Encrypted Media: Support Audio Decrypt-Only.

media/filters/audio_decoder_factory.cc

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "media/filters/audio_decoder_factory.h"
+
+#include "base/bind.h"
+#include "base/callback_helpers.h"
+#include "base/logging.h"
+#include "base/message_loop_proxy.h"
+#include "media/base/audio_decoder_config.h"
+#include "media/base/bind_to_loop.h"
+#include "media/base/demuxer_stream.h"
+#include "media/base/pipeline.h"
+#include "media/filters/decrypting_audio_decoder.h"
+#include "media/filters/decrypting_demuxer_stream.h"
+
+namespace media {
+
+AudioDecoderFactory::AudioDecoderFactory(
+    const scoped_refptr<base::MessageLoopProxy>& message_loop,
+    const AudioDecoderList& decoders,
+    const RequestDecryptorNotificationCB& request_decryptor_notification_cb)
+    : message_loop_(message_loop),
+      precreated_decoders_(decoders),
+      request_decryptor_notification_cb_(request_decryptor_notification_cb),
+      ALLOW_THIS_IN_INITIALIZER_LIST(weak_ptr_factory_(this)),
+      weak_this_(weak_ptr_factory_.GetWeakPtr()) {
+}
+
+void AudioDecoderFactory::InitAudioDecoder(
+    const scoped_refptr<DemuxerStream>& stream,
+    const StatisticsCB& statistics_cb,
+    const InitDoneCB& init_done_cb) {
+  DCHECK(message_loop_->BelongsToCurrentThread());
+  DVLOG(2) << "InitAudioDecoder()";
+  DCHECK(stream);
+
+  init_done_cb_ = BindToCurrentLoop(init_done_cb);
+
+  const AudioDecoderConfig& config = stream->audio_decoder_config();
+  if (!config.IsValidConfig()) {
+    DLOG(ERROR) << "Invalid audio stream config.";
+    base::ResetAndReturn(&init_done_cb_).Run(NULL, NULL);
+    return;
+  }
+
+  input_stream_ = stream;
+  statistics_cb_ = statistics_cb;
+
+  if (!config.is_encrypted()) {
+    if (precreated_decoders_.empty()) {
+      DLOG(ERROR) << "No audio decoder can be used to decode the input stream.";
+      base::ResetAndReturn(&init_done_cb_).Run(NULL, NULL);
+      return;
+    }
+
+    InitializeNextPrecreatedDecoder();
+    return;
+  }
+
+  // This could happen if Encrypted Media Extension (EME) is not enabled.
+  if (request_decryptor_notification_cb_.is_null()) {
+    base::ResetAndReturn(&init_done_cb_).Run(NULL, NULL);
+    return;
+  }
+
+  audio_decoder_ = new DecryptingAudioDecoder(
+      message_loop_, request_decryptor_notification_cb_);
+
+  audio_decoder_->Initialize(
+      input_stream_,
+      BindToCurrentLoop(base::Bind(
+          &AudioDecoderFactory::DecryptingAudioDecoderInitDone, weak_this_)),
+      statistics_cb_);
+}
+
+void AudioDecoderFactory::DecryptingAudioDecoderInitDone(
+    PipelineStatus status) {
+  DCHECK(message_loop_->BelongsToCurrentThread());
+
+  if (status == PIPELINE_OK) {
+    precreated_decoders_.clear();
+    base::ResetAndReturn(&init_done_cb_).Run(audio_decoder_, NULL);
+    return;
+  }
+
+  audio_decoder_ = NULL;
+
+  if (precreated_decoders_.empty()) {
+    DLOG(ERROR) << "No audio decoder can be used to decode the input stream.";
+    base::ResetAndReturn(&init_done_cb_).Run(NULL, NULL);
+    return;
+  }
+
+  decrypted_stream_ = new DecryptingDemuxerStream(
+      message_loop_, request_decryptor_notification_cb_);
+
+  decrypted_stream_->Initialize(
+      input_stream_,
+      BindToCurrentLoop(base::Bind(
+          &AudioDecoderFactory::DecryptingDemuxerStreamInitDone, weak_this_)));
+}
+
+void AudioDecoderFactory::DecryptingDemuxerStreamInitDone(
+    PipelineStatus status) {
+  DCHECK(message_loop_->BelongsToCurrentThread());
+
+  if (status != PIPELINE_OK) {
+    decrypted_stream_ = NULL;
+    base::ResetAndReturn(&init_done_cb_).Run(NULL, NULL);
+    return;
+  }
+
+  DCHECK(!decrypted_stream_->audio_decoder_config().is_encrypted());
+  input_stream_ = decrypted_stream_;
+  InitializeNextPrecreatedDecoder();
+}
+
+void AudioDecoderFactory::InitializeNextPrecreatedDecoder() {
+  DCHECK(message_loop_->BelongsToCurrentThread());
+  DCHECK(!precreated_decoders_.empty());
+
+  audio_decoder_ = precreated_decoders_.front();
+  precreated_decoders_.pop_front();
+  DCHECK(audio_decoder_);
+  audio_decoder_->Initialize(
+      input_stream_,
+      BindToCurrentLoop(base::Bind(
+          &AudioDecoderFactory::PrecreatedDecoderInitDone, weak_this_)),
+      statistics_cb_);
+}
+
+void AudioDecoderFactory::PrecreatedDecoderInitDone(PipelineStatus status) {
+  DCHECK(message_loop_->BelongsToCurrentThread());
+
+  if (status != PIPELINE_OK) {
+    if (!precreated_decoders_.empty())
+      InitializeNextPrecreatedDecoder();
+    else
+      base::ResetAndReturn(&init_done_cb_).Run(NULL, NULL);
+    return;
+  }
+
+  precreated_decoders_.clear();
+  base::ResetAndReturn(&init_done_cb_).Run(audio_decoder_, decrypted_stream_);
+}
+
+AudioDecoderFactory::~AudioDecoderFactory() {}
+
+}  // namespace media