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<a href="http://tvtime.sourceforge.net/why.html">why tvtime?</a></td></tr>
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<a href="http://tvtime.sourceforge.net/downloads.php">download tvtime!</a></td></tr>
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<a href="http://tvtime.sourceforge.net/">home</a></td></tr>
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<tr><th class="docbox">support</td></tr>
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<a href="help.html">help and faq</a></td></tr>
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<a href="usage.html">using tvtime</a></td></tr>
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<a href="problems.html">common problems</a></td></tr>
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<a href="http://www.sourceforge.net/tracker/?group_id=64301&atid=506987">report bugs</a></td></tr>
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<a href="mailto:vektor@dumbterm.net">email the webmaster</a></td></tr>
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<table width="90%" class="centered">
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<h2 class="center">Where to get help</h2>
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<li>IRC with us at <tt>#livid</tt> on <a href="http://www.freenode.net">irc.freenode.net</a>.
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<li>Post bugs on <a href="http://www.sourceforge.net/tracker/?group_id=64301&atid=506987">our
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Sourceforge bug tracker</a>.
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<a href="http://sourceforge.net/mail/?group_id=64301">tvtime development mailing list</a>.
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<h2 class="center">Frequently asked questions</h2>
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<li><a href="#nodeint">How do I disable deinterlacing?</a>
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<li><a href="#recording">Does tvtime support recording?</a>
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<li><a href="#screenshots">Why is the tvtime window appear
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pink in screenshots?</a>
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<li><a href="#macrovision">I see purple lines in the video from my
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DVD player. How do I avoid Macrovision copy-protection?</a>
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<li><a href="#noise">Interference problems with soundcards</a>
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<li><a href="#tvout">Optimal settings for tvtime on TV
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<li><a href="#bsd">Does tvtime support FreeBSD or NetBSD?</a>
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<li><a href="#ssname">How do I force the screenshots to be a specific filename?</a>
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<li><a href="#architectures">Does tvtime support any architectures besides x86?</a>
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<li><a href="#canadacable">Where is the "canada-cable" frequency table?</a>
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<li><a href="#audioconnect">How can I map audio to my digital
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<li><a href="#noaudio">My capture card does not have an audio
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output jack, what do I do?</a>
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<h3><a name="nodeint">1. How do I disable deinterlacing?</a></h3>
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<p>Many users seem confused about what the deinterlacing plugins do
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and what it means to disable them. The signal output from almost any
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video source, be it a Gamecube or cable TV, is an interlaced video
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signal. Implicitly when you display this on a computer screen, you are
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deinterlacing: you're taking interlaced content and displaying it on a
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non-interlaced display.</p>
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<p>The simplest way to do this, and the default in some TV applications,
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is to buffer every two consecutive fields together and show them
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as a single frame. You can do this in tvtime by setting it to one of
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our Progressive modes. That's about as close to "not deinterlacing"
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as you can get, but it's still deinterlacing.</p>
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<p>Ideally, tvtime would be able to detect progressive content sent
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over an interlaced channel, such as the output from some video games
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or DV cameras in progressive mode. This feature is something we
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would like to have in a future release.</p>
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<h3><a name="recording">2. Does tvtime support recording?</a></h3>
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<p>tvtime does not support recording or playback of recorded
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streams, and it is unclear to us if this is in the scope of what
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tvtime should try to accomplish. Many users ask for this feature,
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but they have very different goals. Some users want a quick way to
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record small, low-quality clips from television. Some want a high
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quality recorder for recording shows. Others want to have a full PVR
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system integrated into tvtime.</p>
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<p>Currently, we would rather focus on making tvtime the best high
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quality live TV viewer for Linux, with a clean and consistent user
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experience. We recommend using <tt>mencoder</tt> for recording
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from television, and systems like <b>MythTV</b> or <b>freevo</b> for
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a PVR system. If you are interested in coding some sort of
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support for recording in tvtime, please contact us so we can discuss
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how it might best be integrated into tvtime.</p>
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<h3><a name="screenshots">3. Why does tvtime appear pink in
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screenshots?</a></h3>
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<p>tvtime outputs video into a <b>video overlay surface</b>, an area
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of video memory outside of the framebuffer, using the <b>XVIDEO</b>
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X extension. Applications which take screenshots such as
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<tt>ksnapshot</tt>, <tt>gimp</tt> or <tt>xwd</tt> only see the
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colourkeyed window, and not output of tvtime.</p>
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<p>We believe it is a design flaw or driver limitation on the X or
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video card hardware that neither can provide the image to screenshot
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applications. For this reason, the only known method of taking
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screenshots of tvtime along with the desktop is to use the
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<b>screenshot</b> feature inside tvtime, and cut-and-paste the
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output into a full desktop screen capture.</p>
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<h3><a name="macrovision">4. I see purple lines in the video from my
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DVD player. How do I avoid Macrovision copy-protection?</a></h3>
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<p>If you are seeing purple lines or having problems with video signal
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quality from an external DVD player, VCR, or Laserdisc player, try
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disabling Macrovision in your bttv driver (if you have a bttv card).
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See <a href="http://www.colby.edu/personal/k/kjseptor/bttv.html">http://www.colby.edu/personal/k/kjseptor/bttv.html</a>
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for information on how to do that.</p>
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<h3><a name="noise">5. Interference problems with soundcards</a></h3>
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<p>If you are experiencing a generally fuzzy picture, try moving your
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tv card one or two slots away from your soundcard (inside your pc).
