/// <summary>
/// Finds the shortest mux path for a given set of input MuxableTypes (ie the
/// encoder output types have all already been chosen here).
/// </summary>
/// Initial stage: if currentMuxPath is empty, it creates a first leg.
/// Recursive step: It tries out adding all possible muxers to the current mux path,
/// and calls itself with this extended mux path. It returns the shortest path.
/// Final step: This will stop recursing if there are no muxers that can help, or if a muxer
/// is found in one step that finalizes the path. This is guaranteed to finish:
/// if no progress is made, then it will not recurse. Otherwise, there is a finite
/// amount of progress (progress is the number of streams muxed), so it will eventually
/// stop progressing.
/// <param name="currentMuxPath">Current mux path to be worked on</param>
/// <param name="unhandledDesiredInputTypes">What remains to be muxed</param>
/// <param name="desiredContainerType">Container type we are aiming at</param>
/// <returns></returns>
private MuxPath getShortestMuxPath(MuxPath currentMuxPath,
List <MuxableType> unhandledDesiredInputTypes, ContainerType desiredContainerType)
{
if (currentMuxPath.IsCompleted())
{
return(currentMuxPath);
}
List <MuxableType> handledInputTypes;
List <MuxableType> unhandledInputTypes;
List <MuxPath> allMuxPaths = new List <MuxPath>();
foreach (IMuxing muxer in mainForm.PackageSystem.MuxerProviders.Values)
{
ProcessingLevel level;
if (currentMuxPath.Length > 0)
{
level = muxer.CanBeProcessed(
currentMuxPath[currentMuxPath.Length - 1].muxerInterface.GetSupportedContainerTypes().ToArray(),
unhandledDesiredInputTypes.ToArray(), out handledInputTypes, out unhandledInputTypes);
}
else
{
level = muxer.CanBeProcessed(unhandledDesiredInputTypes.ToArray(), out handledInputTypes, out unhandledInputTypes);
}
if (level != ProcessingLevel.NONE)
{
MuxPath newMuxPath = currentMuxPath.Clone();
MuxPathLeg currentMPL = new MuxPathLeg();
currentMPL.muxerInterface = muxer;
currentMPL.handledInputTypes = handledInputTypes;
currentMPL.unhandledInputTypes = unhandledInputTypes;
newMuxPath.Add(currentMPL);
if (unhandledInputTypes.Count == 0)
{
// All the streams have been muxed into some file. Now let's
// just make sure that we can convert this file to the format we want
// (or leave it alone if it already is in that format).
List <IMuxing> allMuxers = new List <IMuxing>();
allMuxers.AddRange(mainForm.PackageSystem.MuxerProviders.Values);
MuxPath shortestPath = getShortestMuxPath(newMuxPath, allMuxers, desiredContainerType);
if (shortestPath != null)
{
allMuxPaths.Add(shortestPath);
}
}
MuxPath aShortestPath = getShortestMuxPath(currentMuxPath, muxer, new List <MuxableType>(), handledInputTypes, unhandledInputTypes, desiredContainerType);
if (aShortestPath != null)
{
allMuxPaths.Add(aShortestPath);
}
}
}
return(comparer.GetBestMuxPath(allMuxPaths));
}
/// <summary>
/// Recurses to find the shortest mux path.
/// </summary>
/// Initial stage: if currentMuxPath is empty, it creates a first leg.
/// Recursive step: It tries out adding all possible muxers to the current mux path,
/// and calls itself with this extended mux path. It returns the shortest path.
/// Final step: This will stop recursing if there are no muxers that can help, or if a muxer
/// is found in one step that finalizes the path. This is guaranteed to finish:
/// if no progress is made, then it will not recurse. Otherwise, there is a finite
/// amount of progress (progress is the number of streams muxed), so it will eventually
/// stop progressing.
