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