Method and system for high density analog data storage retrieval, and transmission

• US 5,006,936 A
• Filed: 11/02/1988
• Issued: 04/09/1991
• Est. Priority Date: 11/27/1985
• Status: Expired due to Term

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: LTV Aerospace and Defense Company
• Inventors: Hooks, John T. Jr.
• Primary Examiner(s): Richardson, Robert L.
• Application Number:
  US07/268,614
• Time in Patent Office: 888 Days
• Field of Search: 360/8, 360/9.1, 360/32, 360/37.1, 360/33.1, 387/29, 387/31, 387/34, 358/310, 358/334, 358/133, 358/138, 358/335
• US Class Current: 386/287
• CPC Class Codes: H04N 5/91 Television signal processing therefor
• CPC Class Codes: H04N 7/002 Special television systems not provided for by H04N7/007 - H04N7/18 still pictures via a television channel H04N1/00098
• CPC Class Codes: H04N 7/01 Conversion of standards , e.g. involving analogue television standards or digital television standards processed at pixel level

Abstract

An encoder circuit utilizes a pair of digital memories clocked at a slower write than read rate to compact analog input data, blanking and synchronization pulse intervals, and generate NTSC video. The NTSC formatted data may be stored utilizing conventional NTSC tape or disc recording equipment or may be transmitted, duplicated, monitored or transcribed utilizing readily available NTSC video equipment. A decoder circuit is provided to reprocess the NTSC video formatted data and restore it to its original form by removing the synchronization and blanking intervals and, utilizing a pair of digital memories clocked at a faster write than read rate, re-stretch the data which was compacted in the time dimension by the encoder circuit.

Claims

1. A bulk analog data storage system comprising:

(a) first means for receiving a continuous analog video input signal;

(b) first sample and hold means coupled to said receiving means for sampling said input data at a first clock rate;

(c) first analog-to-digital converter means for converting each of said samples to a digital code;

(d) first and second digital memory means;

(e) first gating means coupled to said first and second memory means for alternately providing digital coded samples of said input data to said first and second memory means;

(f) first clock means coupled to said first sample and hold means and to said first and second memory means for clocking said memory means at said first clock rate when data is being written into said memory means;

(g) second gating means coupled to said first and second memory means for multiplexing the digital coded samples of said input data as such data is alternately read from said memory means;

(h) second clocking means for clocking said first and second memory at a second clock rate which is of a higher frequency than said first clock rate;

(i) first digital-to-analog converter means for converting the digital coded samples as they are read from said second gating means into an analog formatted signal;

(j) first interval generator means for generating intervals of duration of a sync/blanking pulse for a selected video format, said intervals being at a repetition rate much lower than said first and second clock rates;

(k) third gating means coupled to said first interval generator and to said second clocking means for inhibiting said second clocking signal to the memory means selected by said second gating means during the generated interval, said inhibiting being for a limited period of time so that the inhibiting of the second clocking signal does not result in overwriting of data in said memory means before said data is read from a memory means;

(l) a sync/blanking format generator for generating sync/blanking pulses for said selected video format;

(m) fourth gating means coupled to said first digital-to-analog converter means and to said sync/blanking format generator for multiplexing the analog formatted signal and the sync/blanking interval into a video signal of said selected video format; and

(n) recorder means for recording said video signals in said selected video format.

2. The bulk storage system according to claim 1 including:

(a) second means coupled to said recorder means for receiving said video signals in said selected video format from said recorder means during playback thereof;

(b) sync stripper means coupled to said second means for detecting the leading edge of sync pulses from said video signals and generating a pulse signal indicative thereof;

(c) said interval generator means responsive to said pulse signal for generating intervals of duration of the sync/blanking pulse for said selected video format, said second interval generator means being responsive to said sync stripper means for establishing the placement in time of each generated interval;

(d) fifth gating means coupled to said second interval generator means and to said second clocking means for inhibiting said second clocking signal during said sync/blanking pulse interval generated by said second interval generator means to generate an interval clock signal;

(e) sync clipper means coupled to said second means and responsive to said interval clock signal for removing said sync/blanking signal from said video signals in said selected video format;

(f) sample and hold means coupled to said sync clipper means and responsive to said interval clock signal for sampling said video signal at said second clock rate;

(g) second analog-to-digital converter means for converting each said samples from said second sample and hold means o a digital code;

(h) third and fourth digital memory means;

(i) sixth gating means coupled to said second analog-to-digital converter means for alternately providing digital coded samples therefrom to said first and second memory means;

(j) means coupling said fifth gating means to each of said third and fourth memory means for writing the digital coded samples provided by said sixth gating means into the selected of said third and fourth means at said second clock rate except during the intervals provided by said second interval generator means;

(k) means coupling said first clocking means to said third and fourth memory means for reading digital coded sample data out of said third and fourth memory means at said first clock rate;

(l) seventh gating means coupled to said third and fourth memory means for receiving the digital coded sample data read out of said third and fourth memory means and multiplexing such data in alternating fashion;

(m) digital-to-analog converter means for converting said multiplexed data from said seventh gating means into a continuous analog signal.

