media/filters/decrypting_video_decoder.cc

   1 // Copyright 2012 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/decrypting_video_decoder.h"
   6
   7 #include "base/functional/bind.h"
   8 #include "base/functional/callback_helpers.h"
   9 #include "base/location.h"
  10 #include "base/logging.h"
  11 #include "base/strings/string_number_conversions.h"
  12 #include "base/task/bind_post_task.h"
  13 #include "base/task/sequenced_task_runner.h"
  14 #include "base/trace_event/trace_event.h"
  15 #include "media/base/cdm_context.h"
  16 #include "media/base/decoder_buffer.h"
  17 #include "media/base/media_log.h"
  18 #include "media/base/video_frame.h"
  19
  20 namespace media {
  21
  22 const char DecryptingVideoDecoder::kDecoderName[] = "DecryptingVideoDecoder";
  23
  24 DecryptingVideoDecoder::DecryptingVideoDecoder(
  25     const scoped_refptr<base::SequencedTaskRunner>& task_runner,
  26     MediaLog* media_log)
  27     : task_runner_(task_runner), media_log_(media_log) {
  28   DETACH_FROM_SEQUENCE(sequence_checker_);
  29 }
  30
  31 VideoDecoderType DecryptingVideoDecoder::GetDecoderType() const {
  32   return VideoDecoderType::kDecrypting;
  33 }
  34
  35 void DecryptingVideoDecoder::Initialize(const VideoDecoderConfig& config,
  36                                         bool /* low_delay */,
  37                                         CdmContext* cdm_context,
  38                                         InitCB init_cb,
  39                                         const OutputCB& output_cb,
  40                                         const WaitingCB& waiting_cb) {
  41   DVLOG(2) << __func__ << ": " << config.AsHumanReadableString();
  42
  43   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  44   DCHECK(state_ == kUninitialized || state_ == kIdle ||
  45          state_ == kDecodeFinished)
  46       << state_;
  47   DCHECK(!decode_cb_);
  48   DCHECK(!reset_cb_);
  49   DCHECK(config.IsValidConfig());
  50
  51   init_cb_ = base::BindPostTaskToCurrentDefault(std::move(init_cb));
  52
  53   if (!cdm_context) {
  54     // Once we have a CDM context, one should always be present.
  55     DCHECK(!support_clear_content_);
  56     std::move(init_cb_).Run(DecoderStatus::Codes::kUnsupportedEncryptionMode);
  57     return;
  58   }
  59
  60   if (!config.is_encrypted() && !support_clear_content_) {
  61     std::move(init_cb_).Run(DecoderStatus::Codes::kUnsupportedEncryptionMode);
  62     return;
  63   }
  64
  65   // Once initialized with encryption support, the value is sticky, so we'll use
  66   // the decryptor for clear content as well.
  67   support_clear_content_ = true;
  68
  69   output_cb_ = base::BindPostTaskToCurrentDefault(output_cb);
  70   config_ = config;
  71
  72   DCHECK(waiting_cb);
  73   waiting_cb_ = waiting_cb;
  74
  75   if (state_ == kUninitialized) {
  76     if (!cdm_context->GetDecryptor()) {
  77       DVLOG(1) << __func__ << ": no decryptor";
  78       std::move(init_cb_).Run(DecoderStatus::Codes::kUnsupportedEncryptionMode);
  79       return;
  80     }
  81
  82     decryptor_ = cdm_context->GetDecryptor();
  83     event_cb_registration_ = cdm_context->RegisterEventCB(
  84         base::BindRepeating(&DecryptingVideoDecoder::OnCdmContextEvent,
  85                             weak_factory_.GetWeakPtr()));
  86   } else {
  87     // Reinitialization (i.e. upon a config change). The new config can be
  88     // encrypted or clear.
