Motion video signal processing for recording or reproducing – Local trick play processing – With randomly accessible medium
Reexamination Certificate
1999-08-06
2002-12-10
Tran, Thai (Department: 2615)
Motion video signal processing for recording or reproducing
Local trick play processing
With randomly accessible medium
C386S349000, C386S349000, C386S349000
Reexamination Certificate
active
06493504
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a rewritable storage medium, a recording apparatus and a playback apparatus for use with the storage medium, a method for recording data on the storage medium, and to a computer program executing the recording method. More particularly, the present invention is adaptive to, and preferably used with, an optical disc on which a large amount of still picture data is recorded.
Large-capacity, rewritable optical disc recording media, such as DVD-RAMs or DVD-RWs, have been made available, and many technologies for recording picture data or audio data on the media are now being developed. Video data coded, for example, in the MPEG (Moving Picture Experts Group) system described in the ISO/IEC11172 or ISO/IEC13818 standard is usually used. Still picture data coded in the intraframe compression method (I picture) of the MPEG (Moving Picture Experts Group) system or in the JPEG system described in the ISO/IEC10918-1 standard is usually used.
Digital VCRs(digital video cassette recorders) using magnetic tapes as recording media or electric still cameras using memories such as a flash memory as recording media are already in practical use for storing coded video or still pictures with audio.
Recording apparatuses using optical discs as recording media, such as DVD-RAMs, have many advantages over conventional digital VCRs or electric still cameras in that they feature random accessibility which cannot be attained by magnetic tapes, large-capacity which cannot be achieved by memories such as a flash memory, and a low cost per bit. Therefore, recording apparatuses using optical disc media allow the user to play back data independently of the sequence in which data was recorded and to process as many as tens of thousands of still pictures. For this reason, optical disc recording media are expected to be widely used as new AV (audio-visual) recording media.
SUMMARY OF THE INVENTION
A DVD-RAM disc allows moving pictures and still pictures to be mixed. Especially, for still pictures, a huge number of still pictures which cannot be recorded by a conventional electric still camera can be recorded. For example, a 4.7 GB DVD-RAM disc can record thereon about 64,000 still pictures each of which is an MPEG-coded still picture (I picture) of about 80 KB.
Unlike a storage medium such as a digital VCR tape from which data is played back in the order in which it was recorded, an optical disc medium such as a DVD-RAM disc allows the user to access data randomly. For data to be accessed randomly, management information, such as the addresses and sizes of still picture data as well as the playback times of audio data recorded with still pictures are recorded.
Playing back still pictures with a playback apparatus requires two steps. First, a still picture data address and so on are read from the management data recorded on the optical disk medium, and then still picture data recorded at the address that was read is played back. Therefore, when playing back a plurality of still pictures, each still picture requires the above two steps.
Also, recording still pictures and so forth onto an optical disc with a recording apparatus requires two steps. First, still picture data is recorded, and then management information such as the still picture data address is recorded. Therefore, when recording a plurality of still pictures, each still picture requires the above two steps.
The optical disc recording or playback apparatus has an optical head for recording and playing back information. This optical head is slow in accessing data because it is larger and heavier than a magnetic head. Therefore, playing back or recording a plurality of still pictures, which requires two steps, takes long and the apparatus cannot perform random access quickly.
To solve this problem, the optical disc recording apparatus and the playback apparatus store management information, read from the optical disc, into memory. Once the management information is stored into memory of the playback apparatus, the apparatus need not read management information from the disc each time it plays back a still picture, thus reducing the time needed to playback a plurality of still pictures. Also, the recording apparatus stores management information about a plurality of still pictures into the memory of the apparatus and records the management information onto the disc at a time. This eliminates the need to record management information each time a still picture is recorded, thus reducing the time needed to record a plurality of still pictures.
However, because a large-capacity storage medium such as a DVD-RAM records tens of thousands of still pictures thereon, the amount of management information on recorded still pictures becomes very large and a large amount of memory capacity is needed in the apparatus. Although the memory price has gone down recently, it is difficult to install megabytes of memory onto an AV apparatus. In addition, considering the memory backup provided for use at emergency, it is unrealistic for an AV apparatus to process megabytes of management information.
To solve this problem, a technology is disclosed in the specification of the European Patent Application No. 99304691.1 filed on Jun. 16, 1999 or the corresponding U.S. patent application Ser. No. 09/332,882 filed on Jun. 15, 1999 by some of the inventors of the present invention. To prevent an increase in the management information size, the technology disclosed in the above patent application records management information, such as data addresses and sizes or audio data playback times, in variable-size management information tables proportional in size to the number of still pictures or the number of audio data pieces.
However, the technology described above does not take the following into account. First, the technology does not support the function to manage still picture data recording times. Because the technology described above does not support a search for data with the use of recording times, there is a problem with processing a request to search a huge number of still pictures for a desired still picture.
For example, as shown in
FIG. 3
, when a recording time (RECTM) is represented by a 7-byte data structure composed of the year (2 bytes), month (1 byte), day (1 byte), hour (1 byte), minute (1 byte), and second (1 byte), adding the recording time (RECTM) to each of about 64,000 still pictures requires that the data size of the management information used by the above-described technology be increased by as many as about 438K bytes (=64,000×7).
As mentioned above, the system controller within the apparatus should have the management information always in its own memory for quick random access. To reduce the memory size (cost reduction) of AV apparatuses, that is, to reduce the cost, the data size of the management information must be minimized.
It is a first object of the present invention to provide a recording apparatus and a playback apparatus, primarily used for optical discs, which allow the user to search for data based on recording times and which have a data structure preventing the data size of management information from increasing, and computer programs which control these apparatuses.
Second, the technology does not support the function to solve problems associated with still picture deletion.
FIG. 12
shows the still picture management method according to the technology described above. First, still picture group management information (VOBGI)
103
is provided to manage a plurality of still picture data pieces (VOB)
101
as a still picture group (VOBG)
102
. The still picture group management information (VOBGI)
103
comprises still picture group identification information (VOBG_ID)
104
, start and end address information (VOBG_Address)
105
on the still picture group (VOBG)
102
, number-of-pictures information (V_I_Number)
1015
representing the number of still pictures managed in this group, picture management information table (V_I_Table)
1016
containing only picture
Date Akira
Ito Tamotsu
Kageyama Masahiro
Antonelli Terry Stout & Kraus LLP
Tran Thai
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