private bool DetectEndOfMedia(int decodedFrameCount, MediaType main)
{
// Detect end of block rendering
// TODO: Maybe this detection should be performed on the BlockRendering worker?
if (decodedFrameCount <= 0 &&
IsWorkerInterruptRequested == false &&
CanReadMoreFramesOf(main) == false &&
Blocks[main].IndexOf(WallClock) >= Blocks[main].Count - 1)
{
if (State.HasMediaEnded == false)
{
// Rendered all and nothing else to read
Clock.Pause();
ChangePosition(Blocks[main].RangeEndTime);
if (State.NaturalDuration != null &&
State.NaturalDuration != TimeSpan.MinValue &&
State.NaturalDuration < WallClock)
{
Log(MediaLogMessageType.Warning,
$"{nameof(State.HasMediaEnded)} conditions met at {WallClock.Format()} but " +
$"{nameof(State.NaturalDuration)} reports {State.NaturalDuration.Value.Format()}");
}
State.UpdateMediaEnded(true);
State.UpdateMediaState(PlaybackStatus.Stop);
foreach (var mt in Container.Components.MediaTypes)
{
InvalidateRenderer(mt);
}
SendOnMediaEnded();
}
}
else
{
State.UpdateMediaEnded(false);
}
return(State.HasMediaEnded);
}
/// <summary>
/// Continually decodes the available packet buffer to have as
/// many frames as possible in each frame queue and
/// up to the MaxFrames on each component
/// </summary>
internal void RunFrameDecodingWorker()
{
// TODO: Don't use State properties in workers as they are only for
// TODO: Check the use of wall clock. Maybe it's be more consistent
// to use a single atomic wallclock value per cycle. Check other workers as well.
// state notification purposes.
// State variables
var wasSyncBuffering = false;
var delay = new DelayProvider(); // The delay provider prevents 100% core usage
var decodedFrameCount = 0;
var rangePercent = 0d;
var main = Container.Components.MainMediaType; // Holds the main media type
var resumeSyncBufferingClock = false;
MediaBlockBuffer blocks = null;
try
{
while (Commands.IsStopWorkersPending == false)
{
#region Setup the Decoding Cycle
// Determine what to do on a priority command
if (Commands.IsExecutingDirectCommand)
{
if (Commands.IsClosing)
{
break;
}
if (Commands.IsChanging)
{
Commands.WaitForDirectCommand();
}
}
// Execute the following command at the beginning of the cycle
if (IsSyncBuffering == false)
{
Commands.ExecuteNextQueuedCommand();
}
// Signal a Seek starting operation and set the initial state
FrameDecodingCycle.Begin();
// Update state properties -- this must be after processing commanmds as
// a direct command might have changed the components
main = Container.Components.MainMediaType;
decodedFrameCount = 0;
#endregion
// The 2-part logic blocks detect a sync-buffering scenario
// and then decodes the necessary frames.
if (State.HasMediaEnded == false && IsWorkerInterruptRequested == false)
{
#region Sync-Buffering
// Capture the blocks for easier readability
blocks = Blocks[main];
// If we are not then we need to begin sync-buffering
if (wasSyncBuffering == false && blocks.IsInRange(WallClock) == false)
{
// Signal the start of a sync-buffering scenario
IsSyncBuffering = true;
wasSyncBuffering = true;
resumeSyncBufferingClock = Clock.IsRunning;
Clock.Pause();
State.UpdateMediaState(PlaybackStatus.Manual);
Log(MediaLogMessageType.Debug, $"SYNC-BUFFER: Started.");
}
#endregion
#region Component Decoding
// We need to add blocks if the wall clock is over 75%
// for each of the components so that we have some buffer.
foreach (var t in Container.Components.MediaTypes)
{
if (IsWorkerInterruptRequested)
{
break;
}
// Capture a reference to the blocks and the current Range Percent
const double rangePercentThreshold = 0.75d;
blocks = Blocks[t];
rangePercent = blocks.GetRangePercent(WallClock);
// Read as much as we can for this cycle but always within range.
while (blocks.IsFull == false || rangePercent > rangePercentThreshold)
{
// Stop decoding under sync-buffering conditions
if (IsSyncBuffering && blocks.IsFull)
{
break;
}
if (IsWorkerInterruptRequested || AddNextBlock(t) == false)
{
break;
}
decodedFrameCount += 1;
rangePercent = blocks.GetRangePercent(WallClock);
// Determine break conditions to save CPU time
if (IsSyncBuffering == false &&
rangePercent > 0 &&
rangePercent <= rangePercentThreshold &&
blocks.IsFull == false &&
blocks.CapacityPercent >= 0.25d &&
blocks.IsInRange(WallClock))
{
break;
}
}
}
// Give it a break if we are still buffering packets
if (IsSyncBuffering)
{
delay.WaitOne();
FrameDecodingCycle.Complete();
continue;
}
#endregion
}
#region Finish the Cycle
// Detect End of Media Scenarios
DetectEndOfMedia(decodedFrameCount, main);
// Resume sync-buffering clock
if (wasSyncBuffering && IsSyncBuffering == false)
{
// Sync-buffering blocks
blocks = Blocks[main];
// Unfortunately at this point we will need to adjust the clock after creating the frames.
// to ensure tha mian component is within the clock range if the decoded
// frames are not with range. This is normal while buffering though.
if (blocks.IsInRange(WallClock) == false)
{
// Update the wall clock to the most appropriate available block.
if (blocks.Count > 0)
{
ChangePosition(blocks[WallClock].StartTime);
}
else
{
resumeSyncBufferingClock = false; // Hard stop the clock.
}
}
// log some message and resume the clock if it was playing
Log(MediaLogMessageType.Debug, $"SYNC-BUFFER: Finished. Clock set to {WallClock.Format()}");
if (resumeSyncBufferingClock && State.HasMediaEnded == false)
{
ResumePlayback();
}
wasSyncBuffering = false;
resumeSyncBufferingClock = false;
}
// Provide updates to decoding stats
State.UpdateDecodingBitrate(
Blocks.Values.Sum(b => b.IsInRange(WallClock) ? b.RangeBitrate : 0));
// Complete the frame decoding cycle
FrameDecodingCycle.Complete();
// Give it a break if there was nothing to decode.
DelayDecoder(delay, decodedFrameCount);
#endregion
}
}
catch { throw; }
finally
{
// Reset decoding stats
State.UpdateDecodingBitrate(0);
// Always exit notifying the cycle is done.
FrameDecodingCycle.Complete();
delay.Dispose();
}
}
