103 lines
4.5 KiB
C#
103 lines
4.5 KiB
C#
using libomtnet;
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using SkiaSharp;
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using System.Runtime.InteropServices;
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/*
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* OMT Graphics Example
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*
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* This example generates a horizontal ticker graphic and sends it via an OMT Sender.
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*
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* This demonstrates the alpha channel functionality built into Open Media Transport.
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*
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*/
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namespace omtgraphicsexample
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{
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internal class Program
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{
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static void Main(string[] args)
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{
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Console.WriteLine("OMT Graphics Example");
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//Create the graphics format we will be sending, in this example this is a standard 1080p video.
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SKImageInfo imageInfo = new SKImageInfo(1920, 1080, SKColorType.Bgra8888, SKAlphaType.Unpremul);
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//This is the surface we will be drawing to to create out frame
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SKSurface image = SKSurface.Create(imageInfo);
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//Canvas contains all the drawing functions we will be utilising
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SKCanvas canvas = image.Canvas;
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//Define a rectangle for our ticker
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SKRect rect = new SKRect(0, 960, 1920, 1080);
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SKRoundRect roundRect = new SKRoundRect(rect, 8);
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//Create a simple gradient background for our ticker
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SKShader gradient = SKShader.CreateLinearGradient(new SKPoint(rect.Left, rect.Top), new SKPoint(rect.Right, rect.Bottom), new[] {
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new SKColor(0, 19, 69, 192), // semi-transparent deep blue
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new SKColor(0, 89, 254, 192) // semi-transparent light blue
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}, null, SKShaderTileMode.Clamp);
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SKPaint gradientPaint = new SKPaint() { Shader = gradient };
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//Create the text formatting to use
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SKFont textFont = new SKFont(SKTypeface.FromFamilyName("Sans Serif", SKFontStyle.Bold), 48);
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SKPaint textPaint = new SKPaint() { IsAntialias = true, Color = SKColors.White };
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//Position text in the middle of the gradient rectangle
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SKFontMetrics fontMetrics = new SKFontMetrics();
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textFont.GetFontMetrics(out fontMetrics);
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SKPoint textPosition =new SKPoint(rect.Right, rect.Top + ((rect.Height - (fontMetrics.Ascent + fontMetrics.Descent)) / 2f));
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//This is the text we will be sending along with an estimate of its width to know when to repeat.
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string tickerText = "This is an example of text rendering in SkiaSharp that is sent over Open Media Transport!";
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float tickerTextWidth = textFont.MeasureText(tickerText);
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//Create our sender
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using (OMTSend send = new OMTSend("Graphics", OMTQuality.Default))
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{
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//Create the media frame that contains the final graphic ready for sending
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OMTMediaFrame frame = new OMTMediaFrame();
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frame.Type = OMTFrameType.Video;
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frame.Codec = (int)OMTCodec.BGRA;
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frame.Width = imageInfo.Width;
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frame.Height = imageInfo.Height;
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frame.FrameRate = 59.94F;
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frame.Flags = OMTVideoFlags.Alpha; //Set premultiplied here also if necessary
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frame.AspectRatio = (float)imageInfo.Width / (float)imageInfo.Height;
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frame.ColorSpace = OMTColorSpace.BT709;
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frame.Stride = imageInfo.Width * 4;
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frame.DataLength = frame.Stride * frame.Height;
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frame.Data = Marshal.AllocHGlobal(frame.DataLength);
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frame.Timestamp = -1; //Important, informs OMT to automatically pace our frames to the frame rate.
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Console.WriteLine("Sending graphics on: \"" + send.Address + "\"");
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Console.WriteLine("");
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while (true)
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{
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canvas.Clear(); //Clear our canvas so it is fully transparent
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canvas.DrawRoundRect(roundRect, gradientPaint);
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canvas.DrawText(tickerText, textPosition, textFont, textPaint);
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if (image.ReadPixels(imageInfo, frame.Data, frame.Stride, 0, 0))
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{
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send.Send(frame);
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Console.Write(".");
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} else
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{
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Console.WriteLine("Failed to read pixels from SkiaSharp Surface, exiting....");
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break;
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}
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//Update text position to scroll along the screen
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textPosition.X -= 4;
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if (textPosition.X < -tickerTextWidth) { textPosition.X = rect.Width; }
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}
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}
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}
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}
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}
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