KR20070113677A - Video mixer capable of a reducing bandwidth and method thereof - Google Patents

Abstract

A video mixer and a method for reducing a bandwidth are provided to reduce the amount of data processed during predetermined time in a video mixer. A system for displaying an image includes a memory(310), a video mixer(300) and a display controller(320). The memory(310) stores a plurality of window images, and stores mask bit maps corresponding to the window images. The video mixer(300) reads a window image and a mask bit map corresponding to a window selection signal if the window selection signal is activated, and selectively processes pixel values of the window image according to the mask bit map. The display controller(320) receives the final image information processed in the video mixer(300) to control the display.

Description

VIDEO MIXER CAPABLE OF A REDUCING BANDWIDTH AND METHOD THEREOF}

1 is a block diagram schematically illustrating a general video mixer.

FIG. 2 illustrates a mixing operation of the video mixer shown in FIG. 1 when the main window and the menu bar are selected.

3 is a block diagram illustrating a system including a video mixer according to a preferred embodiment of the present invention.

FIG. 4 is a diagram illustrating a configuration of a multi-window screen according to the operation of the video mixer shown in FIG. 3.

FIG. 5 is a diagram illustrating a mask bitmap setting corresponding to each window image and each window image when the main window and the menu bar are selected according to an exemplary embodiment of the present invention.

FIG. 6 is a diagram illustrating a mask bitmap setting corresponding to each window image and each window image when a main window, a menu bar, a pull-down menu, and a pop-up menu are selected according to an exemplary embodiment of the present invention.

7 is a block diagram schematically showing the video mixer shown in FIG. 3 according to a preferred embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100,300,700: Video Mixer 110,310: Memory

340: CPU 350: input unit

101,301,701: DMA controller 1021 to 1024,3021 to 3024: DMA

1031 to 1033,3031 to 3033: Multiplier 120,320: Display control unit

330: display 210,401: main window

202, 402: menu bar 403: pull down menu

404: popup menu 501,601: main window mask bitmap

502, 602: menu bar mask bitmap 603: pull-down menu mask bitmap

604: Popup menu mask bitmap 503,605: Final output screen

The present invention relates to a video display device, and more particularly, to a video mixer included in a video display device.

In general, an image processing apparatus includes a video mixer, which processes multiple images using image processing techniques such as mixing, overlay, and color keying, and finally It is a device for generating image information processed as a. Such video mixers are widely used in such fields as mobile phones, DVD players, and the like, which must support multiple windows.

1 is a block diagram schematically illustrating a general video mixer.

Referring to FIG. 1, a general video mixer 100 includes a plurality of direct memory access devices (hereinafter, referred to as a direct memory access (DMA) device) 1021 to 1024. The DMA devices 1021 to 1024 respectively read pixel information of corresponding window images from the memory 110 under the control of the DMA controller 101. For example, the DMA devices 1021-1024 can access the main window, menu bar, pull down menu, and pop up menu from the memory 110. The pixel information is read as the corresponding window image, respectively. The multipliers 1031 to 1033 of the video mixer 100 mix pixel information of each window image read from the memory 110 and output the mixed pixel information to the display controller 120. .

FIG. 2 illustrates a mixing operation of the video mixer shown in FIG. 1 when the main window and the menu bar are selected.

Referring to FIG. 2, when the main window and the menu bar are selected by the user, the general video mixer 100 reads all pixel information of the main window 201 and all pixel information of the menu bar 202. The video mixer 100 mixes all the read pixel information, and outputs the information on the final image screen 203 to the display controller 120 as the mixed pixel information.

However, as shown in FIG. 2, the video mixer 100 shown in FIG. 1 reads and processes pixel information corresponding to the partial region 2031 of the main window covered by the menu bar from the memory 110. . Therefore, unnecessary pixel information that is not output as the final screen is processed. Therefore, the general video mixer has a problem of wasting bandwidth because the amount of data to be processed at a predetermined time increases.

Accordingly, an object of the present invention is to provide a video mixer and a method thereof capable of efficiently using a predetermined bandwidth.

According to a feature of the present invention for achieving the above object, the image display system stores a plurality of window images, and in response to the corresponding window selection input signals, mask bit maps corresponding to the window images, respectively; A memory configured to store; When a window selection input signal corresponding to any one of the window images is activated, a window image and a mask bit map corresponding to the activated window selection input signal are read from the memory and the window is read according to the read mask bit map. A video mixer for selectively processing pixel values of an image; And a display controller configured to control the display by receiving the final image information processed by the video mixer, and when the corresponding bit value of the read mask bit map is 1, pixel values of the read window image are overlayed / mixed. It is characterized in that the operation. The video mixer includes: a DMA controller which operates in response to an external command and address information; A plurality of DMAs, each of which reads a corresponding window image and a mask bitmap from the memory in response to the address information provided from the DMA controller, and selectively outputs pixel values of the window image according to the read mask bitmap; And a multiplier circuit configured of a plurality of multipliers and processing the window image output from the plurality of DMAs to output the final image information.

