I'm working on a project and i'm trying to capture a webcam and use a codex to save the file to the hard disk. but i can't find a program for it ?
It would be cool if the program is controllable from the outside but its not necessary.
(it has to capture the audio to)
vlc can do the recording and conversion directly if given the proper command line options (that however is not trivial but reasonably well documented).
Also there is the library libvlc that you can use to do anything that vlc does; I only used it for playback but I suppose that capturing and saving to file should be not too difficult.
You didn't tell your platform, but both vlc and libvlc are windows/linux/osx and so that shouldn't be a big problem.
This is for example a vlc command line I use to start recording from my webcam
vlc v4l2:// :v4l2-dev=/dev/video0 :v4l2-width=320 :v4l2-height=240
--sout "#transcode{vcodec=x264,acodec=mpga,vb=800,ab=128}
:standard{access=file,dst=capture.avi}"
Related
Boss handed me a bit of a challenge that is a bit out of my usual ballpark and I am having trouble identifying which technologies/projects I should use. (I don't mind, I asked for something 'new' :)
Job: Build a .NET server-side process that can pick up a bitmap from a buffer 10 times per second and produce/serve a 10fps video stream for display in a modern HTML5 enabled browser.
What Lego blocks should I be looking for here?
Dave
You'll want to use FFmpeg. Here's the basic flow:
Your App -> FFmpeg STDIN -> VP8 or VP9 video wrapped in WebM
If you're streaming in these images, probably the easiest thing to do is decode the bitmap into a raw RGB or RGBA bitmap, and then write each frame to FFmpeg's STDIN. You will have to read the first bitmap first to determine the size and color information, then execute the FFmpeg child process with the correct parameters. When you're done, close the pipe and FFmpeg will finish up your output file. If you want, you can even redirect FFmpeg's STDOUT to somewhere like blob storage on S3 or something.
If all the images are uploaded at once and then you create the video, it's even easier. Just make a list of the files in-order and execute FFmpeg. When FFmpeg is done, you should have a video.
One additional bit of information that will help you understand how to build an FFmpeg command line: WebM is a container format. It doesn't do anything but keep track of how many video streams, how many audio streams, what codecs to use for those streams, subtitle streams, metadata (like thumbnail images), etc. WebM is basically Matroska (.mkv), but with some features disabled to make adopting the WebM standard easier for browser makers. Inside WebM, you'll want at least one video stream. VP8 and VP9 are very compatible codecs. If you want to add audio, Opus is a standard codec you can use.
Some resources to get you started:
FFmpeg Documentation (https://ffmpeg.org/documentation.html)
Converting raw images to video (https://superuser.com/a/469517/48624)
VP8 Encoding (http://trac.ffmpeg.org/wiki/Encode/VP8)
FFmpeg Binaries for Windows (https://ffmpeg.zeranoe.com/builds/)
I have mp4 video file,which i need to load on my page,i am using MSE for that,but i don't know how can i get my video in segments with .m4s extensions,with header.m4s as parent segment with all information about my video file stored in it?Please help.
I believe that if a video is embedded on the website, it can be downloaded.
The only thing you could do is make it difficult for download.
This might be helpful. It says using a flash video is a good option to make downloading videos a bit difficult. Never used it but you could give it a try.
To protect the video, you should probably not try to artificially obfuscate the video loading. MPEG DASH supports encrypted MP4 video and common encryption (CENC), that could be a thing you can look into.
I am currently using NAudio to do the audio output. Everything is fine except there is an annoying echo in the background. What can I eliminate such noise?
Thanks,
Adam
If you are not using a headset for a network chat program, then the received audio can get recorded by the microphone again, resulting in an annoying echo. There are some fairly complex echo suppression algorithms that programs like Skype use to detect and eliminate these echoes. Unfortunately NAudio does not include such an algorithm, so you'd need to find a third party one, or write your own.
I am trying to record audio from a microphone/iSight camera from Mac to a NSData object.
I have tried to do it using QTKit, but I found out that you could only save it as a .mov file.
But the fact is that I want to recode the audio into a FLAC file. Is that posible, or I'll need to use another framework?.
Thanks.
Grab the source for VLC (if you can deal w/GPL -- it has limitations on use that many find onerous) and have a read. It does transcoding, amongst other things.
Beyond that, one dead simple approach is to save as AIFF and then use a command line tool (via NSTask) to do the conversion.
Or you could just go with Apple Lossless -- it is open source these days.
Of course, this also begs the question; why do you need lossless compression when recording voice [low bandwidth in the first place] via a relatively sub-par microphone?
Hi I have an adobe air 2 project which records some short sounds via the microphone. I am able to save the streams as wav files but require them to be saved as mp3 (For replaying in the flash player).
Does anyone know if this is possible?
If it isn't is there anyway to get the flash player to player audio in wav form?
Any hints appreciated.
If you are using Adobe AIR v2 then you should be looking for a Non-AS3 commandline tool to convert the wav file to mp3. The process is fairly CPU intensive and would take a LONG time in Actionscript even if there was a library out there that accomplished the task (which I haven't heard of).
My suggestion is to include a tool like LAME with you application and pass your wave file to it (essentially running the process in another thread in C). The only downside is providing an executable for each potential OS you'll be deploying to, if you intend on support Windows, Mac, and Linux that could be up to three different Wave->Mp3 commandline tools.
Link for LAME: http://lame.sourceforge.net/
Seems to be possible: http://www.jordansthings.com/blog/?p=5. No ready source, but libraries listed there should help. (I would just decompile it if need be.)