JustKernel

some code snippets to explain the audio implementation in Virtualbox and how the code changed from earlier QEMU based monolithic blob. Taking an example of AC97 Device: DevIchAc97.cpp PPDMGSTVOICEIN voice_pi[2]; // corresponds to 2 LUNS in audio in direction (recording) + /** PCM out */ + PPDMGSTVOICEOUT voice_po[2]; //corresponds to 2 LUNs in audio out […]

In addition the architectural changes discussed in the previous post, i also implemented multiple LUNs so that audio samples can be send to multiple audio backends simultaneously for eg. a guest VM is opened in the desktop, also through VRDP. So audio song being played on the guest should be audible on the host desktop […]

Currently Virtualbox uses QEMU audio code. QEMU audio code is a big monolithic blog with single file auido.c implementing most of the audio functionality and 100s of preprocessor directives  (glue etc) in audio_template.h providing most of the helper functionalities for different platform. My task here was to modify the audio code to and implement it […]