/// <summary>
/// Creates a frame source object given the raw FFmpeg frame reference.
/// </summary>
/// <param name="framePointer">The raw FFmpeg frame pointer.</param>
/// <returns>The media frame</returns>
protected override unsafe MediaFrame CreateFrameSource(IntPtr framePointer)
{
// Validate the audio frame
var frame = (AVFrame *)framePointer;
if (frame == null || (*frame).extended_data == null || frame->channels <= 0 ||
frame->nb_samples <= 0 || frame->sample_rate <= 0)
{
return(null);
}
if (string.IsNullOrWhiteSpace(FilterString) == false)
{
InitializeFilterGraph(frame);
}
AVFrame *outputFrame = null;
// Filtergraph 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).
// threfore, 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);
}
/// <summary>
/// Creates a frame source object given the raw FFmpeg frame reference.
/// </summary>
/// <param name="frame">The raw FFmpeg frame pointer.</param>
/// <returns>The media frame</returns>
protected override unsafe MediaFrame CreateFrameSource(ref AVFrame *frame)
{
if (string.IsNullOrWhiteSpace(FilterString) == false)
{
InitializeFilterGraph(frame);
}
AVFrame *outputFrame = null;
// TODO: Support real-time changes in Audio Filtergraph by checking if MediaOptions.AudioFilterGraph has changed
// Maybe expose the AudioFilterGraph 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->nb_samples <= 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->nb_samples <= 0)
{
return(null);
}
var frameHolder = new AudioFrame(outputFrame, this);
return(frameHolder);
}
/// <summary>
/// Creates a frame source object given the raw FFmpeg frame reference.
/// </summary>
/// <param name="frame">The raw FFmpeg frame pointer.</param>
/// <returns></returns>
protected override unsafe MediaFrame CreateFrameSource(AVFrame *frame)
{
var frameHolder = new AudioFrame(frame, this);
return(frameHolder);
}
