CM-iGLX: Linux: Video Input Port
Contents
Introduction
CM-iGLX has Video Input Port (VIP in short) integrated into Geode LX processor. The VIP receives data from video decoder (for instance SAA7113h assembled on the SB-iGLX) and this data can be stored as a video stream or presented as a display overlay. This functionality can be enabled in using "Video for Linux 2 (v4l2)" API. CompuLab provides geodelx-v4l2 package which contains a driver that implements the v4l2 API on CM-iGLX (geodelx-v4l2/geode_lx_video.patch) and application examples for video capture (geodelx-v4l2/examples/capture.c) and video overlay (geodelx-v4l2/examples/overlay.c).
Kernel configuration
The v4l2 driver for CM-iGLX included in the geodelx-v4l2 package is available as a patch vs. Linux kernel 2.6.24. After applying the patch to kernel source tree you will need to enable the #Geode LX framebuffer driver and #Geode LX v4l2 driver. After updating kernel configuration as described below, build the kernel and install the resulting image and loadable kernel modules to CM-iGLX.
Geode LX framebuffer driver
In the "Device Drivers -> Graphics support" menu enable "Support for frame buffer devices":
.config - Linux Kernel v2.6.24 Configuration ────────────────────────────────────────────────────────────────────────────── ┌─────────────────────────── Graphics support ────────────────────────────┐ │ Arrow keys navigate the menu. <Enter> selects submenus --->. │ │ Highlighted letters are hotkeys. Pressing <Y> includes, <N> excludes, │ │ <M> modularizes features. Press <Esc><Esc> to exit, <?> for Help, </> │ │ for Search. Legend: [*] built-in [ ] excluded <M> module < > │ │ ┌─────────────────────────────────────────────────────────────────────┐ │ │ │ < > /dev/agpgart (AGP Support) ---> │ │ │ │ < > Direct Rendering Manager (XFree86 4.1.0 and higher DRI suppor│ │ │ │ < > Lowlevel video output switch controls │ │ │ │ <*> Support for frame buffer devices ---> │ │ │ │ [ ] Backlight & LCD device support ---> │ │ │ │ Display device support ---> │ │ │ │ Console display driver support ---> │ │ │ │ [ ] Bootup logo ---> │ │ │ └─────────────────────────────────────────────────────────────────────┘ │ ├─────────────────────────────────────────────────────────────────────────┤ │ <Select> < Exit > < Help > │ └─────────────────────────────────────────────────────────────────────────┘
and in the "Support for frame buffer devices" menu enable "AMD Geode family framebuffer support" and "AMD Geode LX framebuffer support":
.config - Linux Kernel v2.6.24 Configuration ────────────────────────────────────────────────────────────────────────────── ┌─────────────────── Support for frame buffer devices ────────────────────┐ │ Arrow keys navigate the menu. <Enter> selects submenus --->. │ │ Highlighted letters are hotkeys. Pressing <Y> includes, <N> excludes, │ │ <M> modularizes features. Press <Esc><Esc> to exit, <?> for Help, </> │ │ for Search. Legend: [*] built-in [ ] excluded <M> module < > │ │ ┌─────────────────────────────────────────────────────────────────────┐ │ │ │ --- Support for frame buffer devices │ │ │ │ [ ] Enable firmware EDID │ │ │ │ [ ] Enable Video Mode Handling Helpers │ │ │ │ [ ] Enable Tile Blitting Support │ │ │ │ *** Frame buffer hardware drivers *** │ │ │ │ < > Cirrus Logic support │ │ │ │ < > Permedia2 support │ │ │ │ < > CyberPro 2000/2010/5000 support │ │ │ │ < > Arc Monochrome LCD board support │ │ ............. │ │ < > 3Dfx Voodoo Graphics (sst1) support │ │ │ │ < > VIA VT8623 support │ │ │ │ < > Cyberblade/i1 support │ │ │ │ < > Trident support │ │ │ │ < > ARK 2000PV support │ │ │ │ < > Permedia3 support (EXPERIMENTAL) │ │ │ │ [*] AMD Geode family framebuffer support (EXPERIMENTAL) │ │ │ │ <*> AMD Geode LX framebuffer support (EXPERIMENTAL) │ │ │ │ < > AMD Geode GX framebuffer support (EXPERIMENTAL) │ │ │ │ < > AMD Geode GX1 framebuffer support (EXPERIMENTAL) │ │ │ │ < > Virtual Frame Buffer support (ONLY FOR TESTING!) │ │ │ └─────────────────────────────────────────────────────────────────────┘ │ ├─────────────────────────────────────────────────────────────────────────┤ │ <Select> < Exit > < Help > │ └─────────────────────────────────────────────────────────────────────────┘
Geode LX v4l2 driver
In the "Device Drivers -> Multimedia devices" menu enable "Video for Linux":
.config - Linux Kernel v2.6.24 Configuration ────────────────────────────────────────────────────────────────────────────── ┌────────────────────────── Multimedia devices ───────────────────────────┐ │ Arrow keys navigate the menu. <Enter> selects submenus --->. │ │ Highlighted letters are hotkeys. Pressing <Y> includes, <N> excludes, │ │ <M> modularizes features. Press <Esc><Esc> to exit, <?> for Help, </> │ │ for Search. Legend: [*] built-in [ ] excluded <M> module < > │ │ ┌─────────────────────────────────────────────────────────────────────┐ │ │ │ <M> Video For Linux │ │ │ │ [ ] Enable Video For Linux API 1 (DEPRECATED) │ │ │ │ [*] Enable Video For Linux API 1 compatible Layer │ │ │ │ [*] Video capture adapters ---> │ │ │ │ [ ] Radio Adapters ---> │ │ │ │ < > DVB for Linux │ │ │ │ [ ] DAB adapters │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ └─────────────────────────────────────────────────────────────────────┘ │ ├─────────────────────────────────────────────────────────────────────────┤ │ <Select> < Exit > < Help > │ └─────────────────────────────────────────────────────────────────────────┘