4. The bulk storage system according to claim 1 including:

(a) second receiving means coupled to said recorder means for receiving said video signals in said selected video format during playback of said recorder means;

(b) sync stripper means coupled to said second means for detecting the leading edge of sync pulses from said video signals and generating a timing pulse signal indicative thereof;

(c) second interval generator means responsive to said timing pulse signal for generating respective intervals at least of the duration of the sync/blanking pulse for said selected video format, said second interval generator means being responsive to said sync timing pulse signal for establishing the placement in time of each such generated interval;

(d) sixth gating means coupled to said second interval generator means and to said second clocking means for inhibiting said second clocking signal during said interval generated by said second interval generator means to provide an intermittent clock signal of said second clock frequency;

(e) sync clipper means coupled to said second means and responsive to said intermittent clock signal for removing said sync/blanking pulse from said video signals in said selected video format;

(f) second sample and hold means coupled to said sync clipper means and responsive to said intermittent clock signal for sampling said video signal at said second clock rate;

(g) second analog-to-digital converter means for converting each of said samples from said second sample and hold means to a digital code;

(h) third and fourth digital memory means;

(i) seventh gating means coupled to said second analog-to-digital converter means for alternately providing digital coded samples therefrom to said first and second memory means;

(j) third means coupling said sixth gating means to each said third and fourth memory means for writing the digital coded samples provided by said seventh gating means into the selected of said third and fourth memory means at said second clock rate except during the intervals provided by said second interval generator means;

(k) fourth means coupling said first clocking means to said third and fourth memory means for selectively reading digital coded sample data out of said third and fourth memory means at said first clock rate;

(l) eighth gating means coupled to said third and fourth memory means for receiving the digital coded sample data read out of said third and fourth memory means and multiplexing such data in alternating fashion;

(m) digital-to-analog converter means for converting said multiplexed data from said eighth gating means into a continuous analog signal.

3. A bulk analog data storage system comprising:

(a) first receiving means for receiving a continuous analog input signal;

(b) first sample and hold means coupled t said first receiving means for sampling said input data at a first clock rate;

(c) first clocking means coupled to said first sample and hold means for clocking said sample and hold means to sample said input data at a first clock rate;

(d) first analog-to-digital converter means for converting each of said samples to a digital code;

(e) first and second digital memory means;

(f) first gating means coupled to said first and second memory means for alternately providing digital coded samples of said input data to said first and second memory means, said first and second memory means being coupled to said first clocking means and being clocked at said first clock rate when data is being written into said first and second memory means;

(g) second gating means coupled to said first and second memory means for multiplexing the digital coded samples of said input data as such data is alternately read from said memory means;

(h) second clocking means for generating a second clocking signal at a second clock rate which is of a higher frequency than said first clock rate for clocking said first and second memory at a second clock rate;

(i) third gating means coupling said second clocking means to said first and second memory means for alternately providing said clocking signal to said first and second memory means when data is being read from said first and second memory means;

(j) first digital-to-analog converter means for converting the digital coded samples as they are read from said second gating means into an analog formatted signal;

(k) first interval generator means for generating intervals at least having a duration of a sync/blanking pulse for a selected video format, the repetition rate of said intervals being much less than said first and second clock rates;

(l) fourth gating means coupled to said first interval generator and to said second clocking means for inhibiting said second clocking signal provided via said third gating means to said first and second memory means selected by said second and third gating means during the generated interval, the time period of said inhibiting being such that an interval of inhibiting ends before data is overwritten in said first or second memory means before being read out of said first or second memory means;

(m) a sync/blanking format generator for generating sync/blanking pulses for said selected video format;

(n) fifth gating means coupled to said first digital-to-analog converter means and to said sync/blanking format generator for multiplexing said analog formatted signal and the sync/blanking pulses into a video signal of said selected video format; and

(o) recorder means for recording said video signals in said selected video format.

