public DecodedVideoFrameParameters(int width, int height, FFmpegPixelFormat pixelFormat)
{
Width = width;
Height = height;
PixelFormat = pixelFormat;
}
/// <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));
}
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);
public static extern int DecodeFrame(IntPtr handle, IntPtr rawBuffer, int rawBufferLength, out int frameWidth,
out int frameHeight, out FFmpegPixelFormat framePixelFormat);
public bool Equals(int width, int height, FFmpegPixelFormat pixelFormat)
{
return(Width == width && Height == height && PixelFormat == pixelFormat);
}
/// <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));
}
