Archived:Development: USB based video drivers

USB Video

see Em2820 for more information about how to write an usb video driver

What we need from you to get your USB Device work

Requested Devices

Device	Status
Genius TVGO u202	video/audio works (720x288 non interlaced half frames, Audio USB Audio) - no tuning yet
ALI Corp 1.3M Pixel USB 2.0	Bad quality video yet
uli-m9205	Driver is in development, quality will be good
Aiptek USB DualCam
Hauppauge	WinTV USB 2.0 -- AUDIO!

Best thing would be to donate(prefered of course for the work :) or send your device to a developer for a few weeks

Working Devices

Device	Status
Pinnacle PCTV USB 2.0	supported (Need support for PAL-M) /* please follow the description on this site and mail the parsed output to mrechberger@gmail.com */
Terratec Cinergy 250 USB 2.0	supported
MSI Vox USB 2.0	supported (res. <= 640x480)
Hauppauge WinTV USB 2.0	supported

Requirements

this site explains how to get empiatech devices or similar running with linux by applying changes which might only work with your device.

USBView output

We also need the linux usbview output of your device

Get usbsnoop for windows

http://benoit.papillault.free.fr/usbsnoop/

http://benoit.papillault.free.fr/stats/get.php?location=../usbsnoop/sniff-bin-1.8.zip

if the link is down, you can also ask in IRC

Set up usbsnoop and start sniffing

Before starting to sniff start up your TV application and set it to the highest resolution (for em2820/em2840 devices the highest resolution should be 720x576 or 720x480 or 640x480?)

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also tell us which resolution you used for it

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attach the sniffer to your device and start logging:

Finally start up your TV application again, everything will slow down after it's started but it's worth doing it that way hardware analyzers cost a few thousand dollars... please sniff about 200 - 300 MB! it will be easier for analyzing.

I wrote the parser for converting the usbsnoop logfile to a human readable format you can find it in my repository (http://linuxtv.org/hg/~mrechberger/v4l-dvb) in v4l_experimental/em2880 the file is called parser.pl

Tools for reverse engineering:

initgen.pl	this tool creates a struct with the usb data that got sent to the device
log2bin.pl	extract videodata from the usbsnoop logfile (try to play it with mplayer(as a rawvideo, you need to figure out the raw videoformat of your device)
usbanalyze.pl	convert the usbsnoop log to a human readable format for analyzing what's going on

USB replay

usb replay is a small tool for replaying sniffed and prepared logfiles to a USB device. It's a simple to use ncurses frontend which shows up all prepared usb messages and lets you select whatever you want to replay. Note the source isn't clean, didn't spend too much time uppon this yet I'll do this by time when I'm bored unless you like to fix up the not freed buffers for me :)

Copyright (C) 2006 Markus Rechberger <mrechberger@gmail.com>

Installation:

hg clone http://linuxtv.org/hg/~mrechberger/v4l-dvb
cd v4l_experimental/em2880 # please also have a look at README there
gcc usbreplay.c -o usbreplay -lusb -lmenu

• sniff a usbdevice in windows with usbsnoop
• parse the logfile with parser.pl (perl parser.pl < usbsnoop.log > analyzed.log)
• run usbreplay as root or privileged user who has access to usbfs (usbreplay analyzed.log)
• select your desired usb device

• start replaying usb data to the usb device, just select a line and press return

Link

Device

Contact

Markus Rechberger/irc mrec