diff options
Diffstat (limited to 'Documentation/DocBook/v4l/compat.xml')
| -rw-r--r-- | Documentation/DocBook/v4l/compat.xml | 131 |
1 files changed, 72 insertions, 59 deletions
diff --git a/Documentation/DocBook/v4l/compat.xml b/Documentation/DocBook/v4l/compat.xml index b9dbdf9e6d29..54447f0d0784 100644 --- a/Documentation/DocBook/v4l/compat.xml +++ b/Documentation/DocBook/v4l/compat.xml @@ -1091,8 +1091,9 @@ signed 64-bit integer. Output devices should not send a buffer out until the time in the timestamp field has arrived. I would like to follow SGI's lead, and adopt a multimedia timestamping system like their UST (Unadjusted System Time). See -http://reality.sgi.com/cpirazzi_engr/lg/time/intro.html. [This link is -no longer valid.] UST uses timestamps that are 64-bit signed integers +http://web.archive.org/web/*/http://reality.sgi.com +/cpirazzi_engr/lg/time/intro.html. +UST uses timestamps that are 64-bit signed integers (not struct timeval's) and given in nanosecond units. The UST clock starts at zero when the system is booted and runs continuously and uniformly. It takes a little over 292 years for UST to overflow. There @@ -2332,15 +2333,26 @@ more information.</para> </listitem> </orderedlist> </section> - </section> + <section> + <title>V4L2 in Linux 2.6.34</title> + <orderedlist> + <listitem> + <para>Added +<constant>V4L2_CID_IRIS_ABSOLUTE</constant> and +<constant>V4L2_CID_IRIS_RELATIVE</constant> controls to the + <link linkend="camera-controls">Camera controls class</link>. + </para> + </listitem> + </orderedlist> + </section> - <section id="other"> - <title>Relation of V4L2 to other Linux multimedia APIs</title> + <section id="other"> + <title>Relation of V4L2 to other Linux multimedia APIs</title> - <section id="xvideo"> - <title>X Video Extension</title> + <section id="xvideo"> + <title>X Video Extension</title> - <para>The X Video Extension (abbreviated XVideo or just Xv) is + <para>The X Video Extension (abbreviated XVideo or just Xv) is an extension of the X Window system, implemented for example by the XFree86 project. Its scope is similar to V4L2, an API to video capture and output devices for X clients. Xv allows applications to display @@ -2351,7 +2363,7 @@ capture or output still images in XPixmaps<footnote> extension available across many operating systems and architectures.</para> - <para>Because the driver is embedded into the X server Xv has a + <para>Because the driver is embedded into the X server Xv has a number of advantages over the V4L2 <link linkend="overlay">video overlay interface</link>. The driver can easily determine the overlay target, &ie; visible graphics memory or off-screen buffers for a @@ -2360,16 +2372,16 @@ overlay, scaling or color-keying, or the clipping functions of the video capture hardware, always in sync with drawing operations or windows moving or changing their stacking order.</para> - <para>To combine the advantages of Xv and V4L a special Xv + <para>To combine the advantages of Xv and V4L a special Xv driver exists in XFree86 and XOrg, just programming any overlay capable Video4Linux device it finds. To enable it <filename>/etc/X11/XF86Config</filename> must contain these lines:</para> - <para><screen> + <para><screen> Section "Module" Load "v4l" EndSection</screen></para> - <para>As of XFree86 4.2 this driver still supports only V4L + <para>As of XFree86 4.2 this driver still supports only V4L ioctls, however it should work just fine with all V4L2 devices through the V4L2 backward-compatibility layer. Since V4L2 permits multiple opens it is possible (if supported by the V4L2 driver) to capture @@ -2377,83 +2389,84 @@ video while an X client requested video overlay. Restrictions of simultaneous capturing and overlay are discussed in <xref linkend="overlay" /> apply.