Author: diego
Date: Wed Aug 18 22:22:01 2010
New Revision: 31978
Log:
Merge TV input and TV teletext chapter into the usage chapter.
This improves the overall structure of the documentation.
Deleted:
trunk/DOCS/xml/en/tvinput.xml
Modified:
trunk/DOCS/xml/en/documentation.xml
trunk/DOCS/xml/en/usage.xml
Changes in other areas also in this revision:
Deleted:
trunk/DOCS/xml/cs/tvinput.xml
trunk/DOCS/xml/de/tvinput.xml
trunk/DOCS/xml/es/tvinput.xml
trunk/DOCS/xml/fr/tvinput.xml
trunk/DOCS/xml/hu/tvinput.xml
trunk/DOCS/xml/it/tvinput.xml
trunk/DOCS/xml/pl/tvinput.xml
trunk/DOCS/xml/ru/tvinput.xml
trunk/DOCS/xml/zh_CN/tvinput.xml
Modified:
trunk/DOCS/xml/cs/documentation.xml
trunk/DOCS/xml/cs/usage.xml
trunk/DOCS/xml/de/documentation.xml
trunk/DOCS/xml/de/usage.xml
trunk/DOCS/xml/es/documentation.xml
trunk/DOCS/xml/es/usage.xml
trunk/DOCS/xml/fr/documentation.xml
trunk/DOCS/xml/fr/usage.xml
trunk/DOCS/xml/hu/documentation.xml
trunk/DOCS/xml/hu/usage.xml
trunk/DOCS/xml/it/documentation.xml
trunk/DOCS/xml/it/usage.xml
trunk/DOCS/xml/pl/documentation.xml
trunk/DOCS/xml/pl/usage.xml
trunk/DOCS/xml/ru/documentation.xml
trunk/DOCS/xml/ru/usage.xml
trunk/DOCS/xml/zh_CN/documentation.xml
trunk/DOCS/xml/zh_CN/usage.xml
Modified: trunk/DOCS/xml/en/documentation.xml
==============================================================================
--- trunk/DOCS/xml/en/documentation.xml Wed Aug 18 21:51:06 2010 (r31977)
+++ trunk/DOCS/xml/en/documentation.xml Wed Aug 18 22:22:01 2010 (r31978)
@@ -166,7 +166,6 @@ can be distributed under the terms of th
&install.xml;
&usage.xml;
-&tvinput.xml;
&radio.xml;
&video.xml;
&ports.xml;
Modified: trunk/DOCS/xml/en/usage.xml
==============================================================================
--- trunk/DOCS/xml/en/usage.xml Wed Aug 18 21:51:06 2010 (r31977)
+++ trunk/DOCS/xml/en/usage.xml Wed Aug 18 22:22:01 2010 (r31978)
@@ -1311,4 +1311,214 @@ your sound card data that is outside the
distorted audio.
</para>
</sect1>
+
+<!-- ********** -->
+
+<sect1 id="tv-input" xreflabel="TV input">
+<title>TV input</title>
+
+<para>
+This section is about how to enable <emphasis role="bold">watching/grabbing
+from V4L compatible TV tuner</emphasis>. See the man page for a description
+of TV options and keyboard controls.
+</para>
+
+<sect2 id="tv-tips">
+<title>Usage tips</title>
+
+<para>
+The full listing of the options is available on the manual page.
+Here are just a few tips:
+
+<itemizedlist>
+<listitem><para>
+ Make sure your tuner works with another TV software in Linux, for
+ example <application>XawTV</application>.
+</para></listitem>
+<listitem><para>
+ Use the <option>channels</option> option. An example:
+ <screen>-tv channels=26-MTV1,23-TV2</screen>
+ Explanation: Using this option, only the 26 and 23 channels will be usable,
+ and there will be a nice OSD text upon channel switching, displaying the
+ channel's name. Spaces in the channel name must be replaced by the
+ "_" character.
