High speed video transmission over telephone lines

• US 6,181,693 B1
• Filed: 10/08/1998
• Issued: 01/30/2001
• Est. Priority Date: 10/08/1998
• Status: Expired due to Term

• Current Assignee: High Speed Video Holding Corp.
• Original Assignee: High Speed Video Incorporated (Video Transfer, Inc.)
• Inventors: Maresca, Michael
• Primary Examiner(s): HSU, ALPUS
• Application Number:
  US09/169,185
• Time in Patent Office: 845 Days
• Field of Search: 370/259, 370/276, 370/280, 370/294, 370/352, 370/353, 370/354, 370/389, 370/465, 370/470, 370/471, 370/474, 370/522, 370/524, 348/6, 348/7, 348/10, 348/14, 348/16, 348/17, 348/403, 348/404, 348/405, 348/407, 348/423, 348/462, 348/467, 348/469, 379/93.01, 379/93.08, 379/93.14, 379/93.15, 709/230, 709/231, 709/246, 709/247
• US Class Current: 370/352
• CPC Class Codes: H04L 65/4046 with distributed floor control
• CPC Class Codes: H04N 21/6137 involving transmission via a telephone network, e.g. POTS

Abstract

A system for sending and receiving full motion, live, full duplex video of broadcast quality over existing telephone lines comprises apparatus for converting audio/video data recorded at a first location into a stream of packets, apparatus for reconverting the stream of packets into audio/video data to be presented at a second location, and apparatus for bypassing telephone company voice switches at central offices, thereby allowing the packets to travel directly from the local telephone lines to the long distance telephone network. The packets are created at the first location and are received at the second location and, in addition to encoded audio/video data, each packet contains a start flag, an end flag, and at least data specifying the encoding algorithm by which the encoded audio/video data was encoded.

Claims

1. A system for sending, in at least one first location, over telephone lines first audio/video data recorded in said at least one first location, receiving, in said at least one first location, over said telephone lines a reproduction of second audio/video data recorded in at least one second location, sending, in said at least one second location, over said telephone lines said second audio/video data recorded in said at least one first location, and receiving, in said at least one second location, over said telephone lines a reproduction of said first audio/video data recorded in said at least one first location, said system comprising:

a. a means for converting said first audio/video data in said at least one first location into a first stream of packets to be sent over said telephone lines;

b. a means for converting a second stream of packets in said at least one first location into said reproduction of said second audio/video data to be presented in said at least one first location;

c. a means for converting said second audio/video data in said at least one second location into said second stream of packets to be sent over said telephone lines;

d. a means for converting said first stream of packets in said at least one second location into said reproduction of said first audio/video data to be presented in said at least one second location; and

e. a total of at least two means for bypassing a telephone company voice switch in at least two telephone company central offices, thereby allowing said first stream of packets and said second stream of packets to pass directly between at least one first local telephone line and at least one second local telephone line, respectively, and at least one long distance network;

said system being capable of sending said first audio/video data and said second audio/video data and receiving said reproduction of said first audio/video data and said reproduction of said second audio/video data in a full duplex, full motion, and live manner.

2. A system as claimed in claim 1, wherein said means for converting said first audio/video data comprises:

a. an audio/video encoder/decoder producing an audio/video encoder output data stream;

b. a packetizer accepting a processed form of said audio/video encoder output data stream after processing of said audio/video encoder output data stream between said audio/video encoder/decoder and said packetizer, said packetizer producing a stream of unbuffered packets; and

c. a Digital Subscriber Lines (DSL) modem accepting said first stream of packets and sending said first stream of packets over said at least one first local telephone line, said first stream of packets being produced by buffering of said stream of unbuffered packets.

3. A system as claimed in claim 2, wherein said audio/video encoder/decoder comprises:

a. a block processor which accepts video data included in said first audio/video data and divides said video data into a plurality of blocks comprising an image;

b. a memory for storing a plurality of said images;

c. a motion sensor for determining an amount of motion between said image and an immediately following image;

d. a motion compensator to decide which block, if any, has changed and to what degree between said image and said immediately following image;

e. a data subtractor which determines an exact difference between said image and said immediately following image and stores said immediately following image into said memory if a change between said image and said immediately following image is sufficient under an encoding algorithm used;

f. at least one selector for selecting a difference between said image and said immediately following image stored in said memory;

g. a quantizer, an inverse quantizer, an orthogonal processor, and an inverse orthogonal process said difference between said image and said immediately following image; and

h. an output coder which accepts input from said block processor and said inverse quantizer and outputs a video data stream.

4. A system as claimed in claim 3, wherein said means for converting said first audio/video data further comprises:

a. an analog to digital converter which accepts audio data included in said first audio/video data and converts said audio data from analog to digital form;

b. a memory which stores said audio data sent to said memory by said analog to digital converter;

c. a timing module which accepts a clock pulse from said video data stream and determines where to insert said audio data in said video data stream to synchronize audio to video; and

d. an audio multiplexer which accepts said video data stream and accepts said audio data from said memory and combines said audio data and said video data stream in accordance with said determination of said timing module to produce an audio/video encoder output data stream.

