[FFmpeg-devel] [PATCH 01/14] avradio/rds: reset station timeout on successfull group decode

[FFmpeg-devel] [PATCH 01/14] avradio/rds: reset station timeout on successfull group decode

[Michael Niedermayer]

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

diff --git a/libavradio/rds.c b/libavradio/rds.c
index 99e5360b72..55b24a0d9e 100644
--- a/libavradio/rds.c
+++ b/libavradio/rds.c
@@ -123,6 +123,9 @@ static int decode_rds_group(SDRContext *sdr, Station *station, uint16_t group[4]
         return 0; // skip first packet with new PI, likely its just damaged
     }
 
+    //sucessfully decoding a RDS group implies that the station has been detected correctly
+    station->timeout = 0;
+
     switch(a) {
     case 0:
         AV_WB16(station->name + 2*(group[1]&3), group[3]);
-- 
2.31.1

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[FFmpeg-devel] [PATCH 02/14] avradio/sdr: Factor demodulate_all_fm out

[Michael Niedermayer]

This is cleaner

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

diff --git a/libavradio/sdr.h b/libavradio/sdr.h
index 6c4647823e..29ac4a2963 100644
--- a/libavradio/sdr.h
+++ b/libavradio/sdr.h
@@ -130,6 +130,7 @@ typedef struct SDRContext {
     int width, height;
     int single_ch_audio_st_index;
     int waterfall_st_index;
+    int demodulate_all_fm;
     int64_t freq;
     int64_t min_freq;
     int64_t max_freq;
diff --git a/libavradio/sdrdemux.c b/libavradio/sdrdemux.c
index e93cf4dd98..2103feaca8 100644
--- a/libavradio/sdrdemux.c
+++ b/libavradio/sdrdemux.c
@@ -1439,6 +1439,7 @@ int ff_sdr_common_init(AVFormatContext *s)
         st->codecpar->height = sdr->height;
         avpriv_set_pts_info(st, 64, 1, (48000/128) << FREQ_BITS);
         sdr->waterfall_st_index = st->index;
+        sdr->demodulate_all_fm = 1;
     } else
         sdr->waterfall_st_index = -1;
 
@@ -1679,7 +1680,7 @@ process_next_block:
         }
     }
 
-    if (sdr->width > 1) {
+    if (sdr->demodulate_all_fm) {
         Station *station_list[1000];
         int nb_stations = ff_sdr_find_stations(sdr, sdr->block_center_freq, sdr->sdr_sample_rate*0.5, station_list, FF_ARRAY_ELEMS(station_list));
         for (int i= 0; i<nb_stations; i++) {
-- 
2.31.1

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[FFmpeg-devel] [PATCH 03/14] avradio/sdrdemux: require better timeout for replacing station

[Michael Niedermayer]

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 2103feaca8..fea4202709 100644
--- a/libavradio/sdrdemux.c
+++ b/libavradio/sdrdemux.c
@@ -216,7 +216,8 @@ static int create_station(SDRContext *sdr, Station *candidate_station) {
         }
     }
     if (best_station) {
-        if (score > best_station->score && conflict == INT_MAX) {
+        if (score > best_station->score && conflict == INT_MAX &&
+            candidate_station->timeout < best_station->timeout) {
             int log_level = fabs(best_station->frequency - freq) < 3.0 ? AV_LOG_DEBUG : AV_LOG_WARNING;
             av_log(sdr->avfmt, log_level, "Update station score:%f -> %f freq: %f %f -> %f\n",
                     best_station->score, score,
-- 
2.31.1

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[FFmpeg-devel] [PATCH 04/14] avradio/sdrdemux: Compute FM station frequency more exactly

[Michael Niedermayer]

