/// <summary>
/// Creates a frame source object given the raw FFmpeg frame reference.
/// </summary>
/// <param name="frame">The raw FFmpeg frame pointer.</param>
/// <returns>Create a managed fraome from an unmanaged one.</returns>
protected override unsafe MediaFrame CreateFrameSource(ref AVFrame *frame)
{
if (string.IsNullOrWhiteSpace(FilterString) == false)
{
InitializeFilterGraph(frame);
}
if (HardwareAccelerator != null)
{
frame = HardwareAccelerator.ExchangeFrame(CodecContext, frame, out IsUsingHardwareDecoding);
}
AVFrame *outputFrame;
// TODO: Support real-time changes in Video Filtergraph by checking if MediaOptions.VideoFilterGraph has changed
// Maybe expose the VideoFilterGraph string as a MediaElement Control Property
if (FilterGraph != null)
{
// Allocate the output frame
outputFrame = ffmpeg.av_frame_clone(frame);
var result = ffmpeg.av_buffersrc_add_frame(SourceFilter, outputFrame);
while (result >= 0)
{
result = ffmpeg.av_buffersink_get_frame_flags(SinkFilter, outputFrame, 0);
}
if (outputFrame->width <= 0 || outputFrame->height <= 0)
{
// If we don't have a valid output frame simply release it and
// return the original input frame
RC.Current.Remove(outputFrame);
ffmpeg.av_frame_free(&outputFrame);
outputFrame = frame;
}
else
{
// the output frame is the new valid frame (output frame).
// threfore, we need to release the original
RC.Current.Remove(frame);
var framePtr = frame;
ffmpeg.av_frame_free(&framePtr);
}
}
else
{
outputFrame = frame;
}
// Check if the output frame is valid
if (outputFrame->width <= 0 || outputFrame->height <= 0)
{
return(null);
}
// Create the frame holder object and return it.
var frameHolder = new VideoFrame(outputFrame, this);
CurrentFrameRate = ffmpeg.av_guess_frame_rate(Container.InputContext, Stream, outputFrame).ToDouble();
return(frameHolder);
}
/// <inheritdoc />
protected override MediaFrame CreateFrameSource(IntPtr framePointer)
{
// Validate the video frame
var frame = (AVFrame *)framePointer;
if (framePointer == IntPtr.Zero || frame->width <= 0 || frame->height <= 0)
{
return(null);
}
// Move the frame from hardware (GPU) memory to RAM (CPU)
if (HardwareAccelerator != null)
{
frame = HardwareAccelerator.ExchangeFrame(CodecContext, frame, out var isHardwareFrame);
IsUsingHardwareDecoding = isHardwareFrame;
}
// Init the filter graph for the frame
if (string.IsNullOrWhiteSpace(FilterString) == false)
{
InitializeFilterGraph(frame);
}
AVFrame *outputFrame;
// Changes in the filter graph can be applied by calling the ChangeMedia command
if (FilterGraph != null)
{
// Allocate the output frame
outputFrame = MediaFrame.CloneAVFrame(frame);
var result = ffmpeg.av_buffersrc_add_frame(SourceFilter, outputFrame);
while (result >= 0)
{
result = ffmpeg.av_buffersink_get_frame_flags(SinkFilter, outputFrame, 0);
}
if (outputFrame->width <= 0 || outputFrame->height <= 0)
{
// If we don't have a valid output frame simply release it and
// return the original input frame
MediaFrame.ReleaseAVFrame(outputFrame);
outputFrame = frame;
}
else
{
// the output frame is the new valid frame (output frame).
// therefore, we need to release the original
MediaFrame.ReleaseAVFrame(frame);
}
}
else
{
outputFrame = frame;
}
// Check if the output frame is valid
if (outputFrame->width <= 0 || outputFrame->height <= 0)
{
return(null);
}
// Create the frame holder object and return it.
return(new VideoFrame(outputFrame, this));
}