  89     decryptor_->DeinitializeDecoder(Decryptor::kVideo);
  90   }
  91
  92   state_ = kPendingDecoderInit;
  93   decryptor_->InitializeVideoDecoder(
  94       config_, base::BindPostTaskToCurrentDefault(
  95                    base::BindOnce(&DecryptingVideoDecoder::FinishInitialization,
  96                                   weak_factory_.GetWeakPtr())));
  97 }
  98
  99 bool DecryptingVideoDecoder::SupportsDecryption() const {
 100   return true;
 101 }
 102
 103 void DecryptingVideoDecoder::Decode(scoped_refptr<DecoderBuffer> buffer,
 104                                     DecodeCB decode_cb) {
 105   DVLOG(3) << "Decode()";
 106   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 107   DCHECK(state_ == kIdle || state_ == kDecodeFinished || state_ == kError)
 108       << state_;
 109   DCHECK(decode_cb);
 110   CHECK(!decode_cb_) << "Overlapping decodes are not supported.";
 111
 112   decode_cb_ = base::BindPostTaskToCurrentDefault(std::move(decode_cb));
 113
 114   if (state_ == kError) {
 115     std::move(decode_cb_).Run(DecoderStatus::Codes::kPlatformDecodeFailure);
 116     return;
 117   }
 118
 119   // Return empty frames if decoding has finished.
 120   if (state_ == kDecodeFinished) {
 121     std::move(decode_cb_).Run(DecoderStatus::Codes::kOk);
 122     return;
 123   }
 124
 125   // One time set of `has_clear_lead_`.
 126   if (!has_clear_lead_.has_value()) {
 127     has_clear_lead_ = !buffer->end_of_stream() && !buffer->decrypt_config();
 128   }
 129
 130   // Although the stream may switch from clear to encrypted to clear multiple
 131   // times (e.g ad-insertions), we only log to the Media log the first switch
 132   // from clear to encrypted.
 133   if (HasClearLead() && !switched_clear_to_encrypted_ &&
 134       !buffer->end_of_stream() && buffer->is_encrypted()) {
 135     MEDIA_LOG(INFO, media_log_)
 136         << "First switch from clear to encrypted buffers.";
 137     switched_clear_to_encrypted_ = true;
 138   }
 139
 140   pending_buffer_to_decode_ = std::move(buffer);
 141   state_ = kPendingDecode;
 142   DecodePendingBuffer();
 143 }
 144
 145 void DecryptingVideoDecoder::Reset(base::OnceClosure closure) {
 146   DVLOG(2) << "Reset() - state: " << state_;
 147   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 148   DCHECK(state_ == kIdle || state_ == kPendingDecode ||
 149          state_ == kWaitingForKey || state_ == kDecodeFinished ||
 150          state_ == kError)
 151       << state_;
 152   DCHECK(!init_cb_);  // No Reset() during pending initialization.
 153   DCHECK(!reset_cb_);
 154
 155   reset_cb_ = base::BindPostTaskToCurrentDefault(std::move(closure));
 156
 157   decryptor_->ResetDecoder(Decryptor::kVideo);
 158
 159   // Reset() cannot complete if the decode callback is still pending.
 160   // Defer the resetting process in this case. The |reset_cb_| will be fired
 161   // after the decode callback is fired - see DecryptAndDecodeBuffer() and
 162   // DeliverFrame().
 163   if (state_ == kPendingDecode) {
 164     DCHECK(decode_cb_);
 165     return;
 166   }
 167
 168   if (state_ == kWaitingForKey) {
 169     CompleteWaitingForDecryptionKey();
 170     DCHECK(decode_cb_);
 171     pending_buffer_to_decode_.reset();
 172     std::move(decode_cb_).Run(DecoderStatus::Codes::kAborted);
 173   }
 174
 175   DCHECK(!decode_cb_);
 176   DoReset();
 177 }
 178
 179 DecryptingVideoDecoder::~DecryptingVideoDecoder() {
 180   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 181
 182   if (state_ == kUninitialized)
 183     return;
 184
 185   if (state_ == kWaitingForKey)
 186     CompleteWaitingForDecryptionKey();
 187   if (state_ == kPendingDecode)
 188     CompletePendingDecode(Decryptor::kError);
 189
 190   if (decryptor_) {
 191     decryptor_->DeinitializeDecoder(Decryptor::kVideo);
 192     decryptor_ = nullptr;
 193   }
 194   pending_buffer_to_decode_.reset();
 195   if (init_cb_)
 196     std::move(init_cb_).Run(DecoderStatus::Codes::kInterrupted);
 197   if (decode_cb_)
 198     std::move(decode_cb_).Run(DecoderStatus::Codes::kAborted);
 199   if (reset_cb_)
 200     std::move(reset_cb_).Run();
 201 }
 202
 203 void DecryptingVideoDecoder::FinishInitialization(bool success) {
 204   DVLOG(2) << "FinishInitialization()";
 205   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 206   DCHECK_EQ(state_, kPendingDecoderInit) << state_;
 207   DCHECK(init_cb_);
 208   DCHECK(!reset_cb_);   // No Reset() before initialization finished.
 209   DCHECK(!decode_cb_);  // No Decode() before initialization finished.
 210
 211   if (!success) {
 212     DVLOG(1) << __func__ << ": failed to init video decoder on decryptor";
 213     // TODO(*) Is there a better reason? Should this method itself take a
 214     // status?