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavradio/sdrdemux.c | 35 ++++++++++++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/libavradio/sdrdemux.c b/libavradio/sdrdemux.c
index fea4202709..fd3f5dd52d 100644
--- a/libavradio/sdrdemux.c
+++ b/libavradio/sdrdemux.c
@@ -383,6 +383,7 @@ static int create_candidate_station(SDRContext *sdr, enum Modulation modulation,
     Station *station_list[1000];
     double snapdistance = modulation == AM ? AM_FREQ_TOLERANCE : FM_FREQ_TOLERANCE;
     int nb_stations = ff_sdr_find_stations(sdr, freq, snapdistance, station_list, FF_ARRAY_ELEMS(station_list));
+    int update_freq = 1;
 
     if (nb_stations) {
         for(int i = 1; i<nb_stations; i++)
@@ -409,12 +410,18 @@ static int create_candidate_station(SDRContext *sdr, enum Modulation modulation,
             goto fail;
     } else {
         station = station_list[0];
+
+        //demodulated FM stations have their frequency computed exactly, so dont mess them up
+        update_freq = station->modulation != FM || !station->in_station_list || !sdr->demodulate_all_fm;
+
         // We will update the frequency so we need to reinsert
         tree_remove(&sdr->station_root, station, station_cmp, &next);
-        station->frequency = station->nb_frequency * station->frequency + freq;
+        if (update_freq)
+            station->frequency = station->nb_frequency * station->frequency + freq;
         station->timeout   = 0;
     }
-    station->frequency /= ++station->nb_frequency;
+    if(update_freq)
+        station->frequency /= ++station->nb_frequency;
 
     station->detection_per_mix_frequency[histogram_index(sdr, freq)] ++;
     station->modulation   = modulation;
@@ -934,6 +941,22 @@ static int probe_fm(SDRContext *sdr)
     return 0;
 }
 
+static void station_update_freq(SDRContext *sdr, Station *station, double freq)
+{
+    struct AVTreeNode *next = NULL;
+    void *tmp;
+
+    //We must reinsert the station if we change the key (frequency)
+    tree_remove(&sdr->station_root, station, station_cmp, &next);
+
+    station->frequency = station->nb_frequency * station->frequency + freq;
+    station->frequency /= ++station->nb_frequency;
+
+    tmp = tree_insert(&sdr->station_root, station, station_cmp, &next);
+    av_assert0(!tmp || tmp == station);
+    av_freep(&next);
+}
+
 static int demodulate_fm(SDRContext *sdr, Station *station, AVStream *st, AVPacket *pkt)
 {
     SDRStream *sst = st ? st->priv_data : NULL;
@@ -953,11 +976,12 @@ static int demodulate_fm(SDRContext *sdr, Station *station, AVStream *st, AVPack
     int len2_4_i    = 2L*sdr->fm_block_size* 2400 / sample_rate;
     double carrier19_i_exact;
     int W= 5;
+    double dc = 0, dcw = 0;
+    int len2 = FFMIN(index, 2*sdr->block_size - index);
 
     av_assert0(!st || (sst == station->stream && sst->station == station));
 
     //If only some of the bandwidth is available, just try with less
-    int len2 = FFMIN(index, 2*sdr->block_size - index);
     if (len2 < len && len2 > len/2)
         len = len2;
 
@@ -979,9 +1003,14 @@ static int demodulate_fm(SDRContext *sdr, Station *station, AVStream *st, AVPack
         sdr->fm_iblock[i].re = atan2(x.im * y.re - x.re * y.im,
                                      x.re * y.re + x.im * y.im) * sdr->fm_window[i];
         sdr->fm_iblock[i].im = 0;
+        dc += sdr->fm_iblock[i].re;
+        dcw+= sdr->fm_window[i] * sdr->fm_window[i];
     }
     sdr->fm_iblock[i].re = 0;
     sdr->fm_iblock[i].im = 0;
+    dc *= M_PI/2 * sqrt((2*sdr->fm_block_size - 1) / dcw);
+
+    station_update_freq(sdr, station, freq-dc);
 
     av_assert0(sdr->fm_block_size_p2 * 2 < sdr->fm_block_size);
     //FIXME this only needs to be a RDFT
-- 
2.31.1

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[FFmpeg-devel] [PATCH 05/14] avradio/sdrdemux: basic warning cleanup

