diff options
Diffstat (limited to 'Documentation/DocBook/v4l/io.xml')
| -rw-r--r-- | Documentation/DocBook/v4l/io.xml | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/Documentation/DocBook/v4l/io.xml b/Documentation/DocBook/v4l/io.xml index f92f24323b2..d424886beda 100644 --- a/Documentation/DocBook/v4l/io.xml +++ b/Documentation/DocBook/v4l/io.xml @@ -589,7 +589,8 @@ number of a video input as in &v4l2-input; field <entry></entry> <entry>A place holder for future extensions and custom (driver defined) buffer types -<constant>V4L2_BUF_TYPE_PRIVATE</constant> and higher.</entry> +<constant>V4L2_BUF_TYPE_PRIVATE</constant> and higher. Applications +should set this to 0.</entry> </row> </tbody> </tgroup> @@ -701,6 +702,16 @@ They can be both cleared however, then the buffer is in "dequeued" state, in the application domain to say so.</entry> </row> <row> + <entry><constant>V4L2_BUF_FLAG_ERROR</constant></entry> + <entry>0x0040</entry> + <entry>When this flag is set, the buffer has been dequeued + successfully, although the data might have been corrupted. + This is recoverable, streaming may continue as normal and + the buffer may be reused normally. + Drivers set this flag when the <constant>VIDIOC_DQBUF</constant> + ioctl is called.</entry> + </row> + <row> <entry><constant>V4L2_BUF_FLAG_KEYFRAME</constant></entry> <entry>0x0008</entry> <entry>Drivers set or clear this flag when calling the @@ -917,8 +928,8 @@ order</emphasis>.</para> <para>When the driver provides or accepts images field by field rather than interleaved, it is also important applications understand -how the fields combine to frames. We distinguish between top and -bottom fields, the <emphasis>spatial order</emphasis>: The first line +how the fields combine to frames. We distinguish between top (aka odd) and +bottom (aka even) fields, the <emphasis>spatial order</emphasis>: The first line of the top field is the first line of an interlaced frame, the first line of the bottom field is the second line of that frame.</para> @@ -971,12 +982,12 @@ between <constant>V4L2_FIELD_TOP</constant> and <row> <entry><constant>V4L2_FIELD_TOP</constant></entry> <entry>2</entry> - <entry>Images consist of the top field only.</entry> + <entry>Images consist of the top (aka odd) field only.</entry> </row> <row> <entry><constant>V4L2_FIELD_BOTTOM</constant></entry> <entry>3</entry> - <entry>Images consist of the bottom field only. + <entry>Images consist of the bottom (aka even) field only. Applications may wish to prevent a device from capturing interlaced images because they will have "comb" or "feathering" artefacts around moving objects.</entry> |