Re: Capturar Video Y Audio Con Vlc
Phyllis Sterlin
Chrome Audio Capture is a Chrome extension that allows users to record any audio playing on the current tab. Multiple tabs can be recorded simultaneously. Recordings can be saved as either .mp3 or .wav files. Users will have the option to mute tabs that are currently being recorded.To begin recording on a tab simply click on the extension icon and use the interface or hotkeys to start and stop the recording. Once the recording is stopped or when the time limit is reached, a new tab will be opened for you to save and name your audio file. Make sure to save your file before closing the tab, otherwise the file will be lost! Check the options page for different output file formats and other features!If you enjoyed the extension, please leave a review on the extension page! Please report any bugs or suggestions using the support tab of the extension page.Note: Currently recordings are limited to 20 minutes due to Chrome memory constraints. Limit can be bypassed, but it is not recommended as more testing is required to determine the maximum time for lower quality settings.Version History:version 1.1.1 - Some fixes improvementsversion 1.1.0 - The long awaited MP3 update! Along with other new features and improvementsversion 1.0.6 - Various bug fixes and better hotkey displayversion 1.0.5 - Fixed keyboard shortcuts macversion 1.0.3 - Reduced max capture time to 20 minutes. Bug fixes.version 1.0.2 - Added timeout function, set max capture time to 25 minutes. Disabled recording on YouTube due to copyright.
An adversary can leverage a computer's peripheral devices (e.g., microphones and webcams) or applications (e.g., voice and video call services) to capture audio recordings for the purpose of listening into sensitive conversations to gather information.[1]
Malware or scripts may be used to interact with the devices through an available API provided by the operating system or an application to capture audio. Audio files may be written to disk and exfiltrated later.
Monitor for API calls associated with leveraging a computer's peripheral devices (e.g., microphones and webcams) or applications (e.g., voice and video call services) to capture audio recordings for the purpose of listening into sensitive conversations to gather information.
Answer: No. There is no single library/solution in python to do video/audio recording simultaneously. You have to implement both separately and merge the audio and video signal in a smart way to end up with a video/audio file.
My solution uses pyaudio for audio recording, opencv for video recording, and ffmpeg for muxing the two signals. To be able to record both simultaneously, I use multithreading. One thread records video, and a second one the audio. I have uploaded my code to github and also have included all the essential parts it here.
Note: opencv is not able to control the fps at which the webcamera does the recording. It is only able to specify in the encoding of the file the desired final fps, but the webcamera usually behaves differently according to specifications and light conditions (I found). So the fps have to be controlled at the level of the code.
To the questions asked above: Yes the code should also works under Python3. I adjusted it a little bit and now works for python2 and python3 (tested it on windows7 with 2.7 and 3.6, though you need to have ffmpeg installed or the executable ffmpeg.exe at least in the same directory, you can get it here: ). Of course you also need all the other libraries cv2, numpy, pyaudio, installed like herewith:
The documentation for the python bindings is extremely light, and most of it seemed centered around the old 0.10 version of GStreamer instead of the new 1.X versions, but GStreamer is a extremely powerful, cross-platform multimedia framework that can stream, mux, transcode, and display just about anything.
I used JRodrigoF's script for a while on a project. However, I noticed that sometimes the threads would hang and it would cause the program to crash. Another issue is that openCV does not capture video frames at a reliable rate and ffmpeg would distort my video when re-encoding.
I came up with a new solution that records much more reliably and with much higher quality for my application. It presently only works for Windows because it uses pywinauto and the built-in Windows Camera app. The last bit of the script does some error-checking to confirm the video successfully recorded by checking the timestamp of the name of the video.
I think the most rated answer above does a great job. However, it did not work perfectly when I was using it,especially when you use a low fps rate (say 10). The main issue is with video recording. In order to properly synchronize video and audio recording with ffmpeg, one has to make sure that cv2.VideoCapture() and cv2.VideoWriter() share exact same FPS, because the recorded video time length is solely determined by fps rate and the number of frames.
With this solution, the camera and the audio will wait for each other.I also tried the FFmpeg Re-encoding and Muxing and even though it was able to synchronize the audio with video, the video had a massive quality drop.