[Michael Niedermayer]

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

diff --git a/libavradio/sdrdemux.c b/libavradio/sdrdemux.c
index fd3f5dd52d..e45d00724b 100644
--- a/libavradio/sdrdemux.c
+++ b/libavradio/sdrdemux.c
@@ -1148,7 +1148,6 @@ static int setup_stream(SDRContext *sdr, int stream_index, Station *station)
     AVFormatContext *s = sdr->avfmt;
     AVStream *st = s->streams[stream_index];
     SDRStream *sst = st->priv_data;
-    int ret;
 
     //For now we expect each station to be only demodulated once, nothing should break though if its done more often
     av_assert0(station->stream == NULL || station->stream == sst);
@@ -1163,9 +1162,9 @@ static int setup_stream(SDRContext *sdr, int stream_index, Station *station)
     station->stream = sst;
 
     if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
+        int block_size;
         free_stream(sdr, stream_index);
 
-        int block_size;
         if (sst->station->modulation == FM) {
             block_size = sdr->fm_block_size;
         } else
-- 
2.31.1

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[FFmpeg-devel] [PATCH 06/14] avradio/rds: Implement clearing radio text

[Michael Niedermayer]

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavradio/rds.c | 9 +++++++--
 libavradio/sdr.h | 2 ++
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/libavradio/rds.c b/libavradio/rds.c
index 55b24a0d9e..e121c9db8e 100644
--- a/libavradio/rds.c
+++ b/libavradio/rds.c
@@ -130,14 +130,19 @@ static int decode_rds_group(SDRContext *sdr, Station *station, uint16_t group[4]
     case 0:
         AV_WB16(station->name + 2*(group[1]&3), group[3]);
     break;
-    case 2:
+    case 2:{
+        int new_ab_flag = group[1] & 16;
+        if (new_ab_flag != station->rt_ab_flag) {
+            memset(station->radiotext, 0, sizeof(station->radiotext));
+            station->rt_ab_flag = new_ab_flag;
+        }
         if (b) {
             AV_WB16(station->radiotext + 2*(group[1]&15)    , group[3]);
         } else {
             AV_WB16(station->radiotext + 4*(group[1]&15)    , group[2]);
             AV_WB16(station->radiotext + 4*(group[1]&15) + 2, group[3]);
         }
-    break;
+    break;}
     case 10:
         if (b==0) {
             AV_WB16(station->programm_type_name + 4*(group[1]&1)    , group[2]);
diff --git a/libavradio/sdr.h b/libavradio/sdr.h
index 29ac4a2963..4b3e14da02 100644
--- a/libavradio/sdr.h
+++ b/libavradio/sdr.h
@@ -75,6 +75,8 @@ typedef struct Station {
     char radiotext[65];
     char programm_type_name[9];
     int program_id[2];
+    uint8_t rt_ab_flag;
+
     enum Modulation modulation;
     double frequency;
     int nb_frequency;       ///< number of detections which are used to compute the frequency
-- 
2.31.1

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[FFmpeg-devel] [PATCH 07/14] avradio/rds: Implement RadioText Plus

[Michael Niedermayer]

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavradio/rds.c        | 44 ++++++++++++++++++++++++++++++++++++++++-
 libavradio/sdr.h        |  7 +++++++
 libavradio/vissualize.c |  5 +++++
 3 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/libavradio/rds.c b/libavradio/rds.c
index e121c9db8e..30e4209ae8 100644
--- a/libavradio/rds.c
+++ b/libavradio/rds.c
@@ -143,6 +143,17 @@ static int decode_rds_group(SDRContext *sdr, Station *station, uint16_t group[4]
             AV_WB16(station->radiotext + 4*(group[1]&15) + 2, group[3]);
         }
     break;}
+    case 3:
+        if (!b) {
+            int application_id = group[3];
+            switch (application_id) {
+            case 0x4BD7:
+                //RadioText Plus / RT+ for group 2A RT - IEC 62106-6:2023
+                station->rtp_appgroup = group[1] & 31;
+                break;
+            }
+        }
+    break;
     case 10:
         if (b==0) {
             AV_WB16(station->programm_type_name + 4*(group[1]&1)    , group[2]);
@@ -152,7 +163,38 @@ static int decode_rds_group(SDRContext *sdr, Station *station, uint16_t group[4]
 //     case 14:
 //     break;
     default:
-        av_log(sdr->avfmt, AV_LOG_DEBUG, "RDS: PI %X, A %X B %X PTY %X\n", pi,a,b,pty);
+        if (2*a + b == station->rtp_appgroup) {
+            int toggle_bit  = group[1]&16;
+            int running_bit = group[1]&8;
+            uint64_t v = ((group[1]&7LL)<<32) + ((uint64_t)group[2]<<16) + group[3];
+            int tag[2][3];
+            if (toggle_bit != station->rtp_toggle_bit) {
+                station->artist[0] =
+                station->title[0] =
+                station->album[0] = 0;
+            }
+            station->rtp_toggle_bit = toggle_bit;
+            for(int i = 0; i<6; i++) {
+                tag[i/3][i%3] = (v>>29) & 63;
+                v <<= 6;
+            }
+            tag[1][2] >>= 1;
+            av_log(0,0, "\n");
+            for(int i = 0; i<2; i++) {
+                char *target= NULL;
+                switch(tag[i][0]) {
+                case 1: target = station->title; break;
+                case 2: target = station->album; break;
+                case 4: target = station->artist; break;
+                default:
+                    av_log(sdr->avfmt, AV_LOG_DEBUG, "Unhandled RT+ code %d\n", tag[i][0]);
+                }
+                if (target) {
+                    memcpy(target, station->radiotext + tag[i][1], 1 + tag[i][2]);
+                    target[1+tag[i][2]] = 0;
+                }
+            }
+        }
     }
 
     return 0;
diff --git a/libavradio/sdr.h b/libavradio/sdr.h
index 4b3e14da02..ac6b7dffe0 100644
--- a/libavradio/sdr.h
+++ b/libavradio/sdr.h
@@ -72,10 +72,17 @@ typedef enum Modulation {
 
 typedef struct Station {
     char name[9];
+
     char radiotext[65];
+    char artist[65];
+    char title[65];
+    char album[65];
     char programm_type_name[9];
     int program_id[2];
     uint8_t rt_ab_flag;
+    uint8_t rtp_toggle_bit;
+    uint8_t rtp_running_bit;
+    uint16_t rtp_appgroup;
 
     enum Modulation modulation;
     double frequency;
diff --git a/libavradio/vissualize.c b/libavradio/vissualize.c
index d87ca167de..a3dcf5801b 100644
--- a/libavradio/vissualize.c
+++ b/libavradio/vissualize.c
@@ -221,6 +221,11 @@ int ff_sdr_vissualization(SDRContext *sdr, AVStream *st, AVPacket *pkt)
             if (s->radiotext[0]) {
                 draw_string(pkt->data, 4*w, s->radiotext, xmid + 8*yd, 320*h2 + 24*yd, xd, yd, color, color, color, w, h);
             }
+            if (s->title[0] || s->artist[0]) {
+                int len = strlen(s->title) + 1;
+                draw_string(pkt->data, 4*w, s->title , xmid + 8*yd, 320*h2 + 2*24*yd, xd, yd, color, color*1.5, color, w, h);
+                draw_string(pkt->data, 4*w, s->artist, xmid + 8*yd + 9*xd*len, 320*h2 + 2*24*yd + 9*yd*len, xd, yd, color, color*2, color, w, h);
+            }
         }
     }
 
-- 
2.31.1

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[FFmpeg-devel] [PATCH 08/14] avradio/rds: Better file title

[Michael Niedermayer]

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

diff --git a/libavradio/rds.c b/libavradio/rds.c
index 30e4209ae8..4b16521e4c 100644
--- a/libavradio/rds.c
+++ b/libavradio/rds.c
@@ -1,5 +1,5 @@
 /*
- * RDS
+ * Radio Data System
  * Copyright (c) 2023 Michael Niedermayer
  *
  * This file is part of FFmpeg.
-- 
2.31.1

