Can any one tell us pls. I am using DE0 board. Reading bmp image from SDCARD display it on VGA instead of SRAM buffer i m using SDRAM. is it possible to display the bmp image.

Yes it's possible.. But you have to do the work to make it happen. If you already have the BMP decoded in SRAM, you just need to send to to the VGA DAC's with the appropriate timing. for the resolution in question.. A place to start is: http://en.wikipedia.org/wiki/video_graphics_array This place has all the correct video timings for different display resolutions. http://tinyvga.com/vga-timing The OLD crt displays were much more forgiving than new LCD panels on display timing. If you aren't close, most likely they will just remain blank. Get the timing correct, you should start seeing an image. I would just try a constant color frame first, until you get the display up, then move forward with the bmp data. Pete

Thanks.... I m using DE0 board....it doesnt have SRAM .So i'm using SDRAM instead of SRAM. I have been used SDCARD controlle for reading the Bmp image . it successfully written to the SDRAM almost got the output but the image displayed it on reverse in the VGA. i have already tried for constant color frame. it successfully displays the image on VGA. Now i m doing Bmp to display on the VGA. Can u tel how the image data get stored in SDRAM.

The format varies depending on the type of BMP image it is (Color resolution) http://en.wikipedia.org/wiki/bmp_file_format#pixel_array_.28bitmap_data.29 Should give you the information you need. Read the header info to locate your data format. Then I suggest you have a line fifo to output the lines at a constant rate. Fill it at the rate the SDRAM can provide and have it read out at the video rate. Pete

how the 16bit bmp file store the values of RGB. i have written the program as first seperate the header file info. after tat bmp data get starts. is it correct...

This is my coding .. i am not able to get the exact ouput .whats wrong with these..anybody can tel us.... int main() { unsigned char byte_r,byte_g,byte_b; int x,i,j; alt_up_sd_card_dev *sd_card_dev = alt_up_sd_card_open_dev("/dev/SDCARD"); sw=IORD_ALTERA_AVALON_PIO_DATA(SWITCH_BASE); if(sw==1) if(sd_card_dev != 0) { if(alt_up_sd_card_is_Present()) { if(alt_up_sd_card_is_FAT16()) printf("Card is FAT16\n"); else printf("Card is not FAT16\n"); sd_fileh= alt_up_sd_card_fopen("Mire.bmp", 0); if(sd_fileh< 0) printf("Problem creating file. Error %i", sd_fileh); else{ printf("\nReading Bmp file"); for(x=0;x<54;x++){ header=(unsigned char)(alt_up_sd_card_read(sd_fileh)); } //printf("%ld",image_size); for(i=0;i<280;i++){for(j=40;j<320;j++) { byte_b=(unsigned char)(alt_up_sd_card_read(sd_fileh)); byte_g=(unsigned char)(alt_up_sd_card_read(sd_fileh)); byte_r=(unsigned char)(alt_up_sd_card_read(sd_fileh)); pixel=((byte_r>>3)<<11)|((byte_g>>2)<<5)|((byte_b>>3)<<0); IOWR_16DIRECT(SDRAM_BASE,(((i+80)*640+(j))-40),pixel); } } } printf("out of loop"); alt_up_sd_card_fclose(sd); } else printf("Card is not available"); } return 0; }

IS it Possible to display bmp image read from SDRAM

12 Replies

Altera_Forum
Honored Contributor
11 years ago
Hi balakumar,
I'm doing the project containing display image stored in SD card, on VGA. Now, I write the module that read successfully data from SD card, but SD RAM and VGA are the tackles. Could you help me ?
By the way, are you using Nios-II or STORM SoC for integrating all of those components ?

Thanks,
Altera_Forum
Honored Contributor
11 years ago
Hi,

You don't need to make any header file. Any .bmp image has by default a header of 54Byte.
So when ever you start reading a image, the first 54 reads will correspond to that header and after that the actual data is being read.

Forum Discussion

IS it Possible to display bmp image read from SDRAM

12 Replies

Recent Discussions

Cannot find download location for Quartus Prime Lite 19.1

Unable to checkout 'intelqsimstarter' license

DE1-SoC to connect a camera via USB

Arria10 Transceiver Oversampling

Donation fpga boards