[FFmpeg-devel] [PATCH 1/6] avradio/sdrdemux: end on EOF dont wraparound

[FFmpeg-devel] [PATCH 1/6] avradio/sdrdemux: end on EOF dont wraparound

[Michael Niedermayer]

This is more usefull for testing

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavradio/sdrdemux.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/libavradio/sdrdemux.c b/libavradio/sdrdemux.c
index d24e09ede2..cb5e7afb2f 100644
--- a/libavradio/sdrdemux.c
+++ b/libavradio/sdrdemux.c
@@ -1045,9 +1045,11 @@ static int sdrfile_read_callback(SDRContext *sdr, FIFOElement *fifo_element, int
     size = FFMIN(remaining, sdr->remaining_file_block_size) * sdr->sample_size;
     ret = avio_read(avfmt->pb, buffer, size);
     if (ret == AVERROR_EOF || (ret > 0 && ret % sdr->sample_size)) {
+        fifo_element->center_frequency = AVERROR_EOF;
+        ret = remaining * sdr->sample_size;
+        sdr->remaining_file_block_size = remaining;
         avio_seek(avfmt->pb, SEEK_SET, 0);
-        av_log(avfmt, AV_LOG_INFO, "EOF, will wraparound\n");
-        return AVERROR(EAGAIN);
+        av_log(avfmt, AV_LOG_INFO, "EOF\n");
     } else if (ret == AVERROR(EAGAIN)) {
         av_log(avfmt, AV_LOG_DEBUG, "read EAGAIN\n");
         return AVERROR(EAGAIN);
@@ -1621,6 +1623,8 @@ process_next_block:
         av_log(s, AV_LOG_DEBUG, "EAGAIN on not enough data\n");
         return AVERROR(EAGAIN);
     }
+    if (fifo_element[0].center_frequency == AVERROR_EOF || fifo_element[1].center_frequency == AVERROR_EOF)
+        return AVERROR_EOF;
     if (fifo_element[0].center_frequency != fifo_element[1].center_frequency) {
         av_log(s, AV_LOG_DEBUG, "Mismatching frequency blocks\n");
 //         fifo_element[0].center_frequency = 0;
-- 
2.31.1

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

[FFmpeg-devel] [PATCH 2/6] avradio: Fill in missing bandwidth values at 80% of frequency

[Michael Niedermayer]

The previous of 100% was a unrealistic default

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavradio/sdrdemux.c   | 2 ++
 libavradio/sdrinradio.c | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/libavradio/sdrdemux.c b/libavradio/sdrdemux.c
index cb5e7afb2f..39e2e54ee7 100644
--- a/libavradio/sdrdemux.c
+++ b/libavradio/sdrdemux.c
@@ -1401,6 +1401,8 @@ static int sdrfile_initial_setup(AVFormatContext *s)
         sdr->bandwidth       = sdr->sdr_sample_rate;
         sdr->fileheader_size = 40;
     }
+    if (sdr->bandwidth >= sdr->sdr_sample_rate)
+        sdr->bandwidth = sdr->sdr_sample_rate * 4 / 5;
 
     //After reading the first packet header we return to the begin so the packet can be read whole
     avio_seek(s->pb, 0, SEEK_SET);
diff --git a/libavradio/sdrinradio.c b/libavradio/sdrinradio.c
index 3a0b7f8ab4..c6f5742436 100644
--- a/libavradio/sdrinradio.c
+++ b/libavradio/sdrinradio.c
@@ -320,7 +320,7 @@ static int sdrindev_initial_hw_setup(AVFormatContext *s)
 
     // rtlsdr doesnt return a valid value
     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);
 
     SoapySDRDevice_activateStream(soapy, soapyRxStream, 0, 0, 0);
-- 
2.31.1

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

[FFmpeg-devel] [PATCH 3/6] avradio/sdrdemux: Skip probing in the area outside the bandwidth

[Michael Niedermayer]

