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.
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I am doing some preliminary work to make a rendering pipeline and I am investigating whether OpenGL is a good option for my use case: from a markup language I need to generate a video, ideally using opengl which already implements most of the primitives I need.
Is there a way to, instead of (or additionally to) updating a framebuffer, to make an mp4 video file using nvenc, without copying data back and forth between the GPU's and main memory?
The nvenc SDK page[1] on the NVidia website suggests that it can, as the current header graphic is of a game being streamed. (Even if it's a Direct3D game, same chip underneath.) A quick search for "nvenc share buffer with OpenGL" turned up a number of people apparently combining the two.
Runs on Linux and MS Windows only, so no joy if you have a Mac.
Hope this helps.
I'm developing a game, actually my first game, so I'm new in this world, I'm using OpenGL with NDK and C++ for the render part, and I call it from java with JNI. I'm stuck with the textures topic, since I need to use PNG with alpha channel and use TTF for some text.
I can include the libpng, but since I'm using the experimental gradle puglin, I don't know how to add the library and use it, I saw that the library can be precompiled and be added, but from what I saw, only for one architecture, then, I don't know if I'm wrong, but I think if I add the source code of the library and compile it with the program, I think, it will be compiled for the architectures that I need (MIPS, 64-bit ARM, x86, 64-bit x86, ARM), so that is one, I was thinking in pre-convert the png in raw RGBA and use that vector directly with opengl but again, I dont know how to do this.
and with the TTF issue, well I am in blank, if you have any advice for this I would greatly appreciate it.
Thanks for your help.
You can build the whole FreeType engine into your code, or you can just use what's already part of Android: use Canvas to render glyphs to a Bitmap. You can find an example of this in Android Breakout. The game is written in Java rather than C++, but the Java-language GLES code is just a thin wrapper around the native stuff, so it's pretty similar.
There's a pretty good blog post about GLES text on Android here.
On a similar note, you already have a copy of libpng in your app. You can call through the Bitmap API to use it.
If you have as a goal the creation of an entirely self-contained native app, then the approach of calling into Canvas/Bitmap isn't viable. I don't think that's a particularly useful goal, however. You're better off separating the "game engine" from the game logic, e.g. have platform-specific "decode PNG" and "pass this pile of RGBA pixels into glTexImage2D()" functions, and platform-agnostic "use texture N".
Taking that one step further, your best approach is to use an existing graphics engine or game engine, and focus on creating the game rather than writing the engine. Learning about engines by writing one is a worthwhile endeavor, but if your actual goal is to write a game then you should focus on the game itself.
I want to manually draw the graphics, what that mean is without using any library or frame work like QT, directX , whindow.h .... like giving command to every pixels on the screen to show some specific color at different time. Every body gives tutorials on based on these library or whatever they are called. What i want is to make my own GUI. As far as I could think it is going to be very complicated, hard to learn and to understand, messy and a lot of time consuming, but I am ready for that. I need some resources to understand that.
and Yes i know C++ so it would better if I had to work with this language but I will learn other language if it is required, just i want to know which language i should learn.
In the old days, you could write directly to video memory with no help from the operating system/ROM. Today, on current hardware, you have to go through the operating system in order to write to the screen. That means using a separate library (like Qt) or using the OS features (windows.h). You could use directX or something and get more raw access to video memory, but that is still using a library/framework.
If you want with C++ and native Windows API (without DirectX) , you should use GDI(Microsoft Graphics device interface) + MFC(Microsoft Foundation Classes) this is a classic implementation of Windows GUI, If you want complicated graphics with shaders you need DirectX/OpenGL without hesitation. meanwhile if you want higher programming framework you can use C#(CSHARP) or Java.
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.
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.