public string WritePart()
{
FFMPEGCommand.AddInput(BaseVideoPath);
foreach (OverlayVideo overlayVideo in OverlayVideos)
{
FFMPEGCommand.AddInput(overlayVideo.Path);
}
FilterComplexFlag filterComplexFlag = new FilterComplexFlag();
// Add the first expression, and that is to merge the first video and the base
for (int n = 0; n < OverlayVideos.Count; n++)
{
OverlayVideo overlayVideo = OverlayVideos[n];
string resultingBaseFromPrevious = (n == 0) ? "0:v" : "res" + n;
FilterComplexExpression timingExpression = new FilterComplexExpression()
.AddInputIdentifier($"{n + 1}")
.AddFilter(new Filter()
.SetName("setpts")
.SetValue($"PTS+{OverlayVideos[n].StartOffsetInSeconds}/TB")
)
.SetOutputIdentifier($"top{n + 1}");
if (overlayVideo.Dimension.Width > 0 || overlayVideo.Dimension.Height > 0)
{
timingExpression.AddFilter(new Filter()
.SetName("scale")
.SetValue($"{overlayVideo.Dimension.Width.ToString()}:{overlayVideo.Dimension.Height.ToString()}")
);
}
filterComplexFlag.AddFilterComplexExpression(timingExpression);
int startOffset = OverlayVideos[n].StartOffsetInSeconds;
int until = startOffset + OverlayVideos[n].DurationInSeconds;
Filter overlayFilter = new Filter()
.SetName("overlay")
.AddAttribute("enable", $"'between(t, {startOffset}, {until})'");
if (overlayVideo.Coordinate.X > 0 || overlayVideo.Coordinate.Y > 0)
{
overlayFilter.AddAttribute("x", overlayVideo.Coordinate.X.ToString())
.AddAttribute("y", overlayVideo.Coordinate.Y.ToString());
}
filterComplexFlag.AddFilterComplexExpression(new FilterComplexExpression()
.AddInputIdentifier(resultingBaseFromPrevious)
.AddInputIdentifier($"top{n + 1}")
.AddFilter(overlayFilter)
.SetOutputIdentifier((n < OverlayVideos.Count - 1) ? $"res{n + 1}" : "")
);
}
FFMPEGCommand.AddFlag(filterComplexFlag);
FFMPEGCommand.AddFlag(new SimpleFlag("y", null));
return(FFMPEGCommand.WritePart());
}
public SuperImposeCommand AddOverlayVideo(OverlayVideo overlayVideo)
{
OverlayVideos.Add(overlayVideo);
return(this);
}