// Draw the captured video frame texture onto a box, rendering to the off-screen frame buffer.
// Read the rendered scene back from the frame buffer and schedule it for playout.
void OpenGLComposite::PlayoutFrameCompleted(IDeckLinkVideoFrame* completedFrame, BMDOutputFrameCompletionResult completionResult)
{
EnterCriticalSection(&pMutex);
// Get the first frame from the queue
IDeckLinkMutableVideoFrame* outputVideoFrame = mDLOutputVideoFrameQueue.front();
mDLOutputVideoFrameQueue.push_back(outputVideoFrame);
mDLOutputVideoFrameQueue.pop_front();
void* pFrame;
outputVideoFrame->GetBytes(&pFrame);
long rowbytes = outputVideoFrame->GetRowBytes();
long height = outputVideoFrame->GetHeight();
long memSize = rowbytes * height;
// make GL context current in this thread
wglMakeCurrent( hGLDC, hGLRC );
// Draw OpenGL scene to the off-screen frame buffer
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, mIdFrameBuf);
// Setup view and projection
GLfloat aspectRatio = (GLfloat)mFrameWidth / (GLfloat)mFrameHeight;
glViewport (0, 0, mFrameWidth, mFrameHeight);
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
gluPerspective( 45.0f, aspectRatio, 0.1f, 100.0f );
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glScalef( aspectRatio, 1.0f, 1.0f ); // Scale x for correct aspect ratio
glTranslatef( 0.0f, 0.0f, -4.0f ); // Move into screen
glRotatef( mRotateAngle, 1.0f, 1.0f, 1.0f ); // Rotate model around a vector
mRotateAngle -= mRotateAngleRate; // update the rotation angle for next iteration
glFinish(); // Ensure changes to GL state are complete
// Draw a colourful frame around the front face of the box
// (provides a pleasing nesting effect when you connect the playout output to the capture input)
glBegin(GL_QUAD_STRIP);
glColor3f( 1.0f, 0.0f, 0.0f );
glVertex3f( 1.2f, 1.2f, 1.0f);
glVertex3f( 1.0f, 1.0f, 1.0f);
glColor3f( 0.0f, 0.0f, 1.0f );
glVertex3f( 1.2f, -1.2f, 1.0f);
glVertex3f( 1.0f, -1.0f, 1.0f);
glColor3f( 0.0f, 1.0f, 0.0f );
glVertex3f(-1.2f, -1.2f, 1.0f);
glVertex3f(-1.0f, -1.0f, 1.0f);
glColor3f( 1.0f, 1.0f, 0.0f );
glVertex3f(-1.2f, 1.2f, 1.0f);
glVertex3f(-1.0f, 1.0f, 1.0f);
glColor3f( 1.0f, 0.0f, 0.0f );
glVertex3f( 1.2f, 1.2f, 1.0f);
glVertex3f( 1.0f, 1.0f, 1.0f);
glEnd();
if (mHasNoInputSource)
{
// Draw a big X when no input is available on capture
glBegin( GL_QUADS );
glColor3f( 1.0f, 0.0f, 1.0f );
glVertex3f( 0.8f, 0.9f, 1.0f );
glVertex3f( 0.9f, 0.8f, 1.0f );
glColor3f( 1.0f, 1.0f, 0.0f );
glVertex3f( -0.8f, -0.9f, 1.0f );
glVertex3f( -0.9f, -0.8f, 1.0f );
glColor3f( 1.0f, 0.0f, 1.0f );
glVertex3f( -0.8f, 0.9f, 1.0f );
glVertex3f( -0.9f, 0.8f, 1.0f );
glColor3f( 1.0f, 1.0f, 0.0f );
glVertex3f( 0.8f, -0.9f, 1.0f );
glVertex3f( 0.9f, -0.8f, 1.0f );
glEnd();
}
else
{
if (mFastTransferExtensionAvailable)
{
// Signal that we're about to draw using mCaptureTexture onto mFBOTexture
mCaptureAllocator->beginTextureInUse();
}
// Pass texture unit 0 to the fragment shader as a uniform variable
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, mCaptureTexture);
glUseProgram(mProgram);
GLint locUYVYtex = glGetUniformLocation(mProgram, "UYVYtex");
glUniform1i(locUYVYtex, 0); // Bind texture unit 0
// Draw front and back faces of box applying video texture to each face
glBegin(GL_QUADS);
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, 1.0f, 1.0f ); // Top right of front side
glTexCoord2f(0.0f, 0.0f); glVertex3f( -1.0f, 1.0f, 1.0f ); // Top left of front side
glTexCoord2f(0.0f, 1.0f); glVertex3f( -1.0f, -1.0f, 1.0f ); // Bottom left of front side
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, -1.0f, 1.0f ); // Bottom right of front side
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, -1.0f, -1.0f ); // Top right of back side
glTexCoord2f(0.0f, 1.0f); glVertex3f( -1.0f, -1.0f, -1.0f ); // Top left of back side
glTexCoord2f(0.0f, 0.0f); glVertex3f( -1.0f, 1.0f, -1.0f ); // Bottom left of back side
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, 1.0f, -1.0f ); // Bottom right of back side
glEnd();
// Draw left and right sides of box with partially transparent video texture
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glBegin(GL_QUADS);
glTexCoord2f(0.1f, 0.0f); glVertex3f( -1.0f, 1.0f, 1.0f ); // Top right of left side
glTexCoord2f(1.0f, 0.0f); glVertex3f( -1.0f, 1.0f, -1.0f ); // Top left of left side
glTexCoord2f(1.0f, 1.0f); glVertex3f( -1.0f, -1.0f, -1.0f ); // Bottom left of left side
glTexCoord2f(0.1f, 1.0f); glVertex3f( -1.0f, -1.0f, 1.0f ); // Bottom right of left side
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, 1.0f, -1.0f ); // Top right of right side
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, 1.0f, 1.0f ); // Top left of right side
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, -1.0f, 1.0f ); // Bottom left of right side
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, -1.0f, -1.0f ); // Bottom right of right side
glEnd();
glDisable(GL_BLEND);
glUseProgram(0);
glDisable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, 0);
}
if (mFastTransferExtensionAvailable)
{
// Finished with mCaptureTexture
mCaptureAllocator->endTextureInUse();
if (! mPlayoutAllocator->transferFrame(pFrame, mFBOTexture))
OutputDebugStringA("Playback: transferFrame() failed\n");
paintGL();
// Wait for transfer to system memory to complete
mPlayoutAllocator->waitForTransferComplete(pFrame);
}
else
{
glReadPixels(0, 0, mFrameWidth, mFrameHeight, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, pFrame);
paintGL();
}
// If the last completed frame was late or dropped, bump the scheduled time further into the future
if (completionResult == bmdOutputFrameDisplayedLate || completionResult == bmdOutputFrameDropped)
mTotalPlayoutFrames += 2;
// Schedule the next frame for playout
HRESULT hr = mDLOutput->ScheduleVideoFrame(outputVideoFrame, (mTotalPlayoutFrames * mFrameDuration), mFrameDuration, mFrameTimescale);
if (SUCCEEDED(hr))
mTotalPlayoutFrames++;
wglMakeCurrent( NULL, NULL );
LeaveCriticalSection(&pMutex);
}