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[FFmpeg-devel] [PATCH 09/14] remove stray av_log()

[Michael Niedermayer]

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

diff --git a/libavradio/rds.c b/libavradio/rds.c
index 4b16521e4c..1f2979d068 100644
--- a/libavradio/rds.c
+++ b/libavradio/rds.c
@@ -179,7 +179,6 @@ static int decode_rds_group(SDRContext *sdr, Station *station, uint16_t group[4]
                 v <<= 6;
             }
             tag[1][2] >>= 1;
-            av_log(0,0, "\n");
             for(int i = 0; i<2; i++) {
                 char *target= NULL;
                 switch(tag[i][0]) {
-- 
2.31.1

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[FFmpeg-devel] [PATCH 10/14] avradio/sdrdemux: Export RT+ metadata updates

[Michael Niedermayer]

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavradio/sdrdemux.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/libavradio/sdrdemux.c b/libavradio/sdrdemux.c
index e45d00724b..bbd756f1d6 100644
--- a/libavradio/sdrdemux.c
+++ b/libavradio/sdrdemux.c
@@ -1677,6 +1677,7 @@ process_next_block:
     for (int stream_index = 0; stream_index < s->nb_streams; stream_index++) {
         AVStream *st = s->streams[stream_index];
         SDRStream *sst = st->priv_data;
+        Station *station = sst->station;
 
         if (sst->processing_index) {
             int skip = 1;
@@ -1686,11 +1687,25 @@ process_next_block:
                     return skip;
             } else if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
                 if (sst->station) {
+                    const char *metadata_keys[] = {"artist", "title"};
+                    const char *metadata_values[] = {station->artist, station->title};
+                    AVDictionaryEntry *t = NULL;
+
                     skip = 0;
                     ret = ff_sdr_modulation_descs[ sst->station->modulation ].demodulate(sdr, sst->station, st, pkt);
                     if (ret < 0) {
                         av_log(s, AV_LOG_ERROR, "demodulation failed ret = %d\n", ret);
                     }
+                    for(int i = 0; i < FF_ARRAY_ELEMS(metadata_keys); i++) {
+                        const char *value = "";
+                        t = av_dict_get(st->metadata, metadata_keys[i], NULL, 0);
+                        if (t)
+                            value = t->value;
+                        if (strcmp(value, metadata_values[i])) {
+                            av_dict_set(&st->metadata, metadata_keys[i], metadata_values[i], 0);
+                            s->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED;
+                        }
+                    }
                 }
             } else
                 av_assert0(0);
-- 
2.31.1

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[FFmpeg-devel] [PATCH 11/14] avradio/sdrdemux: Basic prefilter for RDS

[Michael Niedermayer]

25% lower error rate

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavradio/sdrdemux.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/libavradio/sdrdemux.c b/libavradio/sdrdemux.c
index bbd756f1d6..c0ca420c84 100644
--- a/libavradio/sdrdemux.c
+++ b/libavradio/sdrdemux.c
@@ -1031,6 +1031,19 @@ static int demodulate_fm(SDRContext *sdr, Station *station, AVStream *st, AVPack
 
