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Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media fixes from Mauro Carvalho Chehab: "Series of fixes for 3.10. There are some usual driver fixes (mostly on s5p/exynos playform drivers), plus some fixes at V4L2 core" * 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (40 commits) [media] soc_camera: error dev remove and v4l2 call [media] sh_veu: fix the buffer size calculation [media] sh_veu: keep power supply until the m2m context is released [media] sh_veu: invoke v4l2_m2m_job_finish() even if a job has been aborted [media] v4l2-ioctl: don't print the clips list [media] v4l2-ctrls: V4L2_CTRL_CLASS_FM_RX controls are also valid radio controls [media] cx88: fix NULL pointer dereference [media] DocBook/media/v4l: update version number [media] exynos4-is: Remove "sysreg" clock handling [media] exynos4-is: Fix reported colorspace at FIMC-IS-ISP subdev [media] exynos4-is: Ensure fimc-is clocks are not enabled until properly configured [media] exynos4-is: Prevent NULL pointer dereference when firmware isn't loaded [media] s5p-mfc: Add NULL check for allocated buffer [media] s5p-mfc: added missing end-of-lines in debug messages [media] s5p-mfc: v4l2 controls setup routine moved to initialization code [media] s5p-mfc: separate encoder parameters for h264 and mpeg4 [media] s5p-mfc: Remove special clock usage in driver [media] s5p-mfc: Remove unused s5p_mfc_get_decoded_status_v6() function [media] v4l2: mem2mem: save irq flags correctly [media] coda: v4l2-compliance fix: add VIDIOC_CREATE_BUFS support ...
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<title>Codec Interface</title>
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<note>
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<title>Suspended</title>
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<para>This interface has been be suspended from the V4L2 API
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implemented in Linux 2.6 until we have more experience with codec
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device interfaces.</para>
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</note>
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<para>A V4L2 codec can compress, decompress, transform, or otherwise
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convert video data from one format into another format, in memory.
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Applications send data to be converted to the driver through a
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&func-write; call, and receive the converted data through a
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&func-read; call. For efficiency a driver may also support streaming
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I/O.</para>
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convert video data from one format into another format, in memory. Typically
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such devices are memory-to-memory devices (i.e. devices with the
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<constant>V4L2_CAP_VIDEO_M2M</constant> or <constant>V4L2_CAP_VIDEO_M2M_MPLANE</constant>
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capability set).
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</para>
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<para>[to do]</para>
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<para>A memory-to-memory video node acts just like a normal video node, but it
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supports both output (sending frames from memory to the codec hardware) and
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capture (receiving the processed frames from the codec hardware into memory)
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stream I/O. An application will have to setup the stream
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I/O for both sides and finally call &VIDIOC-STREAMON; for both capture and output
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to start the codec.</para>
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<para>Video compression codecs use the MPEG controls to setup their codec parameters
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(note that the MPEG controls actually support many more codecs than just MPEG).
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See <xref linkend="mpeg-controls"></xref>.</para>
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<para>Memory-to-memory devices can often be used as a shared resource: you can
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open the video node multiple times, each application setting up their own codec properties
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that are local to the file handle, and each can use it independently from the others.
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The driver will arbitrate access to the codec and reprogram it whenever another file
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handler gets access. This is different from the usual video node behavior where the video properties
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are global to the device (i.e. changing something through one file handle is visible
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through another file handle).</para>
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@ -493,7 +493,7 @@ and discussions on the V4L mailing list.</revremark>
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</partinfo>
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<title>Video for Linux Two API Specification</title>
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<subtitle>Revision 3.9</subtitle>
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<subtitle>Revision 3.10</subtitle>
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<chapter id="common">
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&sub-common;
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