Hi, For rts_osd2_type_text when the string buffer has more than 31 characters, the trailing characters are not printing sometimes and total text ignored if more than 36+ characters are available. The OSD demo provided ameba-rtos-pro2/component/video/osd2/isp_osd_example.c at main · Ameba-AIoT/ameb…

Hi @yugandhar , While we are working on the library update, you may apply this patch for the immediate fix. The value of OSD_TEXT_STR_MAX is set to 128, so technically you can print up to 127 characters per block as long as they can fit into the display by adjusting the width and height. Thank you…

Hi @yugandhar , May we know how many characters are you planning to print? Thank you.

Hi @KevinKL , The length of text may vary based on user input, but we can allow upto 100 characters for Text OSD. Thanks, Yugandhar

Hi @yugandhar , As the changes of maximum char limit might involve the update of library, would you mind to print the characters in multiple separate blocks, where each block prints up to 31 char? Thank you.

Hi @KevinKL , I didn’t see any maximum char limit supported by Text OSD in SDK code or Realtek AmebaPro2 application note — AmebaPro2's Documentation v0.1 documentation , the only example you provided has char array of 64 bytes, so anynone can assume like it may support upto 63 characters, but in r…

Hi @yugandhar , To answer your questions, The maximum supported characters length is OSD_TEXT_STR_MAX - 1, i.e. 31 according to the current macro definition in ameba-rtos-pro2/component/soc/8735b/fwlib/rtl8735b/lib/source/ram/video/hal_osd_util.h at main · Ameba-AIoT/ameba-rtos-pro2 · GitHub Yes,…

Text OSD with 31+ characters has issues

FreeRTOS Multimedia

yugandhar May 29, 2026, 10:45am 8

Hi @KevinKL ,

Is this patch covers OSD text with black color showing black rectangles instead of characters - #10 by yugandhar issue also, recently I got an OSD patch from Pammy.

Thank you.

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Text OSD with 31+ characters has issues

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