According to an aspect of the present invention for achieving the above object, a window image processing method of an image display system for processing an input image signal includes: a mask bit map corresponding to each corresponding window image according to a plurality of window selection input signals Respectively generating and storing the generated mask bit maps in a memory; Reading a bit value of a mask bitmap corresponding to a pixel value of a window image from the memory in response to an external command and address information; Selectively processing pixel values of the window image according to the read mask bit map to generate final image information; And displaying the final image information, and when the corresponding bit value of the read mask bit map is 1, pixel values of the read window image are overlayed / mixed.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

In a preferred embodiment of the present invention, the CPU generates mask bit map information indicating information on a portion to be finally output on the screen for a plurality of windows, and stores each generated mask bit map information in a memory. . The mask bit map allocates 1 bit to each pixel position corresponding to the window image. When the video mixer reads a pixel value for each window image from the memory, the video mixer reads a value of a mask bitmap corresponding to each window image from the memory. Thereafter, the video mixer performs an overlay or mixing operation on the pixel value of each window image only when the bit value of the mask bitmap corresponding to each window image is 1, and outputs the processed final image information to the display controller. . The display controller displays the final image information.

3 is a block diagram illustrating a system including a video mixer according to a preferred embodiment of the present invention.

Referring to FIG. 3, a system according to a preferred embodiment of the present invention includes an input unit 350, a CPU 340, a memory 310, a video mixer 300, a display control unit 320, and a display 330. do. The video mixer 300 includes a DMA controller 301, a plurality of DMA devices 3021-3024, and a multiplication circuit. The multiplication circuit includes a plurality of multipliers 3031-3033. The DMA devices 3021-3024 each include a buffer (not shown in the figure). The input unit 350 may receive a signal for selecting a window image as an input device such as a button of a mobile phone or a mouse of a computer. The CPU 340 sends a command signal to the DMA controller 301 to control the DMA devices 3021 to 3024, respectively, according to an input signal for selecting a window image of the input unit 350. The CPU 340 generates mask bit maps representing pixels to be finally output on the screen in response to input signals for selecting a plurality of window images, and stores the generated mask bit map information in the memory 310, respectively. The mask bit map allocates one bit to each pixel position corresponding to the window image. The memory 310 stores information about the window image and mask bit map information corresponding to the window image input signal. The video mixer 300 reads pixel values of the plurality of window images and mask bitmap values corresponding to the plurality of window images from the memory 310. The video mixer 300 performs a mixing or overlay operation on the pixel values of the window image only when the bit value of the mask bit map is 1, and outputs the processed final image information to the display controller 320. The display 330 displays the final image under the control of the display controller 320.

The DMA controller 301 of the video mixer 300 receives a command signal from the CPU 340 and controls a plurality of DMA devices 3021 to 3024. The DMA controller 301 of the video mixer 300 sends address information including the selected window information and the mask bitmap information corresponding thereto to the DMA devices 3021 to 3024, and the window information and the corresponding address in the memory. The DMA devices 3021 to 3024 are controlled to read information of the mask bitmap. The DMA devices 3021 to 3024 of the video mixer 300 are controlled by the DMA controller 301, and the main window 3101 and corresponding mask bitmap information 3105 from the memory 310 and the menu bar ( 3102, mask bitmap information 3106 corresponding thereto, pull-down menu 3103 and mask bitmap information 3107 corresponding thereto, and pop-up menu 3104 and mask bitmap information 3108 corresponding thereto are read. It is. The DMA devices 3021 to 3024 send the pixel value for the corresponding window information to the multiplication circuit including the multipliers 3031 to 3033 only when the bit value of the read mask bit map information is one. The multiplication circuit including the multipliers 3031 to 3033 generates final image information by mixing or overlaying pixel values of each window information and outputs the generated final image information to the display controller. Each buffer of the plurality of DMA devices 3021 to 3024 serves to delay information read from memory from the video mixer having a relatively slow processing speed.

FIG. 4 is a diagram illustrating a configuration of a multi-window screen according to the operation of the video mixer shown in FIG. 3.

Referring to FIG. 4, the multi-window screen configuration according to the operation of the video mixer 300 includes a main window 401, a menu bar 402, a pull-down menu 403, and a pop-up menu 404. Multiple windows according to a preferred embodiment of the present invention may be configured with more windows, not limited to the main window 401, menu bar 402, pull-down menu 403, and pop-up menu 404. For example, another sub-popup menu may exist in the pop-up menu 404. Depending on the number of windows, the video mixer may include more DMA devices.

