System to capture, store, and retrieve composite video for transmission over telephone lines

• US 6,380,967 B1
• Filed: 12/07/1996
• Issued: 04/30/2002
• Est. Priority Date: 12/07/1996
• Status: Expired due to Fees

• Current Assignee: Frank Sacca
• Original Assignee: Frank Sacca
• Inventors: Sacca, Frank
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): Ramakrishnaiah, Melur.
• Application Number:
  US08/762,884
• Time in Patent Office: 1,970 Days
• Field of Search: 379/53, 358/85, 358/296, 370/94.2, 360/32, 348/714, 348/15, 348/14, 348/17, 348/18, 348/22, 375/240, 375/241, 375/372
• US Class Current: 348/14.01
• CPC Class Codes: H04N 7/141 between two video terminals, e.g. videophone telephonic communication systems combined with television receiver for reception of entertainment or information matter H04M11/085

Abstract

A simple, low-cost videophone system for transmitting and receiving still video images over a standard telephone line in response to a user command. A video processor circuit, comprising an A/D converter, a digital memory, a digital timing circuit, and a D/A converter, can grab a video image from a standard video camera and store one-half the number of lines of a video frame in the digital memory. A still video image can be displayed in a standard TV monitor by repeatedly sending the data stored in the digital memory to the D/A converter. The data stored in the digital memory can be transmitted using a standard modem to the digital memory of an equivalent system at a remote location, and the same still video image can be displayed at the remote location within a short time. Data compression is accomplished during transmission by decreasing the number of significant bits of the data being transmitted and using standard protocols adopted by the modem. Voice communication on the telephone line is temporarily suspended while data is transmitted, and automatically resumed when transmission is complete.

Claims

1. A system for capturing, storing, and retrieving an analog composite video signal having a plurality of signal components, comprising:

an analog-to-digital converter for converting said analog composite video signal from a video source to digital composite video data at a specified video sampling rate, without first decomposing said analog composite video signal into its signal components;

a digital memory for storing said digital composite video data between a start address and an end address in sequential order, without first decomposing said digital composite video data into its signal components;

a digital counter having a plurality of logic elements for controlling the transfer and storage of said digital composite video data from said analog-to-digital converter to said digital memory sequentially at said video sampling rate;

a plurality of digital elements for steering said digital counter to a ring counter in which a last count corresponding to said end address of said digital memory is followed by a first count corresponding to said start address of the digital memory; and

a digital interface for advancing said ring counter at an arbitrary speed, accessing said digital memory sequentially, and retrieving said digital composite video data.

2. The system of claim 1, further including a digital-to-analog converter means for accessing said digital memory through said digital interface at said video sampling rate, and converting said digital composite video data back to an analog composite video signal suitable for display on a monitor.

3. The system of claim 2, further including a control logic circuit for increasing and decreasing a count of said start address or a count of said end address of said ring counter in steps of at least one, so as to increase or decrease the total number of memory addresses accessed by said digital-to-analog converter means.

4. The system of claim 3, further including a video synchronization detector for detecting a vertical or horizontal synchronization pulse in said composite video signal, said digital counter being synchronized to store digital composite video data corresponding to said vertical or horizontal synchronization pulse at said start address location in the digital memory.

5. The system of claim 1, further including a microcontroller means for accessing said digital memory through said digital interface, retrieving said digital composite video data at an arbitrary speed controlled by said microcontoller means, and processing said digital composite video data to a signal suitable for display on a monitor.

6. The system of claim 1, further including a modem means for accessing said digital memory through said digital interface, retrieving said digital composite video data at an arbitrary speed controlled by said modem means, and transferring said digital composite video data to a remote system over a telecommunications channel.

7. A system for storing and displaying an analog composite video signal having a plurality of signal components, comprising:

a digital memory for storing digital composite video data representing said analog composite video signal between a start address and an end address in sequential order;

a digital-to-analog converter for converting said digital composite video data stored in said digital memory to said analog composite video signal for display on a monitor;

a digital counter having a plurality of logic elements for controlling the transfer of said digital composite video data from said digital memory to said digital-to-analog converter means sequentially at a video sampling rate;

a plurality of digital elements for steering said digital counter to a ring counter in which a last count corresponding to said end address of said digital memory is followed by a first count corresponding to said start address of the digital memory; and

a digital interface for advancing said ring counter at an arbitrary speed and storing said digital composite video data in said digital memory sequentially.

