linux/Documentation/video4linux/README.ivtv
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   2ivtv release notes
   3==================
   4
   5This is a v4l2 device driver for the Conexant cx23415/6 MPEG encoder/decoder.
   6The cx23415 can do both encoding and decoding, the cx23416 can only do MPEG
   7encoding. Currently the only card featuring full decoding support is the
   8Hauppauge PVR-350.
   9
  10NOTE: this driver requires the latest encoder firmware (version 2.06.039, size
  11376836 bytes). Get the firmware from here:
  12
  13http://dl.ivtvdriver.org/ivtv/firmware/firmware.tar.gz
  14
  15NOTE: 'normal' TV applications do not work with this driver, you need
  16an application that can handle MPEG input such as mplayer, xine, MythTV,
  17etc.
  18
  19The primary goal of the IVTV project is to provide a "clean room" Linux
  20Open Source driver implementation for video capture cards based on the
  21iCompression iTVC15 or Conexant CX23415/CX23416 MPEG Codec.
  22
  23Features:
  24 * Hardware mpeg2 capture of broadcast video (and sound) via the tuner or
  25   S-Video/Composite and audio line-in.
  26 * Hardware mpeg2 capture of FM radio where hardware support exists
  27 * Supports NTSC, PAL, SECAM with stereo sound
  28 * Supports SAP and bilingual transmissions.
  29 * Supports raw VBI (closed captions and teletext).
  30 * Supports sliced VBI (closed captions and teletext) and is able to insert
  31   this into the captured MPEG stream.
  32 * Supports raw YUV and PCM input.
  33
  34Additional features for the PVR-350 (CX23415 based):
  35 * Provides hardware mpeg2 playback
  36 * Provides comprehensive OSD (On Screen Display: ie. graphics overlaying the
  37   video signal)
  38 * Provides a framebuffer (allowing X applications to appear on the video
  39   device) (this framebuffer is not yet part of the kernel. In the meantime it
  40   is available from www.ivtvdriver.org).
  41 * Supports raw YUV output.
  42
  43IMPORTANT: In case of problems first read this page:
  44           http://www.ivtvdriver.org/index.php/Troubleshooting
  45
  46See also:
  47
  48Homepage + Wiki
  49http://www.ivtvdriver.org
  50
  51IRC
  52irc://irc.freenode.net/ivtv-dev
  53
  54----------------------------------------------------------
  55
  56Devices
  57=======
  58
  59A maximum of 12 ivtv boards are allowed at the moment.
  60
  61Cards that don't have a video output capability (i.e. non PVR350 cards)
  62lack the vbi8, vbi16, video16 and video48 devices. They also do not
  63support the framebuffer device /dev/fbx for OSD.
  64
  65The radio0 device may or may not be present, depending on whether the
  66card has a radio tuner or not.
  67
  68Here is a list of the base v4l devices:
  69crw-rw----    1 root     video     81,   0 Jun 19 22:22 /dev/video0
  70crw-rw----    1 root     video     81,  16 Jun 19 22:22 /dev/video16
  71crw-rw----    1 root     video     81,  24 Jun 19 22:22 /dev/video24
  72crw-rw----    1 root     video     81,  32 Jun 19 22:22 /dev/video32
  73crw-rw----    1 root     video     81,  48 Jun 19 22:22 /dev/video48
  74crw-rw----    1 root     video     81,  64 Jun 19 22:22 /dev/radio0
  75crw-rw----    1 root     video     81, 224 Jun 19 22:22 /dev/vbi0
  76crw-rw----    1 root     video     81, 228 Jun 19 22:22 /dev/vbi8
  77crw-rw----    1 root     video     81, 232 Jun 19 22:22 /dev/vbi16
  78
  79Base devices
  80============
  81
  82For every extra card you have the numbers increased by one. For example,
  83/dev/video0 is listed as the 'base' encoding capture device so we have:
  84
  85 /dev/video0  is the encoding capture device for the first card (card 0)
  86 /dev/video1  is the encoding capture device for the second card (card 1)
  87 /dev/video2  is the encoding capture device for the third card (card 2)
  88
  89Note that if the first card doesn't have a feature (eg no decoder, so no
  90video16, the second card will still use video17. The simple rule is 'add
  91the card number to the base device number'. If you have other capture
  92cards (e.g. WinTV PCI) that are detected first, then you have to tell
  93the ivtv module about it so that it will start counting at 1 (or 2, or
  94whatever). Otherwise the device numbers can get confusing. The ivtv
  95'ivtv_first_minor' module option can be used for that.
  96
  97
  98/dev/video0
  99The encoding capture device(s).
 100Read-only.
 101
 102Reading from this device gets you the MPEG1/2 program stream.
 103Example:
 104
 105cat /dev/video0 > my.mpg (you need to hit ctrl-c to exit)
 106
 107
 108/dev/video16
 109The decoder output device(s)
 110Write-only. Only present if the MPEG decoder (i.e. CX23415) exists.
 111
 112An mpeg2 stream sent to this device will appear on the selected video
 113display, audio will appear on the line-out/audio out.  It is only
 114available for cards that support video out. Example:
 115
 116cat my.mpg >/dev/video16
 117
 118
 119/dev/video24
 120The raw audio capture device(s).
 121Read-only
 122
 123The raw audio PCM stereo stream from the currently selected
 124tuner or audio line-in.  Reading from this device results in a raw
 125(signed 16 bit Little Endian, 48000 Hz, stereo pcm) capture.
 126This device only captures audio. This should be replaced by an ALSA
 127device in the future.
 128Note that there is no corresponding raw audio output device, this is
 129not supported in the decoder firmware.
 130
 131
 132/dev/video32
 133The raw video capture device(s)
 134Read-only
 135
 136The raw YUV video output from the current video input. The YUV format
 137is non-standard (V4L2_PIX_FMT_HM12).
 138
 139Note that the YUV and PCM streams are not synchronized, so they are of
 140limited use.
 141
 142
 143/dev/video48
 144The raw video display device(s)
 145Write-only. Only present if the MPEG decoder (i.e. CX23415) exists.
 146
 147Writes a YUV stream to the decoder of the card.
 148
 149
 150/dev/radio0
 151The radio tuner device(s)
 152Cannot be read or written.
 153
 154Used to enable the radio tuner and tune to a frequency. You cannot
 155read or write audio streams with this device.  Once you use this
 156device to tune the radio, use /dev/video24 to read the raw pcm stream
 157or /dev/video0 to get an mpeg2 stream with black video.
 158
 159
 160/dev/vbi0
 161The 'vertical blank interval' (Teletext, CC, WSS etc) capture device(s)
 162Read-only
 163
 164Captures the raw (or sliced) video data sent during the Vertical Blank
 165Interval. This data is used to encode teletext, closed captions, VPS,
 166widescreen signalling, electronic program guide information, and other
 167services.
 168
 169
 170/dev/vbi8
 171Processed vbi feedback device(s)
 172Read-only. Only present if the MPEG decoder (i.e. CX23415) exists.
 173
 174The sliced VBI data embedded in an MPEG stream is reproduced on this
 175device. So while playing back a recording on /dev/video16, you can
 176read the embedded VBI data from /dev/vbi8.
 177
 178
 179/dev/vbi16
 180The vbi 'display' device(s)
 181Write-only. Only present if the MPEG decoder (i.e. CX23415) exists.
 182
 183Can be used to send sliced VBI data to the video-out connector.
 184
 185---------------------------------
 186
 187Hans Verkuil <hverkuil@xs4all.nl>
 188
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