FIG. 5 is a diagram illustrating a mask bitmap setting corresponding to each window image and each window image when the main window and the menu bar are selected according to an exemplary embodiment of the present invention.

Referring to FIG. 5, when the user selects the main window 401 and the menu bar 402, the CPU 340 may correspond to the mask bit map 501 and the menu bar 402 corresponding to the main window 401. Each mask bit map 502 is set, and the set mask bit map information is stored in the memory 310, respectively. The mask bit map allocates 1 bit to each pixel position corresponding to the window image.

In the case of the main window 401 and the final image output screen 503 of the menu bar 402 according to the operation of the video mixer 300, the menu bar 402 is overlaid on the main window area 401. . When the video mixer 300 reads image information of the main window 401 and the menu bar 402 from the memory 310 to process the window image information, the main window area 5031 overlapped by the menu bar 402. ) Is an area where image processing is not necessary. Therefore, in the mask bitmap 501 corresponding to the main window 402, the area corresponding to the menu bar 402 (unhatched area) is an area that is not displayed on the final image output screen. The bit value of the bitmap is zero. In the mask bitmap 501 corresponding to the main window 401, an area (hatched area) except the overlapping portion of the menu bar 402 is an area to be displayed on the final image output screen, and the bit value of the mask bitmap is 1 Becomes In the mask bit map 502 corresponding to the menu bar 402, all areas (hatched areas) are displayed on the final image output screen, so that the bit value of the mask bit map is 1.

FIG. 6 is a diagram illustrating mask window setting corresponding to each window image and each window image when a main window, a menu bar, a pull-down menu, and a pop-up menu are selected according to an exemplary embodiment of the present invention.

Referring to FIG. 6, when the user selects the main window 401, the menu bar 402, the pull-down menu 403, and the pop-up menu 404, the CPU 340 may correspond to the main window 401. Mask bit map 601, mask bit map 602 corresponding to menu bar 402, mask bit map 603 corresponding to pull-down menu 403, and mask bits corresponding to pop-up menu 404. Each map 604 is set, and the set mask bit map information is stored in the memory 310, respectively. The mask bit map allocates 1 bit to each pixel position corresponding to the window image.

In the case of the final image output screen 605 of the main window 401, the menu bar 402, the pull-down menu 403, and the pop-up menu 404 according to the operation of the video mixer 300, the main window area 401 ), The menu bar 402, pull-down menu 403, and pop-up menu 404 are overlaid. When the video mixer 300 reads image information of the main window 401, the menu bar 402, the pull-down menu 403, and the pop-up menu 404 from the memory 310 to process the window image information. The main window areas 6061 to 6063 overlapped by the menu bar 402, the pull-down menu 403, and the pop-up menu 404 are areas that do not require image processing. Therefore, in the mask bitmap 601 corresponding to the main window 401, an area (not shaded area) overlapping the menu bar 420, the pull-down menu 403, and the pop-up menu 404 is displayed in the final image output screen. Since there is no need to perform image processing as an area not displayed on the mask, the bit value of the mask bitmap is zero. However, in the mask bitmap 601 corresponding to the main window 401, an area (hatched area) except for the portion overlapping with the menu bar 402, the pull-down menu 403, and the pop-up menu 404 is displayed. As the area to be displayed on the screen, the bit value of the mask bitmap is 1. In the mask bit map 602 corresponding to the menu bar 402, all areas (hatched areas) are displayed on the final image output screen, so that the bit value of the mask bit map is 1.

In the case of the final image output screen 605 of the main window 401, the menu bar 402, the pull-down menu 403, and the pop-up menu 404 according to the operation of the video mixer 300, the pull-down menu 403 ), Some areas of the pop-up menu 404 are overlaid. When the video mixer 300 reads image information of the pull-down menu 403 and pop-up menu 404 from the memory 310 to mix the window image information, the pull-down menu overlapped by the pop-up menu 404. An area 6604 is an area where image processing is not necessary. Therefore, in the mask bitmap 603 corresponding to the pull-down menu 403, an area (not hatched) overlapped by the pop-up menu 404 is an area which is not displayed on the final image output screen, and thus it is not necessary to process the image. Therefore, the bit value of the mask bitmap is zero. However, in the mask bitmap 603 corresponding to the pull-down menu 403, an area (hatched area) except the area overlapped by the pop-up menu 404 is an area to be displayed on the final image output screen and is a bit of the mask bit map. The value becomes 1. The mask bitmap 604 corresponding to the pop-up menu 404 has a bit value of 1 in the mask bitmap since all areas (hatched areas) should be displayed on the final image output screen.

