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Documentation / video4linux / README.ivtv

Based on kernel version 2.6.26. Page generated on 2008-07-16 21:13 EST.

1	
2	ivtv release notes
3	==================
4	
5	This is a v4l2 device driver for the Conexant cx23415/6 MPEG encoder/decoder.
6	The cx23415 can do both encoding and decoding, the cx23416 can only do MPEG
7	encoding. Currently the only card featuring full decoding support is the
8	Hauppauge PVR-350.
9	
10	NOTE: this driver requires the latest encoder firmware (version 2.06.039, size
11	376836 bytes). Get the firmware from here:
12	
13	http://dl.ivtvdriver.org/ivtv/firmware/firmware.tar.gz
14	
15	NOTE: 'normal' TV applications do not work with this driver, you need
16	an application that can handle MPEG input such as mplayer, xine, MythTV,
17	etc.
18	
19	The primary goal of the IVTV project is to provide a "clean room" Linux
20	Open Source driver implementation for video capture cards based on the
21	iCompression iTVC15 or Conexant CX23415/CX23416 MPEG Codec.
22	
23	Features:
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	
34	Additional 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	
43	IMPORTANT: In case of problems first read this page:
44		   http://www.ivtvdriver.org/index.php/Troubleshooting
45	
46	See also:
47	
48	Homepage + Wiki
49	http://www.ivtvdriver.org
50	
51	IRC
52	irc://irc.freenode.net/ivtv-dev
53	
54	----------------------------------------------------------
55	
56	Devices
57	=======
58	
59	A maximum of 12 ivtv boards are allowed at the moment.
60	
61	Cards that don't have a video output capability (i.e. non PVR350 cards)
62	lack the vbi8, vbi16, video16 and video48 devices. They also do not
63	support the framebuffer device /dev/fbx for OSD.
64	
65	The radio0 device may or may not be present, depending on whether the
66	card has a radio tuner or not.
67	
68	Here is a list of the base v4l devices:
69	crw-rw----    1 root     video     81,   0 Jun 19 22:22 /dev/video0
70	crw-rw----    1 root     video     81,  16 Jun 19 22:22 /dev/video16
71	crw-rw----    1 root     video     81,  24 Jun 19 22:22 /dev/video24
72	crw-rw----    1 root     video     81,  32 Jun 19 22:22 /dev/video32
73	crw-rw----    1 root     video     81,  48 Jun 19 22:22 /dev/video48
74	crw-rw----    1 root     video     81,  64 Jun 19 22:22 /dev/radio0
75	crw-rw----    1 root     video     81, 224 Jun 19 22:22 /dev/vbi0
76	crw-rw----    1 root     video     81, 228 Jun 19 22:22 /dev/vbi8
77	crw-rw----    1 root     video     81, 232 Jun 19 22:22 /dev/vbi16
78	
79	Base devices
80	============
81	
82	For 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	
89	Note that if the first card doesn't have a feature (eg no decoder, so no
90	video16, the second card will still use video17. The simple rule is 'add
91	the card number to the base device number'. If you have other capture
92	cards (e.g. WinTV PCI) that are detected first, then you have to tell
93	the ivtv module about it so that it will start counting at 1 (or 2, or
94	whatever). 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
99	The encoding capture device(s).
100	Read-only.
101	
102	Reading from this device gets you the MPEG1/2 program stream.
103	Example:
104	
105	cat /dev/video0 > my.mpg (you need to hit ctrl-c to exit)
106	
107	
108	/dev/video16
109	The decoder output device(s)
110	Write-only. Only present if the MPEG decoder (i.e. CX23415) exists.
111	
112	An mpeg2 stream sent to this device will appear on the selected video
113	display, audio will appear on the line-out/audio out.  It is only
114	available for cards that support video out. Example:
115	
116	cat my.mpg >/dev/video16
117	
118	
119	/dev/video24
120	The raw audio capture device(s).
121	Read-only
122	
123	The raw audio PCM stereo stream from the currently selected
124	tuner or audio line-in.  Reading from this device results in a raw
125	(signed 16 bit Little Endian, 48000 Hz, stereo pcm) capture.
126	This device only captures audio. This should be replaced by an ALSA
127	device in the future.
128	Note that there is no corresponding raw audio output device, this is
129	not supported in the decoder firmware.
130	
131	
132	/dev/video32
133	The raw video capture device(s)
134	Read-only
135	
136	The raw YUV video output from the current video input. The YUV format
137	is non-standard (V4L2_PIX_FMT_HM12).
138	
139	Note that the YUV and PCM streams are not synchronized, so they are of
140	limited use.
141	
142	
143	/dev/video48
144	The raw video display device(s)
145	Write-only. Only present if the MPEG decoder (i.e. CX23415) exists.
146	
147	Writes a YUV stream to the decoder of the card.
148	
149	
150	/dev/radio0
151	The radio tuner device(s)
152	Cannot be read or written.
153	
154	Used to enable the radio tuner and tune to a frequency. You cannot
155	read or write audio streams with this device.  Once you use this
156	device to tune the radio, use /dev/video24 to read the raw pcm stream
157	or /dev/video0 to get an mpeg2 stream with black video.
158	
159	
160	/dev/vbi0
161	The 'vertical blank interval' (Teletext, CC, WSS etc) capture device(s)
162	Read-only
163	
164	Captures the raw (or sliced) video data sent during the Vertical Blank
165	Interval. This data is used to encode teletext, closed captions, VPS,
166	widescreen signalling, electronic program guide information, and other
167	services.
168	
169	
170	/dev/vbi8
171	Processed vbi feedback device(s)
172	Read-only. Only present if the MPEG decoder (i.e. CX23415) exists.
173	
174	The sliced VBI data embedded in an MPEG stream is reproduced on this
175	device. So while playing back a recording on /dev/video16, you can
176	read the embedded VBI data from /dev/vbi8.
177	
178	
179	/dev/vbi16
180	The vbi 'display' device(s)
181	Write-only. Only present if the MPEG decoder (i.e. CX23415) exists.
182	
183	Can be used to send sliced VBI data to the video-out connector.
184	
185	---------------------------------
186	
187	Hans Verkuil <hverkuil[AT]xs4all[DOT]nl>
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