JP3421568B2 - Video signal playback device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital video reproducing technique for a DVD player or the like, and particularly to a circuit technique field for improving image quality.

[0002]

2. Description of the Related Art With the spread of DVD players, the number of titles of DVD software is also increasing significantly. This DVD video disc has various titles such as movies, karaoke, animation, and live music.

Of these, the movie title is DVD encoded (MPE) because the film state is 24 frames / second.
G2 compression encoding) is performed at 24 frames / second, and is recorded on the DVD disc in that state.

At the time of reproduction, the circuit built in the AV decoder converts it into 60 fields / sec.
When the reproduced video signal is viewed on a general television, the screen of a movie title appears darker than other titles.

This is because since the motion picture film has 24 frames / sec, flicker is likely to be noticeable, and the brightness is lowered for the purpose of alleviating the flicker.

Therefore, such movie software makes it difficult to see a dark scene in a bright room.

Therefore, in order to make it easier to watch a movie in the living room of a home, a digital gamma correction circuit as disclosed in Japanese Patent Laid-Open No. 8-18826 has been developed. This circuit is a circuit that makes it easy to see by brightening only the dark part of the image that is difficult to see.

However, even if such a circuit is mounted, it is necessary for the user to adjust the image quality of the video output signal in accordance with the software content of the disc to be reproduced, which is a troublesome operation.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a technical object thereof is to automatically adjust the image quality of a video output signal according to the content of reproduced video software. .

[0010]

In order to solve the above problems, the present invention provides a video signal reproducing apparatus for reproducing video software via a recording medium, a communication medium, or the like, and a video for discriminating the type of video software. If a software discriminating unit and a video signal processing unit that controls the luminance signal level of the video signal are provided, and the video software that the video software discriminating unit discriminates is a specific type of video software, the luminance signal of the video to be reproduced. It is characterized by controlling.

Then, the video software discriminating unit discriminates based on the aspect ratio of the video signal. For example, when the aspect ratio is 16: 9, the video signal processing unit raises the luminance level of the low luminance portion of the video signal. It is characterized by

Further, the video software discriminating unit makes a discrimination based on the caption information of the video signal, and if it discriminates that it has the caption information, the video signal processing unit raises the luminance level of the low luminance portion of the video signal. .

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a video signal reproducing apparatus of the present invention will be described below with reference to FIGS.

FIG. 1 is a block diagram of a video signal reproducing apparatus according to the present invention.

In the figure, (1) is a recording medium such as a DVD disk, in which video management information about the video such as the aspect ratio of the digital video and subtitle information is recorded together with the digital video compressed by MPEG2 or the like.

Reference numeral (2) is a pickup, which optically extracts the pit information recorded on the recording medium (1) and outputs it as an RF signal.

The RF amplifier (3) amplifies the RF signal output from the pickup (2).

(4) is a DVD decoder, which comprises a circuit for converting an RF signal into a digital signal, a demodulation circuit for demodulating data coded by 8/16 modulation and an error correction circuit.

Reference numeral (5) is an AV decoder which carries out video signal processing and audio signal processing which will be described later.

A video encoder (6) converts the signal output from the AV decoder (5) into an NTSC or PAL digital video signal.

(7) is an image quality adjusting circuit, which performs gamma correction of the digital video signal.

(8) is a video D / A converter,
Converts digital video signals to analog signals.

(9) is an audio D / A converter which converts a digital audio signal into an analog signal.

Reference numeral (10) is a CPU, which controls the image quality adjusting circuit on the basis of the information relating to the image obtained by the AV decoder (5).

The reproducing operation of the video signal reproducing apparatus is performed as follows.

When the reproducing operation is instructed from the microcomputer, first, the recording medium (1) is rotated by the control of the spindle motor, and the information of the recording medium (1) is detected by the pickup (2). The detected information is output as an RF signal and amplified by the RF amplifier (3).

This amplified RF signal is sent to the DVD decoder (4).

The DVD decoder (4) converts the RF signal into a digital signal, demodulates and error-corrects the data recorded and coded by 8/16 modulation, and the AV decoder (5)
Sent to.

In the portion related to the video signal processing in the AV decoder (5), MPEG2 main video signal demodulation and sub-picture
(Sub-picture signal) After being subjected to processing such as demodulation, it is sent to the video encoder (6) and converted into an NTSC or PAL system digital picture signal.

After passing through the image quality adjustment circuit (7), this signal is converted into an analog signal by the video D / A converter (8) and output as a video signal from the DVD video player.

Furthermore, in the portion related to audio signal processing in the AV decoder (5), in addition to linear PCM, there is a demodulation circuit such as Dolby Digital or MPEG audio, and the digital audio signal demodulated by this is an audio signal.
It is sent to the D / A converter (9), converted into an analog signal and output from the DVD player.

The AV decoder (5) decodes various video management information for controlling the state of the DVD video player.

For example, it is possible to decipher the aspect ratio of the main video recorded on the disc, the number of sub-picture streams, the number of audio streams, and the like, and further transfer those video management information to the CPU (10).

On the other hand, a disc on which a video aspect ratio is recorded at 16: 9 is often a movie title disc, and a disc on which a sub-picture stream, which is mainly subtitle information, is recorded, is also a movie title disc. It is often a disc.

Therefore, when the sub-picture stream exists in the information decoded by the AV decoder (5),
Alternatively, when the aspect ratio of the main video is 16: 9, or when the sub-picture stream is present and the aspect ratio is 16: 9 at the same time, or when the sub-picture stream is present or the aspect ratio of the main video is 16: 9. If it is, it is determined that the disc is a movie title disc.

