linux/Documentation/video4linux/README.ivtv
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   1
   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/
  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)
  40 * Supports raw YUV output.
  41
  42IMPORTANT: In case of problems first read this page:
  43           http://www.ivtvdriver.org/index.php/Troubleshooting
  44
  45See also:
  46
  47Homepage + Wiki
  48http://www.ivtvdriver.org
  49
  50IRC
  51irc://irc.freenode.net/ivtv-dev
  52
  53----------------------------------------------------------
  54
  55Devices
  56=======
  57
  58A maximum of 12 ivtv boards are allowed at the moment.
  59
  60Cards that don't have a video output capability (i.e. non PVR350 cards)
  61lack the vbi8, vbi16, video16 and video48 devices. They also do not
  62support the framebuffer device /dev/fbx for OSD.
  63
  64The radio0 device may or may not be present, depending on whether the
  65card has a radio tuner or not.
  66
  67Here is a list of the base v4l devices:
  68crw-rw----    1 root     video     81,   0 Jun 19 22:22 /dev/video0
  69crw-rw----    1 root     video     81,  16 Jun 19 22:22 /dev/video16
  70crw-rw----    1 root     video     81,  24 Jun 19 22:22 /dev/video24
  71crw-rw----    1 root     video     81,  32 Jun 19 22:22 /dev/video32
  72crw-rw----    1 root     video     81,  48 Jun 19 22:22 /dev/video48
  73crw-rw----    1 root     video     81,  64 Jun 19 22:22 /dev/radio0
  74crw-rw----    1 root     video     81, 224 Jun 19 22:22 /dev/vbi0
  75crw-rw----    1 root     video     81, 228 Jun 19 22:22 /dev/vbi8
  76crw-rw----    1 root     video     81, 232 Jun 19 22:22 /dev/vbi16
  77
  78Base devices
  79============
  80
  81For every extra card you have the numbers increased by one. For example,
  82/dev/video0 is listed as the 'base' encoding capture device so we have:
  83
  84 /dev/video0  is the encoding capture device for the first card (card 0)
  85 /dev/video1  is the encoding capture device for the second card (card 1)
  86 /dev/video2  is the encoding capture device for the third card (card 2)
  87
  88Note that if the first card doesn't have a feature (eg no decoder, so no
  89video16, the second card will still use video17. The simple rule is 'add
  90the card number to the base device number'. If you have other capture
  91cards (e.g. WinTV PCI) that are detected first, then you have to tell
  92the ivtv module about it so that it will start counting at 1 (or 2, or
  93whatever). Otherwise the device numbers can get confusing. The ivtv
  94'ivtv_first_minor' module option can be used for that.
  95
  96
  97/dev/video0
  98The encoding capture device(s).
  99Read-only.
 100
 101Reading from this device gets you the MPEG1/2 program stream.
 102Example:
 103
 104cat /dev/video0 > my.mpg (you need to hit ctrl-c to exit)
 105
 106
 107/dev/video16
 108The decoder output device(s)
 109Write-only. Only present if the MPEG decoder (i.e. CX23415) exists.
 110
 111An mpeg2 stream sent to this device will appear on the selected video
 112display, audio will appear on the line-out/audio out.  It is only
 113available for cards that support video out. Example:
 114
 115cat my.mpg >/dev/video16
 116
 117
 118/dev/video24
 119The raw audio capture device(s).
 120Read-only
 121
 122The raw audio PCM stereo stream from the currently selected
 123tuner or audio line-in.  Reading from this device results in a raw
 124(signed 16 bit Little Endian, 48000 Hz, stereo pcm) capture.
 125This device only captures audio. This should be replaced by an ALSA
 126device in the future.
 127Note that there is no corresponding raw audio output device, this is
 128not supported in the decoder firmware.
 129
 130
 131/dev/video32
 132The raw video capture device(s)
 133Read-only
 134
 135The raw YUV video output from the current video input. The YUV format
 136is non-standard (V4L2_PIX_FMT_HM12).
 137
 138Note that the YUV and PCM streams are not synchronized, so they are of
 139limited use.
 140
 141
 142/dev/video48
 143The raw video display device(s)
 144Write-only. Only present if the MPEG decoder (i.e. CX23415) exists.
 145
 146Writes a YUV stream to the decoder of the card.
 147
 148
 149/dev/radio0
 150The radio tuner device(s)
 151Cannot be read or written.
 152
 153Used to enable the radio tuner and tune to a frequency. You cannot
 154read or write audio streams with this device.  Once you use this
 155device to tune the radio, use /dev/video24 to read the raw pcm stream
 156or /dev/video0 to get an mpeg2 stream with black video.
 157
 158
 159/dev/vbi0
 160The 'vertical blank interval' (Teletext, CC, WSS etc) capture device(s)
 161Read-only
 162
 163Captures the raw (or sliced) video data sent during the Vertical Blank
 164Interval. This data is used to encode teletext, closed captions, VPS,
 165widescreen signalling, electronic program guide information, and other
 166services.
 167
 168
 169/dev/vbi8
 170Processed vbi feedback device(s)
 171Read-only. Only present if the MPEG decoder (i.e. CX23415) exists.
 172
 173The sliced VBI data embedded in an MPEG stream is reproduced on this
 174device. So while playing back a recording on /dev/video16, you can
 175read the embedded VBI data from /dev/vbi8.
 176
 177
 178/dev/vbi16
 179The vbi 'display' device(s)
 180Write-only. Only present if the MPEG decoder (i.e. CX23415) exists.
 181
 182Can be used to send sliced VBI data to the video-out connector.
 183
 184---------------------------------
 185
 186Hans Verkuil <hverkuil@xs4all.nl>
 187
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