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authorPrashant Laddha <prladdha@cisco.com>2015-02-04 06:07:32 -0300
committerMauro Carvalho Chehab <mchehab@osg.samsung.com>2015-03-02 14:53:04 -0300
commitd585c1e14a84f08a4a714553d9fc459ee697ff95 (patch)
treedbc16d8257dff37067deb5292934d763f36c17a0 /drivers/media
parent4e30a37345e6f723553d457becc423efa4bf2703 (diff)
downloadop-kernel-dev-d585c1e14a84f08a4a714553d9fc459ee697ff95.zip
op-kernel-dev-d585c1e14a84f08a4a714553d9fc459ee697ff95.tar.gz
[media] vivid sdr: fix broken sine tone generated for sdr FM
FM (frequency modulated) signal for SDR is generated by varying the phase, where phase variation is proportional to input signal. It is seen that, the larger phase increments leads to discontinuities in the signal recovered after demodulation. Reducing the extent of phase variation with respect to input signal, equivalent to reducing the modulation index. Tested using FM receiver flow graph in gnuradio-companion. Cc: Antti Palosaari <crope@iki.fi> Signed-off-by: Prashant Laddha <prladdha@cisco.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Diffstat (limited to 'drivers/media')
-rw-r--r--drivers/media/platform/vivid/vivid-sdr-cap.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/media/platform/vivid/vivid-sdr-cap.c b/drivers/media/platform/vivid/vivid-sdr-cap.c
index 5e089cb..caf1316 100644
--- a/drivers/media/platform/vivid/vivid-sdr-cap.c
+++ b/drivers/media/platform/vivid/vivid-sdr-cap.c
@@ -454,7 +454,7 @@ void vivid_sdr_cap_process(struct vivid_dev *dev, struct vivid_buffer *buf)
FIXP_2PI) >> (31 - FIXP_N);
dev->sdr_fixp_src_phase += src_phase_step;
- dev->sdr_fixp_mod_phase += mod_phase_step;
+ dev->sdr_fixp_mod_phase += mod_phase_step / 4;
/*
* Transfer phases to [0 / 2xPI] in order to avoid variable
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