Line data    Source code

       1             : /*
       2             :  *  Copyright (c) 2012 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_NETEQ_TIMESTAMP_SCALER_H_
      12             : #define WEBRTC_MODULES_AUDIO_CODING_NETEQ_TIMESTAMP_SCALER_H_
      13             : 
      14             : #include "webrtc/base/constructormagic.h"
      15             : #include "webrtc/modules/audio_coding/neteq/packet.h"
      16             : #include "webrtc/typedefs.h"
      17             : 
      18             : namespace webrtc {
      19             : 
      20             : // Forward declaration.
      21             : class DecoderDatabase;
      22             : 
      23             : // This class scales timestamps for codecs that need timestamp scaling.
      24             : // This is done for codecs where one RTP timestamp does not correspond to
      25             : // one sample.
      26             : class TimestampScaler {
      27             :  public:
      28           0 :   explicit TimestampScaler(const DecoderDatabase& decoder_database)
      29           0 :       : first_packet_received_(false),
      30             :         numerator_(1),
      31             :         denominator_(1),
      32             :         external_ref_(0),
      33             :         internal_ref_(0),
      34           0 :         decoder_database_(decoder_database) {}
      35             : 
      36           0 :   virtual ~TimestampScaler() {}
      37             : 
      38             :   // Start over.
      39             :   virtual void Reset();
      40             : 
      41             :   // Scale the timestamp in |packet| from external to internal.
      42             :   virtual void ToInternal(Packet* packet);
      43             : 
      44             :   // Scale the timestamp for all packets in |packet_list| from external to
      45             :   // internal.
      46             :   virtual void ToInternal(PacketList* packet_list);
      47             : 
      48             :   // Returns the internal equivalent of |external_timestamp|, given the
      49             :   // RTP payload type |rtp_payload_type|.
      50             :   virtual uint32_t ToInternal(uint32_t external_timestamp,
      51             :                               uint8_t rtp_payload_type);
      52             : 
      53             :   // Scales back to external timestamp. This is the inverse of ToInternal().
      54             :   virtual uint32_t ToExternal(uint32_t internal_timestamp) const;
      55             : 
      56             :  private:
      57             :   bool first_packet_received_;
      58             :   int numerator_;
      59             :   int denominator_;
      60             :   uint32_t external_ref_;
      61             :   uint32_t internal_ref_;
      62             :   const DecoderDatabase& decoder_database_;
      63             : 
      64             :   RTC_DISALLOW_COPY_AND_ASSIGN(TimestampScaler);
      65             : };
      66             : 
      67             : }  // namespace webrtc
      68             : #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_TIMESTAMP_SCALER_H_