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1
2 The ivtv driver
3 ===============
4
5 Author: Hans Verkuil <hverkuil@xs4all.nl>
6
7 This is a v4l2 device driver for the Conexant cx23415/6 MPEG encoder/decoder.
8 The cx23415 can do both encoding and decoding, the cx23416 can only do MPEG
9 encoding. Currently the only card featuring full decoding support is the
10 Hauppauge PVR-350.
11
12 .. note::
13
14 #) This driver requires the latest encoder firmware (version 2.06.039, size
15 376836 bytes). Get the firmware from here:
16
17 https://linuxtv.org/downloads/firmware/#conexant
18
19 #) 'normal' TV applications do not work with this driver, you need
20 an application that can handle MPEG input such as mplayer, xine, MythTV,
21 etc.
22
23 The primary goal of the IVTV project is to provide a "clean room" Linux
24 Open Source driver implementation for video capture cards based on the
25 iCompression iTVC15 or Conexant CX23415/CX23416 MPEG Codec.
26
27 Features
28 --------
29
30 * Hardware mpeg2 capture of broadcast video (and sound) via the tuner or
31 S-Video/Composite and audio line-in.
32 * Hardware mpeg2 capture of FM radio where hardware support exists
33 * Supports NTSC, PAL, SECAM with stereo sound
34 * Supports SAP and bilingual transmissions.
35 * Supports raw VBI (closed captions and teletext).
36 * Supports sliced VBI (closed captions and teletext) and is able to insert
37 this into the captured MPEG stream.
38 * Supports raw YUV and PCM input.
39
40 Additional features for the PVR-350 (CX23415 based)
41 ---------------------------------------------------
42
43 * Provides hardware mpeg2 playback
44 * Provides comprehensive OSD (On Screen Display: ie. graphics overlaying the
45 video signal)
46 * Provides a framebuffer (allowing X applications to appear on the video
47 device)
48 * Supports raw YUV output.
49
50 IMPORTANT: In case of problems first read this page:
51 https://help.ubuntu.com/community/Install_IVTV_Troubleshooting
52
53 See also
54 --------
55
56 https://linuxtv.org
57
58 IRC
59 ---
60
61 irc://irc.freenode.net/#v4l
62
63 ----------------------------------------------------------
64
65 Devices
66 -------
67
68 A maximum of 12 ivtv boards are allowed at the moment.
69
70 Cards that don't have a video output capability (i.e. non PVR350 cards)
71 lack the vbi8, vbi16, video16 and video48 devices. They also do not
72 support the framebuffer device /dev/fbx for OSD.
73
74 The radio0 device may or may not be present, depending on whether the
75 card has a radio tuner or not.
76
77 Here is a list of the base v4l devices:
78
79 .. code-block:: none
80
81 crw-rw---- 1 root video 81, 0 Jun 19 22:22 /dev/video0
82 crw-rw---- 1 root video 81, 16 Jun 19 22:22 /dev/video16
83 crw-rw---- 1 root video 81, 24 Jun 19 22:22 /dev/video24
84 crw-rw---- 1 root video 81, 32 Jun 19 22:22 /dev/video32
85 crw-rw---- 1 root video 81, 48 Jun 19 22:22 /dev/video48
86 crw-rw---- 1 root video 81, 64 Jun 19 22:22 /dev/radio0
87 crw-rw---- 1 root video 81, 224 Jun 19 22:22 /dev/vbi0
88 crw-rw---- 1 root video 81, 228 Jun 19 22:22 /dev/vbi8
89 crw-rw---- 1 root video 81, 232 Jun 19 22:22 /dev/vbi16
90
91 Base devices
92 ------------
93
94 For every extra card you have the numbers increased by one. For example,
95 /dev/video0 is listed as the 'base' encoding capture device so we have:
96
97 - /dev/video0 is the encoding capture device for the first card (card 0)
98 - /dev/video1 is the encoding capture device for the second card (card 1)
99 - /dev/video2 is the encoding capture device for the third card (card 2)
100
101 Note that if the first card doesn't have a feature (eg no decoder, so no
102 video16, the second card will still use video17. The simple rule is 'add
103 the card number to the base device number'. If you have other capture
104 cards (e.g. WinTV PCI) that are detected first, then you have to tell
105 the ivtv module about it so that it will start counting at 1 (or 2, or
106 whatever). Otherwise the device numbers can get confusing. The ivtv
107 'ivtv_first_minor' module option can be used for that.
108
109
110 - /dev/video0
111
112 The encoding capture device(s).
113
114 Read-only.
115
116 Reading from this device gets you the MPEG1/2 program stream.
117 Example:
118
119 .. code-block:: none
120
121 cat /dev/video0 > my.mpg (you need to hit ctrl-c to exit)
122
123
124 - /dev/video16
125
126 The decoder output device(s)
127
128 Write-only. Only present if the MPEG decoder (i.e. CX23415) exists.
129
130 An mpeg2 stream sent to this device will appear on the selected video
131 display, audio will appear on the line-out/audio out. It is only
132 available for cards that support video out. Example:
133
134 .. code-block:: none
135
136 cat my.mpg >/dev/video16
137
138
139 - /dev/video24
140
141 The raw audio capture device(s).
142
143 Read-only
144
145 The raw audio PCM stereo stream from the currently selected
146 tuner or audio line-in. Reading from this device results in a raw
147 (signed 16 bit Little Endian, 48000 Hz, stereo pcm) capture.
148 This device only captures audio. This should be replaced by an ALSA
149 device in the future.
150 Note that there is no corresponding raw audio output device, this is
151 not supported in the decoder firmware.
152
153
154 - /dev/video32
155
156 The raw video capture device(s)
157
158 Read-only
159
160 The raw YUV video output from the current video input. The YUV format
161 is non-standard (V4L2_PIX_FMT_HM12).
162
163 Note that the YUV and PCM streams are not synchronized, so they are of
164 limited use.
165
166
167 - /dev/video48
168
169 The raw video display device(s)
170
171 Write-only. Only present if the MPEG decoder (i.e. CX23415) exists.
172
173 Writes a YUV stream to the decoder of the card.
174
175
176 - /dev/radio0
177
178 The radio tuner device(s)
179
180 Cannot be read or written.
181
182 Used to enable the radio tuner and tune to a frequency. You cannot
183 read or write audio streams with this device. Once you use this
184 device to tune the radio, use /dev/video24 to read the raw pcm stream
185 or /dev/video0 to get an mpeg2 stream with black video.
186
187
188 - /dev/vbi0
189
190 The 'vertical blank interval' (Teletext, CC, WSS etc) capture device(s)
191
192 Read-only
193
194 Captures the raw (or sliced) video data sent during the Vertical Blank
195 Interval. This data is used to encode teletext, closed captions, VPS,
196 widescreen signalling, electronic program guide information, and other
197 services.
198
199
200 - /dev/vbi8
201
202 Processed vbi feedback device(s)
203
204 Read-only. Only present if the MPEG decoder (i.e. CX23415) exists.
205
206 The sliced VBI data embedded in an MPEG stream is reproduced on this
207 device. So while playing back a recording on /dev/video16, you can
208 read the embedded VBI data from /dev/vbi8.
209
210
211 - /dev/vbi16
212
213 The vbi 'display' device(s)
214
215 Write-only. Only present if the MPEG decoder (i.e. CX23415) exists.
216
217 Can be used to send sliced VBI data to the video-out connector.