I am studying Chrome extensions that do screen recording and make videos out of them. I can not understand how they work yet but I found a common pattern among them all.
They all have a file called video_encoder_main-x86-64.nexe and castify_edit_main-x86-64.nexe which I can not find both them.
I was wondering if anyone who worked before with a similar case where a native client is collecting screen capture to make a webm video or mp4 that I can upload to YouTube.
I want this project to prove a concept for a training company that want to upload screen capture of students solving homework.
Related
I'd like to get the current time of a playing video and then read from a relevant subtitle file and stream the subtitles at the right time to a terminal-like window. Getting the subtitles directly from the video file would probably be more efficient, but I'd like to tackle one problem at a time.
What's the best way to do this?
I've looked at VLC's modules and such, but it seems I'd have to completely recompile it with my module for each targeted platform. Which I'd rather just have a standalone project in C++.
I've tried reversing through cheat engine so I could ReadProcessMemory(). but can't seem to find anything related to current time. Tried VLC and Windows Media Player.
I created a book app and used Cocos2D and physics engine (Chipmunk) to create it. I would like to add "read aloud" feature to it.
So far I found instructions/books and tutorials how to add read aloud feature when book is created with iBook Author (but I couldn't use iBook Author due to some limitations) using Epub3 and SMIL.
I also found a good tutorial from J. Shapiro how to make narrated book using AVSpeechSynthesizer. This helps, only that I would like to use recorded voice, rather than synthesized sound. I don't know if this approach can be modified to do so?
I also know how it can be done in Sprite Kit framework.
The only info that I couldn't find is how to add "read aloud" feature to the app written using Cocos2D. Could it be done within SimpleAudioEngine, or it can be combined with some other engine (possibly from Sprite Kit framework)?
I would appreciate very much if somebody can give me some references/pointers or tutorial links where to look for some answers how to add this feature.
Thanking you in advance.
I would like to use recorded voice, rather than synthesized sound
Good. Add your voice recording audio files (caf, wav or mp3 format) to the project. Play it back at the appropriate time using:
[[SimpleAudioEngine sharedEngine] playEffect:#"someVoiceRecordingFile.wav"];
Define what read aloud means to you because I find that a lot of terms, especially semi-vague ones like this, are used differently depending on who is using it.
When you say read aloud book do you essentially mean a digital storybook that reads the story to you by simply playing narration audio? I've created dozens of these and what you are asking has multiple steps depending on what features you are going for in your book. If you mean simply playing audio and that is it, then yes you could do that in cocos2d using SimpleAudioEngine (as one option) but I assume you already knew that which is why this question has a tab bit of vagueness to it. Either way you probably wouldn't want to play narration as an effect but rather stream it. To do that along with background music you'd stream background music via the left channel and narration via the right. You can easily add a method to SimpleAudioEngine to make this nice and neat. To get you started something similar to this can be used to access the right channel:
CDLongAudioSource* sound = [[CDAudioManager sharedManager] audioSourceForChannel:kASC_Right];
if ([sound isPlaying])
{
[sound stop];
}
[sound load:fileName];
Also use the proper settings and recommended formats for streaming audio such as aifc (or really all audio in general). Although I believe you can stream mp3 without it being decompressed first, the problem is with timing. If you are using highlighted text or looping audio then aifc is the better option. Personally I've never had a reason to use mp3. Wav with narration is something I'd avoid even if just for the file size increase. If the mp3 is decompressed even for streaming (which I'm not sure if it is off the top of my head) then you'd have a huge spike in memory that will be both highly unwanted and at times down right bad.
There are many other things that can go into it but those are the basic first steps. If you want to do things like highlighted text, per-word animations, etc then that will take more work of course and you'd need to be comfortable with cocos2d, SpriteKit, or whatever you decide to use. I'll be doing a tutorial series on it one day soon so I'll cover all of that stuff.
On the other hand, if you are talking about recording someone's voice and having it playback i.e. a mother recording herself reading the story so her child can hear her voice whenever they are using your app, then you'd simply record the audio like you would any other piece of audio, save it to the device, and play it back when the page is displayed in the proper reading mode (or whatever you personally call it). One place to look is the AVAudioRecorder that is part of the AVFoundation framework. Simply Google "iOS audio recording" for examples if you need them.
I'm sure this question would have been asked before but I've searched and can't find anything specific to help a solution.
I'll start out outlining the initial concerns and if more indepth technical information is needed then I can give it. Hopefully there is enough information for the initial question(s).
I'm writing an app using c++ and directshow in visual studio 2010. The main project specification is for a live preview and, at any time of choosing, record the video to mpeg2 to harddrive then to dvd to be played in a standard dvd player, all the time the live preview is not to be interrupted.
The capturing seems a pretty trivial standard straight forward thing to do with directshow.
There are a couple of custom filters that i wrote. Nothing amazing but we wanted our own custom screen overlay information - time and date etc - this must be in the preview and the recorded file. I use the avi decompressor connected to the capture card video out pin, and connect the avi decompressor to my filter to give me an rgb image that i can manipulate. The output from this filter is then split via an inftee filter, one goes to the screen, the other goes into the ms mpeg2 encoder. The audio goes from the capture card audio out into the same mpeg2 encoder. Output from the mpeg2 encoder then goes to a file. That file then gets authored for dvd and burnt to dvd.
