/// <summary>
/// </summary>
/// <param name="consumer"></param>
/// <param name="frameIndex"></param>
internal void RequestFrame(FilterInputSlot consumer, long frameIndex)
{
this.sync.WaitOne();
try
{
}
finally
{
// Thread synchronization has to work to maintain reliability.
this.sync.ReleaseMutex();
}
}
internal void BindConsumer(FilterInputSlot consumer)
{
Contract.Requires(consumer != null);
this.Mutex.WaitOne();
try
{
if (this.consumers.Contains(consumer))
{
return;
}
this.consumers.Add(consumer);
}
finally
{
this.Mutex.ReleaseMutex();
}
}
/// <summary>
/// For a given input slot on the current filter, determines which frame indices are required from that slot
/// for the current filter to render the specified frame index.
/// </summary>
/// <remarks>
/// The default behavior is to go by the FramesBefore and FramesAfter values that have been assigned to the slot.
/// </remarks>
/// <param name="slot"></param>
/// <param name="index"></param>
/// <returns></returns>
public virtual IEnumerable <int> GetInputFramesRequired(FilterInputSlot slot, long index)
{
Contract.Requires(slot != null);
Contract.Requires(slot.Owner == this);
Contract.Requires(index >= 0);
if (!slot.IsBound)
{
yield break;
}
// default behavior should be acceptable for almost all filter implementations.
int start = Math.Max(0 - slot.FramesBefore, 0);
int end = slot.FramesAfter;
// TODO: Fix end so we don't overflow the clip.
for (int i = start; i <= end; ++i)
{
yield return(i);
}
}
internal void UnbindConsumer(FilterInputSlot consumer)
{
Contract.Requires(consumer != null);
this.consumers.Remove(consumer);
}
