Variable length code recording/playback apparatus

• US 5,751,893 A
• Filed: 03/24/1993
• Issued: 05/12/1998
• Est. Priority Date: 03/24/1992
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Shimoda, Kenji, Abe, Shuji, Kurihara, Kouichi
• Primary Examiner(s): Sniezek, Andrew L.
• Application Number:
  US08/035,755
• Time in Patent Office: 1,875 Days
• Field of Search: 360/10.1-10.3, 360/33.1, 360/18, 360/24, 358/133, 358/335, 348/384, 348/397, 348/398, 348/423, 348/390, 348/553, 386/111, 386/68, 386/33
• US Class Current: 386/220
• CPC Class Codes: H04N 5/78266 using more than one track for the recording of one television field or frame, i.e. segmented recording
• CPC Class Codes: H04N 5/783 Adaptations for reproducing at a rate different from the recording rate
• CPC Class Codes: H04N 9/8042 involving data reduction
• CPC Class Codes: H04N 9/8045 using predictive coding
• CPC Class Codes: H04N 9/8227 the additional signal being at least another television signal

Abstract

A variable length code recording/playback apparatus, which by encoding intra-frame data and inter-frame data in variable length code, records them as recorded codes on prescribed locations of tracks of a recording medium and plays them back, which includes a data rearranger for recording the data in areas to be played back at least two specific speed mode playbacks on the tracks by rearranging prescribed data out of the data encoded in variable length code, a variable length decoder for playing back the data recorded on the recording medium and decoding it in variable length code, a data restorer for controlling and restoring the time series of the output of the variable length decoder to the original data train before the rearrangement, and a decoder for constructing a playback picture from the decoded outputs for several frames in the specific speed mode playback by decoding the output of this data restorer.

Claims

1. A variable length code encoding apparatus for encoding video data to be recorded on a recording medium with a plurality of tracks, comprising:

multiplexing means for multiplexing said video data and outputting multiplexed data, said multiplexed data comprising interframe data, AC components of intraframe data, and DC components of intraframe data;

subtracting means for subtracting from said multiplexed data a preceding frame data when said interframe data is being encoded;

encoding means for variable length encoding said multiplexed data and outputting variable length encoded data, said variable length encoded data comprising variable length encoded interframe data, variable length encoded AC components of intraframe data and variable length encoded DC components of intraframe data;

memory means for storing said variable length encoded data, said memory means comprising intraframe AC memory means for storing said variable length encoded AC components of intraframe data, intraframe DC memory means for storing said variable length encoded DC components of intraframe data, and interframe memory means for storing said variable length encoded interframe data; and

data rearrangement means for rearranging said variable length encoded data so that said variable length encoded DC components of intraframe data are to be recorded at prescribed locations on said recording medium.

2. A variable length code encoding apparatus as in claim 1, wherein said prescribed locations are locations which would be played back if said recording medium was to be played back in an enhanced speed mode.

3. A variable length code encoding apparatus as in claim 2, wherein said enhanced speed mode is a five-times speed mode.

4. A variable length code encoding apparatus as in claim 2, wherein said prescribed locations are identical to locations which would be played back if said recording medium was to be played back in a reverse direction enhanced speed mode.

5. A variable length code encoding apparatus as in claim 1, wherein said prescribed locations are locations in odd numbered tracks which would be played back if said recording medium was to be played back in an enhanced speed mode and locations in even numbered tracks which would be played back if said recording medium was to be played back in a reverse direction enhanced speed mode.

6. A variable length code encoding apparatus as in claim 5, wherein said enhanced speed mode is a five-times speed mode.

7. A variable length code encoding apparatus as in claim 1, wherein said prescribed locations are locations in X contiguous tracks which would be played back if said recording medium was to be played back in a first enhanced speed mode and locations in Y contiguous tracks, immediately following said X contiguous tracks, which would be played back if said recording medium was played back in a second enhanced speed mode, where Y and X are integers and Y is equal to X multiplied by an integer.

8. A variable length code encoding apparatus as in claim 7, wherein X=3 and Y=6.

9. A variable length code encoding apparatus as in claim 7, wherein said locations to be recorded in said X contiguous tracks are identical to locations which would be played back if said recording medium was to be played back in a reverse direction first enhanced speed mode and said locations to be recorded in said Y contiguous are identical to locations which would be played back if said recording medium was to be played back in a reverse direction second enhanced speed mode.

10. A variable length code encoding apparatus as claimed in claim 1, further comprising data length limiter means for limiting bits of said variable length encoded DC components of intraframe data to a prescribed number.