkipped:
 419         continue;
 420       case DecoderPriority::kNormal:
 421         decoders_.push_back(std::move(decoder));
 422         break;
 423       case DecoderPriority::kDeprioritized:
 424         deprioritized_decoders.push_back(std::move(decoder));
 425         break;
 426     }
 427   }
 428
 429   // Post-insert deprioritized decoders
 430   std::move(deprioritized_decoders.begin(), deprioritized_decoders.end(),
 431             std::inserter(decoders_, decoders_.end()));
 432 }
 433
 434 // These forward declarations tell the compiler that we will use
 435 // DecoderSelector with these arguments, allowing us to keep these definitions
 436 // in our .cc without causing linker errors. This also means if anyone tries to
 437 // instantiate a DecoderSelector with anything but these two specializations
 438 // they'll most likely get linker errors.
 439 template class DecoderSelector<DemuxerStream::AUDIO>;
 440 template class DecoderSelector<DemuxerStream::VIDEO>;
 441
 442 }  // namespace media