path: root/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml
diff options
Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-g-fmt.xml')
1 files changed, 7 insertions, 6 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml b/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml
index 52acff193a6..ee8f56e1bac 100644
--- a/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml
@@ -81,7 +81,7 @@ the application calls the <constant>VIDIOC_S_FMT</constant> ioctl
with a pointer to a <structname>v4l2_format</structname> structure
the driver checks
and adjusts the parameters against hardware abilities. Drivers
-should not return an error code unless the input is ambiguous, this is
+should not return an error code unless the <structfield>type</structfield> field is invalid, this is
a mechanism to fathom device capabilities and to approach parameters
acceptable for both the application and driver. On success the driver
may program the hardware, allocate resources and generally prepare for
@@ -107,6 +107,10 @@ disabling I/O or possibly time consuming hardware preparations.
Although strongly recommended drivers are not required to implement
this ioctl.</para>
+ <para>The format as returned by <constant>VIDIOC_TRY_FMT</constant>
+must be identical to what <constant>VIDIOC_S_FMT</constant> returns for
+the same input or output.</para>
<table pgwide="1" frame="none" id="v4l2-format">
<title>struct <structname>v4l2_format</structname></title>
<tgroup cols="4">
@@ -170,9 +174,7 @@ capture and output devices.</entry>
- <entry>Place holder for future extensions and custom
-(driver defined) formats with <structfield>type</structfield>
-<constant>V4L2_BUF_TYPE_PRIVATE</constant> and higher.</entry>
+ <entry>Place holder for future extensions.</entry>
@@ -187,8 +189,7 @@ capture and output devices.</entry>
<para>The &v4l2-format; <structfield>type</structfield>
-field is invalid, the requested buffer type not supported, or the
-format is not supported with this buffer type.</para>
+field is invalid or the requested buffer type not supported.</para>