diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/DocBook/media/v4l/dev-codec.xml | 35 | ||||
| -rw-r--r-- | Documentation/DocBook/media/v4l/v4l2.xml | 2 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/media/exynos-fimc-lite.txt | 2 |
3 files changed, 24 insertions, 15 deletions
diff --git a/Documentation/DocBook/media/v4l/dev-codec.xml b/Documentation/DocBook/media/v4l/dev-codec.xml index dca0ecd54dc6..ff44c16fc080 100644 --- a/Documentation/DocBook/media/v4l/dev-codec.xml +++ b/Documentation/DocBook/media/v4l/dev-codec.xml @@ -1,18 +1,27 @@ <title>Codec Interface</title> - <note> - <title>Suspended</title> + <para>A V4L2 codec can compress, decompress, transform, or otherwise +convert video data from one format into another format, in memory. Typically +such devices are memory-to-memory devices (i.e. devices with the +<constant>V4L2_CAP_VIDEO_M2M</constant> or <constant>V4L2_CAP_VIDEO_M2M_MPLANE</constant> +capability set). +</para> - <para>This interface has been be suspended from the V4L2 API -implemented in Linux 2.6 until we have more experience with codec -device interfaces.</para> - </note> + <para>A memory-to-memory video node acts just like a normal video node, but it +supports both output (sending frames from memory to the codec hardware) and +capture (receiving the processed frames from the codec hardware into memory) +stream I/O. An application will have to setup the stream +I/O for both sides and finally call &VIDIOC-STREAMON; for both capture and output +to start the codec.</para> - <para>A V4L2 codec can compress, decompress, transform, or otherwise -convert video data from one format into another format, in memory. -Applications send data to be converted to the driver through a -&func-write; call, and receive the converted data through a -&func-read; call. For efficiency a driver may also support streaming -I/O.</para> + <para>Video compression codecs use the MPEG controls to setup their codec parameters +(note that the MPEG controls actually support many more codecs than just MPEG). +See <xref linkend="mpeg-controls"></xref>.</para> - <para>[to do]</para> + <para>Memory-to-memory devices can often be used as a shared resource: you can +open the video node multiple times, each application setting up their own codec properties +that are local to the file handle, and each can use it independently from the others. +The driver will arbitrate access to the codec and reprogram it whenever another file +handler gets access. This is different from the usual video node behavior where the video properties +are global to the device (i.e. changing something through one file handle is visible +through another file handle).</para> diff --git a/Documentation/DocBook/media/v4l/v4l2.xml b/Documentation/DocBook/media/v4l/v4l2.xml index bfc93cdcf696..bfe823dd0f31 100644 --- a/Documentation/DocBook/media/v4l/v4l2.xml +++ b/Documentation/DocBook/media/v4l/v4l2.xml @@ -493,7 +493,7 @@ and discussions on the V4L mailing list.</revremark> </partinfo> <title>Video for Linux Two API Specification</title> - <subtitle>Revision 3.9</subtitle> + <subtitle>Revision 3.10</subtitle> <chapter id="common"> &sub-common; diff --git a/Documentation/devicetree/bindings/media/exynos-fimc-lite.txt b/Documentation/devicetree/bindings/media/exynos-fimc-lite.txt index 3f62adfb3e0b..de9f6b78ee51 100644 --- a/Documentation/devicetree/bindings/media/exynos-fimc-lite.txt +++ b/Documentation/devicetree/bindings/media/exynos-fimc-lite.txt @@ -2,7 +2,7 @@ Exynos4x12/Exynos5 SoC series camera host interface (FIMC-LITE) Required properties: -- compatible : should be "samsung,exynos4212-fimc" for Exynos4212 and +- compatible : should be "samsung,exynos4212-fimc-lite" for Exynos4212 and Exynos4412 SoCs; - reg : physical base address and size of the device memory mapped registers; |