Next, go to "Video capture adapters" menu and enable "Geode LX Video capture interface":
.config - Linux Kernel v2.6.24 Configuration ────────────────────────────────────────────────────────────────────────────── ┌──────────────────────── Video capture adapters ─────────────────────────┐ │ Arrow keys navigate the menu. <Enter> selects submenus --->. │ │ Highlighted letters are hotkeys. Pressing <Y> includes, <N> excludes, │ │ <M> modularizes features. Press <Esc><Esc> to exit, <?> for Help, </> │ │ for Search. Legend: [*] built-in [ ] excluded <M> module < > │ │ ┌─────────────────────────────────────────────────────────────────────┐ │ │ │ --- Video capture adapters │ │ │ │ [ ] Enable advanced debug functionality │ │ │ │ [ ] Autoselect pertinent encoders/decoders and other helper chi│ │ │ │ Encoders/decoders and other helper chips ---> │ │ │ │ < > Virtual Video Driver │ │ │ │ < > SAA5246A, SAA5281 Teletext processor │ │ │ │ < > SAA5249 Teletext processor │ │ │ │ < > Philips SAA7134 support │ │ │ │ < > Hexium HV-PCI6 and Orion frame grabber │ │ │ │ < > Hexium Gemini frame grabber │ │ │ │ < > Conexant 2388x (bt878 successor) support │ │ │ │ <M> Geode LX Video capture interface ---> │ │ │ │ < > Marvell 88ALP01 (Cafe) CMOS Camera Controller support │ │ │ │ [ ] V4L USB devices ---> │ │ │ └─────────────────────────────────────────────────────────────────────┘ │ ├─────────────────────────────────────────────────────────────────────────┤ │ <Select> < Exit > < Help > │ └─────────────────────────────────────────────────────────────────────────┘
If you are using SB-iGLX base board disable "Autoselect pertinent encoders/decoders and other helper chips" option and select SAA7113 video decoder:
.config - Linux Kernel v2.6.24 Configuration ────────────────────────────────────────────────────────────────────────────── ┌─────────────── Encoders/decoders and other helper chips ────────────────┐ │ Arrow keys navigate the menu. <Enter> selects submenus --->. │ │ Highlighted letters are hotkeys. Pressing <Y> includes, <N> excludes, │ │ <M> modularizes features. Press <Esc><Esc> to exit, <?> for Help, </> │ │ for Search. Legend: [*] built-in [ ] excluded <M> module < > │ │ ┌─────────────────────────────────────────────────────────────────────┐ │ │ │ *** Audio decoders *** │ │ │ │ < > Philips TDA9840 audio processor │ │ │ │ < > Philips TEA6415C audio processor │ │ │ │ < > Philips TEA6420 audio processor │ │ │ │ < > Micronas MSP34xx audio decoders │ │ │ │ < > Cirrus Logic CS53L32A audio ADC │ │ │ │ < > Texas Instruments TLV320AIC23B audio codec │ │ │ │ < > Wolfson Microelectronics WM8775 audio ADC with input mixer │ │ │ │ < > Wolfson Microelectronics WM8739 stereo audio ADC │ │ │ │ < > Panasonic VP27s internal MPX │ │ │ │ *** Video decoders *** │ │ │ │ < > OmniVision OV7670 sensor support │ │ │ │ < > TCM825x camera sensor support │ │ │ │ <M> Philips SAA7113/4/5 video decoders │ │ │ │ < > Texas Instruments TVP5150 video decoder │ │ │ │ *** Video and audio decoders *** │ │ │ │ < > Conexant CX2584x audio/video decoders │ │ │ │ *** MPEG video encoders *** │ │ │ │ < > Conexant CX2341x MPEG encoders │ │ │ │ *** Video encoders *** │ │ │ │ < > Philips SAA7127/9 digital video encoders │ │ │ │ *** Video improvement chips *** │ │ │ │ < > NEC Electronics uPD64031A Ghost Reduction │ │ │ │ < > NEC Electronics uPD64083 3-Dimensional Y/C separation │ │ │ └─────────────────────────────────────────────────────────────────────┘ │ ├─────────────────────────────────────────────────────────────────────────┤ │ <Select> < Exit > < Help > │ └─────────────────────────────────────────────────────────────────────────┘
Application examples
The geodelx-v4l2 package includes two simple examples for video capture and video overlay.
Capture
The capture example accepts the following command line options:
-d | --device name Video device name [/dev/video] -h | --help Print this message -m | --mmap Use memory mapped buffers -r | --read Use read() calls -o | --output Capture to file [file]
Overlay
The overlay example accepts the following command line options:
-d | --device name Video device name [/dev/video] -w | --width value Overlay window width [640] -e | --height value Overlay window height [480] -l | --left value Overlay window left coord [0] -t | --top value Overlay window top coord [0] -s | --steps value Steps for control adjustment [] -v | --verbose Verbose output -h | --help Print this message
