K230 Image Practical - Boot Video and Boot Logo

Overview

This document explains how to implement boot video and boot logo on the K230 EVB development board through video decoding. The video decoding module supports H.264/H.265/MJPEG decoding, with a maximum screen display resolution of 1920x1080 and can be rotated.

1. Environment Preparation

1.1 Hardware Environment

• K230-USIP-LP3-EVB-V1.0/K230-UNSIP-LP3-EVB-V1.1

• Type-C USB cable for power supply.

• SD card

• Screen and cables

• Camera sub-board (IMX335)

1.2 Software Environment

The k230_sdk provides toolchains located in the following paths.

• Large core rt-smart toolchain

k230_sdk/toolchain/riscv64-linux-musleabi_for_x86_64-pc-linux-gnu

• Small core Linux toolchain

k230_sdk/toolchain/Xuantie-900-gcc-linux-5.10.4-glibc-x86_64-V2.6.0

You can also download the toolchains via the following links:

wget https://download.rt-thread.org/rt-smart/riscv64/riscv64-unknown-linux-musl-rv64imafdcv-lp64d-20230222.tar.bz2
wget https://occ-oss-prod.oss-cn-hangzhou.aliyuncs.com/resource//1659325511536/Xuantie-900-gcc-linux-5.10.4-glibc-x86_64-V2.6.0-20220715.tar.gz

2. Source Code Location

The SDK contains a user-space decoding demo located at k230_sdk/src/big/mpp/userapps/sample/sample_vdec. The compiled executable file is located at k230_sdk/src/big/mpp/userapps/sample/elf/sample_vdec.elf. By default, it is not loaded into the large core image and requires modification of the Makefile as described in the execution section to generate the executable file in the /mnt directory after the large core starts.

Source Code Analysis

1. sample_vb_init: Configure vb pool count and initialize vb.

2. vb_create_pool: Configure the block size and number of each pool in vb.

3. kd_mpi_vdec_create_chn: Create a decoding channel.

4. kd_mpi_vdec_start_chn: Start the decoding channel.

5. sample_vdec_bind_vo: Bind the decoder to vo.

6. input_thread: Read data from the file and call kd_mpi_vdec_send_stream to send the data to the VPU.

7. output_thread: Retrieve decoded data from the VPU.

3. Program Execution

1. Modify the mpp-apps compilation script in k230_sdk/Makefile. Change

   cp userapps/sample/fastboot_elf/* $(RTSMART_SRC_DIR)/userapps/root/bin/; \
   

   to

   cp userapps/sample/elf/sample_vdec.elf $(RTSMART_SRC_DIR)/userapps/root/bin/; \
   

2. Copy the H.264/H.265/MJPEG/JPEG files to be displayed into the k230_sdk/src/big/rt-smart/userapps/root/bin directory.

3. Modify k230_sdk/src/big/rt-smart/init.sh with the following command:

   /bin/sample_vdec -i <filename> [-t <sec>]
   

   • <filename> is the video file copied in the previous step.

   • -t is used only when displaying images, specifying the display duration.

4. Execute the make command in the k230_sdk directory.

5. Write the compiled k230_sdk/output/k230_evb_defconfig/images/sysimage-sdcard.img to the SD card, set all DIP switches on the EVB board to OFF (boot from SD card), and the boot video will be displayed.

The display effect is as follows: