daad777的专栏

原创 黎曼猜想的验证

黎曼猜想简单验证

原创 两个震子如何调整发送信号时间差来调整波束

这个式子中 d是振子的距离不变 λ是波长可以根据频率知道...所以要控制θ 就要控制两个振子的相位差 也就是控制振子a与振子b的时间差就能控制θ。

原创 黎曼猜想推导的数学基础

等比数列求和公式 (1) 等比数列：a (n+1)/an=q (n∈N).(2) 通项公式：an=a1×q^(n-1)；推广式：an=am×q^(n-m)；(3) 求和公式：Sn=n×a1 (q=1) Sn=a1(1-q^n)/(1-q) =(a1-an×q)/(1-q) (q≠1) (q为公比,n为项数）第二道也是哥德巴赫提出的问题,并由欧拉解决,其答案就是伽马函数.第三道题就是黎曼猜想他与质数分布有着一定的关联.伽玛函数（Gamma函数），也叫欧拉第二类积分。欧拉恒等式与泰勒级数的关系。

原创 float base

int main()return 0;

原创 一个极点是e的函数

F(x) = x^n。

原创 拉氏变换笔记

1.拉式变换笔记

原创 docker jupyter notebook pandas

官网参考Jupyter Docker Stacks — Docker Stacks documentation (jupyter-docker-stacks.readthedocs.io)jupyter dockerhttps://jupyter-docker-stacks.readthedocs.io/en/latest/docker run -p 10000:8888 jupyter/scipy-notebook:6b49f3337709http://10.183.67.175:10000/?toke

原创 3gpp 笔记2 序列算法

m=0:1:63zi=cos(pi*25*m.*(m+1)/63)zq=-sin(pi*25*m.*(m+1)/63)scatter(zi,zq)

原创 3gpp笔记

原创 矩阵图解中

图解和差化积内积与x乘 涉及物理意义

原创 语音识别 asr 实践基础之 mfcc

https://colab.research.google.com/github/charlieholy/blog/blob/master/mel.ipynb

原创 GLIBC2.29 gcc2.29

因为环境问题过不了ci发现ci上用的环境依赖GLIBC2.29​在阿里云上编译glibc2.29[root@iZbp1cgthh0yibb7tvfzdiZ build]# cat /etc/redhat-releaseCentOS Linux release 8.3.2011wget http://ftp.gnu.org/gnu/glibc/glibc-2.29.tar.gz ​提示bison没有yum install bison -ymkdir buildcd bui.

原创 yocto

git clone -b gatesgarth git://git.yoctoproject.org/poky.gitsource oe-init-build-env报错了bitbake --versionBitBake Build Tool Core version 1.48.0[root@iZbp1cgthh0yibb7tvfzdiZ build]# bitbakeERROR: The following required tools (as specified by HOSTT.

原创 c\c++ matrix profile

Elem 是 complex 也就是複數計算 vector<32> A matrix<32,32> Bcalc AH dot B dot Aimport numpy as npnp.set_printoptions(suppress=True)import timedef time_me(fn): def _wrapper(*args, **kwargs): start = time.clock() fn(*args, *...

原创 boost sml fiber

https://www.boost.org/b2 --prefix=`pwd`/outputhttps://github.com/boost-ext/sml.gitfiberg++ libs/fiber/examples/simple.cpp -lboost_fiber -lboost_context -g

原创 em-odp

Event machine Open data planeodp-linux - https://github.com/OpenDataPlane/odp./bootstrap./configure --prefix=`pwd`/output && make && make installhttps://github.com/openeventmachine/em-odp.gitexport PKG_CONFIG_PATH=/opt/source/o.

原创 gtest gmock

默认的gtest库是不带调试信息的git clonehttps://github.com/google/googletest.gitgit checkout -b v1.8remotes/origin/v1.8.xcd googletest编译带调试信息的gtest库g++ -fPIC -shared -o libgg.so src/gtest-all.cc -I. -g -O0编译一个测试demo用于调试g++ 1.cpp -L. -lgg -lpthread...

原创 stun turn 抓包

环境家里一个电信wifi 一个移动wifi用两台android手机安装webrtc app进入同一个房间ICE服务var hmac = function (key, content) { var method = crypto.createHmac('sha1', key) method.setEncoding('base64') method.write(content) method.end() return method.read()}...