/// <param name="currentMuxPath">Current mux path to be worked on</param>
/// <param name="unhandledDesiredInputTypes">What remains to be muxed</param>
/// <param name="desiredContainerType">Container type we are aiming at</param>
/// <returns></returns>
private MuxPath getShortestMuxPath(MuxPath currentMuxPath,
List <MuxableType> unhandledDesiredInputTypes, ContainerType desiredContainerType)
{
List <MuxableType> handledInputTypes = new List <MuxableType>();
List <MuxableType> unhandledInputTypes = new List <MuxableType>();
List <MuxPath> allMuxPaths = new List <MuxPath>();
if (currentMuxPath.IsCompleted())
{
return(currentMuxPath);
}
foreach (IMuxing muxer in mainForm.PackageSystem.MuxerProviders.Values)
{
ProcessingLevel level;
if (currentMuxPath.Length > 0)
{
level = muxer.CanBeProcessed(
currentMuxPath[currentMuxPath.Length - 1].muxerInterface.GetSupportedContainerTypes().ToArray(),
unhandledDesiredInputTypes.ToArray(), out handledInputTypes, out unhandledInputTypes);
}
else
{
level = muxer.CanBeProcessed(unhandledDesiredInputTypes.ToArray(), out handledInputTypes, out unhandledInputTypes);
}
if (level != ProcessingLevel.NONE)
{
MuxPath newMuxPath = currentMuxPath.Clone();
MuxPathLeg currentMPL = new MuxPathLeg();
currentMPL.muxerInterface = muxer;
currentMPL.handledInputTypes = handledInputTypes;
currentMPL.unhandledInputTypes = unhandledInputTypes;
newMuxPath.Add(currentMPL);
if (unhandledInputTypes.Count == 0)
{
List <IMuxing> allMuxers = new List <IMuxing>();
allMuxers.AddRange(mainForm.PackageSystem.MuxerProviders.Values);
MuxPath shortestPath = getShortestMuxPath(newMuxPath, allMuxers, desiredContainerType);
if (shortestPath != null)
{
allMuxPaths.Add(shortestPath);
}
}
MuxPath aShortestPath = getShortestMuxPath(currentMuxPath, muxer, new List <MuxableType>(), handledInputTypes, unhandledInputTypes, desiredContainerType);
if (aShortestPath != null)
{
allMuxPaths.Add(aShortestPath);
}
}
}
return(comparer.GetBestMuxPath(allMuxPaths));
}
/// <summary>
/// Given a mux path in which all the inputs have already been handled,
/// this finds the shortest mux path to achieve the desired container type.
/// </summary>
/// <param name="currentMuxPath"></param>
/// <param name="remainingMuxers">List of muxers which haven't yet been used
/// in this final stage. There's no point having a muxer twice in this final
/// stage, as the output of the second time could substitute the output of
/// the first time.</param>
/// <param name="desiredContainerType"></param>
/// <returns></returns>
private MuxPath getShortestMuxPath(MuxPath currentMuxPath,
List <IMuxing> remainingMuxers, ContainerType desiredContainerType)
{
if (currentMuxPath.IsCompleted())
{
return(currentMuxPath);
}
List <MuxPath> allMuxPaths = new List <MuxPath>();
List <IMuxing> newRemainingMuxers = new List <IMuxing>();
newRemainingMuxers.AddRange(remainingMuxers);
foreach (IMuxing muxer in remainingMuxers)
{
bool supportsInput = currentMuxPath[currentMuxPath.Length - 1].muxerInterface.GetContainersInCommon(muxer).Count > 0;
if (!supportsInput)
{
continue;
}
MuxPath newMuxPath = currentMuxPath.Clone();
MuxPathLeg currentMPL = new MuxPathLeg();
currentMPL.muxerInterface = muxer;
currentMPL.handledInputTypes = new List <MuxableType>();
currentMPL.unhandledInputTypes = new List <MuxableType>();
newMuxPath.Add(currentMPL);
newRemainingMuxers.Remove(muxer);
MuxPath shortestPath = getShortestMuxPath(newMuxPath, newRemainingMuxers, desiredContainerType);
if (shortestPath != null)
{
allMuxPaths.Add(shortestPath);
}
newRemainingMuxers.Add(muxer);
}
return(comparer.GetBestMuxPath(allMuxPaths));
}