---
 libavradio/sdrdemux.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/libavradio/sdrdemux.c b/libavradio/sdrdemux.c
index 39e2e54ee7..90f6805c3b 100644
--- a/libavradio/sdrdemux.c
+++ b/libavradio/sdrdemux.c
@@ -394,6 +394,7 @@ static int probe_am(SDRContext *sdr)
     int i;
     int bandwidth_f = 6000;
     int half_bw_i = bandwidth_f * (int64_t)sdr->block_size / sdr->sdr_sample_rate;
+    int border_i = (sdr->sdr_sample_rate - sdr->bandwidth) * sdr->block_size / sdr->sdr_sample_rate;
     double avg = 0;
 
     if (2*half_bw_i > 2*sdr->block_size)
@@ -408,6 +409,10 @@ static int probe_am(SDRContext *sdr)
         avg += sdr->len2block[i + half_bw_i];
         score = half_bw_i * mid / (avg - mid);
         avg -= sdr->len2block[i - half_bw_i];
+
+        if (i < border_i || i > 2*sdr->block_size - border_i)
+            continue;
+
         //TODO also check for symmetry in the spectrum
         if (mid > 0 && score > AM_THRESHOLD &&
             sdr->len2block[i - 1] <  mid          && sdr->len2block[i + 1] <= mid &&
@@ -703,6 +708,7 @@ static int probe_fm(SDRContext *sdr)
     int half_bw_i = bandwidth_f * (int64_t)sdr->block_size / sdr->sdr_sample_rate;
     double avg[2] = {0}, tri = 0;
     float last_score[3] = {FLT_MAX, FLT_MAX, FLT_MAX};
+    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;
@@ -726,6 +732,8 @@ static int probe_fm(SDRContext *sdr)
         last_score[2] = last_score[1];
         last_score[1] = last_score[0];
         last_score[0] = tri / (b * half_bw_i);
+        if (i < border_i || i > 2*sdr->block_size - border_i)
+            continue;
 
         if (last_score[1] >= last_score[0] &&
             last_score[1] > last_score[2] &&
-- 
2.31.1

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

[FFmpeg-devel] [PATCH 4/6] avradio/sdrdemux: adjust frequency precission in probing depending on modulation

[Michael Niedermayer]

for AM we can find the frequency very precissely, for FM currently not so
much

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavradio/sdrdemux.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavradio/sdrdemux.c b/libavradio/sdrdemux.c
index 90f6805c3b..92b1e2b170 100644
--- a/libavradio/sdrdemux.c
+++ b/libavradio/sdrdemux.c
@@ -166,9 +166,10 @@ static int create_station(SDRContext *sdr, Station *candidate_station) {
         return best_station_index;
     }
     for (i=0; i<sdr->nb_candidate_stations; i++) {
+        int freq_precission = modulation == AM ? 5 : 50;
         double delta = fabs(sdr->candidate_station[i]->frequency - freq);
         // Station already added, or we have 2 rather close stations
-        if (modulation == sdr->candidate_station[i]->modulation && delta < 10 && sdr->candidate_station[i] != candidate_station) {
+        if (modulation == sdr->candidate_station[i]->modulation && delta < freq_precission && sdr->candidate_station[i] != candidate_station) {
             nb_candidate_match++;
         }
         if (modulation != sdr->candidate_station[i]->modulation && delta < (bandwidth + sdr->candidate_station[i]->bandwidth)/2.1)
-- 
2.31.1

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

[FFmpeg-devel] [PATCH 5/6] avradio/sdrdemux: When searching for stations move in smaller steps

[Michael Niedermayer]

