[FFmpeg-devel] [PATCH 06/14] avradio/sdrdemux: do not hack bandwidth value in random places

[Michael Niedermayer]

Instead do a basic check for totally invalid values during setup
and warn the user for things that are still suspicious

Bounding the value in the middle of the code would lead to
growing complexity to consider that.
Instead the code assumes now the value is correct after setup

Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavradio/sdrdemux.c   | 5 ++++-
 libavradio/sdrinradio.c | 2 +-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/libavradio/sdrdemux.c b/libavradio/sdrdemux.c
index 07b43dec1c..c284f7d8d8 100644
--- a/libavradio/sdrdemux.c
+++ b/libavradio/sdrdemux.c
@@ -863,7 +863,7 @@ static int probe_fm(SDRContext *sdr)
     int half_bw_i = 200*1000 * (int64_t)sdr->block_size / sdr->sdr_sample_rate;
     int floor_bw_i = 10*1000 * (int64_t)sdr->block_size / sdr->sdr_sample_rate;
     float last_score[3] = {FLT_MAX, FLT_MAX, FLT_MAX};
-    int border_i = (sdr->sdr_sample_rate - FFMIN(sdr->bandwidth, sdr->sdr_sample_rate*7/8)) * sdr->block_size / sdr->sdr_sample_rate;
+    int border_i = (sdr->sdr_sample_rate - sdr->bandwidth) * sdr->block_size / sdr->sdr_sample_rate;
 
     if (2*half_bw_i > 2*sdr->block_size)
         return 0;
@@ -1516,6 +1516,9 @@ int ff_sdr_common_init(AVFormatContext *s)
     sdr->avfmt = s;
     s->ctx_flags |= AVFMTCTX_NOHEADER;
 
+    if (sdr->bandwidth > sdr->sdr_sample_rate * 7 / 8)
+        av_log(s, AV_LOG_WARNING, "Bandwidth looks suspicious\n");
+
     if (sdr->width>1 && sdr->height>1) {
         /* video stream */
         st = avformat_new_stream(s, NULL);
diff --git a/libavradio/sdrinradio.c b/libavradio/sdrinradio.c
index f824a1d190..d569842a9c 100644
--- a/libavradio/sdrinradio.c
+++ b/libavradio/sdrinradio.c
@@ -379,7 +379,7 @@ static int sdrindev_initial_hw_setup(AVFormatContext *s)
     sdr->bandwidth = SoapySDRDevice_getBandwidth(soapy, SOAPY_SDR_RX, 0);
 
     // rtlsdr doesnt return a valid value
-    if (!sdr->bandwidth)
+    if (!sdr->bandwidth || sdr->bandwidth >= sdr->sdr_sample_rate)
         sdr->bandwidth = sdr->sdr_sample_rate * 4 / 5;
     av_log(s, AV_LOG_INFO, "bandwidth %"PRId64"\n", sdr->bandwidth);
 
-- 
2.31.1