I was randomly getting "[Errno -9999] Unanticipated host error" while using JRodrigoF's solution and found that it's due to a race condition where an audio stream can be closed just before being read for the last time inside record() of AudioRecorder class.
I modified slightly so that all the closing procedures are done after the while loop and added a function list_audio_devices() that shows the list of audio devices to select from. I also added an audio device index as a parameter to choose an audio device.
So, how do I capture audio, use it in a Niagara script and then NOT send that audio back out to the computer? Basically, I just want to capture the audio and not play it back. It seems sill that this is impossible to do.
In order to send the system audio from a Mac system running vMix Desktop Capture for NDI (that is the audio of any programs such as web browsers video players etc), a 3rd party audio driver needs to be installed from the below web site: Once installed the Soundflower driver will need to be selected as both the Sound Output and Sound Input devices in OSX Sound Preferences. The output will route all of the systems audio to Soundflower and the Input will be used by vMix Desktop Capture to send the audio.
I suggest turning on microphone monitoring in alsamixer (if available) to check if capture levels in ALSA are optimal
If monitoring of microphone is not possible arecord can create a test recording direct from ALSA source and parecord can record from PulseAudio
Or use Audacity to record from ALSA source and via Pulse plugin
I 've been using OBS Studio for a long time now and I had to switch to the Flatpack, since the regular package did no longer want to start.
So far I have no issues with the flatpak, recording works flawlessly with four audio streams, screen capture is perfect and also video capture from my webcam.
A shadowplay-like screen recorder for Linux. The fastest screen recorder for Linux.
This is a screen recorder that has minimal impact on system performance by recording a window using the GPU only, similar to shadowplay on windows. This is the fastest screen recording tool for Linux.
HTML5 to the rescue. It might not be apparent, but the rise of HTML5 has broughta surge of access to device hardware. Geolocation (GPS),the Orientation API (accelerometer), WebGL (GPU),and the Web Audio API (audio hardware) are perfect examples. These featuresare ridiculously powerful, exposing high level JavaScript APIs that siton top of the system's underlying hardware capabilities.
Several variants of "Media Capture APIs" have evolved over the past few years.Many folks recognized the need to be able to access native devices on the web, butthat led everyone and their mom to put together a new spec. Things gotso messy that the W3C finally decided to form a working group. Their sole purpose?Make sense of the madness! The Device APIs Policy (DAP) Working Grouphas been tasked to consolidate + standardize the plethora of proposals.
Kinda nice right? I particularly like that it reuses a file input. Semantically,it makes a lot of sense. Where this particular "API" falls short is the ability to do realtime effects(e.g. render live webcam data to a and apply WebGL filters).HTML Media Capture only allows you to record a media file or take a snapshot in time.
Many thought HTML Media Capture was too limiting, so a new specemerged that supported any type of (future) device. Not surprisingly, the design calledfor a new element, the element,which became the predecessor to getUserMedia().
Opera was among the first browsers to create initial implementationsof video capture based on the element. Soon after(the same day to be precise),the WhatWG decided to scrap the tag in favor of another up and comer, this time a JavaScript API callednavigator.getUserMedia(). A week later, Opera put out new builds that includedsupport for the updated getUserMedia() spec. Later that year,Microsoft joined the party by releasing a Lab for IE9supporting the new spec.
Unfortunately, no released browser ever included .One less API to worry about I guess :) did have two great things goingfor it though: 1.) it was semantic, and 2.) it was easily extendible to supportmore than just audio/video devices.
The pace to find a suitable capture API accelerated thanks to the larger WebRTC (Web Real Time Communications) effort. That spec is overseen by the W3C WebRTC Working Group. Google, Opera, Mozilla, and a few others have implementations.
With navigator.mediaDevices.getUserMedia(), we can finally tap into webcam and microphone input without a plugin.Camera access is now a call away, not an install away. It's baked directly into the browser. Excited yet?
To use the webcam or microphone, we need to request permission.The first parameter to navigator.mediaDevices.getUserMedia() is an object specifying the details andrequirements for each type of media you want to access. For example, if you want to access the webcam, the first parameter should be video: true. To use both the microphone and camera,pass video: true, audio: true:
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