private VideoDecoder(VideoCodecId videoCodecId, IntPtr decoderHandle)
{
this.videoCodecId = videoCodecId;
this.decoderHandle = decoderHandle;
currentFrameParms = new DecodedVideoFrameParameters(0, 0, FFmpegPixelFormat.None);
scalersMap = new Dictionary <TransformParameters, DecodedVideoScaler>();
}
public unsafe IDecodedVideoFrame TryDecode(RawVideoFrame frame)
{
fixed(byte *rawBufferPtr = &frame.Segment.Array[frame.Segment.Offset])
{
int resultCode;
if (frame 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])
{
resultCode = FFmpegVideoPInvoke.SetVideoDecoderExtraData(decoderHandle, (IntPtr)initDataPtr, extraData.Length);
if (resultCode != 0)
{
throw new DecoderException($"An error occurred while setting video extra data, {videoCodecId} codec, code: {resultCode}");
}
}
}
}
lock (disposalLock)
{
if (disposed)
{
return(null);
}
resultCode =
FFmpegVideoPInvoke.DecodeFrame(decoderHandle, (IntPtr)rawBufferPtr, frame.Segment.Count, out int width, out int height, out FFmpegPixelFormat pixelFormat);
if (resultCode != 0)
{
return(null);
}
if (!currentFrameParms.Equals(width, height, pixelFormat))
{
currentFrameParms = new DecodedVideoFrameParameters(width, height, pixelFormat);
DropAllVideoScalers();
}
}
return(new DecodedVideoFrame(TransformTo, currentFrameParms));
}
}
/// <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));
}
public DecodedVideoFrame(Action <IntPtr, int, TransformParameters> transformAction, DecodedVideoFrameParameters frameParms)
{
this.transformAction = transformAction ?? throw new ArgumentNullException(nameof(transformAction));
FrameParms = frameParms ?? throw new ArgumentNullException(nameof(frameParms));
}