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Interference from the soundcard can mess up some channels.</p>
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<h3><a name="tvout">6. Optimal settings for tvtime on TV output</a></h3>
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<p>Some people are interested in using tvtime even when their output
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itself a television. Usually this is in the context of setting up a
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home theatre PC system. Ideally for television output, no
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deinterlacing is required; the interlaced signal is sent to the output
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such that every top field in the input is mapped to a top field in the
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<p>Unfortunately, there is no standard TV output API under Linux. The
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VESA framebuffer setup for TV output cannot tell us which field is
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currently being displayed. Similarily, some TV output setups under
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Linux have it as a second head in X, but again, with no field
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information. We cannot know how to supply it with interlaced content
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to ensure that fields are shown in the right order.</p>
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<p>There are two possible solutions. I have been told that with the
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NVIDIA TV output drivers, when using XVIDEO, if you supply them with
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<b>top-field-first</b> frames, they will display the fields correctly.
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To experiment, try tvtime using the <b>Progressive: Top Field First</b>
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deinterlacer. This may give good results. The second option would be
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using a card with a TV output driver that gives field information.
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An example is the Matrox G400/G450/G550 driver in <b>DirectFB</b>.
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We have an output mode in tvtime specifically for this driver, but
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it is experimental and currently not being further developed.</p>
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<h3><a name="bsd">7. Does tvtime support FreeBSD or NetBSD?</a></h3>
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<p>Currently, tvtime will not work on BSD-based systems, but the
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code to get it to work should not be too difficult.</p>
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<p>There is a driver for bt848 and bt878-based cards under BSD called
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<b>bsdbt848</b>. The API for this driver is different from Linux's
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video4linux that tvtime was written for, so the first job would be to
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do the input code in tvtime to handle this driver. See
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<a href="http://mplayerhq.hu">mplayer</a> for one example of some code
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that uses this driver.</p>
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<p>The only other Linux-specific features that we use would be the
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/dev/rtc code to do high performance timing (I assume there is a BSD
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equivalent of this), and potentially the wine loader for the DScaler
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DLLs may need updating.</p>
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<p>If you make any progress on any of these, please let us know.
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<h3><a name="ssname">8. How do I force the screenshots to be a
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specific filename?</a></h3>
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<p>tvtime's screenshots can be given a filename when requested
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using <b>tvtime-command</b>. Simply do:</p>
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tvtime-command SCREENSHOT "current.png"
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<p>And the screenshot will output as <b>current.png</b>. This is
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useful for scripts which upload the latest image from the TV to a
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webpage, for example.</p>
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<h3><a name="architectures">9. Does tvtime support any architectures
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besides x86??</a></h3>
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<p>Some work was done by Helge Kreutzmann to try tvtime on
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alpha Linux. We determined that disabling the wine loader was
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enough to get tvtime to compile and run. tvtime 0.9.11 should
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compile at least on this architecture.</p>
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<p>Besides that, most other architectures are simply untested.
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If anyone is seriously interested in another architecture, has
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some coding ability, and has sufficient hardware resources to try
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tvtime on another architecture, please email me at
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<a href="mailto:vektor@dumbterm.net">vektor@dumbterm.net</a>.</p>
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<p>As a miminum, your system should have a video card that can
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handle high bandwidth uploads (in our default configuration we
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upload 40 megabytes per second) and supports hardware video
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overlays, preferably using the XVIDEO extension. As well, we require
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a video4linux or video4linux2-compatible driver and about the CPU
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power of a reasonable P3.</p>
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<h3><a name="canadacable">10. Where is the "canada-cable" frequency
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<p>If you needed to use the "<tt>canada-cable</tt>" frequency table in
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another TV application, then your capture card's tuner has been
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misdetected as a PAL tuner when it is actually an NTSC tuner. Please
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see <a href="problems.html#tvwonder">this support question on our
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hardware support page</a> for information on how to fix this
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<h3><a name="audioconnect">11. How can I map audio to my digital
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<p>Many bt878-based cards also support digital capture of the
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audio. This can be accessed using the <tt>btaudio</tt> kernel
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module, which registers an OSS sound device that supports 32 KHz
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audio capture. On a capable card, loading the module gives
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something like this in your system logs:</p>
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btaudio: driver version 0.7 loaded [digital+analog]
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btaudio: Bt878 (rev 2) at 01:0b.1, irq: 6,
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latency: 64, mmio: 0xf16ff000
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btaudio: using card config "default"
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btaudio: registered device dsp2 [digital]
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btaudio: registered device dsp3 [analog]
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btaudio: registered device mixer1
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<p>On my system <tt>/dev/dsp2</tt> can now be used to read
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digital audio from the card at 32 KHz. This can be then sent
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out to an arbitrary soundcard using a program such
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sox -r 32000 -w -t ossdsp /dev/dsp2 -t ossdsp /dev/dsp
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<p>This command reads the input at 32 KHz from
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<tt>/dev/dsp2</tt> and writes it out to my soundcard
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at <tt>/dev/dsp</tt>. Having this run while using tvtime
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will enable you to perform arbitrary maps of the audio, such
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as playing it out the digital output of your soundcard.</p>
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<h3><a name="noaudio">12. My capture card does not have an audio
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output jack, what do I do?</a></h3>
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<p>If your capture card does not has a pass-through audio
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jack, you can use the <a href="#audioconnect">technique
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described above</a> to map the audio from the internal
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digital capture out to your soundcard.</p>
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