Anzeigen der neuesten Beiträge
0 Mitglieder und 1 Gast betrachten dieses Thema.
This quick update for DirectShow Filter Graph Spy adds tracing for (deprecated) IAMFilterData interface, and also fixes problem with Media Player Classic – Home Cinema, when the player crashes in External Filters windows.
A small update to the DirectShow Spy: DirectShow Filter Graph Spy prints memory allocator properties as a part of graph topology trace on transition to running state. Why is that and what it is for? Filters normally agree on allocator properties (ALLOCATOR_PROPERTIES, obtained from IMemAllocator, obtained from IMemInputPin) themselves without interference from controlling application. Sometimes an undesired choice of buffers can cause sick runtime behavior, including but not limited to the following:1.live audio capture buffers are too long, and introduce significant latency, including from live video capture stream taking place in parallel; controlling application might need to take advantage of IAMBufferNegotiation::SuggestAllocatorProperties and request shorter buffers.2.a filter, such as for example DMO Wrapper Filter, may default to 1 buffer on allocator, which means that if a buffer reference is for some reason held for future reference (e.g. a video filter might be holding a reference to be able to re-push a video sample if an application is requesting video update), the entire streaming might lock.3.some filters are requesting unreasonably many/large buffers and consume vast spaces of RAM, such as MainConcept MXF Demultiplexer requesting 200 buffers x 640 kilobytes each (128 MB in total out of sudden)4.some filters are requesting unreasonably few/small buffers resulting in inability to pre-buffer dataIn a chase for answers to questions "Where is my memory?", "Why is it so choppy?", "I would really appreciate a nice lipsync" and to troubleshoot the mentioned scenarios it is helpful to understand buffering configuration. DirectShow Filter Spy is here to deliver this information. Once the graph is put into running state, spy prints out topology data into log file (which is in most cases C:\ProgramData\DirectShowSpy.log)
A small issue appears to be affecting DirectShow applications with DirectShow Spy installed. As underlying COM base is non-standard, the spy implements a few hacks to run smoothly and to keep reference counting correct in particular. Under certain conditions, DirectShow-enabled ActiveX control hosted by Internet Explorer seems to be unable to put its graph onto Running Object Table (ROT). What happened next is that Spy assumed ROT operation to succeed, and compensated reference counting, which under bad assumption could cause E_UNEXPECTED error while creating a filter graph. This updated fixes the issue.Another small improvement is that similarly to SDK proppage.dll, Spy registration UI also assists in registering another DLL – evrprop.dll, should it be there near the spy module.
