0001 .. SPDX-License-Identifier: GPL-2.0
0002
0003 The ivtv driver
0004 ===============
0005
0006 Author: Hans Verkuil <hverkuil@xs4all.nl>
0007
0008 This is a v4l2 device driver for the Conexant cx23415/6 MPEG encoder/decoder.
0009 The cx23415 can do both encoding and decoding, the cx23416 can only do MPEG
0010 encoding. Currently the only card featuring full decoding support is the
0011 Hauppauge PVR-350.
0012
0013 .. note::
0014
0015 #) This driver requires the latest encoder firmware (version 2.06.039, size
0016 376836 bytes). Get the firmware from here:
0017
0018 https://linuxtv.org/downloads/firmware/#conexant
0019
0020 #) 'normal' TV applications do not work with this driver, you need
0021 an application that can handle MPEG input such as mplayer, xine, MythTV,
0022 etc.
0023
0024 The primary goal of the IVTV project is to provide a "clean room" Linux
0025 Open Source driver implementation for video capture cards based on the
0026 iCompression iTVC15 or Conexant CX23415/CX23416 MPEG Codec.
0027
0028 Features
0029 --------
0030
0031 * Hardware mpeg2 capture of broadcast video (and sound) via the tuner or
0032 S-Video/Composite and audio line-in.
0033 * Hardware mpeg2 capture of FM radio where hardware support exists
0034 * Supports NTSC, PAL, SECAM with stereo sound
0035 * Supports SAP and bilingual transmissions.
0036 * Supports raw VBI (closed captions and teletext).
0037 * Supports sliced VBI (closed captions and teletext) and is able to insert
0038 this into the captured MPEG stream.
0039 * Supports raw YUV and PCM input.
0040
0041 Additional features for the PVR-350 (CX23415 based)
0042 ---------------------------------------------------
0043
0044 * Provides hardware mpeg2 playback
0045 * Provides comprehensive OSD (On Screen Display: ie. graphics overlaying the
0046 video signal)
0047 * Provides a framebuffer (allowing X applications to appear on the video
0048 device)
0049 * Supports raw YUV output.
0050
0051 IMPORTANT: In case of problems first read this page:
0052 https://help.ubuntu.com/community/Install_IVTV_Troubleshooting
0053
0054 See also
0055 --------
0056
0057 https://linuxtv.org
0058
0059 IRC
0060 ---
0061
0062 irc://irc.freenode.net/#v4l
0063
0064 ----------------------------------------------------------
0065
0066 Devices
0067 -------
0068
0069 A maximum of 12 ivtv boards are allowed at the moment.
0070
0071 Cards that don't have a video output capability (i.e. non PVR350 cards)
0072 lack the vbi8, vbi16, video16 and video48 devices. They also do not
0073 support the framebuffer device /dev/fbx for OSD.
0074
0075 The radio0 device may or may not be present, depending on whether the
0076 card has a radio tuner or not.
0077
0078 Here is a list of the base v4l devices:
0079
0080 .. code-block:: none
0081
0082 crw-rw---- 1 root video 81, 0 Jun 19 22:22 /dev/video0
0083 crw-rw---- 1 root video 81, 16 Jun 19 22:22 /dev/video16
0084 crw-rw---- 1 root video 81, 24 Jun 19 22:22 /dev/video24
0085 crw-rw---- 1 root video 81, 32 Jun 19 22:22 /dev/video32
0086 crw-rw---- 1 root video 81, 48 Jun 19 22:22 /dev/video48
0087 crw-rw---- 1 root video 81, 64 Jun 19 22:22 /dev/radio0
0088 crw-rw---- 1 root video 81, 224 Jun 19 22:22 /dev/vbi0
0089 crw-rw---- 1 root video 81, 228 Jun 19 22:22 /dev/vbi8
0090 crw-rw---- 1 root video 81, 232 Jun 19 22:22 /dev/vbi16
0091
0092 Base devices
0093 ------------
0094
0095 For every extra card you have the numbers increased by one. For example,
0096 /dev/video0 is listed as the 'base' encoding capture device so we have:
0097
0098 - /dev/video0 is the encoding capture device for the first card (card 0)
0099 - /dev/video1 is the encoding capture device for the second card (card 1)
0100 - /dev/video2 is the encoding capture device for the third card (card 2)
0101
0102 Note that if the first card doesn't have a feature (eg no decoder, so no
0103 video16, the second card will still use video17. The simple rule is 'add
0104 the card number to the base device number'. If you have other capture
0105 cards (e.g. WinTV PCI) that are detected first, then you have to tell
0106 the ivtv module about it so that it will start counting at 1 (or 2, or
0107 whatever). Otherwise the device numbers can get confusing. The ivtv
0108 'ivtv_first_minor' module option can be used for that.
