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Recording apparatus and method, playback apparatus and method, and recording medium therefor

Recording apparatus and method, playback apparatus and method, and recording medium therefor description/claims

1. Field of the Invention

The present invention relates to recording apparatuses and methods, playback apparatuses and methods, and to recording media therefor. More particularly, the invention relates to a recording apparatus and method suitable for, for example, compressing audiovisual (AV) signals and recording them on information recording media, and to a recording medium therefor. The invention also pertains to a playback apparatus and method suitable for, for example, converting AV signals recorded on information recording media as packetized elementary stream packets into transport streams and outputting them, and to a recording medium therefor. The invention also relates to a recording apparatus and method and a playback apparatus and method suitable for, for example, recording and reading different types of data streams on and from information recording media, and to a recording medium therefor.

2. Description of the Related Art

As the DV format used for consumer video cassette recorders (VCRs), a system is provided for coding video signals by performing intra-frame compression and coding the corresponding audio signals without compressing them or coding the audio signals so that they can be instantaneously companded, and then for recording the encoded video signals and audio signals on magnetic tape.

Video signals and audio signals encoded in the DV format and recorded on recording media are suitable for editing the corresponding images and sound so that they can be spliced at a certain position.

However, because of a low compression rate of the DV format, a system having a high transfer rate and a medium having a large storage capacity are required, and also, the recording time becomes shorter if the capacity of an information recording medium is limited.

To overcome the above-described drawbacks, a system for compressing video signals and audio signals according to an Moving Picture Experts Group (MPEG) method and for recording them in the form of transport stream (hereinafter sometimes referred to as “TS”) has been proposed and is used.

According to the system using the MPEG method, video signals are encoded by compressing a long group of pictures (GOP) formed of a plurality of frames according to the inter-frame compression method, while audio signals are encoded by compressing a plurality of samples according to the frame compression method, thereby achieving a high compression rate. Accordingly, the provision of a recording system having a high transfer rate becomes unnecessary, space can be saved on the recording medium, and the recording time becomes longer compared to a DV-format system even if the capacity of the recording medium is limited.

However, in a system in which MPEG-compressed video signals and audio signals are recorded in the form of TS, the following problems are presented.

That is, as stated above, video signals are MPEG-compressed in units of long GOPs, the length of one frame of an image varies according to the type of image (Intra (I) picture, Predictive (P) picture, and Bidirectionally predictive (B) picture) or the design of the image. In other words, the video signals are not compressed at a constant rate. In contrast, audio signals are compressed at a fixed rate. Accordingly, even if the video signals and the corresponding audio signals are simultaneously encoded, the packets of the video signals and the corresponding packets of the audio signals may disadvantageously be separately disposed on a TS.

In this case, if images and sound are edited so that they are spliced at a certain position on a TS, there may be temporal displacement in the continuity between video frames and audio frames, or one of the video frames or the audio frames may be missing.

It is also necessary to add to a TS a TS header, a time stamp indicating the arrival time of video signals and audio signals at a decoder, and a program clock reference (PCR) packet for storing a PCR, which is the reference time for a decoding operation. Accordingly, the overhead becomes larger, and the recording rate is lowered.

In addition, it is difficult to perform so-called “jog playback”, such as pause, slow, and reverse playback, on video signals and audio signals. To enable the jog playback operation, it is necessary to convert TSs to elementary streams.

Moreover, an error may occur in a video signal or an audio signal in the form of a TS during a reading or playback operation, thereby adversely influencing the image quality or the sound quality.

Accordingly, in view of the above background, it is an object of the present invention to avoid any inconvenience caused by recording MPEG-compressed video signals and audio signals on an information recording medium as packetized elementary streams when video and audio editing is performed.

It is another object of the present invention to record MPEG-compressed video signals and audio signals as packetized elementary streams and to output them as TSs.

It is still another object of the present invention to correctly detect an error occurring during a recording or playback operation.

In order to achieve the above-described objects, according to one aspect of the present invention, there is provided a recording apparatus for recording an audio signal and a video signal on an information recording medium. The recording apparatus includes a video packetized elementary stream packet generator for generating video packetized elementary stream packets by dividing a video elementary stream in which a video signal is compressed and coded according to a predetermined method by a predetermined number of video frames and by adding a header. An audio packetized elementary stream packet generator generates audio packetized elementary stream packets by dividing an audio elementary stream in which an audio signal is compressed and coded according to a predetermined method by a predetermined number of audio frames and by adding a header. A video packetized elementary stream packet unit generator generates a video packetized elementary stream packet unit by combining a predetermined number of the video packetized elementary stream packets. An audio packetized elementary stream packet unit generator generates an audio packetized elementary stream packet unit by combining the audio packetized elementary stream packets corresponding to the video packetized elementary stream packet unit. A sync block generator generates sync blocks by alternately disposing the video packetized elementary stream packet unit and the audio packetized elementary stream packet unit and by converting the video packetized elementary stream packet unit and the audio packetized elementary stream packet unit into a predetermined recording format. A recording unit records the sync blocks on the information recording medium.

The video packetized elementary stream packet generator may generate the video packetized elementary stream packets by dividing the video elementary stream by one video frame, and by adding the header in which at least one of a presentation time stamp and a decoding time stamp is recorded.

The audio packetized elementary stream packet generator may generates the audio packetized elementary stream packets by dividing the audio elementary stream by one audio frame, and by adding the header in which at least a presentation time stamp is recorded.

The audio packetized elementary stream packet unit generator may generate the audio packetized elementary stream packet unit by combining the audio packetized elementary stream packets having a presentation time stamp which is after the earliest value of the presentation time stamps recorded in the headers of the video packetized elementary stream packets forming the current video packetized elementary stream packet unit and which is before the earliest value of the presentation time stamps recorded in the headers of the video packetized elementary stream packets forming the subsequent video packetized elementary stream packet unit.

• Provisional Patent
• Utility Patent

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