Revert r7798 ("Move the AudioDecoder interface out of NetEq")

Apparently, it caused all sorts of problems I don't have time to
straighten out right now.

TBR=henrika@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/25289004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7799 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_coding/neteq/interface/audio_decoder.h b/webrtc/modules/audio_coding/neteq/interface/audio_decoder.h
new file mode 100644
index 0000000..be85c4d
--- /dev/null
+++ b/webrtc/modules/audio_coding/neteq/interface/audio_decoder.h
@@ -0,0 +1,145 @@
+/*
+ *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_MODULES_AUDIO_CODING_NETEQ_INTERFACE_AUDIO_DECODER_H_
+#define WEBRTC_MODULES_AUDIO_CODING_NETEQ_INTERFACE_AUDIO_DECODER_H_
+
+#include <stdlib.h>  // NULL
+
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/modules/audio_coding/codecs/cng/include/webrtc_cng.h"
+#include "webrtc/typedefs.h"
+
+namespace webrtc {
+
+enum NetEqDecoder {
+  kDecoderPCMu,
+  kDecoderPCMa,
+  kDecoderPCMu_2ch,
+  kDecoderPCMa_2ch,
+  kDecoderILBC,
+  kDecoderISAC,
+  kDecoderISACswb,
+  kDecoderISACfb,
+  kDecoderPCM16B,
+  kDecoderPCM16Bwb,
+  kDecoderPCM16Bswb32kHz,
+  kDecoderPCM16Bswb48kHz,
+  kDecoderPCM16B_2ch,
+  kDecoderPCM16Bwb_2ch,
+  kDecoderPCM16Bswb32kHz_2ch,
+  kDecoderPCM16Bswb48kHz_2ch,
+  kDecoderPCM16B_5ch,
+  kDecoderG722,
+  kDecoderG722_2ch,
+  kDecoderRED,
+  kDecoderAVT,
+  kDecoderCNGnb,
+  kDecoderCNGwb,
+  kDecoderCNGswb32kHz,
+  kDecoderCNGswb48kHz,
+  kDecoderArbitrary,
+  kDecoderOpus,
+  kDecoderOpus_2ch,
+  kDecoderCELT_32,
+  kDecoderCELT_32_2ch,
+};
+
+// This is the interface class for decoders in NetEQ. Each codec type will have
+// and implementation of this class.
+class AudioDecoder {
+ public:
+  enum SpeechType {
+    kSpeech = 1,
+    kComfortNoise = 2
+  };
+
+  // Used by PacketDuration below. Save the value -1 for errors.
+  enum { kNotImplemented = -2 };
+
+  AudioDecoder() : channels_(1) {}
+  virtual ~AudioDecoder() {}
+
+  // Decodes |encode_len| bytes from |encoded| and writes the result in
+  // |decoded|. The number of samples from all channels produced is in
+  // the return value. If the decoder produced comfort noise, |speech_type|
+  // is set to kComfortNoise, otherwise it is kSpeech.
+  virtual int Decode(const uint8_t* encoded, size_t encoded_len,
+                     int16_t* decoded, SpeechType* speech_type) = 0;
+
+  // Same as Decode(), but interfaces to the decoders redundant decode function.
+  // The default implementation simply calls the regular Decode() method.
+  virtual int DecodeRedundant(const uint8_t* encoded, size_t encoded_len,
+                              int16_t* decoded, SpeechType* speech_type);
+
+  // Indicates if the decoder implements the DecodePlc method.
+  virtual bool HasDecodePlc() const;
+
+  // Calls the packet-loss concealment of the decoder to update the state after
+  // one or several lost packets.
+  virtual int DecodePlc(int num_frames, int16_t* decoded);
+
+  // Initializes the decoder.
+  virtual int Init() = 0;
+
+  // Notifies the decoder of an incoming packet to NetEQ.
+  virtual int IncomingPacket(const uint8_t* payload,
+                             size_t payload_len,
+                             uint16_t rtp_sequence_number,
+                             uint32_t rtp_timestamp,
+                             uint32_t arrival_timestamp);
+
+  // Returns the last error code from the decoder.
+  virtual int ErrorCode();
+
+  // Returns the duration in samples of the payload in |encoded| which is
+  // |encoded_len| bytes long. Returns kNotImplemented if no duration estimate
+  // is available, or -1 in case of an error.
+  virtual int PacketDuration(const uint8_t* encoded, size_t encoded_len);
+
+  // Returns the duration in samples of the redandant payload in |encoded| which
+  // is |encoded_len| bytes long. Returns kNotImplemented if no duration
+  // estimate is available, or -1 in case of an error.
+  virtual int PacketDurationRedundant(const uint8_t* encoded,
+                                      size_t encoded_len) const;
+
+  // Detects whether a packet has forward error correction. The packet is
+  // comprised of the samples in |encoded| which is |encoded_len| bytes long.
+  // Returns true if the packet has FEC and false otherwise.
+  virtual bool PacketHasFec(const uint8_t* encoded, size_t encoded_len) const;
+
+  // If this is a CNG decoder, return the underlying CNG_dec_inst*. If this
+  // isn't a CNG decoder, don't call this method.
+  virtual CNG_dec_inst* CngDecoderInstance();
+
+  // Returns true if |codec_type| is supported.
+  static bool CodecSupported(NetEqDecoder codec_type);
+
+  // Returns the sample rate for |codec_type|.
+  static int CodecSampleRateHz(NetEqDecoder codec_type);
+
+  // Creates an AudioDecoder object of type |codec_type|. Returns NULL for
+  // for unsupported codecs, and when creating an AudioDecoder is not
+  // applicable (e.g., for RED and DTMF/AVT types).
+  static AudioDecoder* CreateAudioDecoder(NetEqDecoder codec_type);
+
+  size_t channels() const { return channels_; }
+
+ protected:
+  static SpeechType ConvertSpeechType(int16_t type);
+
+  size_t channels_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(AudioDecoder);
+};
+
+}  // namespace webrtc
+#endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_INTERFACE_AUDIO_DECODER_H_
diff --git a/webrtc/modules/audio_coding/neteq/interface/neteq.h b/webrtc/modules/audio_coding/neteq/interface/neteq.h
index 2c0dbdc..b630e86 100644
--- a/webrtc/modules/audio_coding/neteq/interface/neteq.h
+++ b/webrtc/modules/audio_coding/neteq/interface/neteq.h
@@ -17,7 +17,7 @@
 
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/common_types.h"
-#include "webrtc/modules/audio_coding/neteq/audio_decoder_impl.h"
+#include "webrtc/modules/audio_coding/neteq/interface/audio_decoder.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {