public static FFmpegVideoDecoder CreateDecoder(FFmpegVideoCodecId videoCodecId)
{
int resultCode;
IntPtr decoderPtr;
if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
{
resultCode = FFmpegVideoPInvokeWin.CreateVideoDecoder(videoCodecId, out decoderPtr);
}
else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
{
resultCode = FFmpegVideoPInvokeLinux.CreateVideoDecoder(videoCodecId, out decoderPtr);
}
else
{
throw new PlatformNotSupportedException();
}
if (resultCode != 0)
{
throw new DecoderException(
$"CreateDecoder say: An error occurred while creating video decoder for {videoCodecId} codec, code: {resultCode}");
}
return(new FFmpegVideoDecoder(videoCodecId, decoderPtr));
}
private void TransformTo(IntPtr buffer, int bufferStride, TransformParameters parameters)
{
if (!_scalersMap.TryGetValue(parameters, out FFmpegDecodedVideoScaler videoScaler))
{
videoScaler = FFmpegDecodedVideoScaler.Create(_currentFrameParameters, parameters);
_scalersMap.Add(parameters, videoScaler);
}
int resultCode;
if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
{
resultCode = FFmpegVideoPInvokeWin.ScaleDecodedVideoFrame(_decoderHandle, videoScaler.Handle, buffer, bufferStride);
}
else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
{
resultCode = FFmpegVideoPInvokeLinux.ScaleDecodedVideoFrame(_decoderHandle, videoScaler.Handle, buffer, bufferStride);
}
else
{
throw new PlatformNotSupportedException();
}
if (resultCode != 0)
{
throw new DecoderException($"An error occurred while converting decoding video frame, {_videoCodecId} codec, code: {resultCode}");
}
}
public void Dispose()
{
if (_disposed)
{
return;
}
_disposed = true;
if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
{
FFmpegVideoPInvokeWin.RemoveVideoScaler(Handle);
}
else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
{
FFmpegVideoPInvokeLinux.RemoveVideoScaler(Handle);
}
else
{
throw new PlatformNotSupportedException();
}
GC.SuppressFinalize(this);
}
public unsafe IDecodedVideoFrame TryDecode(RawVideoFrame rawVideoFrame)
{
fixed(byte *rawBufferPtr = &rawVideoFrame.FrameSegment.Array[rawVideoFrame.FrameSegment.Offset])
{
int resultCode;
if (rawVideoFrame is RawH264IFrame rawH264IFrame)
{
if (rawH264IFrame.SpsPpsSegment.Array != null &&
!_extraData.SequenceEqual(rawH264IFrame.SpsPpsSegment))
{
if (_extraData.Length != rawH264IFrame.SpsPpsSegment.Count)
{
_extraData = new byte[rawH264IFrame.SpsPpsSegment.Count];
}
Buffer.BlockCopy(rawH264IFrame.SpsPpsSegment.Array, rawH264IFrame.SpsPpsSegment.Offset,
_extraData, 0, rawH264IFrame.SpsPpsSegment.Count);
fixed(byte *initDataPtr = &_extraData[0])
{
if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
{
resultCode = FFmpegVideoPInvokeWin.SetVideoDecoderExtraData(_decoderHandle, (IntPtr)initDataPtr, _extraData.Length);
}
else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
{
resultCode = FFmpegVideoPInvokeLinux.SetVideoDecoderExtraData(_decoderHandle, (IntPtr)initDataPtr, _extraData.Length);
}
else
{
throw new PlatformNotSupportedException();
}
if (resultCode != 0)
{
throw new DecoderException(
$"TryDecode say: An error occurred while setting video extra data, {_videoCodecId} codec, code: {resultCode}");
}
}
}
}
FFmpegPixelFormat pixelFormat;
int width, height;
if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
{
resultCode = FFmpegVideoPInvokeWin.DecodeFrame(_decoderHandle, (IntPtr)rawBufferPtr,
rawVideoFrame.FrameSegment.Count, out width, out height,
out pixelFormat);
}
else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
{
resultCode = FFmpegVideoPInvokeLinux.DecodeFrame(_decoderHandle, (IntPtr)rawBufferPtr,
rawVideoFrame.FrameSegment.Count, out width, out height,
out pixelFormat);
}
else
{
throw new PlatformNotSupportedException();
}
if (resultCode != 0)
{
return(null);
}
if (_currentFrameParameters.Width != width || _currentFrameParameters.Height != height ||
_currentFrameParameters.PixelFormat != pixelFormat)
{
_currentFrameParameters = new DecodedVideoFrameParameters(width, height, pixelFormat);
DropAllVideoScalers();
}
return(new DecodedVideoFrame(TransformTo));
}
}
/// <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));
}
