public static extern int CreateVideoScaler ( int sourceLeft, int sourceTop, int sourceWidth, int sourceHeight, FFmpegPixelFormat sourcePixelFormat, int scaledWidth, int scaledHeight, FFmpegPixelFormat scaledPixelFormat, FFmpegScalingQuality qualityFlags, out IntPtr handle );
/// <exception cref="DecoderException"></exception> public static FFmpegDecodedVideoScaler Create(DecodedVideoFrameParameters decodedVideoFrameParameters, PostVideoDecodingParameters postVideoDecodingParameters) { if (decodedVideoFrameParameters == null) { throw new ArgumentNullException(nameof(decodedVideoFrameParameters)); } if (postVideoDecodingParameters == null) { throw new ArgumentNullException(nameof(postVideoDecodingParameters)); } int sourceLeft = 0; int sourceTop = 0; int sourceWidth = decodedVideoFrameParameters.Width; int sourceHeight = decodedVideoFrameParameters.Height; int scaledWidth = decodedVideoFrameParameters.Width; int scaledHeight = decodedVideoFrameParameters.Height; if (!postVideoDecodingParameters.RegionOfInterest.IsEmpty) { sourceLeft = (int)(decodedVideoFrameParameters.Width * postVideoDecodingParameters.RegionOfInterest.Left); sourceTop = (int)(decodedVideoFrameParameters.Height * postVideoDecodingParameters.RegionOfInterest.Top); sourceWidth = (int)(decodedVideoFrameParameters.Width * postVideoDecodingParameters.RegionOfInterest.Width); sourceHeight = (int)(decodedVideoFrameParameters.Height * postVideoDecodingParameters.RegionOfInterest.Height); } if (!postVideoDecodingParameters.TargetFrameSize.IsEmpty) { scaledWidth = postVideoDecodingParameters.TargetFrameSize.Width; scaledHeight = postVideoDecodingParameters.TargetFrameSize.Height; ScalingPolicy scalingPolicy = postVideoDecodingParameters.ScalePolicy; float srcAspectRatio = (float)sourceWidth / sourceHeight; float destAspectRatio = (float)scaledWidth / scaledHeight; if (scalingPolicy == ScalingPolicy.Auto) { float relativeChange = Math.Abs(srcAspectRatio - destAspectRatio) / srcAspectRatio; scalingPolicy = relativeChange > MaxAspectRatioError ? ScalingPolicy.RespectAspectRatio : ScalingPolicy.Stretch; } if (scalingPolicy == ScalingPolicy.RespectAspectRatio) { if (destAspectRatio < srcAspectRatio) { scaledHeight = sourceHeight * scaledWidth / sourceWidth; } else { scaledWidth = sourceWidth * scaledHeight / sourceHeight; } } } PixelFormat scaledPixelFormat = postVideoDecodingParameters.TargetFormat; FFmpegPixelFormat scaledFFmpegPixelFormat = GetFFmpegPixelFormat(scaledPixelFormat); FFmpegScalingQuality scaleQuality = GetFFmpegScaleQuality(postVideoDecodingParameters.ScaleQuality); int resultCode = FFmpegVideoPInvoke.CreateVideoScaler(sourceLeft, sourceTop, sourceWidth, sourceHeight, decodedVideoFrameParameters.PixelFormat, scaledWidth, scaledHeight, scaledFFmpegPixelFormat, scaleQuality, out var handle); if (resultCode != 0) { throw new DecoderException(@"An error is occurred while creating scaler, code: {resultCode}"); } return(new FFmpegDecodedVideoScaler(handle, scaledWidth, scaledHeight, scaledPixelFormat)); }
/// <exception cref="DecoderException"></exception> public static DecodedVideoScaler Create(DecodedVideoFrameParameters decodedVideoFrameParms, TransformParameters transformParms) { if (decodedVideoFrameParms == null) { throw new ArgumentNullException(nameof(decodedVideoFrameParms)); } if (transformParms == null) { throw new ArgumentNullException(nameof(transformParms)); } int sourceLeft = 0; int sourceTop = 0; int sourceWidth = decodedVideoFrameParms.Width; int sourceHeight = decodedVideoFrameParms.Height; int scaledWidth = decodedVideoFrameParms.Width; int scaledHeight = decodedVideoFrameParms.Height; if (!transformParms.Region.IsEmpty) { sourceLeft = transformParms.Region.Left; sourceTop = transformParms.Region.Top; sourceWidth = transformParms.Region.Width; sourceHeight = transformParms.Region.Height; } if (!transformParms.TargetSize.IsEmpty) { scaledWidth = transformParms.TargetSize.Width; scaledHeight = transformParms.TargetSize.Height; ScalingPolicy scalingPolicy = transformParms.ScalePolicy; float srcAspectRatio = (float)sourceWidth / sourceHeight; float destAspectRatio = (float)scaledWidth / scaledHeight; if (scalingPolicy == ScalingPolicy.Auto) { float relativeChange = Math.Abs(srcAspectRatio - destAspectRatio) / srcAspectRatio; scalingPolicy = relativeChange > MaxAspectRatioError ? ScalingPolicy.RespectAspectRatio : ScalingPolicy.Stretch; } if (scalingPolicy == ScalingPolicy.RespectAspectRatio) { if (destAspectRatio < srcAspectRatio) { scaledHeight = sourceHeight * scaledWidth / sourceWidth; } else { scaledWidth = sourceWidth * scaledHeight / sourceHeight; } } } FFmpegPixelFormat pixelFormat = ToFFmpegPixelFormat(transformParms.PixelFormat); FFmpegScalingQuality scaleQuality = ToFFmpegScaleQuality(transformParms.ScaleQuality); int resultCode = FFmpegVideoPInvoke.CreateVideoScaler ( sourceLeft, sourceTop, sourceWidth, sourceHeight, decodedVideoFrameParms.PixelFormat, scaledWidth, scaledHeight, pixelFormat, scaleQuality, out var handle ); if (resultCode != 0) { throw new DecoderException(@"An error occurred while creating scaler, code: {resultCode}"); } return(new DecodedVideoScaler(handle, scaledWidth, scaledHeight, transformParms.PixelFormat)); }
/// <exception cref="DecoderException"></exception> public static FFmpegDecodedVideoScaler Create(DecodedVideoFrameParameters decodedVideoFrameParameters, TransformParameters transformParameters) { if (decodedVideoFrameParameters == null) { throw new ArgumentNullException(nameof(decodedVideoFrameParameters)); } if (transformParameters == null) { throw new ArgumentNullException(nameof(transformParameters)); } int sourceLeft = 0; int sourceTop = 0; int sourceWidth = decodedVideoFrameParameters.Width; int sourceHeight = decodedVideoFrameParameters.Height; int scaledWidth = decodedVideoFrameParameters.Width; int scaledHeight = decodedVideoFrameParameters.Height; if (!transformParameters.RegionOfInterest.IsEmpty) { sourceLeft = (int)(decodedVideoFrameParameters.Width * transformParameters.RegionOfInterest.Left); sourceTop = (int)(decodedVideoFrameParameters.Height * transformParameters.RegionOfInterest.Top); sourceWidth = (int)(decodedVideoFrameParameters.Width * transformParameters.RegionOfInterest.Width); sourceHeight = (int)(decodedVideoFrameParameters.Height * transformParameters.RegionOfInterest.Height); } if (!transformParameters.TargetFrameSize.IsEmpty) { scaledWidth = transformParameters.TargetFrameSize.Width; scaledHeight = transformParameters.TargetFrameSize.Height; ScalingPolicy scalingPolicy = transformParameters.ScalePolicy; float srcAspectRatio = (float)sourceWidth / sourceHeight; float destAspectRatio = (float)scaledWidth / scaledHeight; if (scalingPolicy == ScalingPolicy.Auto) { float relativeChange = Math.Abs(srcAspectRatio - destAspectRatio) / srcAspectRatio; scalingPolicy = relativeChange > MaxAspectRatioError ? ScalingPolicy.RespectAspectRatio : ScalingPolicy.Stretch; } if (scalingPolicy == ScalingPolicy.RespectAspectRatio) { if (destAspectRatio < srcAspectRatio) { scaledHeight = sourceHeight * scaledWidth / sourceWidth; } else { scaledWidth = sourceWidth * scaledHeight / sourceHeight; } } } PixelFormat scaledPixelFormat = transformParameters.TargetFormat; FFmpegPixelFormat scaledFFmpegPixelFormat = GetFFmpegPixelFormat(scaledPixelFormat); FFmpegScalingQuality scaleQuality = GetFFmpegScaleQuality(transformParameters.ScaleQuality); int resultCode; IntPtr handle; if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows)) { resultCode = FFmpegVideoPInvokeWin.CreateVideoScaler(sourceLeft, sourceTop, sourceWidth, sourceHeight, decodedVideoFrameParameters.PixelFormat, scaledWidth, scaledHeight, scaledFFmpegPixelFormat, scaleQuality, out handle); } else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux)) { resultCode = FFmpegVideoPInvokeLinux.CreateVideoScaler(sourceLeft, sourceTop, sourceWidth, sourceHeight, decodedVideoFrameParameters.PixelFormat, scaledWidth, scaledHeight, scaledFFmpegPixelFormat, scaleQuality, out handle); } else { throw new PlatformNotSupportedException(); } if (resultCode != 0) { throw new DecoderException(@"An error occurred while creating scaler, code: {resultCode}"); } return(new FFmpegDecodedVideoScaler(handle, scaledWidth, scaledHeight, scaledPixelFormat)); }