Add DecryptingDemuxerStream.

media/filters/decrypting_demuxer_stream.cc

Index: media/filters/decrypting_demuxer_stream.cc
diff --git a/media/filters/decrypting_demuxer_stream.cc b/media/filters/decrypting_demuxer_stream.cc
new file mode 100644
index 0000000000000000000000000000000000000000..02ee0c501d11e78bc2820007f91b847758940d1d
--- /dev/null
+++ b/media/filters/decrypting_demuxer_stream.cc
@@ -0,0 +1,350 @@
+// 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/decrypting_demuxer_stream.h"
+
+#include "base/bind.h"
+#include "base/callback_helpers.h"
+#include "base/location.h"
+#include "base/logging.h"
+#include "base/message_loop_proxy.h"
+#include "media/base/audio_decoder_config.h"
+#include "media/base/video_decoder_config.h"
+#include "media/base/bind_to_loop.h"
+#include "media/base/decoder_buffer.h"
+#include "media/base/decryptor.h"
+#include "media/base/demuxer_stream.h"
+#include "media/base/pipeline.h"
+
+namespace media {
+
+#define BIND_TO_LOOP(function) \
+    media::BindToLoop(message_loop_, base::Bind(function, this))
+
+DecryptingDemuxerStream::DecryptingDemuxerStream(
+    const MessageLoopFactoryCB& message_loop_factory_cb,
+    const RequestDecryptorNotificationCB& request_decryptor_notification_cb)
+    : message_loop_factory_cb_(message_loop_factory_cb),
+      state_(kUninitialized),
+      stream_type_(UNKNOWN),
+      request_decryptor_notification_cb_(request_decryptor_notification_cb),
+      decryptor_(NULL),
+      key_added_while_decrypt_pending_(false) {
+}
+
+void DecryptingDemuxerStream::Initialize(
+    const scoped_refptr<DemuxerStream>& stream,
+    const PipelineStatusCB& status_cb) {
+  DCHECK(!message_loop_);
+  message_loop_ = base::ResetAndReturn(&message_loop_factory_cb_).Run();
+  message_loop_->PostTask(FROM_HERE, base::Bind(
+      &DecryptingDemuxerStream::DoInitialize, this,
+      stream, status_cb));
+}
+
+void DecryptingDemuxerStream::Read(const ReadCB& read_cb) {
+  DVLOG(3) << "Read()";
+  DCHECK(message_loop_->BelongsToCurrentThread());
+  DCHECK_EQ(state_, kIdle) << state_;
+  DCHECK(!read_cb.is_null());
+  CHECK(read_cb_.is_null()) << "Overlapping reads are not supported.";
+
+  read_cb_ = read_cb;
+  state_ = kPendingDemuxerRead;
+  demuxer_stream_->Read(
+      base::Bind(&DecryptingDemuxerStream::DecryptBuffer, this));
+}
+
+void DecryptingDemuxerStream::Reset(const base::Closure& closure) {
+  if (!message_loop_->BelongsToCurrentThread()) {
+    message_loop_->PostTask(FROM_HERE, base::Bind(
+        &DecryptingDemuxerStream::Reset, this, closure));
+    return;
+  }
+
+  DVLOG(2) << "Reset() - state: " << state_;
+  DCHECK(state_ != kUninitialized && state_ != kDecryptorRequested) << state_;
+  DCHECK(init_cb_.is_null());  // No Reset() during pending initialization.
+  DCHECK(reset_cb_.is_null());
+
+  reset_cb_ = closure;
+
+  decryptor_->CancelDecrypt(GetDecryptorStreamType());
+
+  // Reset() cannot complete if the read callback is still pending.
+  // Defer the resetting process in this case. The |reset_cb_| will be fired
+  // after the read callback is fired - see DoDecryptBuffer() and
+  // DoDeliverBuffer().
+  if (state_ == kPendingDemuxerRead || state_ == kPendingDecrypt) {
+    DCHECK(!read_cb_.is_null());
+    return;
+  }
+
+  if (state_ == kWaitingForKey) {
+    DCHECK(!read_cb_.is_null());
+    pending_buffer_to_decrypt_ = NULL;
+    base::ResetAndReturn(&read_cb_).Run(kAborted, NULL);
+  }
+
+  DCHECK(read_cb_.is_null());
+  DoReset();
+}
+
+const AudioDecoderConfig& DecryptingDemuxerStream::audio_decoder_config() {
+  DCHECK(state_ != kUninitialized && state_ != kDecryptorRequested) << state_;
+  CHECK_EQ(stream_type_, AUDIO);
+  return *audio_config_;
+}
+
+const VideoDecoderConfig& DecryptingDemuxerStream::video_decoder_config() {
+  DCHECK(state_ != kUninitialized && state_ != kDecryptorRequested) << state_;
+  CHECK_EQ(stream_type_, VIDEO);
+  return *video_config_;
+}
+
+DemuxerStream::Type DecryptingDemuxerStream::type() {
+  DCHECK(state_ != kUninitialized && state_ != kDecryptorRequested) << state_;
+  return stream_type_;
+}
+
+void DecryptingDemuxerStream::EnableBitstreamConverter() {
+  demuxer_stream_->EnableBitstreamConverter();
+}
+
+DecryptingDemuxerStream::~DecryptingDemuxerStream() {}
+
+void DecryptingDemuxerStream::DoInitialize(
+    const scoped_refptr<DemuxerStream>& stream,
+    const PipelineStatusCB& status_cb) {
+  DVLOG(2) << "DoInitialize()";
+  DCHECK(message_loop_->BelongsToCurrentThread());
+  DCHECK_EQ(state_, kUninitialized) << state_;
+
+  // Only valid potentially encrypted audio or video stream is accepted.