         memcpy(sdr->fm_block + i, sdr->fm_block + 3*carrier19_i, sizeof(AVComplexFloat)*len2_4_i);
         memcpy(sdr->fm_block + i + 2*sdr->fm_block_size_p2 - len2_4_i, sdr->fm_block + 3*carrier19_i - len2_4_i, sizeof(AVComplexFloat)*len2_4_i);
+
+        //This improves the decoder performace from an error rate per packet of 0.539578 to 0.410425
+        for (int j= 0; j<len2_4_i; j++) {
+            float J = j / (float)len2_4_i;
+            float W = 1 - J*J;
+            sdr->fm_block[i+j].re *= W;
+            sdr->fm_block[i+j].im *= W;
+            if (j) {
+                sdr->fm_block[i + 2*sdr->fm_block_size_p2 - j].re *= W;
+                sdr->fm_block[i + 2*sdr->fm_block_size_p2 - j].im *= W;
+            }
+        }
+
         sdr->fm_ifft_p2(sdr->fm_ifft_p2_ctx, sdr->fm_iside   , sdr->fm_block + i, sizeof(AVComplexFloat));
         synchronous_am_demodulationN(sdr->fm_iside, sdr->fm_icarrier, sdr->fm_window_p2, 2*sdr->fm_block_size_p2, 3);
         ff_sdr_decode_rds(sdr, station, sdr->fm_iside);
-- 
2.31.1

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[FFmpeg-devel] [PATCH 12/14] avradio/sdrdemux: Reduce FM audio bandwidth down toward reality

[Michael Niedermayer]

This avoids useless computations

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavradio/sdrdemux.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/libavradio/sdrdemux.c b/libavradio/sdrdemux.c
index c0ca420c84..54d7622809 100644
--- a/libavradio/sdrdemux.c
+++ b/libavradio/sdrdemux.c
@@ -1519,9 +1519,9 @@ int ff_sdr_common_init(AVFormatContext *s)
     av_log(s, AV_LOG_INFO, "Block size %d\n", sdr->block_size);
 
     sdr->block_time = sdr->block_size / (double)sdr->sdr_sample_rate;
-    sdr->am_bandwidth    =   6 * 1000;
-    sdr->fm_bandwidth    = 180 * 1000;
-    sdr->fm_bandwidth_p2 =  18 * 1000;
+    sdr->am_bandwidth    =   6   * 1000;
+    sdr->fm_bandwidth    = 180   * 1000;
+    sdr->fm_bandwidth_p2 =  16.5 * 1000; // Officially Stereo Broadcast FM has 15khz audio bandwidth
 
     sdr->am_block_size    = find_block_size(sdr, sdr->am_bandwidth);
     sdr->fm_block_size    = find_block_size(sdr, sdr->fm_bandwidth);
-- 
2.31.1

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[FFmpeg-devel] [PATCH 13/14] avradio/sdrdemux: deemphasis filter fixes

[Michael Niedermayer]

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavradio/sdrdemux.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/libavradio/sdrdemux.c b/libavradio/sdrdemux.c
index 54d7622809..b69b13d075 100644
--- a/libavradio/sdrdemux.c
+++ b/libavradio/sdrdemux.c
@@ -67,7 +67,7 @@
 #define AM_MAX4  0.02
 
 //Least squares fit at 1khz points of frequency response shown by Frank McClatchie, FM SYSTEMS, INC. 800-235-6960
-static double emphasis75us(int f)
+static double emphasis75us(double f)
 {
     return ((((((((- 4.79546E-9 * f + 5.32101E-7) * f - 0.0000254577) * f + 0.000687225) * f
                    - 0.0114925) * f + 0.122781  ) * f - 0.827885    ) * f + 3.25025    ) * f - 4.6049) * f + 2.06937;
@@ -76,15 +76,16 @@ static double emphasis75us(int f)
 /**
  * Apply emphasis filter in frequency domain
  */
-static void apply_deemphasis(SDRContext *sdr, AVComplexFloat *data, int len, int sample_rate, int dir)
+static void apply_deemphasis(SDRContext *sdr, AVComplexFloat *data, int len, int block_size, int sample_rate, int dir)
 {
+    double factor = sample_rate / (2000.0*block_size);
     if (sdr->emphasis_mode == EMPHASIS_NONE)
         return;
 
