// Oprogramowanie Roman Ryltsov
In order to obtain a reference audio source and especially useful for debugging purposes, including: audio input device unrelated to physical device, to avoid conditions when device is already in use by someone else non-zero audio signal which is independent of certain speaker or broadcasting service, including one that makes capture, transmission or rendering issues…
In order to better troubleshoot network cameras and other devices, I added a new DirectShow filter to write HTTP response headers and body into a single file, one file (actually a pairs of files, the second file contains UTF-8 formatted HTTP response headers) per HTTP response. While troubleshootting JPEG artefact issue with I used the…
Having DirectShow Filter Graph Spy installed in the system, I noticed a new and weird effect that when Media Player Classic plays a list of files and each MP3 file being currently decoded shows decoder’s system tray icon, a switch to a new file leaves an old icon in place and adds a new icon…
At the time of original implementation I intentionally left off a variation of Filter Graph Manager that runs on application thread, CLSID_FilterGraphNoThread. MSDN says: CLSID_FilterGraphNoThread creates the Filter Graph Manager on the application’s thread. If you use this CLSID, the thread that calls CoCreateInstance must have a message loop that dispatches messages; otherwise, deadlocks can…
Inspired by a post on DirectShow Development Forum, it is sometimes useful to find out how certain application is using DirectShow to capture live video and/or audio, or play certain file etc. Filter graph topology, details about media types on the pins, used interfaces and call order. There is quite an easy step for the…
Provided that there already is a JPEG Multi File Source Filter that can act as a video source streaming video from local JPEG files, it looked to be useful to build a virtual camera on top of this filter. This is the main difference: an existing filter is generic and customizable: it requires to be…
While playing around with a camera DirectShow video source filter, AMCap, which is widely used sample and which I believed to be very stable, started crashing in an inner call CDeviceMoniker::IsEqual: devenum.dll!CDeviceMoniker::IsEqual() + 0x13 bytes > AmCap.exe!ChooseDevices(IMoniker * pmVideo=0x003e9a38, IMoniker * pmAudio=0x00000000) Line 2672 + 0x2a bytes C++ AmCap.exe!ChooseDevices(wchar_t * szVideo=0x0013f5b8, wchar_t * szAudio=0x0013edb0) Line…