In the present invention, a case in which the user selects the main window 401, the menu bar 402, the pull-down menu 403, or selects more windows may be considered, but with reference to FIGS. It may be described together, so it is omitted.

7 is a block diagram schematically illustrating a video mixer according to a preferred embodiment of the present invention.

Referring to FIG. 7, a video mixer according to a preferred embodiment of the present invention includes a function of reading a mask bitmap and a function of processing a pixel value of a window image only when the bit value of the mask bitmap is 1. . The DMA controller 301 of the video mixer 300 sends address information including the selected window information and the corresponding mask bitmap information to the DMA devices 3021 to 3024 and transmits the window information to the corresponding address of the memory 310. The DMA devices 3021 to 3024 are controlled to read information of the mask bit map corresponding thereto. The DMA devices 3021-3024 of the video mixer 300 may control the main window W1, the menu bar W2, the pulldown menu W3, and the popup menu W4 from the memory under the control of the DMA controller 301. ) W1 [i] [j], W2 [i] [j], W3 [i] [j], W4 [i] [j] and the main window (W1) of the pixel value at position (i, j) for the information. Corresponds to the value B1 [i] [j] of the mask bitmap corresponding to), the value B2 [i] [j] of the mask bitmap corresponding to the menu bar W2, and the pull-down menu W3. The value B3 [i] [j] of the mask bitmap to be read and the value B4 [i] [j] of the mask bitmap corresponding to the pop-up menu W4 are read. The DMA devices 3021 to 3024 have bit values B1 [i] [j], B2 [i] [j], B3 [i] [j], and B4 [i] of each mask bitmap read from memory. Only when [j]) is 1, pixel values of the corresponding window image are output. P1, P2, P3, and P4 of FIG. 7 are pixel values corresponding to (i, j) positions of windows W1, W2, W3, and W4, respectively, and bit values B1 [i] [j] and B2 [of the mask bitmap. i] [j], B3 [i] [j]) and B4 [i] [j]) equal to 1, the pixel values of the corresponding window are output. The multiplication circuit including the multipliers 3031 to 3033 of the video mixer 300 outputs the final image information to the display controller 320 by mixing or overlaying the output pixel values. The display 330 displays the final image under the control of the display controller 320.

As a result, the video mixer 300 processes only the respective window information for the portion to be finally displayed in the plurality of window images read from the memory and outputs the final image information. Therefore, the video mixer 300 may reduce the amount of data to be processed at a predetermined time, thereby reducing bandwidth.

The mask bitmap allocates 1 bit to each pixel position corresponding to the window image, but as the size of the window increases, the size of the map can create another bandwidth waste problem. It is generated by run-length encoding to maintain the 1-bit allocation of.

This is difficult to apply to blending or mixing, where the window behind it can be displayed on the screen, but most video mixers use overlay techniques, which can save bandwidth through mask bitmaps.

In the above, the configuration and operation of the circuit according to the present invention are shown in accordance with the above description and drawings, but this is merely an example, and various changes and modifications are possible without departing from the technical spirit of the present invention. .

According to the present invention as described above, the video mixer 300 outputs the final image information by processing only the respective window information for the portion to be finally displayed in the plurality of window images read from the memory. Therefore, the video mixer 300 may reduce the amount of data to be processed at a predetermined time, thereby reducing bandwidth.

Claims (5)

A memory configured to store a plurality of window images and to store mask bit maps corresponding to the window images in response to corresponding window selection input signals; When a window selection input signal corresponding to any one of the window images is activated, a window image and a mask bit map corresponding to the activated window selection input signal are read from the memory and the window is read according to the read mask bit map. A video mixer for selectively processing pixel values of an image; And And a display controller configured to control the display by receiving the final image information processed by the video mixer. The method of claim 1, And the pixel values of the read window image are overlayed / mixed when the corresponding bit value of the read mask bit map is 1. The method of claim 1, The video mixer A DMA controller which operates in response to commands and address information from the outside; A plurality of DMAs, each of which reads a corresponding window image and a mask bitmap from the memory in response to the address information provided from the DMA controller, and selectively outputs pixel values of the window image according to the read mask bitmap; And And a multiplier circuit comprising a plurality of multipliers and processing the window image output from the plurality of DMAs to output the final image information. In the window image processing method of an image display system for processing an input image signal: Generating a mask bit map corresponding to each window image according to a plurality of window selection input signals, and storing the generated mask bit map in a memory; Reading a bit value of a mask bitmap corresponding to a pixel value of a window image from the memory in response to an external command and address information; Selectively processing pixel values of the window image according to the read mask bit map to generate final image information; And And displaying the final image information. The method of claim 4, wherein And if the corresponding bit value of the read mask bit map is 1, pixel values of the read window image are overlayed / mixed.

Images