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: TimestampScaler(const DecoderDatabase & decoder_database)28 explicit TimestampScaler(const DecoderDatabase& decoder_database) 29 : first_packet_received_(false), 30 numerator_(1), 31 denominator_(1), 32 external_ref_(0), 33 internal_ref_(0), 34 decoder_database_(decoder_database) {} 35 ~TimestampScaler()36 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_ 69