author Mike Gorchak <>
Fri, 24 Apr 2009 03:46:54 +0000
changeset 3107 3cf236d3cd81
parent 3099 82e60908fab1
child 3192 ec126b077b96
permissions -rw-r--r--
Update README for QNX 6.x

README.QNX by Mike Gorchak <>, <>
Last changed at 23 Mar 2009.

QNX Photon and GF drivers are being constructed.
QNX QSA (QNX Sound Architecture) driver is ready.
QNX CDROM driver is ready.
QNX HID input driver is being constructed.

 -- SDL QSA driver --

   Due to QNX Sound Architecture limitations software could  not  determine
what playback channels are designed for, so some casus can be. For example,
output after testmultiaudio test utility execution:

Using audio driver: qsa
playing on device #0: ('Vortex 8820 @ fb000000 d0')...done.
playing on device #1: ('Vortex 8820 @ fb000000 d1')...done.
playing on device #2: ('i8x0 @ d800 d0')...done.
playing on device #3: ('i8x0 @ d800 d1')...done.
playing on all devices...
Open device 3 failed: QSA: snd_pcm_channel_params failed: Invalid argument

If  speakers  are  connected  to  both  audio  cards: Vortex 8820 and Intel
Integrated Audio we can hear sound playback on device #0 and devices #2, #3
only. Device #1 is an unknown PCM channel which does not produce any sound.

As for error during device #3 opening, it's caused  by QSA  software  mixer
channel, because  it can't open real hardware device #2, since it's already
opened by SDL.

After simultaneous sound playback  on  all  devices  utility testmultiaudio
stays running waiting for  sound playback  finish  on  device #1,  which is
locked up due to some Aureal Vortex 8820 driver limitations.

 -- SDL GF driver --

Here is an additional information about SDL GF driver:
 * 0. Introduction.
 * 1. Environment variables which SDL GF driver supports.
 * 2. Custom video modes.
 * 3. Limitations.

0. Introduction.

   SDL GF driver is a layer between  SDL  and  QNX Graphics Framework (GF).
SDL GF driver also supports OpenGL ES  through the  QNX Graphics Framework.
Hardware accelerated features which SDL can support depend on real hardware

1. Environment variables which GF driver supports.

   GF  driver  supports  the  following  environment  variables for  QNX GF
specific customization options:
   a) SDL_VIDEO_GF_REFRESH_RATE - refresh  rate  of  video  output  in  Hz.
      Without this environment variable declaration  SDL  controls  refresh
      rate of your display.  If this enironment  variable is set  to 0, SDL
      will control  refresh  rate  of  display,  otherwise  value  of  flag
      SDL_VIDEO_GF_REFRESH_RATE  is  used  for  all  screen  resolutions as
      refresh rate. This example will set 60Hz refresh rate as refresh rate
      for all graphics modes:


2. Custom video modes.

   Since most QNX graphics drivers support GENERIC  video  modes, i.e.  you
can specify any horizontal and vertical resolution and  any  refresh  rate,
SDL GF driver uses its own fullscreen modes list, which can be  incomplete.
You can add any custom video mode, which your QNX graphics driver  supports
by  editing  file  ./src/video/qnxgf/SDL_qnxgf.c.   Custom   graphics  mode
definition looks like this:

   {0, 1024, 640, 60, NULL},   /* 1024x640 mode is 60Hz only             */

You must specify horizontal resolution as  the  second  parameter, vertical
resolution as the third one and  refresh  rate  as  the  fourth  parameter.
Please leave the first and the last parameters as 0 and NULL.  Then send me
your changes to e-mail address which is specified in  the  header  of  this

3. Limitations.

   There are few limitations while using SDL GF driver:

   a) Since  GF   driver   supports   fullscreen  modes  only,   when  flag
SDL_WINDOW_FULLSCREEN is not specified, SDL GF driver will try to find  the
fullscreen graphics mode which corresponds to SDL window size. Refresh rate
will be the  lowest  available,  if  SDL_VIDEO_GF_REFRESH_RATE  environment
variable is not set.
   b) As confirmed by QSSL none of existing video  drivers  has  support of
doublescan low-resolution video modes.  So  modes  below  640x480  are  not
supported. If your video driver supports low-resolution video modes, please
add SDL_GF_LOWRESOLUTION flag to the gf_devicename array in the SDL_qnxgf.c
source file.

 -- SDL Photon driver --

 -- SDL HID input driver --