JPH10112847A - Video decoder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change a display position of a sub video image by converting a display address for display control data into a designated display address. SOLUTION: Main video image data are given to a main video image decoder 101, sub video image data are given to a sub video image decoder 102, picture element data in the sub video image data are given to a picture element decoder 104 and display control data are given to a display control decoder 105 respectively. The decoder 104 converts the picture element data into bit map data. The decoder 105 kinds a display style and a display position of the bit map data and provides an output of the result to a display address conversion section 106, which compares a transmitter side designation address outputted from the decoder 105 with a sub video data display position designated by a display position designation section 107, calculates bit map data display address and provides an output of a display address to an on-screen setting section 108. The setting section 108 sets the bit map data display position being an output of the decoder 104 based on the result of analysis of the conversion section 106 and a video image mixer 103 superimposes the sub video image on the main video image and provides an output of the result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a video decoder for decoding main video data and sub video data and superimposing and displaying a sub video on a main video.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing a conventional video decoder. In FIG. 5, main video data is input to a main video decoder 501, and sub video data is input to a sub video decoder 502. After being decoded, the main video data and the sub video data are mixed by the video mixing unit 503 and displayed on a monitor or the like.

Here, the video data is composed of main video data which is video data such as a still image and a moving image, and sub video data such as characters, and the sub video data is transmitted together with the main video data. The sub-picture data includes, for example, pixel data for forming and expressing a character as a set of pixels, and display control data for determining a display style (change of display color, mixture ratio, display color) or display position of the pixel data. It is composed of

[0004] Of the sub-picture data, pixel data is input to a pixel data decoder 504 and display control data is input to a display control data decoder 505. The pixel data decoder 504 converts the pixel data into bitmap data, and the display control data decoder 505 obtains a display style, a display position, and the like of the pixel data from the display control data and outputs them to the on-screen setting unit 506. Pixel data, which is bitmap data, is a serially arranged data string, and the bitmap data can be rearranged into character information or the like by display control data. Here, the bitmap data represents, for example, a screen by subdividing one screen in the X-axis direction and the Y-axis direction, and displaying the presence or absence of pixels in the video to be displayed in subdivided blocks. is there.

[0005] An on-screen setting unit 506 determines the display color, display position, and the like of the bitmap data based on the output from the display control data decoder 505. And
The bitmap data is mixed with the main video from the main video decoder in the video mixing unit 503 and displayed on a monitor or the like.

FIG. 6 is a schematic diagram showing display addresses of sub-pictures on a screen. In FIG. 6, the display start position and the display end position of the sub-picture are specified by coordinate display in which the top left of the screen is (0, 0), the pixel direction is the X axis, and the line direction is the Y axis. The display range of the sub-picture is determined by the start position and the display end position. That is,
The sub-picture is displayed on the screen according to the display address determined by the sender of the picture data.

The display address is, for example, NTSC (Nation
al Television System Committee), it is the address of the area of 720 × 480 shown in FIG. The sub-picture is displayed at a position within a 720 × 480 area intended by the sender. For example, if the display start address is (X, Y) =
(5, 3), the display end address is (X, Y) = (71
6, 478), the sub-picture is displayed in a region surrounded by oblique lines shown in FIG.

[0008]

However, since the display position of the sub-image is determined by the display address intended by the sender, when displaying the sub-image and the main image on a monitor or the like, the main image is displayed. Sometimes the part you want to see overlaps the sub-picture and cannot be seen. For example, when a caption is displayed in a scene such as a movie where a signboard or the like is at the bottom of the screen, the signboard and the caption may overlap, and characters on the signboard may not be read.

In addition, when comparing caption information included in the main image with subtitles of the sub-image, etc., in the video used as language material, the caption information (for example, characters of teletext) and the sub-image overlap. In some cases, the display of the sub-picture becomes difficult to see. Even in such a case, the receiver cannot change the display position of the sub-picture.

Therefore, an object of the present invention is to receive video data in which both main video data and sub-video data are transmitted,
It is an object of the present invention to provide a video decoder capable of changing a display position of a sub-video and displaying the sub-video on a screen.

[0011]

Therefore, according to the present invention, there is provided a main video decoder for decoding main video data to obtain a main video, and pixel data of sub-video data sent together with the main video data. A pixel data decoder for decoding and converting to bitmap data, a display control data decoder for decoding display control data of sub-picture data and obtaining a display address of bitmap data, and a bit based on a display address of the display control data decoder. An image including an on-screen setting unit for setting a display position at which map data is superimposed on a main image as a sub-image, and an image mixing unit for mixing the sub-image and the main image based on the display position set by the on-screen setting unit In the decoder, the display position specifying unit that specifies the display position and the display address obtained from the display control data are displayed. Is characterized by comprising a display address conversion unit for converting the display address specified by the location specifying unit.

