Device for storing video data

• US 6,031,574 A
• Filed: 08/29/1996
• Issued: 02/29/2000
• Est. Priority Date: 08/29/1995
• Status: Expired due to Fees

• Current Assignee: Alcatel NV (Nokia Corporation)
• Original Assignee: Alcatel NV (Nokia Corporation)
• Inventors: Muller, Detlef
• Primary Examiner(s): Le, Vu
• Application Number:
  US08/697,643
• Time in Patent Office: 1,279 Days
• Field of Search: 348/410, 348/409, 348/400, 348/401, 348/411-412, 348/415, 348/6, 348/7, 348/12-14, 348/17-19, 386/27, 386/33, 386/109, 386/111, 382/232, 382/236, 382/244
• US Class Current: 375/240.12
• CPC Class Codes: H04N 19/30 using hierarchical techniques, e.g. scalability H04N19/63 takes precedence
• CPC Class Codes: H04N 19/40 using video transcoding, i.e. partial or full decoding of a coded input stream followed by re-encoding of the decoded output stream
• CPC Class Codes: H04N 5/9262 using predictive coding
• CPC Class Codes: H04N 7/17318 Direct or substantially direct transmission and handling of requests
• CPC Class Codes: H04N 7/17336 Handling of requests in head-ends

Abstract

To reduce the data in a video-server (SER), a compression of the video data of a video film is performed by coding according to the interframe method (K1). In addition, the video data of predetermined individual video pictures are coded according to the intraframe method (K2), and are stored (MEMO) as entry points parallel to the corresponding interframe-coded video data. When the video film is transmitted, only the interframe-coded video data are transmitted. In response to a request for fast forward or fast backward mode only, the video data of the entry point are transmitted intraframe-coded, and all subsequent video pictures are transmitted interframe-coded.

Claims

1. A device (V) for encoding and storing video data wherein received picture information is divided into video frames and encoded before said storing, comprising

a first encoder (K1) for coding said received picture information divided into video frames according to an interframe coding,

a second encoder (K2) for coding said received picture information according to an intraframe coding,

a memory (MEMO), and

a control unit (CTRL) for controlling both encoders (K1, K2)

for intraframe coding a first frame of said video frames, and thereafter

for interframe coding every frame of said video frames of said received picture information,

for intraframe coding only predetermined individual frames of said received picture information,

for storing said every interframe-coded frame as well as said intraframe-coded predetermined individual frames in the memory (MEMO),

for reading and transmitting an intraframe-coded video data frame followed by a sequence of interframe-coded video data frames for transmission without interruption by intraframe-coded video data frames until a fast forward or fast backward command is received, and

for reading and transmitting one intraframe-coded video data frame of said predetermined individual frames followed by a sequence of interframe coded frames upon receipt of said fast forward or fast backward command.

2. A device (V) as claimed in claim 1, further comprising a decoder (DEC) for decoding interframe-coded frames of video data, and for providing interframe-coded frames of video data of the predetermined individual frames of video data to the second encoder (K2).

3. A device (V) as claimed in claim 1, wherein the control unit controls storing a particular frame of picture information in an interframe-coded video frame and an intraframe-coded video frame of said particular frame in the memory (MEMO) with different reading addresses and with the same Go-To address.

4. A device (V) as claimed in claim 1, for use in a video-server (SER).

5. A method for storing video data, wherein picture information is divided into a sequence of video frames, wherein, a first frame of said sequence is coded according to an intraframe coding method and stored as intraframe-coded video data and every subsequent frame is coded according to an interframe method and stored as interframe-coded video data, and wherein predetermined individual video frames of said sequence of video frames are separately coded according to an intraframe method, resulting in an intraframe-coded video frame and a corresponding but separate interframe-coded video frame, and wherein said predetermined frames that are intraframe-coded are stored as entry points parallel to the corresponding interframe-coded video data.

6. A method for transmitting video data wherein picture information is divided into video frames, wherein, a first frame of said sequence is coded according to an intraframe coding method and all subsequent video frames are interframe-coded and wherein predetermined frames of said subsequent video frames are intraframe-coded as well, resulting in said predetermined frames being both an intraframe-coded video frame and a corresponding interframe-coded video frame, wherein said interframe-coded video frames are transmitted sequentially, and wherein the transmitting of intraframe-coded video frames at closely-spaced regular intervals is avoided except in response to a request for fast forward or fast backward mode, wherein at an entry point intraframe-coded video data of one video frame are transmitted first instead of the interframe-coded video data, and then subsequently interframe-coded video frames.

7. A method as claimed in claim 6, wherein said transmitting of intraframe-coded video frames at regular intervals is not entirely avoided but rather wherein intraframe-coded video frames are inserted at widely-spaced, regular intervals into the sequential video data stream.

8. A method as claimed in claim 6, wherein the video frames are transmitted to a video telephone via an integrated services digital network (ISDN).

9. Method, comprising the steps of:

receiving a sequence of video frames for compression;

encoding a first frame of said sequence of video frames for compression according to an intraframe-encoding method and all subsequent frames according to an interframe-encoding method;

separately encoding predetermined frames of said subsequent frames according to said intraframe-encoding method; and

storing said first frame encoded according to said intraframe encoding method, said all subsequent frames encoded according to said interframe-encoding method, and said predetermined frames of said subsequent frames encoded according to said intraframe-encoding method for retrieval in a sequence of compressed comprising first said first frame followed by said all subsequent frames encoded according to said interframe-encoding method interrupted by one of said separately encoded predetermined frames in response to a user request for fast-forward or rewind.

10. Apparatus, comprising:

means for receiving a sequence of video frames for compression;

means for encoding a first frame of said sequence of video frames for compression according to an intraframe-encoding method and all subsequent frames according to an interframe-encoding method;

means for separately encoding predetermined frames of said subsequent frames according to said intraframe-encoding method; and

means for storing said first frame encoded according to said intraframe encoding method, said all subsequent frames encoded according to said interframe-encoding method, and said predetermined frames of said subsequent frames encoded according to said intraframe-encoding method for retrieval in a sequence of compressed comprising first said first frame followed by said all subsequent frames encoded according to said interframe-encoding method interrupted by one of said separately encoded predetermined frames in response to a user request for fast-forward or rewind.