</para> - <para>Only marginally related to V4L2, XFree86 extended Xv to + <para>Only marginally related to V4L2, XFree86 extended Xv to support hardware YUV to RGB conversion and scaling for faster video playback, and added an interface to MPEG-2 decoding hardware. This API is useful to display images captured with V4L2 devices.</para> - </section> + </section> - <section> - <title>Digital Video</title> + <section> + <title>Digital Video</title> - <para>V4L2 does not support digital terrestrial, cable or + <para>V4L2 does not support digital terrestrial, cable or satellite broadcast. A separate project aiming at digital receivers exists. You can find its homepage at <ulink url="http://linuxtv.org">http://linuxtv.org</ulink>. The Linux DVB API has no connection to the V4L2 API except that drivers for hybrid hardware may support both.</para> - </section> + </section> - <section> - <title>Audio Interfaces</title> + <section> + <title>Audio Interfaces</title> - <para>[to do - OSS/ALSA]</para> + <para>[to do - OSS/ALSA]</para> + </section> </section> - </section> - <section id="experimental"> - <title>Experimental API Elements</title> + <section id="experimental"> + <title>Experimental API Elements</title> - <para>The following V4L2 API elements are currently experimental + <para>The following V4L2 API elements are currently experimental and may change in the future.</para> - <itemizedlist> - <listitem> - <para>Video Output Overlay (OSD) Interface, <xref + <itemizedlist> + <listitem> + <para>Video Output Overlay (OSD) Interface, <xref linkend="osd" />.</para> - </listitem> + </listitem> <listitem> - <para><constant>V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY</constant>, + <para><constant>V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY</constant>, &v4l2-buf-type;, <xref linkend="v4l2-buf-type" />.</para> - </listitem> - <listitem> - <para><constant>V4L2_CAP_VIDEO_OUTPUT_OVERLAY</constant>, + </listitem> + <listitem> + <para><constant>V4L2_CAP_VIDEO_OUTPUT_OVERLAY</constant>, &VIDIOC-QUERYCAP; ioctl, <xref linkend="device-capabilities" />.</para> - </listitem> - <listitem> - <para>&VIDIOC-ENUM-FRAMESIZES; and + </listitem> + <listitem> + <para>&VIDIOC-ENUM-FRAMESIZES; and &VIDIOC-ENUM-FRAMEINTERVALS; ioctls.</para> - </listitem> - <listitem> - <para>&VIDIOC-G-ENC-INDEX; ioctl.</para> - </listitem> - <listitem> - <para>&VIDIOC-ENCODER-CMD; and &VIDIOC-TRY-ENCODER-CMD; + </listitem> + <listitem> + <para>&VIDIOC-G-ENC-INDEX; ioctl.</para> + </listitem> + <listitem> + <para>&VIDIOC-ENCODER-CMD; and &VIDIOC-TRY-ENCODER-CMD; ioctls.</para> - </listitem> - <listitem> - <para>&VIDIOC-DBG-G-REGISTER; and &VIDIOC-DBG-S-REGISTER; + </listitem> + <listitem> + <para>&VIDIOC-DBG-G-REGISTER; and &VIDIOC-DBG-S-REGISTER; ioctls.</para> - </listitem> - <listitem> - <para>&VIDIOC-DBG-G-CHIP-IDENT; ioctl.</para> - </listitem> - </itemizedlist> - </section> + </listitem> + <listitem> + <para>&VIDIOC-DBG-G-CHIP-IDENT; ioctl.</para> + </listitem> + </itemizedlist> + </section> - <section id="obsolete"> - <title>Obsolete API Elements</title> + <section id="obsolete"> + <title>Obsolete API Elements</title> - <para>The following V4L2 API elements were superseded by new + <para>The following V4L2 API elements were superseded by new interfaces and should not be implemented in new drivers.</para> - <itemizedlist> - <listitem> - <para><constant>VIDIOC_G_MPEGCOMP</constant> and + <itemizedlist> + <listitem> + <para><constant>VIDIOC_G_MPEGCOMP</constant> and <constant>VIDIOC_S_MPEGCOMP</constant> ioctls. Use Extended Controls, <xref linkend="extended-controls" />.</para> - </listitem> - </itemizedlist> + </listitem> + </itemizedlist> + </section> </section> <!-- |