5. A method of retrieving a continuous analog data signal from a broadcast television format signal having a plurality of synchronization pulses disposed between adjacent segments of analog data signal, each segment of analog data signal having an initial redundant portion identical to a final portion of the previous segment, comprising the steps of:

creating gaps between adjacent segments of analog data signal by deleting each of said synchronization pulses and a first fixed portion of said broadcast television standard format signal prior to each of said synchronization pulses and a second fixed portion of said broadcast television standard format signal after each of said synchronization pulses wherein timing variations of said synchronization pulses will result in the deletion of a redundant portion of said analog data signal;

sampling said segments of analog data signal at a first clock rate;

alternately storing said sampled segments of analog data signal in at least two storage devices at said first clock rate; and

alternately retrieving said sampled analog data signal from said at least two storage devices at a second clock rate which is of a lower frequency than said first clock rate whereby said gaps created by said deletion are eliminated by the expansion of said segments of analog data signal into a continuous analog data signal.

6. A method for retrieving a continuous analog signal from a broadcast television format signal according to claim 5, further including the steps of converting each of said samples of said segments of analog data signal to a digital code prior to storing said sampled analog data signal at said first clock rate.

7. A method for storing and retrieving continuous analog electrical data signals with conventional NTSC video equipment, comprising the steps of:

(a) storing the data signals, including the steps of;

(i) converting segments of the continuous analog electrical data signals to shorter segments of NTSC video format compatible analog video having intervals between said shorter segments for inserting horizontal synchronization and blanking pulses;

said segments being condensed in time span by said step of converting to produce said shorter segments;

(ii) adding NTSC video horizontal synchronization and blanking pulses to the NTSC video format compatible analog video in said intervals without significant overwriting or deleting of video corresponding to said continuous analog electrical data signals, to generate NTSC video formatted data; and

(iii) storing the NTSC video formatted data with conventional NTSC video equipment; and

(b) retrieving the data, including the steps of;

(i) retrieving the NTSC video formatted data;

(ii) removing the NTSC video synchronization and blanking pulses from the NTSC video formatted data; and

(iii) converting said shorter segments of NTSC video formatted data having said intervals into continuous electrical data signals having no said intervals.

8. A method for storing continuous analog electrical data signals with conventional NTSC video equipment, comprising the steps of:

(a) converting segments of the continuous analog electrical data signals to shorter segments of NTSC video format compatible analog video having intervals between said shorter segments for insertion of horizontal synchronization and blanking pulses;

said segments being condensed in time span by said step of converting to produce said shorter segments;

(b) adding NTSC video horizontal synchronization and blanking pulses to the NTSC video format compatible analog video in said intervals without substantial deleting of said continuous analog electrical data signals in time periods adjacent said intervals, to generate NTSC video formatted data; and

(c) storing the NTSC video formatted data with conventional NTSC video equipment.

9. A method for retrieving and restoring from memory storage NTSC video formatted data containing compressed continuous analog electrical data signals and NTSC video synchronization and blanking pulses, with conventional NTSC video equipment, comprising the steps of:

(a) retrieving the NTSC video formatted data from memory storage;

(b) removing said NTSC video synchronization and blanking pulses from intervals in the NTSC video formatted data; and

(c) converting the NTSC video formatted data into continuous analog electrical data signals by deleting said intervals without deleting significant portions of video data signals adjacent the intervals and expanding the remaining NTSC video formatted data in time span to restore said continuous analog electrical data signals.

10. A method for transmitting and receiving continuous analog electrical data signals using conventional NTSC video equipment, comprising the steps of:

(a) transmitting the data signals, including the steps of;

(i) converting segments of the continuous analog electrical data signals to shorter segments of NTSC video format compatible analog video signals including intervals between said shorter segments for inserting horizontal synchronization and blanking pulses;

said segments being condensed in time span by said step of converting to produce said shorter segments;

(ii) adding NTSC video horizontal synchronization and blanking pulses to the NTSC video format compatible analog video signals in said intervals without deleting significant parts of said analog video corresponding to said analog electrical data signals in time periods adjacent said intervals to generate NTSC video formatted data; and

(iii) transmitting the NTSC video formatted data; and

(b) receiving and restoring the data signals, including the steps of;

(i) receiving the NTSC video formatted data;

(ii) removing the NTSC video synchronization and blanking pulses from the NTSC video formatted data at said intervals; and

(iii) converting said shorter segments of the NTSC video formatted data into said segments of continuous electrical data signals by expanding said shorter segments in time and removing said intervals without deleting significant parts of said analog electrical data signals.

11. A method for transmitting continuous analog electrical data signals using conventional NTSC video equipment, comprising the steps of:

(a) converting segments of the continuous analog electrical data signals to shorter segments of NTSC video format compatible analog video signals including intervals between said shorter segments for insertion of horizontal synchronization and blanking pulses, without deleting or omitting substantial parts of said continuous analog electrical data signals adjacent said intervals;

said segments being condensed in time span by said step of converting to produce said shorter segments;

(b) adding horizontal synchronization and blanking pulses to the NTSC video format compatible analog video in said intervals to generate NTSC video formatted data; and

(c) transmitting the NTSC video formatted data.

