diff options
Diffstat (limited to 'v4l2-spec/dev-radio.sgml')
| -rw-r--r-- | v4l2-spec/dev-radio.sgml | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/v4l2-spec/dev-radio.sgml b/v4l2-spec/dev-radio.sgml index ae8367219..4d521d2a8 100644 --- a/v4l2-spec/dev-radio.sgml +++ b/v4l2-spec/dev-radio.sgml @@ -1,7 +1,7 @@ <title>Radio Interface</title> <para>This interface is intended for AM and FM (analog) radio -receivers.</para> +receivers and transmitters.</para> <para>Conventionally V4L2 radio devices are accessed through character device special files named <filename>/dev/radio</filename> @@ -14,7 +14,8 @@ numbers 64 to 127.</para> <para>Devices supporting the radio interface set the <constant>V4L2_CAP_RADIO</constant> and -<constant>V4L2_CAP_TUNER</constant> flag in the +<constant>V4L2_CAP_TUNER</constant> or +<constant>V4L2_CAP_MODULATOR</constant> flag in the <structfield>capabilities</structfield> field of &v4l2-capability; returned by the &VIDIOC-QUERYCAP; ioctl. Other combinations of capability flags are reserved for future extensions.</para> @@ -25,7 +26,7 @@ capability flags are reserved for future extensions.</para> <para>Radio devices can support <link linkend="control">controls</link>, and must support the <link -linkend="tuner">tuner</link> ioctls.</para> +linkend="tuner">tuner or modulator</link> ioctls.</para> <para>They do not support the video input or output, audio input or output, video standard, cropping and scaling, compression and @@ -38,11 +39,12 @@ methods are reserved for future extensions.</para> <para>Radio devices may have a couple audio controls (as discussed in <xref linkend="control">) such as a volume control, possibly custom -controls. Further all radio devices have one tuner (these are +controls. Further all radio devices have one tuner or modulator (these are discussed in <xref linkend="tuner">) with index number zero to select the radio frequency and to determine if a monaural or FM stereo -program is received. Drivers switch automatically between AM and FM -depending on the selected frequency. The &VIDIOC-G-TUNER; ioctl +program is received/emitted. Drivers switch automatically between AM and FM +depending on the selected frequency. The &VIDIOC-G-TUNER; or +&VIDIOC-G-MODULATOR; ioctl reports the supported frequency range.</para> </section> |