 215     std::move(init_cb_).Run(DecoderStatus::Codes::kFailed);
 216     decryptor_ = nullptr;
 217     event_cb_registration_.reset();
 218     state_ = kError;
 219     return;
 220   }
 221
 222   // Success!
 223   state_ = kIdle;
 224   std::move(init_cb_).Run(DecoderStatus::Codes::kOk);
 225 }
 226
 227 void DecryptingVideoDecoder::DecodePendingBuffer() {
 228   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 229   DCHECK_EQ(state_, kPendingDecode) << state_;
 230
 231   auto& buffer = pending_buffer_to_decode_;
 232
 233   // Note: Traces require a unique ID per decode, if we ever support multiple
 234   // in flight decodes, the trace begin+end macros need the same unique id.
 235   DCHECK_EQ(GetMaxDecodeRequests(), 1);
 236   const bool is_end_of_stream = buffer->end_of_stream();
 237   const bool is_encrypted = !is_end_of_stream && buffer->decrypt_config();
 238   const auto timestamp_us =
 239       is_end_of_stream ? 0 : buffer->timestamp().InMicroseconds();
 240   TRACE_EVENT_NESTABLE_ASYNC_BEGIN2(
 241       "media", "DecryptingVideoDecoder::DecodePendingBuffer", this,
 242       "is_encrypted", is_encrypted, "timestamp_us", timestamp_us);
 243
 244   if (!DecoderBuffer::DoSubsamplesMatch(*buffer)) {
 245     MEDIA_LOG(ERROR, media_log_)
 246         << "DecryptingVideoDecoder: Subsamples for Buffer do not match";
 247     state_ = kError;
 248     std::move(decode_cb_).Run(DecoderStatus::Codes::kPlatformDecodeFailure);
 249     return;
 250   }
 251
 252   decryptor_->DecryptAndDecodeVideo(
 253       buffer,
 254       base::BindPostTaskToCurrentDefault(base::BindRepeating(
 255           &DecryptingVideoDecoder::DeliverFrame, weak_factory_.GetWeakPtr())));
 256 }
 257
 258 void DecryptingVideoDecoder::DeliverFrame(Decryptor::Status status,
 259                                           scoped_refptr<VideoFrame> frame) {
 260   DVLOG(3) << "DeliverFrame() - status: " << status;
 261   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 262   DCHECK_EQ(state_, kPendingDecode) << state_;
 263   DCHECK(decode_cb_);
 264   DCHECK(pending_buffer_to_decode_.get());
 265   CompletePendingDecode(status);
 266
 267   bool need_to_try_again_if_nokey_is_returned = key_added_while_decode_pending_;
 268   key_added_while_decode_pending_ = false;
 269
 270   scoped_refptr<DecoderBuffer> scoped_pending_buffer_to_decode =
 271       std::move(pending_buffer_to_decode_);
 272
 273   if (reset_cb_) {
 274     std::move(decode_cb_).Run(DecoderStatus::Codes::kAborted);
 275     DoReset();
 276     return;
 277   }
 278
 279   DCHECK_EQ(status == Decryptor::kSuccess, frame.get() != nullptr);
 280
 281   if (status == Decryptor::kError) {
 282     DVLOG(2) << "DeliverFrame() - kError";
 283     MEDIA_LOG(ERROR, media_log_) << GetDecoderType() << ": decode error";
 284     state_ = kError;
 285     std::move(decode_cb_).Run(DecoderStatus::Codes::kPlatformDecodeFailure);
 286     return;
 287   }
 288
 289   if (status == Decryptor::kNoKey) {
 290     std::string key_id =
 291         scoped_pending_buffer_to_decode->decrypt_config()->key_id();
 292     std::string log_message =
 293         "no key for key ID " + base::HexEncode(key_id.data(), key_id.size()) +
 294         "; will resume decoding after new usable key is available";
 295     DVLOG(1) << __func__ << ": " << log_message;
 296     MEDIA_LOG(INFO, media_log_) << GetDecoderType() << ": " << log_message;
 297
 298     // Set |pending_buffer_to_decode_| back as we need to try decoding the
 299     // pending buffer again when new key is added to the decryptor.
