[Pkg-virtualbox-devel] Bug#877385: virtualbox (no video or audio reproduction)

[ermac god]

Package: virtualbox
Version: 5.1.28-dfsg-1~bpo9+1 (and the original oracle package)

After upgrade from virtualbox version 5.1.26 to 5.1.28 on the guest os (debian 9 x64) the video/audio reproduction with mplayer, vlc, firefox htlm 5 ecc no video reproduction.

After several attempts find the problem is located on the audio settings, in fact on the oracle site change logs read:
VirtualBox 5.1.28 (released 2017-09-13)
[...]
Audio: fixed accidental crashes when using the AC'97 sound emulation (bug #16959)
Audio: fixed crash when default input or output devices have changed (bugs #16968, #16969, #17004)
Audio: fixed recording when using the ALSA backend
Audio: fixed handle leak when using the OSS backend 
[...]
in fact if change the audio guest controller from "ICH AC47" to "intel hd audio" or "sound blaster 16" the video reproduction is ok but no audio output. 
Same problem with original virtualbox release by oracle.

The host system:
OS: debian 9 x64 with kde and without pulseaudio (virtualbox hostaudio ALSA Audio Driver)
CPU: i7_920 with all virtualized option active
VIDEO: Radeon HD 5850 (audio hdmi disabled)
AUDIO: Creative Labs EMU20k2

GUEST OS: debian 9 x64 with lxde and without pulseaudio