-    len = FFMIN(len, len * 19000 / sample_rate);
+    len = FFMIN(len, len * 2 * 19000 / sample_rate);
 
     for (int i = 1; i < len; i++) {
-        double index = 1.0 + i / 1000;
+        double index = 1.0 + i * factor;
         double scale;
 
         if (sdr->emphasis_mode == EMPHASIS_50us)
@@ -1051,8 +1052,8 @@ static int demodulate_fm(SDRContext *sdr, Station *station, AVStream *st, AVPack
         if (st) {
             memcpy(sdr->fm_block + i, sdr->fm_block + 2*carrier19_i, sizeof(AVComplexFloat)*len17_i);
             memcpy(sdr->fm_block + i + 2*sdr->fm_block_size_p2 - len17_i, sdr->fm_block + 2*carrier19_i - len17_i, sizeof(AVComplexFloat)*len17_i);
-            apply_deemphasis(sdr, sdr->fm_block + i, sdr->fm_block_size_p2, sample_rate_p2, + 1);
-            apply_deemphasis(sdr, sdr->fm_block + i + 2*sdr->fm_block_size_p2, sdr->fm_block_size_p2, sample_rate_p2, - 1);
+            apply_deemphasis(sdr, sdr->fm_block + i, sdr->fm_block_size_p2, sdr->fm_block_size_p2, sample_rate_p2, + 1);
+            apply_deemphasis(sdr, sdr->fm_block + i + 2*sdr->fm_block_size_p2, sdr->fm_block_size_p2, sdr->fm_block_size_p2, sample_rate_p2, - 1);
             sdr->fm_ifft_p2(sdr->fm_ifft_p2_ctx, sdr->fm_iside   , sdr->fm_block + i, sizeof(AVComplexFloat));
             synchronous_am_demodulationN(sdr->fm_iside, sdr->fm_icarrier, sdr->fm_window_p2, 2*sdr->fm_block_size_p2, 2);
         }
@@ -1061,7 +1062,7 @@ static int demodulate_fm(SDRContext *sdr, Station *station, AVStream *st, AVPack
         return 0;
 
     memset(sdr->fm_block + len17_i, 0, (2*sdr->fm_block_size_p2 - len17_i) * sizeof(AVComplexFloat));
-    apply_deemphasis(sdr, sdr->fm_block, 2*sdr->fm_block_size_p2, sample_rate_p2, + 1);
+    apply_deemphasis(sdr, sdr->fm_block, sdr->fm_block_size_p2, sdr->fm_block_size_p2, sample_rate_p2, + 1);
     sdr->fm_ifft_p2(sdr->fm_ifft_p2_ctx, sdr->fm_iblock  , sdr->fm_block, sizeof(AVComplexFloat));
     memset(sdr->fm_iblock + 2*sdr->fm_block_size_p2, 0 ,(2*sdr->fm_block_size -2*sdr->fm_block_size_p2) * sizeof(AVComplexFloat));
 
-- 
2.31.1

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[FFmpeg-devel] [PATCH 14/14] avradio/sdrdemux: Print log_debug level message on metadata changes

[Michael Niedermayer]

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

diff --git a/libavradio/sdrdemux.c b/libavradio/sdrdemux.c
index b69b13d075..d40b92dd24 100644
--- a/libavradio/sdrdemux.c
+++ b/libavradio/sdrdemux.c
@@ -1716,6 +1716,7 @@ process_next_block:
                         if (t)
                             value = t->value;
                         if (strcmp(value, metadata_values[i])) {
+                            av_log(s, AV_LOG_DEBUG, "METADATA %s update %s -> %s\n", metadata_keys[i], value, metadata_values[i]);
                             av_dict_set(&st->metadata, metadata_keys[i], metadata_values[i], 0);
                             s->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED;
                         }
-- 
2.31.1

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Re: [FFmpeg-devel] [PATCH 01/14] avradio/rds: reset station timeout on successfull group decode

[Michael Niedermayer]

[-- Attachment #1.1: Type: text/plain, Size: 452 bytes --]

On Thu, Jul 13, 2023 at 01:36:53AM +0200, Michael Niedermayer wrote:
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavradio/rds.c | 3 +++
>  1 file changed, 3 insertions(+)

will apply

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

Dictatorship naturally arises out of democracy, and the most aggravated
form of tyranny and slavery out of the most extreme liberty. -- Plato

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

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

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