Method and terminal for synchronously recording sounds and images of opposite ends based on circuit domain video telephone

1. A method for synchronously recording voices and images of an opposite end based on a circuit domain videophone, comprising steps of:

receiving, by a terminal used by a party in a video call, a recording instruction sent by a user, taking a local time as a reference time, and performing frame analyzing for received audio and video code-streams; and

writing audio frames and video frames obtained by analyzing, as well as a duration corresponding to each frame, into a 3GP file; wherein, the duration of each of the audio or video frames except the first audio or video frame written into the 3GP file is respectively a difference between a relative time when the audio or video frame is obtained by analyzing and d relative time when a previous frame corresponding to the audio or video frame is obtained by analyzing, and the value of the relative time when each of the audio or video frames is obtained by analyzing is respectively a difference between a local time when the audio or video frame is obtained by analyzing and said reference time.

2. The method of claim 1 , wherein,

the duration of the first audio frame written into the 3GP file is 20 ms, and the duration of the first video frame written into the 3GP file is ((N*8)/an actual network bandwidth occupied by the video)*1000 ms, wherein N is the number of bytes included in the video frame.

3. The method of claim 1 , wherein,

the step of writing the video frames obtained by analyzing into the 3GP file comprises:

judging, by said terminal, each video frame obtained by analyzing in turn until a certain video frame is judged to be an I frame, and then starting to write a current video frame and subsequent video frames into the 3GP file;

the step of writing the audio frames obtained by analyzing into the 3GP file comprises:

before writing the first audio frame into the 3GP file, determining whether said terminal has already judged a certain video frame to be the I frame by then; if yes, writing a current audio frame and subsequent audio frames into the 3GP file, otherwise, continuing the determination operation.

4. The method of claim 3 , wherein,

said terminal is configured with a flag bit;

the step of judging, by said terminal, each video frame obtained by analyzing in turn comprises setting the flag bit when said terminal judges a certain video frame to be the I frame; and

the step of determining whether said terminal has already judged a certain video frame to be the I frame by then comprises determining whether the flag bit is set.

5. The method of claim 3 , wherein, after said terminal receives the recording instruction sent by the user, said method further comprises sending an I frame request to the opposite end.

6. The method of claim 2 , wherein,

the value of the actual network bandwidth occupied by the video is 48 k bit rate or an empirical value.

7. The method of claim 1 , wherein,

said party in the video call is a calling user and/or a called user.

8. A method of claim 1 , further comprising:

after said terminal receives a stop recording command sent by the user, stopping analyzing the audio and video streams and closing the 3GP file.

9. A terminal for synchronously recording voices and images of an opposite end based on a circuit domain videophone, comprising an audio and video frame analysis module, an audio frame write-in module, a video frame write-in module, and a frame duration calculation module, wherein,

said audio and video frame analysis module is configured to receive a recording instruction sent by a user, send a start timing command to said frame duration calculation module, and perform frame analyzing for received audio and video code-streams; and further configured to record a local time when each audio or video frame is obtained by analyzing and send the local time to said frame duration calculation module;

said audio frame write-in module is configured to write the audio frames obtained by the analyzing by said audio and video frame analysis module and a duration corresponding to each audio frame into a 3GP file;

said video frame write-in module is configured to write the video frames obtained by the analyzing by said audio and video frame analysis module and a duration corresponding to each video frame into the 3GP file; and

said frame duration calculation module is configured to take the local time as a reference time when receiving said start timing command; and further configured to calculate the duration of each of the audio or video frames except the first audio or video frame written into the 3GP file, and send the calculated duration to the audio or video frame write-in module corresponding to the audio or video frame, wherein the value of the duration is respectively a difference between a relative time when each of the audio or video frames is obtained by analyzing and a relative time when a previous frame corresponding to the audio or video frame is obtained by analyzing, and the value of the relative time when each of the audio or video frames is obtained by analyzing is respectively a difference between a local time when the audio or video frame is obtained by analyzing and said reference time.

10. The terminal of claim 9 , wherein,

the duration of the first audio frame written into the 3GP file is 20 ms, and the duration of the first video frame written into the 3GP file is ((N*8)/an actual network bandwidth occupied by the video)*1000 ms, wherein N is the number of bytes included in the video frame.

11. The terminal of claim 9 , wherein,

said video frame write-in module is further configured to judge each of the video frames obtained by analyzing in turn until a certain video frame is judged to be an I frame, and then start to write a current video frame and subsequent video frames into the 3GP file; and

said audio frame write-in module is further configured to determine whether said video frame write-in module has already judged a certain video frame to be the I frame before writing the first audio frame into the 3GP file; if yes, write a current audio frame and subsequent audio frames into the 3GP file, otherwise, continue the determination operation.

12. The method of claim 4 , wherein, after said terminal receives the recording instruction sent by the user, said method further comprises sending an I frame request to the opposite end.