 300     pending_buffer_to_decode_ = std::move(scoped_pending_buffer_to_decode);
 301
 302     if (need_to_try_again_if_nokey_is_returned) {
 303       // The |state_| is still kPendingDecode.
 304       MEDIA_LOG(INFO, media_log_)
 305           << GetDecoderType() << ": key was added, resuming decode";
 306       DecodePendingBuffer();
 307       return;
 308     }
 309
 310     TRACE_EVENT_NESTABLE_ASYNC_BEGIN0(
 311         "media", "DecryptingVideoDecoder::WaitingForDecryptionKey", this);
 312     state_ = kWaitingForKey;
 313     waiting_cb_.Run(WaitingReason::kNoDecryptionKey);
 314     return;
 315   }
 316
 317   if (status == Decryptor::kNeedMoreData) {
 318     DVLOG(2) << "DeliverFrame() - kNeedMoreData";
 319     state_ = scoped_pending_buffer_to_decode->end_of_stream() ? kDecodeFinished
 320                                                               : kIdle;
 321     std::move(decode_cb_).Run(DecoderStatus::Codes::kOk);
 322     return;
 323   }
 324
 325   DCHECK_EQ(status, Decryptor::kSuccess);
 326   CHECK(frame);
 327
 328   // Frame returned with kSuccess should not be an end-of-stream frame.
 329   DCHECK(!frame->metadata().end_of_stream);
 330
 331   // If color space is not set, use the color space in the |config_|.
 332   if (!frame->ColorSpace().IsValid()) {
 333     DVLOG(3) << "Setting color space using information in the config.";
 334     if (config_.color_space_info().IsSpecified())
 335       frame->set_color_space(config_.color_space_info().ToGfxColorSpace());
 336   }
 337
 338   output_cb_.Run(std::move(frame));
 339
 340   if (scoped_pending_buffer_to_decode->end_of_stream()) {
 341     // Set |pending_buffer_to_decode_| back as we need to keep flushing the
 342     // decryptor.
 343     pending_buffer_to_decode_ = std::move(scoped_pending_buffer_to_decode);
 344     DecodePendingBuffer();
 345     return;
 346   }
 347
 348   state_ = kIdle;
 349   std::move(decode_cb_).Run(DecoderStatus::Codes::kOk);
 350 }
 351
 352 void DecryptingVideoDecoder::OnCdmContextEvent(CdmContext::Event event) {
 353   DVLOG(2) << __func__;
 354   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 355
 356   if (event != CdmContext::Event::kHasAdditionalUsableKey)
 357     return;
 358
 359   if (state_ == kPendingDecode) {
 360     key_added_while_decode_pending_ = true;
 361     return;
 362   }
 363
 364   if (state_ == kWaitingForKey) {
 365     CompleteWaitingForDecryptionKey();
 366     MEDIA_LOG(INFO, media_log_)
 367         << GetDecoderType() << ": key added, resuming decode";
 368     state_ = kPendingDecode;
 369     DecodePendingBuffer();
 370   }
 371 }
 372
 373 void DecryptingVideoDecoder::DoReset() {
 374   DCHECK(!init_cb_);
 375   DCHECK(!decode_cb_);
 376   state_ = kIdle;
 377   std::move(reset_cb_).Run();
 378 }
 379
 380 void DecryptingVideoDecoder::CompletePendingDecode(Decryptor::Status status) {
 381   DCHECK_EQ(state_, kPendingDecode);
 382   TRACE_EVENT_NESTABLE_ASYNC_END1(
 383       "media", "DecryptingVideoDecoder::DecodePendingBuffer", this, "status",
 384       Decryptor::GetStatusName(status));
 385 }
 386
 387 void DecryptingVideoDecoder::CompleteWaitingForDecryptionKey() {
 388   DCHECK_EQ(state_, kWaitingForKey);
 389   TRACE_EVENT_NESTABLE_ASYNC_END0(
 390       "media", "DecryptingVideoDecoder::WaitingForDecryptionKey", this);
 391 }
 392
 393 }  // namespace media