+</para></listitem>
+<listitem><para>
+ Choose some sane image dimensions. The dimensions of the resulting image
+ should be divisible by 16.
+</para></listitem>
+<listitem>
+ <para>
+ If you capture the video with the vertical resolution higher than half
+ of the full resolution (i.e. 288 for PAL or 240 for NTSC), then the
+ 'frames' you get will really be interleaved pairs of fields.
+ Depending on what you want to do with the video you may leave it in
+ this form, destructively deinterlace, or break the pairs apart into
+ individual fields.
+ </para>
+ <para>
+ Otherwise you'll get a movie which is distorted during
+ fast-motion scenes and the bitrate controller will be probably even unable
+ to retain the specified bitrate as the interlacing artifacts produce high
+ amount of detail and thus consume lot of bandwidth. You can enable
+ deinterlacing with <option>-vf pp=DEINT_TYPE</option>.
+ Usually <option>pp=lb</option> does a good job, but it can be matter of
+ personal preference.
+ See other deinterlacing algorithms in the manual and give it a try.
+ </para>
+</listitem>
+<listitem><para>
+ Crop out the dead space. When you capture the video, the areas at the edges
+ are usually black or contain some noise. These again consume lots of
+ unnecessary bandwidth. More precisely it's not the black areas themselves
+ but the sharp transitions between the black and the brighter video image
+ which do but that's not important for now. Before you start capturing,
+ adjust the arguments of the <option>crop</option> option so that all the
+ crap at the margins is cropped out. Again, don't forget to keep the resulting
+ dimensions sane.
+</para></listitem>
+<listitem><para>
+ Watch out for CPU load. It shouldn't cross the 90% boundary for most of the
+ time. If you have a large capture buffer, <application>MEncoder</application>
+ can survive an overload for few seconds but nothing more. It's better to
+ turn off the 3D OpenGL screensavers and similar stuff.
+</para></listitem>
+<listitem><para>
+ Don't mess with the system clock. <application>MEncoder</application> uses the
+ system clock for doing A/V sync. If you adjust the system clock (especially
+ backwards in time), <application>MEncoder</application> gets confused and you
+ will lose frames. This is an important issue if you are hooked to a network
+ and run some time synchronization software like NTP. You have to turn NTP
+ off during the capture process if you want to capture reliably.
+</para></listitem>
+<listitem><para>
+ Don't change the <option>outfmt</option> unless you know what you are doing
+ or your card/driver really doesn't support the default (YV12 colorspace).
+ In the older versions of <application>MPlayer</application>/
+ <application>MEncoder</application> it was necessary to specify the output
+ format. This issue should be fixed in the current releases and
+ <option>outfmt</option> isn't required anymore, and the default suits the
+ most purposes. For example, if you are capturing into DivX using
+ <systemitem class="library">libavcodec</systemitem> and specify
+ <option>outfmt=RGB24</option> in order to increase the quality of the captured
+ images, the captured image will be actually later converted back into YV12 so
+ the only thing you achieve is a massive waste of CPU power.
+</para></listitem>
+<listitem><para>
+ There are several ways of capturing audio. You can grab the sound either using
+ your sound card via an external cable connection between video card and
+ line-in, or using the built-in ADC in the bt878 chip. In the latter case, you
+ have to load the <emphasis role="bold">btaudio</emphasis> driver. Read the
+ <filename>linux/Documentation/sound/btaudio</filename> file (in the kernel
+ tree, not <application>MPlayer</application>'s) for some instructions on using
+ this driver.
+</para></listitem>
+<listitem><para>
+ If <application>MEncoder</application> cannot open the audio device, make
+ sure that it is really available. There can be some trouble with the sound
+ servers like aRts (KDE) or ESD (GNOME). If you have a full duplex sound card
+ (almost any decent card supports it today), and you are using KDE, try to
+ check the "full duplex" option in the sound server preference menu.
