waveform

Get better quality from SoundCloud's Waveform.js lib

半世苍凉 提交于 2019-12-09 23:02:39
问题 Currently I'm using Waveform.js (http://waveformjs.org) to generate waveforms from SoundCloud tracks. Unfortunately the generated canvas has a very low image quality (especially on Retina): I would like to create Waveform very similar to the Soundcloud one: Do you know how can I improve the quality of an image? Maybe there's a better solution for generating such waveforms? My app is completely client-side, everything is done in the browser, so perfect scenario for me will be: Send waveform

Sound from mic vs sound from speaker

二次信任 提交于 2019-12-08 12:02:26
问题 I want to capture audio from both the mic and the speaker - separately. How can I distinguish between them? I can capture one or the other using the Wave API, e.g., WaveInOpen(). When I enumerate the devices using waveInGetNumDevs() and waveInGetDevCaps()/waveoutGetDevCaps(), there seems to be no information related to a particular end-point device (e.g., mic or speaker). I only see the following, which are adapter devices: HD Read Audio Input HD Read Audio Output Webcam ... 回答1: I've

ffplay / ffmpeg setup table with audio and video filters

[亡魂溺海] 提交于 2019-12-08 07:33:13
问题 Regards , I want to create a table with ffplay, that display the audio and video monitoring, from a signal like this: Unfortunately I can do only the video section: ffplay -i bar.mxf -vf "split=4[a][b][c][d],[d]vectorscope=m=color3:g=color[dd],[a]waveform=m=1:d=0:r=0:c=7[aa],\[b]waveform=m=0:d=0:r=0:c=7[bb],[c][aa]vstack[V],[bb][dd]vstack[V2],[V][V2]hstack" I can't put together an audio filters with video filters, actually I can't even do the audio section, I've audio filters independent but

ffplay / ffmpeg setup table with audio and video filters

不羁的心 提交于 2019-12-07 16:12:29
Regards , I want to create a table with ffplay, that display the audio and video monitoring, from a signal like this: Unfortunately I can do only the video section: ffplay -i bar.mxf -vf "split=4[a][b][c][d],[d]vectorscope=m=color3:g=color[dd],[a]waveform=m=1:d=0:r=0:c=7[aa],\[b]waveform=m=0:d=0:r=0:c=7[bb],[c][aa]vstack[V],[bb][dd]vstack[V2],[V][V2]hstack" I can't put together an audio filters with video filters, actually I can't even do the audio section, I've audio filters independent but I can't put it together. SHOWVOLUME ffplay -f lavfi "amovie=input.mka, asplit [a][out1]; [a] showvolume

Waveform Visualization in Ruby

你。 提交于 2019-12-07 08:12:37
问题 I'm about to start a project that will record and edit audio files, and I'm looking for a good library (preferably Ruby, but will consider anything other than Java or .NET) for on-the-fly visualization of waveforms. Does anybody know where I should start my search? 回答1: That's a lot of data to be streaming into a browser. Flash or Flex charts is probably the only solution that will be memory efficient. Javascript charting tends to break-down for large data sets. 回答2: When displaying an audio

asp.net create waveform image from mp3

守給你的承諾、 提交于 2019-12-06 11:54:36
问题 I am looking for a way to create a graphical waveform of mp3 files uploaded to a server. From a little research i beleive the mp3 would need converting to a raw format first...but i have no idea on how to create a .gif format of the waveform for this sound file. 90% of the sound files would be over 60 minutes in length. I understand this wouldn't be able to done right after it is uploaded, it would need to be placed into a queue and processed. I have looked at several libaries such as lame,

R equivalent of MATLAB's filter function

时光毁灭记忆、已成空白 提交于 2019-12-06 03:02:18
问题 I'm adapting MATLAB code to R and trying to generate a waveform using ARMA formula. Is there a simple R equivalent function for MATLAB's filter to take AR/MA coefficients to build a waveform? npts = 100; a = [1 0.6]; % AR coeffs b = [1 0.25 3]; % MA coeffs e = randn(npts,1); % generate gaussian white noise waveform = filter(b,a,e); % generate waveform 回答1: Hmm can't you achieve that with filter function in the package signal ? require(signal) a = c(1,0.6) b = c(1,0.25,3) e = rnorm(100)

Calculate saw and triangle wave from specific data

試著忘記壹切 提交于 2019-12-05 05:33:32
问题 I need to calculate a triangle and saw wave but it is a little complicate because of my model and the data I'm able to work with (but maybe I'm just confused). I'm able to calculate my sine wave but I'm not really using a frame counter. What I do is, calculate a theta_increment variable which I can use the next time I need to calculate a sample. This works like this: float x = note.frequency / AppSettings::sampleRate; float theta_increment = 2.0f * M_PI * x; float value = 0; if(waveType ==

How can I load only waveform and wait to user click 'play' to download the audio on Wavesurfer-js?

梦想与她 提交于 2019-12-05 02:19:43
On my server I use Audiowaveform to generate JSON data from my audio files. On frontend I use Wavesurfer-JS to draw the waveform based on previous JSON data. The problem is that on page ready the Wavesurfer-JS download on background the audio file all the time (and not only when the user hit the play button). This is my try. This is the salient part: <div id="waveform"> <audio id="song" style="display: none" preload="false" src="http://api.soundcloud.com/tracks/45398925/stream?client_id=fa791b761f68cafa375ab5f7ea51927a"></audio> </div> <script> var wavesurfer = WaveSurfer.create({ container: '

Generating a static waveform with webaudio

旧时模样 提交于 2019-12-05 01:13:14
问题 I'm trying to generate a static waveform like in audio editing apps with webaudio and canvas. Right now I'm loading an mp3, creating a buffer, iterating over the data returned by getChannelData. The problem is.. I don't really understand what's being returned. What is being returned by getChannelData - is it appropriate for a waveform? How to adjust (sample size?) to get one peak == one second? Why are ~50% of the values are negative? ctx.decodeAudioData(req.response, function(buffer) { buf =