I got video frames decoded with vaapi/ffmpeg into a VASurface. Now I want to render them using an OpenGL texture. I was able to load the frames into software (with vaDeriveImage und vaMapBuffer) and update a texture with the received data. But that was really slow and that is not my goal here. Then I found EGL used in a few other repos.
So I found this repo, which does render the frames entirely with EGL as far as I see. This is not what I want. I need it in texture for later use.
Then I came across fmor's demo program. This looks really like magic to me. There are like 2 steps on init and then he can use the texture with no problems.
//in player.c before the decoding happens:
egl_image = egl_create_image_from_va( &surface, player->video_va_display, player->video_cc->width, player->video_cc->height );
if( egl_image == EGL_NO_IMAGE )
goto LBL_FAILED;
glGenTextures( 1, &player->video_texture );
glBindTexture( GL_TEXTURE_2D, player->video_texture );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glEGLImageTargetTexture2DOES( GL_TEXTURE_2D, egl_image );
//in util.c:
EGLImage egl_create_image_from_va(VASurfaceID* _va_surface, VADisplay va_display, int width, int height)
{
EGLImage egl_image;
VASurfaceID va_surface;
VASurfaceAttrib va_surface_attrib;
VADRMPRIMESurfaceDescriptor va_surface_descriptor;
int r;
egl_image = EGL_NO_IMAGE;
va_surface = VA_INVALID_SURFACE;
va_surface_attrib.type = VASurfaceAttribPixelFormat;
va_surface_attrib.flags = VA_SURFACE_ATTRIB_SETTABLE;
va_surface_attrib.value.type = VAGenericValueTypeInteger;
va_surface_attrib.value.value.i = VA_FOURCC_RGBA;
r = vaCreateSurfaces( va_display, VA_RT_FORMAT_RGB32, width, height, &va_surface, 1, &va_surface_attrib, 1 );
if( r != VA_STATUS_SUCCESS )
goto LBL_FAILED;
r = vaExportSurfaceHandle( va_display, va_surface, VA_SURFACE_ATTRIB_MEM_TYPE_DRM_PRIME_2, VA_EXPORT_SURFACE_READ_ONLY, &va_surface_descriptor );
if( r != 0 )
goto LBL_FAILED;
EGLAttrib egl_img_attributes[] = {
EGL_LINUX_DRM_FOURCC_EXT, va_surface_descriptor.layers[0].drm_format,
EGL_WIDTH, va_surface_descriptor.width,
EGL_HEIGHT, va_surface_descriptor.height,
EGL_DMA_BUF_PLANE0_FD_EXT, va_surface_descriptor.objects[va_surface_descriptor.layers[0].object_index[0]].fd,
EGL_DMA_BUF_PLANE0_OFFSET_EXT, va_surface_descriptor.layers[0].offset[0],
EGL_DMA_BUF_PLANE0_PITCH_EXT, va_surface_descriptor.layers[0].pitch[0],
EGL_NONE
};
egl_image = eglCreateImage( eglGetCurrentDisplay(), EGL_NO_CONTEXT, EGL_LINUX_DMA_BUF_EXT, NULL, egl_img_attributes );
if( egl_image == EGL_NO_IMAGE )
goto LBL_FAILED;
*_va_surface = va_surface;
return egl_image;
LBL_FAILED:
if( va_surface != VA_INVALID_SURFACE )
vaDestroySurfaces( va_display, &va_surface, 1 );
return EGL_NO_IMAGE;
}
Can someone tell me what is happening here? And how I can reproduce this without using glew?
My hardest guess is that with the EGL_LINUX_DMA_BUF_EXT parameter for the eglImage creation there is some direct memory accessing ongoing. Is vaapi rendering right into the OpenGL texture here?
Also here is vaExportSurfaceHandle used and I don't really get what this is doing.
Edit: I read through a lot of EGL related posts now. I think I understand a bit more now. But when I looked at fmor's demo program again I got confused. There are several calls of eglGetCurrentDisplay() but I can't find where this Display is set, so I can reproduce that. Could it be, that glew is doing something behind the scenes or am I missing something else?
Even eglInitialze() is never called once.
When I try to instantiate an EGLDisplay on my own with eglGetDisplay(native_display), like it was done in ffvademo, what do I put in for the native_display? In ffvademo there got X11 Display or a DRM Display (?) inserted. Both are as far as I know used to render to the screen, or not? Also I think inserting the vaapi Display would be not the right thing here.
I could really use some help here guys...
