/// <summary>
/// Attaches a hardware accelerator to this video component.
/// </summary>
/// <param name="selectedConfig">The selected configuration.</param>
/// <returns>
/// Whether or not the hardware accelerator was attached.
/// </returns>
public bool AttachHardwareDevice(HardwareDeviceInfo selectedConfig)
{
// Check for no device selection
if (selectedConfig == null)
{
return(false);
}
try
{
var accelerator = new HardwareAccelerator(this, selectedConfig);
AVBufferRef *devContextRef = null;
var initResultCode = ffmpeg.av_hwdevice_ctx_create(&devContextRef, accelerator.DeviceType, null, null, 0);
if (initResultCode < 0)
{
throw new MediaContainerException($"Unable to initialize hardware context for device {accelerator.Name}");
}
HardwareDeviceContext = devContextRef;
HardwareAccelerator = accelerator;
CodecContext->hw_device_ctx = ffmpeg.av_buffer_ref(HardwareDeviceContext);
CodecContext->get_format = accelerator.GetFormatCallback;
return(true);
}
catch (Exception ex)
{
this.LogError(Aspects.Component, "Could not attach hardware decoder.", ex);
return(false);
}
}
/// <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
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));
}