8. The system of claim 7, further including a control logic circuit for increasing and decreasing a count of said start address or a count of said end address of said ring counter in steps of at least one, so as to increase or decrease the total number of memory addresses accessed by said digital-to-analog converter.

9. The system of claim 7, further including a plurality of digital elements for programming a start address and an end address of said ring counter and accessing different sections of said digital memory for storing or displaying multiple video frames.

10. The system of claim 7, further including a microcontroller for accessing said digital memory through said digital interface and storing said digital composite video data at an arbitrary speed controlled by said microcontroller, said microcontroller being arranged to convert video data into digital composite video data for display on a monitor.

11. The system of claim 7, further including a modem for accessing said digital memory through said digital interface and storing said digital composite video data at an arbitrary speed controlled by said modem means, said modem being arranged to receive data from a remote system over a telecommunications channel.

12. A method for capturing, storing, and retrieving an analog composite video signal having a plurality of signal components, comprising:

digitizing said analog composite video signal to a digital composite video by an analog-to-digital converting means at a specified video sampling rate, without first decomposing said analog composite video signal into its signal components;

storing said digitized composite video data in a digital storage means having a plurality of storage addresses, by advancing a storage address from a start address to an end address in sequential order, without first decomposing said digital composite video data into its signal components;

controlling the transfer of said digitized composite video from said analog-to-digital converting means to said digital storage means in sequential order by a digital counter means at said video sampling rate;

steering said digital counter means by a plurality of digital elements to a ring counter means in which a last count corresponding to said end address of said digital memory means is followed by a first count corresponding to said start address of the digital memory means; and

advancing said ring counter means by a digital interface means at an arbitrary speed to access said digital memory means and retrieve said digital composite video data.

13. The method of claim 12, further including a digital-to-analog converting means for accessing said digital memory means through said digital interface means at said video sampling rate, and converting said digital composite video data back to an analog composite video signal suitable for display on a monitor.

14. The method of claim 13, further including control logic means for increasing and decreasing a count of said start address or a count of said end address of said ring counter means in steps of at least one, so as to increase or decrease the total number of memory addresses accessed by said digital-to-analog converter means.

15. The method of claim 14, further including a video synchronization means for detecting a vertical or horizontal video synchronization pulse in said composite video signal, said digital counter means being synchronized to store digital composite video data corresponding to said vertical or horizontal synchronization pulse at said start address location in said digital memory means.

16. The method of claim 12, further including a microcontroller means for accessing said digital memory means through said digital interface means, retrieving said digital composite video data at an arbitrary speed controlled by said microcontoller means, and processing said digital composite video data to a signal suitable for display on a monitor means.

17. The system of claim 12, further including a modem means for accessing said digital memory through said digital interface means, retrieving said digital composite video data at an arbitrary speed controlled by said modem means, and transferring said digital composite video data to a remote system over a telecommunications channel means.

18. A method for storing and displaying an analog composite video signal having a plurality of signal components, comprising:

storing digital composite video data representing said analog composite video signal in a digital storage means from a start address to an end address in sequential order;

converting said digital composite video data by a digital-to-analog converting means to said analog composite video signal for display on a monitor;

controlling the transfer of said digitized composite video data in sequential order from said digital storage means to said digital-to-analog converting means by a digital counter means having a plurality of logic elements;

steering said digital counter means by a plurality of digital control means to a ring counter means in which a last count corresponding to said end address of said digital memory means is followed by a first count corresponding to said start address of the digital memory means; and

advancing said ring counter means by a digital interface means at an arbitrary speed to access said digital memory means and store said digital composite video data in said digital memory sequentially.

19. The method of claim 18, further including digital control means for increasing and decreasing a count of said start address or a count of said end address of said ring counter means in steps of at least one, so as to increase or decrease the total number of memory addresses accessed by said digital-to-analog converting means.

20. The method of claim 18, further including digital control means for programming a start address and an end address of said ring counter means and accessing different sections of said digital memory means for storing or displaying multiple video frames.

21. The method of claim 18, further including a microcontroller means for accessing said digital memory means through said digital interface means and storing said digital composite video data at an arbitrary speed controlled by said microcontoller means, said microcontroller means being arranged to convert video data into said digital composite video data for display on a monitor means.

22. The method of claim 18, further including a modem means for accessing said digital memory means through said digital interface means and storing said digital composite video data at an arbitrary speed controlled by said modem means, said modem means being arranged to receive data from a remote system over a telecommunications channel means.