原创 uboot s3c回忆录

●移植环境：①LINUX系统 如：Red Hat Enterprise Linux 5②交叉编译器 如：EABI_4.3.3③SecureCRT（超级终端）和USB下载工具④U-Boot-1.3.4●开发板相关硬件资源：①CPU：S3C2440AL②SDRAM：型号为K4S561632N，大小为64MB③NOR FLASH：型号为EN29LV160AB-70TCP，大小为2MB④NAND FLASH：型号为K9F2G08U0B，大小为256MB⑤NIC：型号为DM9000EP，位宽为16

原创 gnu radio

https://www.gnuradio.org/doc/doxygen-3.7.2/page_pfb.html

原创 crtmpserver

1.Pulse2.handshake3.readyForSend4.BuildFrame. And. FeedData

原创 qemu linux

http://vault.centos.org/7.4.1708/os/Source/SPackages/把packName.src.rpm解包，会生成一个.tar.gz或者.tar.bz2的压缩包，那个就是源码rpm2cpio packName.src.rpm|cpio-idcentos. kernel compileyum install setools-console httpd policycoreutils-python setools-console vsftpd ft...

原创 viabtc 搭建记录

viabtc服务器搭建一台ubuntu16的系统workspace /home/test/git clone https://github.com/viabtc/viabtc_exchange_server.git viabtc参考 https://github.com/djpnewton/viabtc_exchange_server/blob/ansible/provisioning/build_viaxch.yml搭建apt install build-essentiallib.

原创 webrtc android

netstat -an | findstr 8001 git config --global http.proxy http://127.0.0.1:8001 git config --global https.proxy http://127.0.0.1:8001 git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git apt instal...

原创 zbar [ zxing ]

export C_INCLUDE_PATH=/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/include/darwin:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/includeCMakeLists.txt# the minimum version of CMake.cmake_minimum_required(VERSION .

原创 cocos2d [ mac ] android

mod .gitmodulegit://github.com/cocos2d/cocos2d-console.git --> https://github.com/cocos2d/cocos2d-console.git..cd cocoscmake .. && make

原创 shell [ ffmpeg ]

./configure --enable-libx264--enable-gplalias ffmpeg_show='ffmpeg -hide_banner -devices'alias ffmpeg_devlist='ffmpeg -hide_banner -f avfoundation -list_devices true -i " "'alias ffmpeg_codecs='ffmpeg -codecs'alias ffmpeg_recordlow='ffmpeg -f avfou.

原创 ffplay [ nginx ] flv

https://github.com/nginx/nginx.gityum install pcre-devel zlib-delvemkdir output&./auto/configure --prefix=`pwd`/output&make&make install

原创 ijkplayer [ srs ]

语音合成https://github.com/festvox/flite.git./output/bin/flite -voice slt doc/alice alice.wav

原创 facebook [ yoga ]

refhttps://github.com/facebook/yoga.gitcmake -DCMAKE_TOOLCHAIN_FILE=/Users/chenpeiwen/Library/Android/sdk/ndk-bundle/build/cmake/android.toolchain.cmake ..

原创 变声 效果 [ smbPitchShift 移植 ]

ref：ttp://blogs.zynaptiq.com/bernsee/pitch-shifting-using-the-ft/ void smbPitchShift(float pitchShift, long numSampsToProcess, long fftFrameSize, long osamp, float sampleRate, float *indata, float *outdata){ fft变换之后将频域值左右移动，向左是低频音，...

原创 根据公式解析离散傅立叶

import numpy as npimport matplotlib.pyplot as pltdef signal_xHz(A, fi, time_s, sample): print(fi * time_s * 2 * np.pi) print(sample* time_s) return A * np.sin(np.linspace(0, fi * time_s * 2 * np.pi , num=sample* time_s))sig = signal_xHz(2

原创 wireshark 导出rtp音频流步骤图解

rtp包详解

原创 numpy 画梯度

import numpy as npimport matplotlib.pyplot as plt# y = wx + bdef compute_error_for_line_given_points(b, w, points): totalError = 0 for i in range(0, len(points)): x = points[i, 0]...

原创 vs2015 linux 调试配置记录

vs2015->工具->选项->cross platform配置ssh账户密码工程目标路径 /home/projectsyum install gdb-gdbserver添加头文件路径右键寄存器选择Other register

原创 freeswitch webrtc

小朋友 你是不是有很多问号为什么用网上的webrtc demo就是各种调不通呢？chrome对于安全是认真的所以http ws请出门左拐我们只用https wssstep1 nginx+https1.1首先编译源码支持https--with-http_ssl_module1.2 生成测试用的openssl genrsa -des3 -out server.k...

原创 kaldi 跑了三天纪念一下

原创 openjdk实践-1

apt install ccachejdk-7u80-linux-x64.tar.gzopenjdk-8u40-src-b25-10_feb_2015.7znani.... 

原创 android emu

/opt/qemu_stm32/arm-softmmu/qemu-system-arm -M stm32-p103 -kernel .bin -serial pty-serial file:/opt/se.out-serial tcp::3333,server,nowait/opt/qemu_stm32/arm-softmmu/qemu-system-arm -M stm32-p103 -gdb ...

原创 enjoy Docker