Moving too quick can lead to missed stations
---
 libavradio/sdrdemux.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavradio/sdrdemux.c b/libavradio/sdrdemux.c
index 92b1e2b170..598dab8f18 100644
--- a/libavradio/sdrdemux.c
+++ b/libavradio/sdrdemux.c
@@ -1216,7 +1216,7 @@ static void *soapy_needs_bigger_buffers_worker(SDRContext *sdr)
         // 2 blocks are needed with windowing to get a clean FFT output
         // Thus > 3 is the minimum for the next frequency update if we want to do something reliable with the data
         if (sdr->seek_direction && block_counter > 5) {
-            sdr->wanted_freq = snap2band(sdr, sdr->wanted_freq, sdr->seek_direction*sdr->bandwidth);
+            sdr->wanted_freq = snap2band(sdr, sdr->wanted_freq, sdr->seek_direction*sdr->bandwidth*0.5);
         }
         if (sdr->wanted_freq != sdr->freq) {
             //We could use a seperate MUTEX for the FIFO and for soapy
-- 
2.31.1

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

[FFmpeg-devel] [PATCH 6/6] avradio/sdrdemux: slightly different normalization of FM scores

[Michael Niedermayer]

This way teh scores now resemble station vs noise floor while before
they where "whatever"
This results in somewhat cleaner results from probing as well

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavradio/sdrdemux.c | 78 ++++++++++++++++++++++++-------------------
 1 file changed, 43 insertions(+), 35 deletions(-)

diff --git a/libavradio/sdrdemux.c b/libavradio/sdrdemux.c
index 598dab8f18..d3f0368d7d 100644
--- a/libavradio/sdrdemux.c
+++ b/libavradio/sdrdemux.c
@@ -72,7 +72,7 @@
 #define AM_MAX23 0.06     //smaller causes failure on synthetic signals
 #define AM_MAX4  0.02
 
-#define FM_THRESHOLD .8 //TODO adjust
+#define FM_THRESHOLD  50 //TODO adjust
 
 //Least squares fit at 1khz points of frequency response shown by Frank McClatchie, FM SYSTEMS, INC. 800-235-6960
 static double emphasis75us(int f)
@@ -707,53 +707,61 @@ static int probe_fm(SDRContext *sdr)
     int bandwidth_f  = 180*1000;
     int bandwidth_p2 =  38*1000; //phase 2 bandwidth
     int half_bw_i = bandwidth_f * (int64_t)sdr->block_size / sdr->sdr_sample_rate;
-    double avg[2] = {0}, tri = 0;
     float last_score[3] = {FLT_MAX, FLT_MAX, FLT_MAX};
     int border_i = (sdr->sdr_sample_rate - sdr->bandwidth) * sdr->block_size / sdr->sdr_sample_rate;
+    double noise_floor = FLT_MAX;
 
     if (2*half_bw_i > 2*sdr->block_size)
         return 0;
 
-    for (i = 0; i<half_bw_i; i++) {
-        avg[0] += sdr->len2block[i];
-        tri    += i*sdr->len2block[i];
-    }
-    for (; i<2*half_bw_i; i++) {
-        avg[1] += sdr->len2block[i];
-        tri    += (2*half_bw_i-i)*sdr->len2block[i];
-    }
+    for (int pass = 0; pass < 2; pass ++) {
+        double avg[2] = {0}, tri = 0;
+        for (i = 0; i<half_bw_i; i++) {
+            avg[0] += sdr->len2block[i];
+            tri    += i*sdr->len2block[i];
+        }
+        for (; i<2*half_bw_i; i++) {
+            avg[1] += sdr->len2block[i];
+            tri    += (2*half_bw_i-i)*sdr->len2block[i];
+        }
 
-    for(i = half_bw_i; i<2*sdr->block_size - half_bw_i; i++) {
-        double b = avg[0] + sdr->len2block[i];
-        avg[0] += sdr->len2block[i] - sdr->len2block[i - half_bw_i];
-        avg[1] -= sdr->len2block[i] - sdr->len2block[i + half_bw_i];
-        b += avg[1];
-        tri += avg[1] - avg[0];
+        for(i = half_bw_i; i<2*sdr->block_size - half_bw_i; i++) {
+            double b = avg[0] + sdr->len2block[i];
+            avg[0] += sdr->len2block[i] - sdr->len2block[i - half_bw_i];
+            avg[1] -= sdr->len2block[i] - sdr->len2block[i + half_bw_i];
+            b += avg[1];
+            tri += avg[1] - avg[0];
 
