/// <summary>
/// Downloads the frame from the hardware into a software frame if possible.
/// The input hardware frame gets freed and the return value will point to the new software frame.
/// </summary>
/// <param name="codecContext">The codec context.</param>
/// <param name="input">The input frame coming from the decoder (may or may not be hardware).</param>
/// <param name="isHardwareFrame">if set to <c>true</c> [comes from hardware] otherwise, hardware decoding was not performed.</param>
/// <returns>
/// The frame downloaded from the device into RAM.
/// </returns>
/// <exception cref="Exception">Failed to transfer data to output frame.</exception>
public AVFrame *ExchangeFrame(AVCodecContext *codecContext, AVFrame *input, out bool isHardwareFrame)
{
isHardwareFrame = false;
if (codecContext->hw_device_ctx == null)
{
return(input);
}
isHardwareFrame = true;
if (input->format != (int)PixelFormat)
{
return(input);
}
var output = MediaFrame.CreateAVFrame();
var result = ffmpeg.av_hwframe_transfer_data(output, input, 0);
ffmpeg.av_frame_copy_props(output, input);
if (result < 0)
{
MediaFrame.ReleaseAVFrame(output);
throw new MediaContainerException("Failed to transfer data to output frame");
}
MediaFrame.ReleaseAVFrame(input);
return(output);
}
/// <inheritdoc />
protected override MediaFrame CreateFrameSource(IntPtr framePointer)
{
// Validate the audio frame
var frame = (AVFrame *)framePointer;
if (framePointer == IntPtr.Zero || frame->channels <= 0 || frame->nb_samples <= 0 || frame->sample_rate <= 0)
{
return(null);
}
// Init the filter graph for the frame
InitializeFilterGraph(frame);
AVFrame *outputFrame;
// Filter Graph can be changed by issuing a 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->nb_samples <= 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).
// theretofore, we need to release the original
MediaFrame.ReleaseAVFrame(frame);
}
}
else
{
outputFrame = frame;
}
// Check if the output frame is valid
if (outputFrame->nb_samples <= 0)
{
return(null);
}
var frameHolder = new AudioFrame(outputFrame, this);
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
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));
}