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      1 /*
      2  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
      3  *
      4  *  Use of this source code is governed by a BSD-style license
      5  *  that can be found in the LICENSE file in the root of the source
      6  *  tree. An additional intellectual property rights grant can be found
      7  *  in the file PATENTS.  All contributing project authors may
      8  *  be found in the AUTHORS file in the root of the source tree.
      9  */
     10 
     11 #ifndef WEBRTC_MODULES_AUDIO_CODING_CODECS_ISAC_AUDIO_ENCODER_ISAC_T_H_
     12 #define WEBRTC_MODULES_AUDIO_CODING_CODECS_ISAC_AUDIO_ENCODER_ISAC_T_H_
     13 
     14 #include <vector>
     15 
     16 #include "webrtc/modules/audio_coding/codecs/audio_encoder.h"
     17 #include "webrtc/modules/audio_coding/codecs/isac/locked_bandwidth_info.h"
     18 
     19 namespace webrtc {
     20 
     21 struct CodecInst;
     22 
     23 template <typename T>
     24 class AudioEncoderIsacT final : public AudioEncoder {
     25  public:
     26   // Allowed combinations of sample rate, frame size, and bit rate are
     27   //  - 16000 Hz, 30 ms, 10000-32000 bps
     28   //  - 16000 Hz, 60 ms, 10000-32000 bps
     29   //  - 32000 Hz, 30 ms, 10000-56000 bps (if T has super-wideband support)
     30   struct Config {
     31     bool IsOk() const;
     32 
     33     LockedIsacBandwidthInfo* bwinfo = nullptr;
     34 
     35     int payload_type = 103;
     36     int sample_rate_hz = 16000;
     37     int frame_size_ms = 30;
     38     int bit_rate = kDefaultBitRate;  // Limit on the short-term average bit
     39                                      // rate, in bits/s.
     40     int max_payload_size_bytes = -1;
     41     int max_bit_rate = -1;
     42 
     43     // If true, the encoder will dynamically adjust frame size and bit rate;
     44     // the configured values are then merely the starting point.
     45     bool adaptive_mode = false;
     46 
     47     // In adaptive mode, prevent adaptive changes to the frame size. (Not used
     48     // in nonadaptive mode.)
     49     bool enforce_frame_size = false;
     50   };
     51 
     52   explicit AudioEncoderIsacT(const Config& config);
     53   explicit AudioEncoderIsacT(const CodecInst& codec_inst,
     54                              LockedIsacBandwidthInfo* bwinfo);
     55   ~AudioEncoderIsacT() override;
     56 
     57   size_t MaxEncodedBytes() const override;
     58   int SampleRateHz() const override;
     59   size_t NumChannels() const override;
     60   size_t Num10MsFramesInNextPacket() const override;
     61   size_t Max10MsFramesInAPacket() const override;
     62   int GetTargetBitrate() const override;
     63   EncodedInfo EncodeInternal(uint32_t rtp_timestamp,
     64                              rtc::ArrayView<const int16_t> audio,
     65                              size_t max_encoded_bytes,
     66                              uint8_t* encoded) override;
     67   void Reset() override;
     68 
     69  private:
     70   // This value is taken from STREAM_SIZE_MAX_60 for iSAC float (60 ms) and
     71   // STREAM_MAXW16_60MS for iSAC fix (60 ms).
     72   static const size_t kSufficientEncodeBufferSizeBytes = 400;
     73 
     74   static const int kDefaultBitRate = 32000;
     75 
     76   // Recreate the iSAC encoder instance with the given settings, and save them.
     77   void RecreateEncoderInstance(const Config& config);
     78 
     79   Config config_;
     80   typename T::instance_type* isac_state_ = nullptr;
     81   LockedIsacBandwidthInfo* bwinfo_ = nullptr;
     82 
     83   // Have we accepted input but not yet emitted it in a packet?
     84   bool packet_in_progress_ = false;
     85 
     86   // Timestamp of the first input of the currently in-progress packet.
     87   uint32_t packet_timestamp_;
     88 
     89   // Timestamp of the previously encoded packet.
     90   uint32_t last_encoded_timestamp_;
     91 
     92   RTC_DISALLOW_COPY_AND_ASSIGN(AudioEncoderIsacT);
     93 };
     94 
     95 }  // namespace webrtc
     96 
     97 #endif  // WEBRTC_MODULES_AUDIO_CODING_CODECS_ISAC_AUDIO_ENCODER_ISAC_T_H_
     98