Convering the Stored Encoded Stream to Mpeg #276

Same problem here. +1

Thanks for your question. We have also observed finicky behavior in runtime speed when exporting outside of \psi to mpeg. It seems the underlying Windows media technology used by our component does a lot of aggressive locking and throttling, and it's easy to get into a state where all messages get queued up in front of it for a long time before being slowly processed.

There are a couple changes to your code that I can suggest, which should hopefully help:

• Create your pipeline with a default delivery policy of DeliveryPolicy.Throttle, and don't use DeliveryPolicy.Unlimited. This ensures that the store reader delivers all messages, but only as fast as the mpeg writer can process them. Otherwise all messages will be pushed into a huge queue at infinite speed, and you might run out of memory if processing larger files. This is good practice for all pipelines that are intended to process existing data, rather than instantiate a live system.
• If your mpeg doesn't have audio, make sure to specify that in its configuration.
• You can simply run the pipeline with the ReplayAll replay descriptor to have it run as fast as possible.

Try something like the code below, and please let us know if the observed execution time improves or stays about the same.

using var pipeline = Pipeline.Create(deliveryPolicy: DeliveryPolicy.Throttle);
IProducer<Shared> participant_feed = store.OpenStream<Shared>("Video");
var writer = new Mpeg4Writer(pipeline, "output.mp4", new Mpeg4WriterConfiguration()
{
 ImageWidth = 640,
 ImageHeight = 480,
 PixelFormat = PixelFormat.BGR_24bpp,
 ContainsAudio = false,
});
participant_feed.Out.Decode().PipeTo(writer.ImageIn);
var startTime = DateTime.Now;
pipeline.RunAsync(ReplayDescriptor.ReplayAll, progress: new Progress<double>(p => Console.Write($"Progress: {p:P} Time elapsed: {DateTime.Now - startTime}\r")));
pipeline.WaitAll();
Console.WriteLine($"Done in {DateTime.Now - startTime}.");