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[原][Matlab][04] Midi音乐键盘
nwang1986 2015-11-20 18:55
以前在网上读到一个用matlab播canon音乐的源码感觉很有意思,但声音还不够好。 http://emuch.net/html/201205/4521134.html http://wenku.baidu.com/view/31fb6dd476a20029bd642d85 于是想做个自己的音乐播放器,有键盘,有对应的钢琴声音,读取乐谱就能播。如下。 (1)按键的音高与频率 从1到下一个音高的1之间有12个音,分别是:1,1#,2,2#,3,4,4#,5,5#,6,6#,7,1(高)。 假设1的音波振动频率是f,而1(高)的频率是2f,那么这十二个半音之间的频率间隔是2对12开方,即2^(1/12)。 于是各个音的相对频率就确定了。 https://en.wikipedia.org/wiki/Piano_key_frequencies http://blog.sciencenet.cn/blog-81613-673825.html (2)按键的绝对中心频率 钢琴C调1的中心频率是261.626Hz,对应88键钢琴中的第24个白键。这样根据中心频率和相对频率,所有琴键的振动频率就都知道了。 http://www.360doc.com/content/11/0815/08/3416571_140455810.shtml http://my.popiano.org/?508271/action_viewspace_itemid_61861.html (3)采样频率 多种音波采样频率,在此选标准的44100Hz,即每秒钟从声音中采集44100个点。 http://baike.baidu.com/view/23380.htm (4)音速与采样时间 通常的节拍每分钟对应120个四分之一音符,即每个1/4音符的时长是0.5秒,由此可得1/2音符是1秒,1/8音符是0.25秒,1/16音符是0.125秒。 https://zh.wikipedia.org/wiki/%E9%80%9F%E5%BA%A6_(%E9%9F%B3%E6%A8%82) (5)乐器音色 不同的乐器演奏出的音色不同,主要是因为发声时不但有中心频率的振动,还有谐波甚至和频波。在网上下载了标准C键钢琴音进行分析。 http://www.vibrationdata.com/piano.htm 频率:将声音波形FFT变换到频域,发现除中心频率,还有2阶到6阶的谐波,各阶的谐波也有对应的强度。 时域:是一个近似的指数衰减,可以通过拟合曲线得到包络参数。 最终可以将基频与谐波的采样曲线线性叠加并乘以时域的包络曲线得到单个钢琴按键的声音。 (6)变音与升降调 有的时候音符需要升降调,感觉很复杂,看不懂,目前我主要采用升降半音或升降一个全音的方式来实现调的转换。 https://zh.wikipedia.org/wiki/%E5%8D%87%E9%9F%B3%E7%AC%A6 https://zh.wikipedia.org/wiki/%E8%87%AA%E7%84%B6%E5%A4%A7%E8%B0%83 这样通过(1)-(6),钢琴的发声基本完成。 (7)键盘布局 标准钢琴共有88键,其中白键52个,黑键26个。白键长144mm*24mm,黑键长86mm*9mm,以以上参数在matlab中使用rectangle函数分别采用edgecolor和facecolor参数设置边框颜色和填充颜色没有问题。 (8)按键的动态显示 当按下键时使用set函数改变对应按键handleID的facecolor可以实现变色。由于会出现图形图层的变化,可以使用uistack函数将白键设置为底层,黑键设置为顶层。 这样通过(7)-(8),钢琴的按键动画基本完成。 (9)按键声音与按键动画的配合 在程序中首先初始化所有声音,钢琴键盘和为每个按键分配一个handleID,将每个ID与该ID进行声音和图像关联。当需要对一个音符响应时,首先将音符翻译到对应的handleID,然后设置该ID的键变色,然后开始播放声音,根据音符的长度使用pause函数停顿对应的时长,然后将ID的按键颜色复原。 (10)乐谱读取 最方便的播放方法是将乐谱写在一个文本文件中,程序读取文本文件,然后翻译成音符,然后再翻译成handleID,然后播放。我用一个6位字符表示一个音符,比如1#+104表示音高为1升半音再高一个八度音符是1/4音符;比如3-216表示音高为3再减2个八度音符是1/16音符;1/4-108表示音高为1的键和音高为4减一个八度的键同时按下持续时长对应1/8音符。 在程序中使用fgets读取文件,并将所有行连接成一个单行字符串,然后使用regexp的split方法将字符串用空格分开,再用split方法用/符号将各元胞分开得到单个音符,然后判断音符的音高,是否升降半音,是否升降八度,音符长度。之后根据音调得到这个按键对应的handleID,是否是黑键,和音符长度。 通过(9)-(10),乐谱读取和播放的功能就实现了。 (11)音乐保存 想把生成的音乐保存下来,首先要把所有的音符根据其时长间隔加到同一个一维数组上,然后使用audiowrite函数保存为文件。 (12)视频保存 想把视频保存下来,首要要把所有的按键响应动画使用getframe获取,然后使用VideoWriter,open,writeVideo,close函数实现。中间需要根据帧速和音符长度设置每帧写入的数量。 (13)合成多媒体 将视频和音乐合成在一起就完美了,但我还没有实现,有个toolbox可以做,但目前由于采样率的不同遇到一些问题。可以在matlab的命令行窗口中输入ex_combine_video_and_andio_streams打开示例查看。最终将matlab生成的视频和音乐用moviemaker合成,可以得到初级的视频效果。 附件: CanonC.mp4 (CanonC调), CanonD.mp4 (CanonD调)
个人分类: [原创]|5986 次阅读|0 个评论
Wiley作者话科研:Wiley Video Abstract
WileyChina 2015-1-7 11:48