5. A system as claimed in claim 4, wherein said means for converting said first audio/video data further comprises:

a. a data counter accepting said audio/video encoder output data stream and outputting flags corresponding to missing or corrupt bits in said audio/video encoder output data stream;

b. a frame memory which accepts said audio/video encoder output data stream from said data counter and outputs said processed audio/video encoder output data stream to said packetizer;

c. a frame memory processor which accepts said flags and notifies said frame memory of said missing or corrupt bits;

d. an image corrector which accepts bit location information of said missing or corrupt bits from said frame memory processor, determines appropriate correction for said missing or corrupt bits, and sends corrected bits to said frame memory; and

e. a network interface converter accepting said stream of unbuffered packets from said packetizer, buffering said stream of unbuffered packets to conform with connection specifications of said DSL modem, thereby producing said first stream of packets, and sending said first stream of packets to said DSL modem.

6. A system as claimed in claim 2, wherein each of said at least two means for bypassing said telephone company voice switch comprises:

a. a line condition detector detecting an off-hook condition on one of said at least one first local telephone line and said at least one second local telephone line generated by a source selected from the group consisting of;

a telephone, a splitter connected to said DSL modem, and a splitter connected to a DSL modem in said at least one second location;

b. a data detection circuit which receives a signal from said source through said one of said at least one first local telephone line and said at least one second local telephone line and through said line condition detector, determines whether said first stream of packets or said second stream of packets is present in said signal, and sends said signal directly to said at least one long distance network if said first or said second stream of packets is present, thereby bypassing said telephone company voice switch;

c. a voice loading coil which receives said signal from said data detection circuit if said first and said second stream of packets is not present in said signal, said voice loading coil transmitting said signal to said telephone company voice switch; and

d. a directional combiner receiving from said at least one long distance network a transmission selected from the group consisting of;

a voice call, said first stream of packets, and said second stream of packets, and sending said transmission to an intended recipient.

7. A system as claimed in claim 1, wherein said means for converting said second stream of packets comprises:

a. a Digital Subscriber Lines (DSL) modem receiving said second stream of packets from said at least one first local telephone line; and

b. an audio/video encoder/decoder receiving an audio/video decoder input data stream from said DSL modem after processing of said second stream of packets between said DSL modem and said audio/video encoder/decoder.

8. A system as claimed in claim 5, wherein said audio/video encoder/decoder comprises:

a. an input decoder receiving said audio/video decoder input data stream and converting a portion of said audio/video decoder input data stream into blocks forming a video frame;

b. a block processor which evaluates those of said blocks which are changed from a video frame immediately before said video frame;

c. a memory which stores blocks forming a video frame and outputs said blocks as a complete video frame in a video output data stream; and

d. a block inserter controlled by said block processor, said block inserter replacing said changed blocks in said memory.

9. A system as claimed in claim 8, wherein said audio/video encoder/decoder further comprises:

a. an audio demultiplexer which receives said audio/video decoder input data stream and outputs audio data included in said audio/video decoder input data stream;

b. a memory receiving said audio data;

c. a timing module which uses a clock pulse taken from said video output data stream to cause said memory to output said audio data in proper time relation with said video output data stream; and

d. a digital to analog converter to convert said audio data output from said memory from digital form back into an analog audio signal.

10. A system as claimed in claim 7, wherein said means for converting said second stream of packets further comprises:

a. a network interface converter which receives said second stream of packets from said DSL modem and removes buffering placed on said second stream of packets by a second network interface converter in said at least one second location;

b. a data counter which receives said second unbuffered stream of packets from said network interface converter and generates flags based on said second unbuffered stream of packets;

c. a frame memory processor which receives said flags from said data counter; and

d. a frame memory which receives said second unbuffered stream of packets from said data counter, which receives communications from said frame memory processor regarding which bits of said second unbuffered stream of packets to discard to allow creation of said reproduction of said second audio/video data, which discards said bits from said second unbuffered stream of packets, and which outputs said audio/video decoder input data stream to said audio/video encoder/decoder.

11. A system as claimed in claim 1, wherein each of said packets are of constant length.

12. A system as claimed in claim 1, wherein each of said packets comprise:

a. a start flag; and

b. an end flag.

13. A system as claimed in claim 12, wherein each of said packets further comprise data specifying an encoding algorithm by which said audio/video data was encoded prior to being converted into said stream of packets.

14. A system as claimed in claim 13, wherein each of said packets further comprise data specifying the length of each of said packets.

15. A system as claimed in claim 1, each said packet of said first stream of packets and of said second stream of packets comprising:

a. a start flag;

b. data specifying an encoding algorithm by which said encoded audio/video data was encoded;

c. said encoded audio/video data; and

d. an end flag.

16. A system as claimed in claim 15, each said packet further comprising data specifying the length of said packet.