12. A method for receiving and restoring continuous analog electrical data signals from video signals formatted as NTSC video formatted data using conventional NTSC video equipment, comprising the steps of:

(a) receiving the video signals as NTSC video formatted data;

(b) removing the NTSC video synchronization and blanking pulses from the NTSC video formatted data to leave spaced segments of compressed-in-time video; and

(c) converting said spaced segments of NTSC video formatted data into continuous electrical data signal format by removing intervals where the synchronization and blanking pulses were removed and expanding said spaced segments in time, thereby restoring original continuous analog electrical data signals without deletions in time periods including or adjacent said intervals.

13. A method of converting a given amount of continuous analog data to NTSC video formatted data, comprising the steps of:

(a) sampling the continuous analog data at a first clock rate to generate sampled magnitudes;

(b) converting the sampled magnitudes to digital samples at the first clock rate;

(c) writing the digital samples into a first digital memory at the first clock rate;

(d) reading the digital samples from the first digital memory at a second clock rate which is faster than the first clock rate;

(e) writing subsequent digital samples into a second digital memory at the first clock rate, wherein the writing of the subsequent digital samples occurs during the reading of the digital samples from the first digital memory;

(f) reading the subsequent digital samples form the second digital memory at the second clock rate;

(g) writing next subsequent digital samples into the first digital memory at the first clock rate, wherein the writing of the next subsequent digital samples occurs during the reading of the subsequent digital samples from the second digital memory;

(h) reading the next subsequent digital samples from the first digital memory at the second clock rate;

(i) interrupting the reading of the digital memories for predetermined time intervals corresponding to the time duration of NTSC video format synchronization and blanking pulses;

(j) converting the digital samples read from the digital memories at the second clock rate to analog video;

(k) inserting NTSC video format synchronization and blanking pulses during the predetermined time intervals to generate NTSC video formatted data; and

(l) repeating steps (a) through (k) for all the given amount of continuous analog data.

14. A method of converting a given amount of continuous analog data to NTSC video formatted data as recited in claim 13 further comprising the steps of:

(a) writing digital samples of a first sequence of input data into a third digital memory at the first clock rate, wherein the writing of the digital samples of the first sequence of input data occurs during the start of writing the digital samples into the first digital memory;

(b) reading the digital samples of the first sequence of input data from the third digital memory at the second clock rate, wherein the reading of the digital samples of the first sequence of input data occurs at the end of reading previous digital samples from the second memory;

(c) writing subsequent digital samples of a first sequence of subsequent input data into the third digital memory at the first clock rate, wherein the writing of the subsequent digital samples of the first sequence of subsequent input data occurs during the start of writing the subsequent digital samples into the second digital memory;

(d) reading the subsequent digital samples of the first sequence of the subsequent input data from the third digital memory at the second clock rate, wherein the reading of the subsequent digital samples of the first sequence of subsequent input data occurs at the end of reading the digital samples from the first memory;

(e) writing next subsequent digital samples of a first sequence of next subsequent input data into the third digital memory at the first clock rate, wherein the writing of the next subsequent digital samples of the first sequence of next subsequent input data occurs during the start of writing the next subsequent digital samples into the first digital memory;

(f) reading the next subsequent digital samples of the first sequence of the next subsequent input data from the third digital memory at the second clock rate, wherein the reading of the next subsequent digital samples of the first sequence of next subsequent input data occurs at the end of reading the subsequent digital samples from the first memory; and

(g) repeating steps (a) through (f) for all the given amount of continuous analog data.

15. A method of converting a given amount of NTSC video formatted data to continuous analog data, comprising the steps of:

(a) stripping NTSC synchronization and blanking pulses from the NTSC video formatted data;

(b) sampling the NTSC video formatted data at a first clock rate to generate sampled magnitudes;

(c) converting the sampled magnitudes to digital samples at the first clock rate;

(d) writing the digital samples into a first digital memory at the first clock rate;

(e) reading the digital samples from the first digital memory at a second clock rate which is slower than the first clock rate;

(f) writing subsequent digital samples into a second digital memory at the first clock rate, wherein the writing of the subsequent digital samples occurs during the reading of the digital samples from the first digital memory;

(g) reading the subsequent digital samples from the second digital memory at the second clock rate;

(h) writing next subsequent digital samples into the first digital memory at the first clock rate, wherein the writing of the next subsequent digital samples occurs during the reading of the subsequent digital samples from the second digital memory;

(i) interrupting the writing of the digital memories for predetermined time intervals corresponding to the time duration of the NTSC synchronization and blanking pulses;

(j) converting the digital samples read from the digital memories at the second clock rate to continuous analog data; and

(k) repeating steps (a) through (j) for all the given amount of NTSC video formatted data.