So my questions are...
Where and how would be the best place to allow starting and stopping of only mpeg2 file output, to be done via user action?
I have tried using smart tee filters - 1 for video and 1 for audio as the last filter BEFORE the mpeg2 encoder, then using the iamstreamcontrol interface to turn off the pins at the appropriate time. Should this cause any timing issues with the final mpeg2? as the output file will play via mplayer and vlc etc but doesnt get converted to be mpeg2 dvd compliant ( for testing - via any dvd authoring software - complaints of a broken file and somteimes gives time references ) - is it possible that time stamps in the file are a problem and giving an error? If the file is captured from the first moment that capture commences ( as opposed to say after 5 mins of streaming ) then everything is ok.
I did think of using the streambuffer route - http://msdn.microsoft.com/en-gb/library/windows/desktop/dd693041(v=vs.85).aspx - but I'm not sure on the best direction to takes things. It seems that are possibly a few choices for the best direction.
Any help and tips would be greatly appreciated. Especially if theres websites/books/information of DirectShow filters,pins,graphs and how they all flow together.
EDIT: I was thinking of making my own copy of the 'Smart Tee' filter that in that I would have 2 pins coming in - audio and video - and 4 out pins - 2 video ( 1 preview and 1 capture ) and 2 of the same for audio, but would I end up with the same issue? And what is the correct way to handle 'switching off' the capture pins of that custom filter. Would I be wasting my time to work on something like this? Is it a simple case of overriding the Active/Inactive methods of the output pin(s) and either send or not send the sample? I feel its not that easy?
Many thanks!
Where and how would be the best place to allow starting and stopping of only mpeg2 file output, to be done via user action?
For this kind of action I would recommend GMFBridge. Creating your own filter is not easy. GMFBridge allows you to use two separate graphs with a dynamic connection. Use the first graph for the preview and the second graph for the file output. And only connect the graphs after a user action.
The Kinect OpenNI library uses a custom video file format to store videos that contain rgb+d information. These videos have the extension *.oni. I am unable to find any information or documentation whatsoever on the ONI video format.
I'm looking for a way to convert a conventional rgb video to a *.oni video. The depth channel can be left blank (ie zeroed out). For example purposes, I have a MPEG-4 encoded .mov file with audio and video channels.
There are no restrictions on how this conversion must be made, I just need to convert it somehow! Ie, imagemagick, ffmpeg, mencoder are all ok, as is custom conversion code in C/C++ etc.
So far, all I can find is one C++ conversion utility in the OpenNI sources. From the looks of it, I this converts from one *.oni file to another though. I've also managed to find a C++ script by a phd student that converts images from a academic database into a *.oni file. Unfortunately the code is in spanish, not one of my native languages.
Any help or pointers much appreciated!
EDIT: As my usecase is a little odd, some explanation may be in order. The OpenNI Drivers (in my case I'm using the excellent Kinect for Matlab library) allow you to specify a *.oni file when creating the Kinect context. This allows you to emulate having a real Kinect attached that is receiving video data - useful when you're testing / developing code (you don't need to have the Kinect attached to do this). In my particular case, we will be using a Kinect in the production environment (process control in a factory environment), but during development all I have is a video file :) Hence wanting to convert to a *.oni file. We aren't using the Depth channel at the moment, hence not caring about it.
I don't have a complete answer for you, but take a look at the NiRecordRaw and NiRecordSynthetic examples in OpenNI/Samples. They demonstrate how to create an ONI with arbitrary or modified data. See how MockDepthGenerator is used in NiRecordSynthetic -- in your case you will need MockImageGenerator.
For more details you may want to ask in the openni-dev google group.
Did you look into this command and its associated documentation
NiConvertXToONI --
NiConvertXToONI opens any recording, takes every node within it, and records it to a new ONI recording. It receives both the input file and the output file from the command line.
I want to make a screen capture utility, so far i am able to capture the screen in regular interval to get a numbered sequence of images and now i want to encode them to a video format preferably flv(because of good compression and web support)
....I tried the ffmpeg.exe for that reason but for some strange reason it did'nt work
on my vista ultimate...only the first picture is encoded while the rest -I dont know what happened to them.
Also I would prefer doing the encoding stuf programatically (using c/c++ library api if any for that purpose) rather than using tools as ffmpeg.exe and i am interested in encoding picture sequence to video not capturing contineouse video directly.
I searched through internet....there are lots of libraries and tutorial for converting between video formats but I did'nt find something usefull for my problem.
I am not verry proficient with video formats and sdk library, I just need a quick way to encode some pictures to video with some basic control (as time interval between two consecutive frames).
So can you help me with some pointers as to which library i should use and how(code fragment and little descriptive answer would greatly help) and please dont recomend any .NET solution I need to learn something out of this and dont want to apply some bruteforce approach to solve the problem.
Sorry for my english....and thanks in advance.
It appears that an .avi file can more or less directly be made of .jpg's:
An AVI file may carry audio/visual data inside the chunks in virtually any compression scheme, including Full Frame (Uncompressed), ..., Motion JPEG.
Also, something very similar has been discussed here before.