The present invention according to claim 2 provides the invention according to claim 1.
In the video decoder described in the above, the display address conversion unit comprises:
When there are a plurality of sub-picture data, the display start address of the sub-picture displayed at the top of the screen and the display end address of the sub-picture displayed at the bottom of the screen are set as the display address of the sub-picture. And

Further, the present invention described in claim 3 is based on claim 1.
In the video decoder described in the above, the display address conversion unit comprises:
When there are a plurality of sub-picture data, the display start address of the sub-picture displayed on the leftmost part of the screen and the display end address of the sub-picture displayed on the rightmost part of the screen shall be the display address of the sub-picture. It is characterized by.

According to the present invention, the pixel data of the sub-picture data is decoded into bitmap data, the display address of the bitmap data is obtained from the display control data of the sub-picture data, and the display address is converted into the specified display address. Since the bitmap data is superimposed and displayed on the main video based on the converted display address, the sub-video can be displayed at an arbitrary position on the main video.

When there are a plurality of sub-picture data, the display address at the uppermost or rightmost part of the plurality of sub-pictures to be displayed is set as the display start address of the plurality of sub-pictures to be displayed, and the lowermost or leftmost is displayed. Since the display address of the section is the display end address of a plurality of sub-pictures to be displayed, a plurality of sub-pictures can be simultaneously superimposed on one main picture and displayed.

[0016]

FIG. 1 is a schematic diagram showing a schematic configuration of one embodiment of a video decoder according to the present invention. In FIG. 1, the video decoder includes a main video decoder 101, a sub video decoder 102, and a video mixing unit 103. The sub-video decoder 102 is used for the pixel data decoder 10.
4, a display control data decoder 105, a display address conversion unit 106, a display position setting unit 107, and an on-screen setting unit 108. Here, the transmitted video data is composed of main video data which is video data such as still images and moving images, and sub-video data such as characters.
The sub-picture data includes, for example, pixel data for forming and expressing a character as a set of pixels, and display control data for determining a display style (change of display color, mixture ratio, display color) or display position of the pixel data. It is composed of

In FIG. 1, main video data is input to a main video decoder 101, and sub video data is input to a sub video decoder 102. The pixel data of the sub-picture data is input to the pixel data tegoder 104, and the display control data is input to the display control data decoder 105.
The pixel data decoder 104 converts pixel data into bitmap data. Display control data decoder 105
Calculates the display style, display position, and the like of the bitmap data and outputs them to the display address conversion unit. The display address conversion unit 106 includes a display address specified by the sender from the display control data decoder 105 and a display position specification unit 107.
The display address of the bitmap data is calculated by comparing with the display position of the sub-video data designated by (1), and the converted display address is output to the on-screen setting unit 108. The on-screen display unit 108 sets the display position of the bitmap data from the pixel data decoder 104 according to the analysis result from the display address conversion unit 106, and causes the video mixing unit 103 to superimpose the sub video on the main video.

A method of converting the display address of the bitmap data in the display address converter 106 will be described. FIG. 2 is a flowchart showing a display address conversion method in the video decoder according to one embodiment of the present invention.
In FIG. 2, for example, the display position of the sub-picture whose display start address is (X, Y) = (Sx, Sy) and whose display end address is (X, Y) = (Ex, Ey) is specified by the sender. The case of moving j columns in the pixel direction and k rows in the line direction will be described. The display start address of the destination is (Sx ', S
y ') and the display end address is (Ex', Ey ').

From the information output from the display control data decoder 105, the display addresses (Sx, Sy), (Ex, Ey)
Is extracted (S1). Next, the movement value (j, k) of the display area is input from the display position designation unit 107 (S2). When the movement value j is a negative value, the display address conversion unit 106
Move the sub-screen display to the left, and if it is a positive value,
Will be moved to the right. If the movement value k is a negative value, the screen display of the sub-picture is moved upward, and if the movement value k is a positive value, the screen display is moved downward.

It is determined whether the value of j is positive or negative (S3).
Is positive and is moved in the X-axis positive direction by that value (S
4) If the display area does not protrude from the screen display area, the display area is shifted by j (S7). If it protrudes, Ex '
Is fixed to the value of 720 at the right end of the X coordinate (S6). When the value of j is negative and the absolute value is moved in the X-axis direction (S
5) If not protruding from the screen display area, the display area is shifted by j (S8). If it protrudes, Sx '
Is fixed to the leftmost value of 0 on the X coordinate (S9).

