Jérôme Labidurie jerome-labidurie

Cheap chinese IP camera with H264 encoding based on Hisilicon 8M (Hi3518E) chip

Video stream url for VLC/DVR:

rtsp://192.168.1.93:554/user=admin&password=&channel=&stream=.sdp?real_stream--rtp-caching=100

Telnet access

telnet 192.168.1.10 23
Localhost login: root
Password: xmhdipc

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

	#!/bin/bash

	modprobe -r ec_sys
	modprobe ec_sys write_support=1

	on="\x8a"
	off="\x0a"

	led(){
	echo -n -e $1 \| dd of="/sys/kernel/debug/ec/ec0/io" bs=1 seek=12 count=1 conv=notrunc 2> /dev/null

	#include <signal.h>
	#include <stdio.h>
	#include <stdint.h>
	#include <string.h>

	#include <mosquitto.h>

	#define mqtt_host "localhost"
	#define mqtt_port 1883