+  if (!((stream->type() == AUDIO &&
+         stream->audio_decoder_config().IsValidConfig() &&
+         stream->audio_decoder_config().is_encrypted()) ||
+        (stream->type() == VIDEO &&
+         stream->video_decoder_config().IsValidConfig() &&
+         stream->video_decoder_config().is_encrypted()))) {
+    status_cb.Run(DEMUXER_ERROR_NO_SUPPORTED_STREAMS);
+    return;
+  }
+
+  DCHECK(!demuxer_stream_);
+  demuxer_stream_ = stream;
+  stream_type_ = stream->type();
+  init_cb_ = status_cb;
+
+  state_ = kDecryptorRequested;
+  request_decryptor_notification_cb_.Run(
+      BIND_TO_LOOP(&DecryptingDemuxerStream::SetDecryptor));
+}
+
+void DecryptingDemuxerStream::SetDecryptor(Decryptor* decryptor) {
+  DVLOG(2) << "SetDecryptor()";
+  DCHECK(message_loop_->BelongsToCurrentThread());
+  DCHECK_EQ(state_, kDecryptorRequested) << state_;
+  DCHECK(!init_cb_.is_null());
+  DCHECK(!request_decryptor_notification_cb_.is_null());
+
+  request_decryptor_notification_cb_.Reset();
+  decryptor_ = decryptor;
+
+  switch (stream_type_) {
+    case AUDIO: {
+      const AudioDecoderConfig& input_audio_config =
+          demuxer_stream_->audio_decoder_config();
+      audio_config_.reset(new AudioDecoderConfig());
+      audio_config_->Initialize(input_audio_config.codec(),
+                                input_audio_config.bits_per_channel(),
+                                input_audio_config.channel_layout(),
+                                input_audio_config.samples_per_second(),
+                                input_audio_config.extra_data(),
+                                input_audio_config.extra_data_size(),
+                                false,  // Output audio is not encrypted.
+                                false);
+      break;
+    }
+
+    case VIDEO: {
+      const VideoDecoderConfig& input_video_config =
+          demuxer_stream_->video_decoder_config();
+      video_config_.reset(new VideoDecoderConfig());
+      video_config_->Initialize(input_video_config.codec(),
+                                input_video_config.profile(),
+                                input_video_config.format(),
+                                input_video_config.coded_size(),
+                                input_video_config.visible_rect(),
+                                input_video_config.natural_size(),
+                                input_video_config.extra_data(),
+                                input_video_config.extra_data_size(),
+                                false,  // Output video is not encrypted.
+                                false);
+      break;
+    }
+
+    default:
+      NOTREACHED();
+      return;
+  }
+
+  decryptor_->RegisterKeyAddedCB(
+      GetDecryptorStreamType(),
+      BIND_TO_LOOP(&DecryptingDemuxerStream::OnKeyAdded));
+
+  state_ = kIdle;
+  base::ResetAndReturn(&init_cb_).Run(PIPELINE_OK);
+}
+
+void DecryptingDemuxerStream::DecryptBuffer(
+    DemuxerStream::Status status,
+    const scoped_refptr<DecoderBuffer>& buffer) {
+  // In theory, we don't need to force post the task here, because we do a
+  // force task post in DeliverBuffer(). Therefore, even if
+  // demuxer_stream_->Read() execute the read callback on the same execution
+  // stack we are still fine. But it looks like a force post task makes the
+  // logic more understandable and manageable, so why not?
+  message_loop_->PostTask(FROM_HERE, base::Bind(
+      &DecryptingDemuxerStream::DoDecryptBuffer, this, status, buffer));
+}
+
+void DecryptingDemuxerStream::DoDecryptBuffer(
+    DemuxerStream::Status status,
+    const scoped_refptr<DecoderBuffer>& buffer) {
+  DVLOG(3) << "DoDecryptBuffer()";
+  DCHECK(message_loop_->BelongsToCurrentThread());
+  DCHECK_EQ(state_, kPendingDemuxerRead) << state_;
+  DCHECK(!read_cb_.is_null());
+  DCHECK_EQ(buffer != NULL, status == kOk) << status;
+
+  if (!reset_cb_.is_null()) {
+    base::ResetAndReturn(&read_cb_).Run(kAborted, NULL);
+    DoReset();
+    return;
+  }
+
+  if (status == kAborted) {
+    DVLOG(2) << "DoDecryptBuffer() - kAborted.";
+    state_ = kIdle;
+    base::ResetAndReturn(&read_cb_).Run(kAborted, NULL);
+    return;
+  }
+
+  if (status == kConfigChanged) {
+    DVLOG(2) << "DoDecryptBuffer() - kConfigChanged.";
+    state_ = kIdle;
+    // TODO(xhwang): Support kConfigChanged!