+</para></listitem>
+</itemizedlist>
+</para>
+</sect2>
+
+<sect2 id="tv-examples">
+<title>Examples</title>
+
+<informalexample><para>
+Dummy output, to AAlib :)
+<screen>mplayer -tv driver=dummy:width=640:height=480 -vo aa tv://</screen>
+</para></informalexample>
+
+<informalexample><para>
+Input from standard V4L:
+<screen>
+mplayer -tv driver=v4l:width=640:height=480:outfmt=i420 -vc rawi420 -vo xv tv://
+</screen>
+</para></informalexample>
+
+<informalexample><para>
+A more sophisticated example. This makes <application>MEncoder</application>
+capture the full PAL image, crop the margins, and deinterlace the picture
+using a linear blend algorithm. Audio is compressed with a constant bitrate
+of 64kbps, using LAME codec. This setup is suitable for capturing movies.
+<screen>
+mencoder -tv driver=v4l:width=768:height=576 -oac mp3lame -lameopts cbr:br=64\
+ -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=900 \
+ -vf crop=720:544:24:16,pp=lb -o <replaceable>output.avi</replaceable> tv://
+</screen>
+</para></informalexample>
+
+<informalexample><para>
+This will additionally rescale the image to 384x288 and compresses the
+video with the bitrate of 350kbps in high quality mode. The vqmax option
+looses the quantizer and allows the video compressor to actually reach so
+low bitrate even at the expense of the quality. This can be used for
+capturing long TV series, where the video quality isn't so important.
+<screen>
+mencoder -tv driver=v4l:width=768:height=576 \
+ -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=350:vhq:vqmax=31:keyint=300 \
+ -oac mp3lame -lameopts cbr:br=48 -sws 1 -o <replaceable>output.avi</replaceable>\
+ -vf crop=720:540:24:18,pp=lb,scale=384:288 tv://
+</screen>
+It's also possible to specify smaller image dimensions in the
+<option>-tv</option> option and omit the software scaling but this approach
+uses the maximum available information and is a little more resistant to noise.
+The bt8x8 chips can do the pixel averaging only in the horizontal direction due
+to a hardware limitation.
+</para></informalexample>
+</sect2>
+</sect1>
+
+<!-- ********** -->
+
+<sect1 id="tv-teletext">
+<title>Teletext</title>
+
+<para>
+ Teletext is currently available only in <application>MPlayer</application>
+ for v4l and v4l2 drivers.
+</para>
+
+<sect2 id="tv-teletext-implementation-notes">
+<title>Implementation notes</title>
+
+<para>
+<application>MPlayer</application> supports regular text, graphics and navigation links.
+Unfortunately, colored pages are not fully supported yet - all pages are shown as grayscaled.
+Subtitle pages (also known as Closed Captions) are supported, too.
+</para>
+
+<para>
+<application>MPlayer</application> starts caching all teletext pages upon
+starting to receive TV input, so you do not need to wait until the requested page is loaded.
+</para>
+
+<para>
+Note: Using teletext with <option>-vo xv</option> causes strange colors.
+</para>
+</sect2>
+
+<sect2 id="tv-teletext-usage">
+<title>Using teletext</title>
+
+<para>
+To enable teletext decoding you must specify the VBI device to get teletext data
+from (usually <filename>/dev/vbi0</filename> for Linux). This can be done by specifying
+<option>tdevice</option> in your configuration file, like shown below:
+<screen>tv=tdevice=/dev/vbi0</screen>
+</para>
+
+<para>
+You might need to specify the teletext language code for your country.
+To list all available country codes use
+<screen>tv=tdevice=/dev/vbi0:tlang=<replaceable>-1</replaceable></screen>
+Here is an example for Russian:
+<screen>tv=tdevice=/dev/vbi0:tlang=<replaceable>33</replaceable></screen>
+</para>
+</sect2>
+
+</sect1>
</chapter>