在谷歌、脸书、推特和YouTube出现之前,世界是印刷的世界。大多数人通过阅读、写作和发表文章来了解新的信息、分享观点和促进研究。现在,因为有了微软Word软件的编辑修改功能,我们可以迅速地避过以往那些耗费时间的工作。除此以外,我们还可以用社交媒体和其他软件完成和扩充我们的观点和研究。 越来越多的新期刊,越来越多的文章,无论对于文章的作者抑或检索相关文章的读者来说,都是不小的新挑战。 我们新近推出了“ Wiley 作者话科研( Wiley Video Abstract )”的短视频项目,为作者与读者提供多一种快捷检索信息的选择。 什么是 “ Wiley 作者话科研( Wiley Video Abstract )” ? 简单来说,是在作者的文章中放入一个介绍性的短视频,作者通过这个视频吸引读者。虽然作者的这篇文章有文字版的摘要,但是这个短视频能在新的层面上吸引读者。 “ Wiley 作者话科研”服务首先由 Wiley 期刊的编辑推荐青年研究者已经发表的文章, Wiley 作者市场部门将与文章的作者合作,拍摄 5 分钟左右的短视频,向读者介绍已经发表文章的相关背景、研究目前和方法、 得到的结果及结论、应用前景等。 “ Wiley 作者话科研( Wiley Video Abstract ) 的优点是什么? 据统计,配有短视频形式摘要的文章,其下载总量比没有此形式文摘的文章要多许多。 2012年至2013年,Wiley市场部在Wiley期刊 Family Process 上实施了市场调查。调查结果显示配有短视频形式摘要的文章平均下载量为每月115次,而不配有短视频形式摘要的文章平均下载量为每月63次。配有短视频形式摘要的文章平均 下载量提高了82% ! Wiley 作者话科研( Wiley Video Abstract ) Title: Biodegradable Thermogelling Polymers: Working Towards Clinical Applications Author: Qing Qing Dou, Sing Shy Liow, Enyi Ye, Rajamani Lakshminarayanan, (Institute of Materials Research and Engineering (IMRE), Singapore, Singapore) Xian Jun Loh (Institute of Materials Research and Engineering;National University of Singapore, Singapore;Singapore Eye Research Institute) Journal: Advanced Healthcare Materials Wiley 作者话科研( Wiley Video Abstract ) Title : Voice-associated static face image releases speech from informational masking Author: Yayue Gao , Shuyang Cao, Tianshu Qu, Xihong Wu, Haifeng Li, Jinsheng Hang, Liang Li (Department of Psychology, Peking University) Journal: PsyCh Journal
个人分类: Videos|2854 次阅读|0 个评论
video文件切割小工具LilyVideoCutter.exe
Riemann7 2013-8-5 17:31
LilyVideoCutter.exe这个工具主要用于切割任意格式的video文件,它是命令行格式的,命令为如下形式: LilyVideoCutter -ss 00:00:00 -i F22.flv -vcodec copy -acodec copy -t 00:01:00 F22_part.flv 其中-i为输入video文件,-ss为切割开始时间( 00:00:00表示时:分:秒 ),- t 为切割持续时间(00:00:00表示时:分:秒),最后为输出文件 ,最后为输出wav文件 下载链接如下: LilyVideoCutter.rar 或者 http://vdisk.weibo.com/s/HMB9h
个人分类: 科研DEMO|2495 次阅读|0 个评论
[转载]知识视界video Library(“知识视界”视频图书馆)开通
icstu1 2013-7-15 11:02
“知识视界Video Library”专业科学教育视频资源,是以视音频资源为基础,配合海量的图片资源及文字资源,为用户呈现集视、听、教、学、研一体的多媒体科教平台。“知识视界Video Library”分为自然科学、人文历史、工程技术、军事侦探、医学保健、专题讲座、语言学习七个大类及二十八个二级分类,库中资源以专业的表现形式、科学严谨的视角、丰富充实的画面信息将知识一一直观地展现在用户面前,为教师的教学科研提供优秀素材,为学生拓展知识面提供强有力的支持。 个性化特性功能: 1 、检索功能 1.1 画面检索:用户能快捷的从上百万个知识点中检索到所需要的画面内容,检索可精确到 每一秒的画面,并支持中英文双语检索。 1.2 高级检索:用户通过名称、简介、国别、分类、发音、章节片段分别对库中的视频、图 片、文本等资源进行全方位的检索。 2 、视频片段保存及下载:用户通过画面检索到想要的视频片段,点击片段保存按钮,选择好起始点即可以将所需要的视频下载到本地。注:所有保存、下载视频的用户需要先登陆。(注册一分钟内可完成)。 3 、双语外挂字幕:用户可选择调用节目相应的中英文字幕。 4 、官方微博及论坛:及时更新节目,发布信息,用户互动交流。 访问网址: http://www.libvideo.com/
个人分类: A 学生的研究指导|984 次阅读|0 个评论
works of RBM on how to model high dimensional sequence data
justinzhao 2013-4-6 07:50
Great work on high dimensional video sequence modelling using RBM.To read... Learning Multilevel Distributed Representations for High-Dimensional Sequences.Ilya Sutskever and Geoffrey Hinton
个人分类: 读书日记|3440 次阅读|0 个评论
[转载]NU 2012, 17-19 Oktober 2012, Göteborg
fgu 2012-11-26 14:56
http://www.nu2012.se/film-univ-tv.shtml It is the address for video. http://www.nu2012.se/konferensbidrag.shtml Powerpoint for Keynotes and others.
个人分类: Conference|1334 次阅读|0 个评论
高大娘66岁怀孕了,还可能是双胞胎,我不太相信
热度 2 xupeiyang 2012-11-17 23:41
太神啦!我搞医学情报30多年了,没有听说过呢。去查查高龄怀孕的信息。 大家可以看看视频 http://t.itc.cn/tN9LJ http://tv.sohu.com/20121117/n357883876.shtml 11月15日中午,家住长春市绿园区大营子村的一位市民反映,说他们那里有位66岁的老人目前已经怀孕9个月了,预产期就在11月18日,后来医生还跟她说,很可能怀的是双胞胎。 http://t.itc.cn/tN9LJ
个人分类: 老年健康|10418 次阅读|5 个评论
[转载]R-Videos_A&M
zhao1198 2011-12-15 20:18