+    base::ResetAndReturn(&read_cb_).Run(kAborted, NULL);
+    return;
+  }
+
+  if (buffer->IsEndOfStream()) {
+    DVLOG(2) << "DoDecryptBuffer() - EOS buffer.";
+    state_ = kIdle;
+    base::ResetAndReturn(&read_cb_).Run(status, buffer);
+    return;
+  }
+
+  pending_buffer_to_decrypt_ = buffer;
+  state_ = kPendingDecrypt;
+  DecryptPendingBuffer();
+}
+
+void DecryptingDemuxerStream::DecryptPendingBuffer() {
+  DCHECK(message_loop_->BelongsToCurrentThread());
+  DCHECK_EQ(state_, kPendingDecrypt) << state_;
+  decryptor_->Decrypt(
+      GetDecryptorStreamType(),
+      pending_buffer_to_decrypt_,
+      base::Bind(&DecryptingDemuxerStream::DeliverBuffer, this));
+}
+
+void DecryptingDemuxerStream::DeliverBuffer(
+    Decryptor::Status status,
+    const scoped_refptr<DecoderBuffer>& decrypted_buffer) {
+  // We need to force task post here because the DecryptCB can be executed
+  // synchronously in Reset(). Instead of using more complicated logic in
+  // those function to fix it, why not force task post here to make everything
+  // simple and clear?
+  message_loop_->PostTask(FROM_HERE, base::Bind(
+      &DecryptingDemuxerStream::DoDeliverBuffer, this,
+      status, decrypted_buffer));
+}
+
+void DecryptingDemuxerStream::DoDeliverBuffer(
+    Decryptor::Status status,
+    const scoped_refptr<DecoderBuffer>& decrypted_buffer) {
+  DVLOG(3) << "DoDeliverBuffer() - status: " << status;
+  DCHECK(message_loop_->BelongsToCurrentThread());
+  DCHECK_EQ(state_, kPendingDecrypt) << state_;
+  DCHECK_NE(status, Decryptor::kNeedMoreData);
+  DCHECK(!read_cb_.is_null());
+  DCHECK(pending_buffer_to_decrypt_);
+
+  bool need_to_try_again_if_nokey = key_added_while_decrypt_pending_;
+  key_added_while_decrypt_pending_ = false;
+
+  if (!reset_cb_.is_null()) {
+    pending_buffer_to_decrypt_ = NULL;
+    base::ResetAndReturn(&read_cb_).Run(kAborted, NULL);
+    DoReset();
+    return;
+  }
+
+  DCHECK_EQ(status == Decryptor::kSuccess, decrypted_buffer.get() != NULL);
+
+  if (status == Decryptor::kError) {
+    DVLOG(2) << "DoDeliverBuffer() - kError";
+    pending_buffer_to_decrypt_ = NULL;
+    state_ = kIdle;
+    base::ResetAndReturn(&read_cb_).Run(kAborted, NULL);
+    return;
+  }
+
+  if (status == Decryptor::kNoKey) {
+    DVLOG(2) << "DoDeliverBuffer() - kNoKey";
+    if (need_to_try_again_if_nokey) {
+      // The |state_| is still kPendingDecrypt.
+      DecryptPendingBuffer();
+      return;
+    }
+
+    state_ = kWaitingForKey;
+    return;
+  }
+
+  DCHECK_EQ(status, Decryptor::kSuccess);
+  pending_buffer_to_decrypt_ = NULL;
+  state_ = kIdle;
+  base::ResetAndReturn(&read_cb_).Run(kOk, decrypted_buffer);
+}
+
+void DecryptingDemuxerStream::OnKeyAdded() {
+  DCHECK(message_loop_->BelongsToCurrentThread());
+
+  if (state_ == kPendingDecrypt) {
+    key_added_while_decrypt_pending_ = true;
+    return;
+  }
+
+  if (state_ == kWaitingForKey) {
+    state_ = kPendingDecrypt;
+    DecryptPendingBuffer();
+  }
+}
+
+void DecryptingDemuxerStream::DoReset() {
+  DCHECK(init_cb_.is_null());
+  DCHECK(read_cb_.is_null());
+  state_ = kIdle;
+  base::ResetAndReturn(&reset_cb_).Run();
+}
+
+Decryptor::StreamType DecryptingDemuxerStream::GetDecryptorStreamType() const {
+  DCHECK(stream_type_ == AUDIO || stream_type_ == VIDEO);
+  return stream_type_ == AUDIO ? Decryptor::kAudio : Decryptor::kVideo;
+}
+
+}  // namespace media