Similarly, it is determined whether the value of k is positive or negative (S
10) When the value of k is positive and the value is moved in the positive direction of the Y-axis by that value (S11), if the value does not protrude from the screen display area, the display area is shifted by k (S14). If it protrudes, Ex 'is fixed to the value of 480 at the bottom of the Y coordinate (S13). If the value of k is negative and the absolute value is moved in the Y-axis direction (S12), the display area is shifted by k if it does not protrude from the screen display area (S15). If it protrudes, Sx 'is fixed to the leftmost value of 0 on the Y coordinate (S16).

As described above, the display start address (Sx ', Sy') of the movement destination and the display end address (Ex ', Ey) so as not to protrude from the screen display area in each of the X-axis direction and the Y-axis direction. '). When the display size of the bitmap data is 720 × 480,
The display position is not changed, assuming that the sender side has intentionally given the instruction.

As another embodiment of the present invention, a case where there is two sub-picture data for one main picture data, for example, a case where there are English and Japanese subtitles will be described.
FIG. 3 is a schematic diagram showing a schematic configuration of another embodiment of the video decoder of the present invention. In FIG. 3, a video decoder includes a main video decoder 301, a sub video decoder 302,
An image mixing unit 303 is provided. Sub-picture decoder 30
2 is a first pixel data decoder 304, a first display control data decoder 305, a second pixel data decoder 3
06, a second display control data decoder 307, a display address conversion unit 308, a display position designation unit 309, and an on-screen setting unit 310.

It is assumed that the user selects sub-picture data to be displayed simultaneously from a plurality of sub-picture data. Here, the first selected sub-picture data is the first sub-picture data, and the second selected sub-picture data is the second sub-picture data. The selected sub video data is selected from the main video data transmitted together, for example, by an ID or the like.

In FIG. 3, main video data is input to a main video decoder 301, and sub video data is input to a sub video decoder 302. The first pixel data of the first sub-picture data is input to the first pixel data tegorder 304, and the first display control data is input to the first display control data decoder 305. The first pixel data decoder 304 converts the first pixel data into bitmap data. The first display control data decoder 305 obtains the display style, display position, and the like of the bitmap data, and outputs them to the display address conversion unit 308.

The second pixel data of the second sub-picture data is input to a second pixel data tegoder 306,
The second display control data is input to the second display control data decoder 307. Second pixel data decoder 30
7 converts the second pixel data into bitmap data. The second display control data decoder 307 obtains a display style, a display position, and the like of the bitmap data and outputs them to the display address conversion unit 308.

Next, the first display control data decoder 30
The display position (display address) of the bitmap data analyzed by the fifth and second display control data decoders 307 is
It is input to the display address conversion unit 308. The display position (display address) specified by the display position specifying unit 309 is compared with the input display address, and the display address of the movement destination is calculated. The on-screen setting unit 310 converts the bitmap data from the first pixel data decoder 304 and the second pixel data decoder 306 according to the analysis result of the first display control data decoder 305 and the second display control data decoder 307. Determine the display position. Then, the video mixing unit 303 superimposes the two bitmap data as one bitmap data on the main video.

A method of converting the display address of the bitmap data in the first display control data decoder 305, the second display control data decoder 307, and the display address conversion unit 308 will be described. FIG. 4 is a flowchart showing a display address conversion method in another embodiment of the video decoder of the present invention. The display start address of the first sub-picture data specified by the sender is (X, Y) = (S1
x, S1y) and the display end address is (X, Y) = (E1
x, E1y). The display start address specified by the sender of the second sub-picture data is (X, Y) = (S2
x, S2y), and the display end address is (X, Y) = (E2
x, E2y). The display start address after the address change is (S1x ', S1y'), (S2x ', S2y'),
The display end address is (E1x ', E1y'), (E2
x ', E2y').

From the information analyzed by the first display control decoder, the display address (S1x, S1x) of the first sub-picture data is obtained.
1y) and (E1x, E1y) are extracted (S1). Similarly, the display address of the second display control decoder (S1x,
S1y) and (E1x, E1y) are extracted (S2). Next, whether or not the display addresses of the first sub-picture data and the second sub-picture data are within the display area of 720 × 480, the second sub-picture data is displayed at the top of the screen of the first sub-picture data. Is determined (S3). If display is possible, Y of the second sub-picture data
The axis display address is converted (S5). If display is not possible, it is determined whether it is possible to display the second sub-picture data at the lower part of the screen of the first sub-picture data (S4).
If display is possible, the Y-axis display address of the second sub-picture data is converted (S6). If display is not possible, the process ends.

