ubifs tools

https://bootlin.com/blog/creating-flashing-ubi-ubifs-images/

Git FW version

https://atadiat.com/en/e-how-to-use-git-to-manage-firmware-versions/

git describe --match=NeVeRmAtCh --always --abbrev=7 --dirty	Return the current commit hash
git describe --abbrev=0	Return the most recent tag name
git show -s --format=%cd --date=format:'-%y-%m-%d'	Return the current commit date
git rev-parse --abbrev-ref HEAD	Return current branch name

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GIT_HASH := $(shell git describe --match=NeVeRmAtCh --always --abbrev=7 --dirty) GIT_BRANCH:=$(shell git rev-parse --abbrev-ref HEAD) GIT_TAG:= $(shell git describe --abbrev=0) COMMIT_DATE := $(shell git show -s --format=%cd --date=format:'-%y-%m-%d' $(GIT_HASH))

.i.e: ‘fw-v.1.13.0-8c0ab15-master-10_1_2020.hex’. 

Alsa G.711, ulaw encode

Alsa Audio Capture

樹莓派sip視頻電話-2：alsa+g711+rtp傳輸音頻

G711 G723 G729線路占多少帶寬問題

image compare similarity

Image Similarity

感知哈希算法（Perceptual hash algorithm）

巴氏系数计算

https://github.com/nivance/image-similarity

ΣCASA

ΣCASA 
https://www.tw.sigmacasa.com/alarm-system

keyword: iot, zwave, apple home kit

u-boot fast boot

https://github.com/ARM-software/u-boot/blob/master/doc/README.android-fastboot-protocol

  

	FastBoot Version 0.4
	----------------------
	The fastboot protocol is a mechanism for communicating with bootloaders
	over USB. It is designed to be very straightforward to implement, to
	allow it to be used across a wide range of devices and from hosts running
	Linux, Windows, or OSX.

EFM32 Gecko

https://siliconlabs.github.io/Gecko_SDK_Doc/efm32g/html/group__LETIMER.html
LETIMER

pthread Barrier

Pthread Barrier:
https://langzi989.github.io/2018/07/05/pthread%E4%BD%BF%E7%94%A8barrier%E6%A0%85%E6%A0%8F%E6%96%B9%E5%BC%8F%E5%90%8C%E6%AD%A5/

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#include <pthread.h> //初始化栅栏，栅栏需要等待到count个线程，才会全部一起放行。 int pthread_barrier_init(pthread_barrier_t *restrict, const pthread_barrierattr_t *restrict, unsigned count); //报道函数，当一个线程到达栅栏的时候，就报道。 //所有的线程都报道后，栅栏自然会放行。 int pthread_barrier_wait(pthread_barrier_t *barrier); 栅栏完成历史使命后，当然是功成身退。 int pthread_barrier_destroy(pthread_barrier_t *barrier);

使用示例

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#include <stdio.h> #include <time.h> #include <stdlib.h> #include <string.h> #include <pthread.h> #include <unistd.h> pthread_barrier_t barrier; void* initor(void* args) { printf("---------------thread init work(%d)--------------\n", time(NULL)); //模拟初始化工作。 sleep(10); //到达栅栏 pthread_barrier_wait(&barrier); printf("--------------thread start work(%d)--------------\n", time(NULL)); sleep(10); printf("--------------thread stop work(%d)--------------\n", time(NULL)); return NULL; } int main(int argc, char* argv[]) { //初始化栅栏，该栅栏等待两个线程到达时放行 pthread_barrier_init(&barrier, NULL, 2); printf("**************main thread barrier init done****************\n"); pthread_t pid; pthread_create(&pid, NULL, &initor, NULL); printf("**************main waiting(%d)********************\n", time(NULL)); //主线程到达，被阻塞，当初始化线程到达栅栏时才放行。 pthread_barrier_wait(&barrier); pthread_barrier_destroy(&barrier); printf("***************main start to work(%d)****************\n", time(NULL)); sleep(30); pthread_join(pid, NULL); printf("***************thread complete(%d)***************\n", time(NULL)); return 0; }

ffmpmeg audio covert

1. ffmpeg -i filename.mp3 newfilename.wav
2.  ffmpeg -i INPUT -f alsa hw:1,7
3.  ffmpeg -i INPUT -f alsa default
4. ffmpeg -re  -i speaker.aac -f wav -ar 48000 -y ee.wav
5. sndfile-resample -to 48000 -c 2 error1.wav e2.wav

Reference:

1. http://manpages.ubuntu.com/manpages/xenial/man1/ffmpeg-devices.1.html
2. https://www.howtoforge.com/tutorial/ffmpeg-audio-conversion/
3. linux/ALSA SRC重采样造成的问题及解决

keyword: alsa, resample, ffmpeg, sndfile-resample, sox, resample, alsa hw