http://dist.stat.tamu.edu/pub/rvideos/ R videos Title File(s) Description Install How to download and install R Libraries and Packages How to download new packages and update to new version of R Reading in Files Reading_in_Files.txt Kids.txt Kids2.csv Kids3.prn Kids4.txt Reading in text, csv, csv2, excel, tab delimited, fixed width, and SAS files Inputting Data Inputting_Data.txt How to get your data into R Getting Help in R Help with R function, search help, search r-project.org Saving Work Saving_Work.txt Bordeaux.csv Using R scripts, saving work as pdf and eps files Basic Statistics Basic_Statistics.txt sum, mean, median, minimum, maximum, standard deviation Sequences Sequences.txt How to create a sequence with various restrictions Random Number Generator Random_Numbers_Generators.txt generating numbers from normal, uniform, t, and chi-square distribution, setting seed Sampling Sampling.txt Random Samples and Permutations Dates Dates.txt How to read in dates of various formats Time Intervals Time_Intervals.txt time intervals and time sequences Graphs Graphs.txt Bordeaux.csv dividing graphics window,linear model,adding a line,identifying points,qqnorm and qqline functions,box cox transformation Simple R Session Simple_R_Session.txt Bordeaux.csv reading in file, quantiles, boxplot, histogram, regression Chi-Square Chi-Square.txt goodness of fit test, pbinom function Power and Sample Size Power_and_Sample_Size.txt finding 'n', finding power, paired t.test, power for proportion test Bootstrapping Bootstrapping.txt resampling, confidence intervals, histograms Omitting Cases Stacking Data Omitting_Cases_Stacking_Data.txt Drug_Example.txt stack function, omitting cases, identify points One Way ANOVA One_Way_ANOVA.txt basic Analysis of Variance ANOVA anova.txt assigning factor levels and Analysis of Variance table Two Way ANOVA with Interaction 2_Way_ANOVA_with_interaction.txt ANOVA with Interaction term Nested with Random Effects Nested_with_Random_Effects.txt ANOVA, mixed effects model (lmer)
个人分类: R&Rstudio|1085 次阅读|0 个评论
[转载] A cool HD video about the Earth
zuojun 2011-11-15 07:35
The planet we call home, seen from 240 miles up http://news.yahoo.com/blogs/sideshow/planet-call-home-seen-240-miles-145006199.html
个人分类: Tea Time/Coffee Break|1596 次阅读|0 个评论
ACS: 如何发表你的研究成果 (Video & Audio)
热度 1 luo971 2011-5-11 19:07
Navigate the Research Publication Process with Publishing Your Research 101 Watch the video ACS Publications knows that effective communication of scientific research is vital both to the scientific community and to your scientific career. But sometimes the process of getting your research from the lab to a peer-reviewed journal isn't always simple. That is why ACS Publications has introduced Publishing Your Research 101 , a new educational video series, to assist authors and reviewers with the processes of writing, submitting, editing, and reviewing manuscripts. The first video in the series, "How to Write a Paper to Communicate Your Research," features Professor George M. Whitesides of Harvard University, whose publishing record includes nearly 600 papers in 17 different ACS journals, and over 1100 articles overall; he has also served on the advisory boards of numerous peer-reviewed