-        last_score[2] = last_score[1];
-        last_score[1] = last_score[0];
-        last_score[0] = tri / (b * half_bw_i);
-        if (i < border_i || i > 2*sdr->block_size - border_i)
-            continue;
+            if (i < border_i || i > 2*sdr->block_size - border_i)
+                continue;
 
-        if (last_score[1] >= last_score[0] &&
-            last_score[1] > last_score[2] &&
-            last_score[1] > FM_THRESHOLD) {
+            if (pass == 0) {
+                noise_floor = FFMIN(noise_floor, tri);
+            } else {
+                last_score[2] = last_score[1];
+                last_score[1] = last_score[0];
+                last_score[0] = tri / (noise_floor);
 
-            float rmax   = max_in_range(sdr, i-half_bw_i/4, i+half_bw_i/4);
-            int lowcount = countbelow(sdr, i-half_bw_i/4, i+half_bw_i/4, rmax / 100);
-            double peak_i;
+                if (last_score[1] >= last_score[0] &&
+                    last_score[1] > last_score[2] &&
+                    last_score[1] > FM_THRESHOLD) {
 
-            if (lowcount / (half_bw_i*0.5) > 0.99)
-                continue;
+                    float rmax   = max_in_range(sdr, i-half_bw_i/4, i+half_bw_i/4);
+                    int lowcount = countbelow(sdr, i-half_bw_i/4, i+half_bw_i/4, rmax / 100);
+                    double peak_i;
 
-            // as secondary check, we could check that without the center 3 samples we are still having a strong signal FIXME
+                    if (lowcount / (half_bw_i*0.5) > 0.99)
+                        continue;
 
-            peak_i = find_peak(sdr, last_score, 1, 3) + i - 1;
-            if (peak_i < 0)
-                continue;
-            av_assert0(fabs(peak_i-i) < 2);
-            create_candidate_station(sdr, FM, peak_i * 0.5 * sdr->sdr_sample_rate / sdr->block_size + sdr->block_center_freq - sdr->sdr_sample_rate/2, bandwidth_f, bandwidth_p2, last_score[1]);
+                    // as secondary check, we could check that without the center 3 samples we are still having a strong signal FIXME
+
+                    peak_i = find_peak(sdr, last_score, 1, 3) + i - 1;
+                    if (peak_i < 0)
+                        continue;
+                    av_assert0(fabs(peak_i-i) < 2);
+                    create_candidate_station(sdr, FM, peak_i * 0.5 * sdr->sdr_sample_rate / sdr->block_size + sdr->block_center_freq - sdr->sdr_sample_rate/2, bandwidth_f, bandwidth_p2, last_score[1]);
+                }
+            }
         }
     }
 
-- 
2.31.1

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-devel] [PATCH 1/6] avradio/sdrdemux: end on EOF dont wraparound

[Michael Niedermayer]

[-- Attachment #1.1: Type: text/plain, Size: 617 bytes --]

On Wed, Jul 05, 2023 at 12:22:57AM +0200, Michael Niedermayer wrote:
> This is more usefull for testing
> 
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavradio/sdrdemux.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)

will apply patchset

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Frequently ignored answer#1 FFmpeg bugs should be sent to our bugtracker. User
questions about the command line tools should be sent to the ffmpeg-user ML.
And questions about how to use libav* should be sent to the libav-user ML.

[-- Attachment #1.2: signature.asc --]
[-- Type: application/pgp-signature, Size: 195 bytes --]

[-- Attachment #2: Type: text/plain, Size: 251 bytes --]

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".