0109
0110
0111 - /dev/video0
0112
0113 The encoding capture device(s).
0114
0115 Read-only.
0116
0117 Reading from this device gets you the MPEG1/2 program stream.
0118 Example:
0119
0120 .. code-block:: none
0121
0122 cat /dev/video0 > my.mpg (you need to hit ctrl-c to exit)
0123
0124
0125 - /dev/video16
0126
0127 The decoder output device(s)
0128
0129 Write-only. Only present if the MPEG decoder (i.e. CX23415) exists.
0130
0131 An mpeg2 stream sent to this device will appear on the selected video
0132 display, audio will appear on the line-out/audio out. It is only
0133 available for cards that support video out. Example:
0134
0135 .. code-block:: none
0136
0137 cat my.mpg >/dev/video16
0138
0139
0140 - /dev/video24
0141
0142 The raw audio capture device(s).
0143
0144 Read-only
0145
0146 The raw audio PCM stereo stream from the currently selected
0147 tuner or audio line-in. Reading from this device results in a raw
0148 (signed 16 bit Little Endian, 48000 Hz, stereo pcm) capture.
0149 This device only captures audio. This should be replaced by an ALSA
0150 device in the future.
0151 Note that there is no corresponding raw audio output device, this is
0152 not supported in the decoder firmware.
0153
0154
0155 - /dev/video32
0156
0157 The raw video capture device(s)
0158
0159 Read-only
0160
0161 The raw YUV video output from the current video input. The YUV format
0162 is a 16x16 linear tiled NV12 format (V4L2_PIX_FMT_NV12_16L16)
0163
0164 Note that the YUV and PCM streams are not synchronized, so they are of
0165 limited use.
0166
0167
0168 - /dev/video48
0169
0170 The raw video display device(s)
0171
0172 Write-only. Only present if the MPEG decoder (i.e. CX23415) exists.
0173
0174 Writes a YUV stream to the decoder of the card.
0175
0176
0177 - /dev/radio0
0178
0179 The radio tuner device(s)
0180
0181 Cannot be read or written.
0182
0183 Used to enable the radio tuner and tune to a frequency. You cannot
0184 read or write audio streams with this device. Once you use this
0185 device to tune the radio, use /dev/video24 to read the raw pcm stream
0186 or /dev/video0 to get an mpeg2 stream with black video.
0187
0188
0189 - /dev/vbi0
0190
0191 The 'vertical blank interval' (Teletext, CC, WSS etc) capture device(s)
0192
0193 Read-only
0194
0195 Captures the raw (or sliced) video data sent during the Vertical Blank
0196 Interval. This data is used to encode teletext, closed captions, VPS,
0197 widescreen signalling, electronic program guide information, and other
0198 services.
0199
0200
0201 - /dev/vbi8
0202
0203 Processed vbi feedback device(s)
0204
0205 Read-only. Only present if the MPEG decoder (i.e. CX23415) exists.
0206
0207 The sliced VBI data embedded in an MPEG stream is reproduced on this
0208 device. So while playing back a recording on /dev/video16, you can
0209 read the embedded VBI data from /dev/vbi8.
0210
0211
0212 - /dev/vbi16
0213
0214 The vbi 'display' device(s)
0215
0216 Write-only. Only present if the MPEG decoder (i.e. CX23415) exists.
0217
0218 Can be used to send sliced VBI data to the video-out connector.