journals. He has made significant contributions to areas as diverse as nuclear magnetic resonance spectroscopy, organic synthesis, materials and surface science, microfluidics, and nanotechnology. Episode 1: How to Write a Paper to Communicate your Research Watch the video Professor Whitesides answers some of the key questions about manuscript preparation, such as: When should I begin to think about writing up my research for publication? How should I handle the approach of writing while I research? How do new technologies help scientists communicate their work? How many drafts should each paper undergo? Should they undergo an internal review? Do I need to be thinking of actively marketing my articles? How concerned should I be about the title and abstract of my papers? Coming Soon Episode 2: Writing Your Cover Letter will be released in June 2011. The video identifies topics to be discussed in the cover letter that accompanies your original research manuscript, such as how best to communicate the significance of the research to the field, and how the subject of the research study fits with the scope of the journal and its audience of readers. It features interviews with: Inorganic Chemistry Editor-in-Chief Richard Eisenberg, University of Rochester Macromolecules Editor-in-Chief TImothy P. Lodge, University of Minnesota ACS Nano Associate Editor Paula T. Hammond, Massachusetts Institute of Technology ACS Nano Associate Editor Jason H. Hafner, Rice University Topics of future episodes will include: The essential elements of an accepted manuscript Ethical considerations for authors and reviewers Selecting a journal for submission Responding to reviewer comments and manuscript rejections Tips for non-native English speakers Be sure to visit http://pubs.acs.org/r/publishing101 regularly for new episodes! 1155 Sixteenth Street NW Washington, DC 20036
6874 次阅读|5 个评论
推荐两个可以看video lecutre 的网站
iamahappyann 2011-3-11 11:32
http://videolectures.net/ http://videocast.nih.gov/ 就当作是练听力了吧..呵呵
2271 次阅读|0 个评论
The stage of mitosis
sunon77 2008-12-10 03:15
This is a wonderful animation to show how cell mitosis works. First, you push through various cells to enter one of them. You see those large silver worm-like objects, which are mitochondrions.They are power plants of a cell.Later you will see a purple multi-folding monster, which is a golgi complex, which is a cargo-ship to transfer nutritions and proteins to and fro inside the cell. Then you enter the cell nucleus and see those purple DNA stuffs in the stage of messy chromatins . They copied themselves and self-organized to flower-like structures. Two golden objects are two centrosomes. They saparate from each other, and form long microtubules (those long lines), which gradually attached themselves to the middle point of each pair of chromosomes. Finally they pull apart and separate into two parts. So do the rest of cell organelles. Two daughter cells are born at last. This is a real nano-machine which works in an amazing way. :-)
个人分类: 生物物理-biophysics|4070 次阅读|0 个评论

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