CN101520989A - Hardware integrated design of the video liquid crystal display control of YUV format and RGB format - Google Patents

Abstract

The invention discloses a hardware integrated design which supports the video display control of an 8-bit 4:2:0 YUV format and a 16-bit computer RGB565 format and supports the liquid crystal display of the formats with the resolution of no more than 1024*1024. In the display of RGB, a hardware utilizes one channel of DMA for obtaining the data of RGB from the memory and then uses the display control of RGB for displaying the data on a liquid crystal screen; in the display of YUV, a hardware utilizes two channels of DMA for respectively caching part of the U and V data in the memory into a special storage space of 1KB in the hardware. Simultaneously, the Y data is read from the memory through one channel of DMA and the YUV format is converted into the RGB format by a YUV-to-RGB computing module and then the Y data is output onto the liquid crystal display.

Description

The integrated design of hardware of the video LCD Controller of yuv format and rgb format

Technical field

The present invention relates to the integrated design of hardware of the video LCD Controller of a kind of compatible yuv format and rgb format, can be widely used in portable set and handheld device, such as mobile phone, camera, MP3, MP4, game machine etc.

Background technology

The display control module of present embedded chip all is to show the RGB data basically, and the view data that current decoder MPEG series video image produces normally adopts yuv format (or the YCrCb of 8 4:2:0 form, be a kind of employing brightness Y-signal, the color coding form of color U signal and saturation degree V signal).Method commonly used is the rgb image data that YUV is changed into 24 RGB or 16 by computed in software, with the memory headroom of RGB data transmission, show then by next RGB data in the internal memory are reflected on the LCD of RGB display control module to display controller.

Adopt aforesaid way to convert the YUV view data to rgb image data, need take a large amount of MPU (Graphics Processing Unit) resource, cause MPU picture decoding speed to descend.

Another kind of disposal route is a look-up table, by tabling look-up, convert the YUV view data to rgb image data and be stored in the memory headroom, though the MPU that this method takies is few, because 16 rgb image data amount is 1.3 times of the YUV image data amount, 24 rgb image data amount is 2 times of YUV image data amount, so, adopt this mode need employ very big memory headroom, generally need to take about 6KB, so just increased the hardware manufacturing cost.

Summary of the invention

Currently to be yuv image and to take the many and big deficiency of committed memory of MPU when playing in order to overcome, the invention provides a kind of hardware design of the video demonstration of 8 YUV 4:2:0 forms of supporting and solved above-mentioned two problems at mpeg decode.The present invention is by integrated operation of data module that is specifically designed to the data-switching rgb format of computing yuv format on hardware design, thereby alleviated the computational burden of MPU, increased the operation efficiency of MPU.The present invention's design is the view data of yuv format owing to what store in memory headroom, thereby has reduced the committed memory space resources.

The U in the yuv data that the present invention is achieved in that increases a 1KB on hardware on-chip SRAM storer comes out as decoding and the buffer area of V component, use simultaneously three passages of DMA when the YUV image shows, this is buffered in specific the time by two passages in three passages of DMA wants data to be put into buffer memory in the data field of the U in internal memory and V respectively.Also increasing a YUV in the hardware changes the hardware realization of RGB.When wanting video to show, from internal memory, take the Y data by a passage in three passages of DMA, directly from buffer memory, take the data of U and V, the hardware computing of changeing RGB through YUV becomes RGB, give the display control module of RGB again, display control module can send to the RGB that computing becomes on the display screen.

The formula that YUV and RGB change mutually is as follows:

R＝Y+1.14V

G＝Y-0.39U-0.58V

B＝Y+2.03U

Beneficial effect: when showing the rgb video picture format, decoding and the speed of playing do not slow down, and when showing the yuv video picture format, the occupancy of MPU has reduced by 5～10 percentage points, the storage space of data has reduced 30%～50%, and the manufacturing cost of hardware is also very low.

Description of drawings

Fig. 1 is system design figure of the present invention;

The sampling model of Fig. 2 yuv format that to be the present invention use when the image that carries out yuv format shows;

Fig. 3 is the arrangement of the present invention's image pixel on the LCD when the image that carries out yuv format shows.

Embodiment

Below in conjunction with description of drawings the specific embodiment of the present invention: referring to Fig. 1,2,3, present embodiment is that the LCD with 6 * 4 resolution is an example, Fig. 2 is the sampling model of yuv data form of the present invention, letter in circle and the rhombus is represented component of signal separately, the public UV component of per four Y components that close on.Fig. 3 is the data ordering of view data on the LCD of 6 * 4 resolution of invention output.

The present invention is in the view data that shows rgb format, the channel transfer of view data by DMA be to YUV and RGB data flow con-trol module, is directly inputted to the RGB display control module by YUV and RGB data flow con-trol module again and shows on LCD.

The present invention is in the view data that shows yuv format, view data is divided into three parts: Y-signal, U signal and V signal, DMA distributes three passages and transmits above-mentioned signal data respectively then, the Y-signal data directly are transferred to YUV and RGB data flow con-trol module, U signal data and V signal data are then passed through U, V buffer memory control module is transferred in the UV buffer memory of about 1KB size that the chip integration of the present invention design becomes, and then be transferred to YUV and RGB data flow con-trol module, and process YUV changes the computing of RGB computing module, the transformation of data of yuv format is become the view data of rgb format, be presented on the LCD by the RGB display control module at last.

Use the present invention, when showing the rgb video picture format, decoding and the speed of playing do not slow down, but when showing the yuv video picture format, because DMA has adopted three passages to transmit the YUV view data, make the occupancy of MPU reduce by 5～10 percentage points, the storage space of data has reduced 30%～50%, and the manufacturing cost of hardware is also very low.

Claims (3)

1. demonstration controlling Design that can show YUV and two kinds of view data of RGB is characterized in that: the present invention mainly by DMA direct memory access passage, YUV and RGB data flow con-trol module, UV buffer memory, YUV change the RGB computing module, the RGB display control module is formed.

2. demonstration controlling Design as claimed in claim 1 is characterized in that: described demonstration controlling Design is when showing yuv data, and DMA adopts three passages to transmit Y-signal, U signal and V signal respectively.

3. demonstration controlling Design as claimed in claim 1, it is characterized in that: described demonstration controlling Design has become the buffer area of about 1KB at chip integration, be used for preserving the U signal data and the V signal data of YUV view data, can open the image that speed ground converts the YUV view data to rgb format so that YUV changes the RGB computing module.

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