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Diffstat (limited to 'drivers/staging/easycap/README')
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diff --git a/drivers/staging/easycap/README b/drivers/staging/easycap/README new file mode 100644 index 000000000000..3775481f05e8 --- /dev/null +++ b/drivers/staging/easycap/README @@ -0,0 +1,130 @@ + + *********************************************************** + * EasyCAP USB 2.0 Video Adapter with Audio, Model DC60 * + * and * + * EasyCAP002 4-Channel USB 2.0 DVR * + *********************************************************** + Mike Thomas <rmthomas@sciolus.org> + + + +SUPPORTED HARDWARE +------------------ + +This driver is intended for use with hardware having USB ID 05e1:0408. +Two kinds of EasyCAP have this USB ID, namely: + + * EasyCAP USB 2.0 Video Adapter with Audio, Model DC60, + having input cables labelled CVBS, S-VIDEO, AUDIO(L), AUDIO(R) + + * EasyCAP002 4-Channel USB 2.0 DVR, having input cables labelled + 1, 2, 3, 4 and an unlabelled input cable for a microphone. + + +BUILD OPTIONS AND DEPENDENCIES +------------------------------ + +If the parameter EASYCAP_IS_VIDEODEV_CLIENT is undefined during compilation +the built module is entirely independent of the videodev module, and when +the EasyCAP is physically plugged into a USB port the special files +/dev/easycap0 and /dev/easysnd1 are created as video and sound sources +respectively. + +If the parameter EASYCAP_IS_VIDEODEV_CLIENT is defined during compilation +the built easycap module is configured to register with the videodev module, +in which case the special files created when the EasyCAP is plugged in are +/dev/video0 and /dev/easysnd0. Use of the easycap module as a client of +the videodev module has received very little testing as of June 2010. + + +KNOWN BUILD PROBLEMS +-------------------- + +(1) Recent gcc versions may generate the message: + + warning: the frame size of .... bytes is larger than 1024 bytes + +This warning can be suppressed by specifying in the Makefile: + + EXTRA_CFLAGS += -Wframe-larger-than=8192 + +but it would be preferable to remove the cause of the warning. + + +KNOWN RUNTIME ISSUES +-------------------- + +(1) Randomly (maybe 5 to 10% of occasions) the driver fails to produce any +output at start-up. Closing mplayer (or whatever the user program is) and +restarting it restores normal performance without any other remedial action +being necessary. The reason for this is not known. + +(2) Intentionally, this driver will not stream material which is unambiguously +identified by the hardware as copy-protected. The video output will freeze +within about a minute when this situation arises. + +(3) The controls for luminance, contrast, saturation, hue and volume may not +always work properly. + +(4) Reduced-resolution S-Video seems to suffer from moire artefacts. No +attempt has yet been made to rememdy this. + + +SUPPORTED TV STANDARDS AND RESOLUTIONS +-------------------------------------- + +The following TV standards are natively supported by the hardware and are +usable as (for example) the "norm=" parameter in the mplayer command: + + PAL_BGHIN, NTSC_N_443, + PAL_Nc, NTSC_N, + SECAM, NTSC_M, NTSC_M_JP, + PAL_60, NTSC_443, + PAL_M. + +The available picture sizes are: + + at 25 frames per second: 720x576, 704x576, 640x480, 360x288, 320x240; + at 30 frames per second: 720x480, 640x480, 360x240, 320x240; + + +WHAT'S TESTED AND WHAT'S NOT +---------------------------- + +This driver is known to work with mplayer, mencoder, tvtime and sufficiently +recent versions of vlc. An interface to ffmpeg is implemented, but serious +audio-video synchronization problems remain. + +The driver is designed to support all the TV standards accepted by the +hardware, but as yet it has actually been tested on only a few of these. + +I have been unable to test and calibrate the S-video input myself because I +do not possess any equipment with S-video output. + +This driver does not understand the V4L1 IOCTL commands, so programs such +as camorama are not compatible. There are reports that the driver does +work with sufficiently recent (V4L2) versions of zoneminder, but I have not +attempted to confirm this myself. + + +UDEV RULES +---------- + +In order that the special files /dev/easycap0 and /dev/easysnd1 are created +with conveniently relaxed permissions when the EasyCAP is plugged in, a file +is preferably to be provided in directory /etc/udev/rules.d with content: + +ACTION!="add|change", GOTO="easycap_rules_end" +ATTRS{idVendor}=="05e1", ATTRS{idProduct}=="0408", \ + MODE="0666", OWNER="root", GROUP="root" +LABEL="easycap_rules_end" + + +ACKNOWLEGEMENTS AND REFERENCES +------------------------------ +This driver makes use of information contained in the Syntek Semicon DC-1125 +Driver, presently maintained at http://sourceforge.net/projects/syntekdriver/ +by Nicolas Vivien. Particularly useful has been a patch to the latter driver +provided by Ivor Hewitt in January 2009. The NTSC implementation is taken +from the work of Ben Trask. + |