Rtp-formatted media clips

Abstract

A transmitter ( 14 ) of audio, video, or other real-time information reads the information from a persistent store ( 22 ) in which the real-time information has been stored in the Real-time-Transport Protocol (“RTP”) format (FIG. 4 ). A receiver ( 18 ) receives the information from the channel ( 16 ) through which the transmitter ( 14 ) has transmitted it, and the receiver may store the information in a persistent store ( 24 ) in RTP format instead of or in addition to playing it by applying it to an appropriate player ( 20 ). Parts of this communications circuit may be tested by a tester unit ( 26 ) that also employs RTP-format information from a persistent store ( 22 ).

1 . A method of performing persistent storage comprising:
 A) taking samples of time-dependent data; and   B) storing a record of the data in a persistent medium as stored RTP packets whose payloads represent the samples' values and whose timestamps represent the times at which the first samples in their respective payloads were taken.   
     
     
         2 . A method as defined in  claim 1  wherein:
 A) the sampled data are audio data; and 
 B) the method further includes retrieving the stored RTP packets and playing the audio data in accordance with the stored packets' RTP timestamps. 
 
     
     
         3 . A method as defined in  claim 1  wherein:
 A) the sampled data are video data; and 
 B) the method further includes retrieving the stored RTP packets and playing the video data in accordance with the stored packets' RTP timestamps. 
 
     
     
         4 . A method as defined in  claim 3  further including:
 A) concurrently with taking the samples of the video data, taking samples of audio data; 
 B) storing a second stored record of the audio data in a persistent medium as second stored RTP packets, whose payloads represent the audio samples' values and whose timestamps represent the times at which the first samples in their respective payloads were taken; and 
 C) playing the second stored record simultaneously with the first-mentioned stored record in accordance with the stored timestamps contained in the second stored record. 
 
     
     
         5 . A method as defined in  claim 1  further including retrieving the stored record and transmitting in accordance with the timestamp in each recorded packet a corresponding transmitted RTP packet including a transmitted RTP timestamp and including a payload the same as that of the recorded packet to which that transmitted packet corresponds. 
     
     
         6 . For storing time-dependent data, an apparatus comprising:
 A) a persistent medium operable to store data and retrieve data thus stored;   B) a sampler that produces a sampled record by taking samples of a time-dependent function; and   C) a persistent-store driver that responds to the sampler by storing in the persistent medium a stored record as stored RTP packets whose payloads represent the samples' values and whose time-stamps represent the times at which the first samples in their respective payloads were taken.   
     
     
         7 . An apparatus as defined in  claim 6  wherein:
 A) the sampled data are audio data; 
 B) the persistent-store driver also retrieves the stored record; and 
 C) the apparatus further includes an audio player and an audio driver that drives the audio player to play the stored record in accordance with the thus-retrieved stored timestamps contained therein. 
 
     
     
         8 . An apparatus as defined in  claim 6  wherein:
 A) the sampled data are video data; 
 B) the persistent-store driver also retrieves the stored record; and 
 C) the apparatus further includes a video player and a video driver that drives the video player to play the thus-retrieved stored record in accordance with the stored timestamps contained therein. 
 
     
     
         9 . An apparatus as defined in  claim 8  wherein:
 A) the sampler additionally produces a second sampled record by taking audio samples of a sound signal; 
 B) the persistent-store driver additionally responds to the sampler by storing in the persistent medium a second stored record as stored RTP packets whose payloads represent the audio samples' values and whose timestamps represent the times at which the first audio samples in their respective payloads were taken; and 
 C) the apparatus further includes an audio player and an audio driver that retrieves the second stored record and drives the audio player; simultaneously with the video driver's driving of the video player, in accordance with the stored timestamps contained in the second stored record. 
 
     
     
         10 . An apparatus as defined in  claim 6  wherein:
 A) the persistent-store driver also retrieves the stored record; and 
 B) the apparatus further includes a transmitter that transmits in accordance with the timestamp in each thus-retrieved recorded packet a corresponding transmitted RTP packet that both includes a transmitted RTP timestamp and includes a payload the same as that of the recorded packet to which that transmitted packet corresponds.