| Message ID | 1438308650-2702-13-git-send-email-crope@iki.fi (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/31/2015 04:10 AM, Antti Palosaari wrote: > It is VIDIOC_G_FREQUENCY which does not use type to identify tuner, > not VIDIOC_S_FREQUENCY. VIDIOC_S_FREQUENCY uses both tuner and type > fields. One of these V4L API weirdness... Actually, that's not what this is about. It's about whether g/s_frequency gets/sets the frequency for the tuner or the modulator. That has nothing to do with the tuner and type fields. The problem described here in the spec is a problem for both G and S_FREQUENCY. Regards, Hans > > Cc: Hans Verkuil <hverkuil@xs4all.nl> > Signed-off-by: Antti Palosaari <crope@iki.fi> > --- > Documentation/DocBook/media/v4l/common.xml | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/Documentation/DocBook/media/v4l/common.xml b/Documentation/DocBook/media/v4l/common.xml > index 8b5e014..f7008ea 100644 > --- a/Documentation/DocBook/media/v4l/common.xml > +++ b/Documentation/DocBook/media/v4l/common.xml > @@ -428,7 +428,7 @@ zero, no video outputs.</para> > modulator. Two separate device nodes will have to be used for such > hardware, one that supports the tuner functionality and one that supports > the modulator functionality. The reason is a limitation with the > -&VIDIOC-S-FREQUENCY; ioctl where you cannot specify whether the frequency > +&VIDIOC-G-FREQUENCY; ioctl where you cannot specify whether the frequency > is for a tuner or a modulator.</para> > > <para>To query and change modulator properties applications use > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 08/10/2015 12:41 PM, Hans Verkuil wrote: > On 07/31/2015 04:10 AM, Antti Palosaari wrote: >> It is VIDIOC_G_FREQUENCY which does not use type to identify tuner, >> not VIDIOC_S_FREQUENCY. VIDIOC_S_FREQUENCY uses both tuner and type >> fields. One of these V4L API weirdness... > > Actually, that's not what this is about. It's about whether g/s_frequency gets/sets > the frequency for the tuner or the modulator. That has nothing to do with the tuner > and type fields. The problem described here in the spec is a problem for both G and > S_FREQUENCY. ah, now I think I see it. There is no tuner type for FM radio modulator - but instead it is capability of tuner type V4L2_TUNER_RADIO. As both radio receiver and transmitter has same tuner type it is not possible to identify it using tuner type... regards Antti
diff --git a/Documentation/DocBook/media/v4l/common.xml b/Documentation/DocBook/media/v4l/common.xml index 8b5e014..f7008ea 100644 --- a/Documentation/DocBook/media/v4l/common.xml +++ b/Documentation/DocBook/media/v4l/common.xml @@ -428,7 +428,7 @@ zero, no video outputs.</para> modulator. Two separate device nodes will have to be used for such hardware, one that supports the tuner functionality and one that supports the modulator functionality. The reason is a limitation with the -&VIDIOC-S-FREQUENCY; ioctl where you cannot specify whether the frequency +&VIDIOC-G-FREQUENCY; ioctl where you cannot specify whether the frequency is for a tuner or a modulator.</para> <para>To query and change modulator properties applications use
It is VIDIOC_G_FREQUENCY which does not use type to identify tuner, not VIDIOC_S_FREQUENCY. VIDIOC_S_FREQUENCY uses both tuner and type fields. One of these V4L API weirdness... Cc: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Antti Palosaari <crope@iki.fi> --- Documentation/DocBook/media/v4l/common.xml | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)