Next, in order to unify the X-axis display addresses of the first sub-picture data and the second sub-picture data, the respective X-axis display start addresses are compared (S7), and the smaller the numerical value is, the better. Unified (S8), (S9). Similarly, the respective X-axis display end addresses are compared (S10),
The values are unified to the larger one (S11), (S12).

As described above, the display start addresses after the change (S1x ', S1y'), (S2) so as not to protrude from the screen display area in each of the X-axis direction and the Y-axis direction.
x ', S2y'), the display end address (E1x ', E1
y ') and (E2x'E2y') are calculated.

If both the first sub-picture data and the second sub-picture data can be displayed, the display start address is (S2
x ', S2y') and the display end address is (E1x ', E1
Processing is performed so that display control is performed as single bitmap data of y ′). However, if there is a difference between the X-axis addresses before the change of the first sub-picture data and the second sub-picture data, the dummy data (0) is set at the right end or both ends of the X-axis of the bitmap data having a small display area. ) Is inserted, and processing is performed so that distortion does not occur in the bitmap data.

When the second sub-picture data cannot be displayed due to the display size of the sub-picture or the display position of the first sub-picture data, that is, the display size of the first sub-picture data is 720 × If it is 480, or if it is displayed at the center of the screen, if the second sub-picture data is not complete, it is assumed that the sender side has intentionally instructed it and the simultaneous display of the two sub-picture data is performed. Don't do it.

[0034]

According to the present invention, the display position of a sub-picture can be changed in a video decoder for receiving video data in which a main picture and a sub-picture are transmitted together and displaying the picture data on a monitor or the like. When there are a plurality of sub-pictures, a plurality of sub-pictures can be displayed simultaneously.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of an embodiment in a video decoder of the present invention.

FIG. 2 is a flowchart illustrating a method of converting a display address in the video decoder according to an embodiment of the present invention.

FIG. 3 is a schematic diagram showing a schematic configuration of another embodiment of the video decoder of the present invention.

FIG. 4 is a flowchart showing a display address conversion method in another embodiment of the video decoder of the present invention.

FIG. 5 is a block diagram showing a conventional video decoder.

FIG. 6 is a schematic diagram showing display addresses of sub-pictures on a screen.

[Explanation of symbols]

 101: Main video decoder 102: Sub video decoder 103: Video mixing unit 104: Pixel data decoder 105: Display control data decoder 106: Display address conversion unit 107: Display position Designating unit 108 On-screen setting unit 301 Main video decoder 302 Sub-video decoder 303 Video mixing unit 304 First pixel data decoder 305 First display control .. Data decoder 306... Second pixel data decoder 307... Second display control data decoder 308... Display address converter 309... Display position designator 310.・ Main video decoder 502 ・ ・ ・ Sub video decoder 503 ・ ・ ・ Video mixing unit 504 ・ ・ ・ Pixel data Coder 505: Display control data decoder 506: On-screen setting unit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04N 7/08 7/081

Claims (3)

[Claims] 1. A main video decoder for decoding main video data to obtain a main video, a pixel data decoder for decoding pixel data of sub-video data sent together with the main video data and converting the data into bitmap data, A display control data decoder for decoding the display control data of the sub-picture data to obtain a display address of the bitmap data; and the bitmap data as a sub-picture based on the display address of the display control data decoder. An image decoder comprising: an on-screen setting unit that sets a display position to be superimposed; and a video mixing unit that mixes the sub-video and the main video based on the display position set by the on-screen setting unit. A display position designating unit for designating the display address obtained from the display control data. Video decoder characterized by comprising a display address conversion unit for converting the display address specified by the location specifying unit. 2. The video decoder according to claim 1, wherein said display address conversion section, when there are a plurality of sub-picture data, a display start address of a sub-picture to be displayed on an uppermost portion on a screen and a lowermost portion on a screen. A display end address of a sub-picture to be displayed as a display address of a sub-picture. 3. The video decoder according to claim 1, wherein the display address conversion section, when there are a plurality of sub-picture data, a display start address of a sub-picture displayed on the leftmost portion on the screen and a display start address on the screen. A video decoder, wherein a display end address of a sub-picture displayed on a right portion is a display address of a sub-picture.