When it is determined that the disc is a movie title disc, the information is sent from the AV decoder (5) to the CPU (10).
Then, the CPU (10) controls the image quality adjustment circuit (7) based on the information.

The image quality adjusting circuit (7) is for adjusting the image quality by digital gamma correction, and has a ROM (11) recording conversion data as shown in FIG.

The video-decoded digital video signal is 8-bit wide data, which is input to the address of the ROM (11).

This ROM (11) stores in advance the data indicated by the broken line in FIG. 3 in association with the input address, and the video signal input to the address input has 1
Corresponding to 1 to output.

The image quality adjusting circuit (7) changes the input / output characteristics by passing the ROM (11) as shown in FIG. A switch (12) for selecting whether or not to change the characteristics is provided, and the CPU (10) controls the switch (12) to switch the input / output characteristics.

As a result, when the sub picture stream is present in the video management information decoded by the AV decoder (5), or the aspect ratio of the main video is 16: 9.
Or if the sub-picture stream exists and the video aspect ratio is 16: 9 at the same time, the information is transferred from the AV decoder (5) to the CPU (9), and the CPU (9) is based on the information. Switch (1
2) is instructed to be connected to the A side, so that the input / output durability of the broken line a in FIG. 3 is provided.

On the other hand, when the sub picture stream does not exist in the video management information decoded by the AV decoder (5) and the aspect ratio of the main video is 4: 3,
By connecting the switch (12) to the B side, the ROM (1
By bypassing 1), the linear input / output characteristic shown by the solid line b in FIG. 3 is provided.

If the video management information has information that the reproduced video is a movie title, and the AV decoder (5) detects this information by decoding the video management information, C
This can also be done by sending an input / output characteristic switching instruction to the image quality adjustment circuit (7) from the PU (10).

Further, in the present embodiment, the case where the video management information is analyzed as a method of detecting the aspect ratio of the main video and the presence / absence of subtitles has been described. However, the video signal to be displayed is analyzed to determine the aspect ratio from the black level. The present invention can also be implemented by using a detection method or a method for determining the presence or absence of subtitles disclosed in Japanese Patent Laid-Open No. 8-212231.

[0045]

As described above, according to the present invention, it is possible to automatically adjust the image quality according to the type of the image to be reproduced, which eliminates the need for the image quality adjustment by the user of the apparatus.
It is possible to obtain an easily viewable image without the user having to make adjustments.

[Brief description of drawings]

FIG. 1 is a block diagram of a video signal reproducing device according to the present invention.

FIG. 2 is a diagram showing an example of an image quality adjustment circuit by digital gamma correction.

FIG. 3 is a diagram showing conversion data for digital gamma correction.

FIG. 4 is a configuration diagram of an image quality adjustment circuit.

[Explanation of sign]

1. recoding media 2. pick up 3. RF amplifier 4. DVD decoder 5. AV decoder 6. Video encoder 7. Image quality adjustment circuit 8. Video D / A converter 9. Audio D / A converter 10. CPU 11. ROM 12. switch

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04N 5/14-5/217 H04N 5/38-5/63 H04N 5/756-5/775 H04N 5/91-5 / 956 H04N 7/00-7/088 G09G 5/00-5/40

Claims (8)

(57) [Claims] 1. A video signal reproducing apparatus for reproducing video software via a recording medium or a communication medium, and a video software discriminating section for discriminating the type of video software, and a video for controlling the luminance signal level of the video signal. A signal processing unit, wherein the video software determination unit determines the type of video software based on the aspect ratio of the video signal, and when the video software determination unit determines that the video software to be played is movie software, The video signal reproducing device, wherein the video signal processing section raises the brightness level of a low brightness part of the video signal to be reproduced. 2. The video signal reproducing apparatus according to claim 1, wherein the aspect ratio is obtained by analyzing video management information. 3. A video signal reproducing apparatus for reproducing video software via a recording medium or a communication medium, and a video software discriminating section for discriminating the type of video software, and a video for controlling the luminance signal level of the video signal. A signal processing unit, and when the video software determination unit determines that the aspect ratio of the video signal is 16: 9, the video signal processing unit determines the luminance level of the low-luminance portion of the video signal to be reproduced. Video signal reproducing device characterized by raising. 4. A video signal reproducing apparatus for reproducing video software via a recording medium or a communication medium, and a video software discriminating section for discriminating the type of video software, and a video for controlling the luminance signal level of the video signal. A signal processing unit, wherein the video software determination unit determines the type of video software based on the presence or absence of the caption information of the video signal, and the video signal processing unit determines whether the video software determination unit determines the type of video software. A video signal reproducing device characterized by performing luminance signal control of a video signal to be reproduced. 5. The video signal reproducing apparatus according to claim 4, wherein the presence or absence of the subtitle information is obtained by analyzing the video management information. 6. The video signal reproduction apparatus according to claim 4, wherein the video signal processing unit raises the low luminance level of the video signal when the video software determination unit determines that the video software determination unit has subtitle information. . 7. A video signal reproducing device for reproducing video software via a recording medium or a communication medium, and a video software discriminating section for discriminating the type of video software, and a video for controlling the luminance signal level of the video signal. A signal processing unit, the aspect ratio of the video signal is 16: 9, and the video software determination unit determines that it has subtitle information,
The video signal reproducing device, wherein the video signal processing unit raises the level of a low luminance portion of the video signal. 8. The video signal processing unit includes a ROM storing input / output characteristic data and a switch means, and a signal input to the video processing unit by the switch means is input to an address of the ROM. The video signal reproducing device according to any one of claims 1 to 7, wherein