I have written a program using SFML Library (in C++) rendering simple 2D animation.
I would like to save the animation to a video file instead of drawing it on the screen.
Does SFML provide such functionality? Is there any other, portable way to do this? (portable between different OSes)
SFML does not have such a feature, especially since video processing is a whole world of its own. You can take a look at FFmpeg and GStreamer. Both libraries are cross-platform and should be able to record, playback and stream videos. If you want a specific codec, you could directly look at the codec's website and/or search for good encoder.
Overall it's not an easy task and depending on what you're trying to do, you could also think about grabbing the rendering directly with an third-party application, e.g. Open Broadcaster Software or (again) FFmpeg.
Related
I need to use DirectShow (C++) for recording a webcam and saving the data to a file.
I really don't know how DirectShow works, this is a "stage" (working experience), but at school we didn't study it.
I think the best way to implement this could be:
List the video devices connected to the computer
Select the correct camera (there will be only one)
Retrieve the video
Save it to a file
Now there are two problems:
Where can I find a good reference book or how do I start?
The saved video shouldn't be too big, does DirectShow provide a way to compress it?
I won't use OpenCV because sometime it doesn't work properly (It doesn't find the camera).
Are there any high level wrapper that could help?
EDIT: the program won't have a window, it will run in background called by a dll.
Where can I find a good reference book or how do I start?
DirectShow introduction material
The saved video shouldn't be too big, does DirectShow provide a way to compress it?
Yes it provides capabilities to attach codecs, that needs to be installed in the system. These are typically third party codecs (for reasons beyond the scope of brief answer). You might want to record into Windows Media files to not depend on third party codecs. SWee more on MSDN: Choosing a Compression Filter.
I am trying to play a .flv file in the GLUT window using OpenGL and C++ in Linux, but I'm not sure where to start.
Is it possible to do this? If so, how?
Make sure you mean .flv not .swf.
It's quite easy. Decode the video with something like libavcodec and you can use raw frames as textures.
If you really want to do this, check out the source code of Gnash. They've a renderer that use OpenGL. However, rendering is just a small part of the job, you also have to decode audio/video, run actionscript, etc.. in order to run a flash file.
It so complicated that even Adobe didn't manage to make it right :)
If you want to play just some video, look at #Banthar's answer, otherwise:
OpenGL is a no-frills drawing API. It gives you the computer equivalent of "pens and brushes" to draw on some framebuffer. Period. No higher level functionality than that.
Flash it a really complex thing. It consists of a vector geometry object system, a script engine (ActionScript), provides sound and video de-/compression etc. All this must be supported by a SWF player. ATM there's only one fully featured SWF player and that's the one Adobe makes. There are free alternatives, but the are behind the official flash players by several major versions (Lightspark, Gnash).
So the most viable thing to do was loading the Flash player browser plugin in your program through the plugin interface, provide it, what a browser provided to a plugin (DOM, HTTP transport, etc.) and have the plugin render to a offscreen buffer which you then copy to OpenGL context. But that's not very efficient.
TL;DR: Complicated as sh**, and probably not worth the effort.
I need you to recommend me a library for c++ to use with visual c++ 2008 to perform an edition ef the frames from a video source before been rendered on the screen. I dont want to perform effects like blur or things like that, I want to change the size en some cases and other stuff.
I have tried with phonon (where I cant access the frames) and opencv (where I can get the frames but I cant display the audio because the library is for other purpose), I have been reading about directshow on windows but I still dont know if I can recover the frame.
Regards, Marco.
Try ffmpeg. It's what OpenCV uses to read frames.
FFMPEG includes a simple player -- ffplay. Have a look at its source for an idea of how to use the library.
As misha said FFMPEG is THE library for videoacquisition. As you use C++, you can try the simpler to use FOBS, which is a C++ encapsulation of FFMPEG. You can look at the sources if you want to do your own C++ wrap around FFMPEG.
my2c
What is the best/easiest way to display a video (with sound!) in an application using XAudio2 and Direct3D9/10?
At the very least it needs to be able to stream potentially larger videos, and take care of the fact that the windows aspect ratio may differ from the videos (eg by adding letter boxes), although ideally Id like the ability to embed the video into a 3D scene.
I could of course work out a way to load each frame into a texture, discarding/reusing the textures once rendered, and playing the audio separately through XAudio2, however as well as writing a loader for at least one format, ive also got to deal with stuff like synchronising the video and audio components, so hopefully there is an eaier solution available or even a ready made free one with a suitable lisence (commercial distribution in binary form, dynamic linking is fine in the case of say LGPL).
In Windows SDK, there is a DirectShow example for rendering video to texture. It handles audio output too.
But there are limitations and I can't honestly call it easy.
Have you looked at Bink video? Its what lots of games use for video playback. Works great and you don't have to code all that video stuff yourself from scratch.
Is there a good solution for playing a compressed video in OpenGL?
It needs to
Be cross-platform (Windows and MacOSX)
Render to a texture (preferably but not 100% needed)
Cost less than Bink
Any ideas?
Qt can be used to render widgets (including a video player) in an OpenGL scene. It has a multimedia framework called phonon that can play video and audio.
See this demo video.
Qt is cross-platform and is now licensed under LGPL.
I recommend the Theora video format.
Here are the benefits:
Totally open, free and patent-unencoumbered specification
Free working library implementation (encoder/decoder) and source-code examples, available under a BSD-style license
Not too shabby documentation.
Portable
The decoder lets you decode to R'G'B', which can easily be uploaded with an OpenGL buffer object and fetched in a shader via a sampler.
if you mean by solution that you can build/code it, i can suggest quicktime (easy on mac with cocoa, strange on windows but it works) or you can checkout mplayer/vlc sources and try to integrate that. there are a lot of demos about this on the web.
since you need cross platform, i guess gstreamer, video4linux and directshow are nothing for you. but there are video players that support different backends on different platforms - like openFrameworks