@@ -68,6 +68,12 @@ typedef enum Modulation {
//QAM, PSK, ...
} Modulation;
+typedef enum SDR_GAIN {
+ GAIN_DEFAULT = -3,
+ GAIN_SW_AGC = -2,
+ GAIN_SDR_AGC = -1,
+} SDR_GAIN;
+
#define HISTOGRAMM_SIZE 9
typedef struct Station {
@@ -105,6 +111,7 @@ typedef struct Station {
typedef struct FIFOElement {
int64_t center_frequency;
+ float gain;
void *halfblock;
} FIFOElement;
@@ -146,7 +153,15 @@ typedef struct SDRContext {
int64_t min_center_freq;
int64_t max_center_freq;
int sdr_sample_rate;
- int sdr_agc;
+ float min_gain;
+ float max_gain;
+ int sdr_gain;
+ float agc_min_headroom;
+ float agc_max_headroom;
+ float agc_max_headroom_time;
+ int agc_low_time;
+ float agc_gain; ///< current gain, should be accessed only by buffer thread after init
+ atomic_int wanted_gain;
int sdr_adcc;
int64_t bandwidth;
int64_t last_pts;
@@ -212,6 +227,12 @@ typedef struct SDRContext {
*/
int64_t (*set_frequency_callback)(struct SDRContext *sdr, int64_t frequency);
+ /**
+ * Setup the hardware for the requested gain
+ * This must only be called from the buffer thread after setup (or more mutex calls are needed)
+ */
+ int (*set_gain_callback)(struct SDRContext *sdr, float gain);
+
/**
* Read from the hardware, block if nothing available with a reasonable timeout
*
@@ -1409,6 +1409,7 @@ static void *soapy_needs_bigger_buffers_worker(SDRContext *sdr)
FIFOElement fifo_element;
int remaining, ret;
int empty_blocks, full_blocks;
+ float wanted_gain = atomic_load(&sdr->wanted_gain) / 65536.0;
//i wish av_fifo was thread safe
pthread_mutex_lock(&sdr->mutex);
@@ -1444,9 +1445,17 @@ static void *soapy_needs_bigger_buffers_worker(SDRContext *sdr)
//And theres not much else we can do, an error message was already printed by ff_sdr_set_freq() in that case
block_counter = 0; // we just changed the frequency, do not trust the next blocks content
}
+ if (sdr->sdr_gain == GAIN_SW_AGC &&
+ fabs(wanted_gain - sdr->agc_gain) > 0.001 &&
+ sdr->set_gain_callback
+ ) {
+ sdr->set_gain_callback(sdr, wanted_gain);
+ sdr->agc_gain = wanted_gain;
+ }
pthread_mutex_unlock(&sdr->mutex);
fifo_element.center_frequency = block_counter > 0 ? sdr->freq : 0;
+ fifo_element.gain = sdr->agc_gain; //we make only small changes so slightly mixing should be ok
remaining = sdr->block_size;
while (remaining && !atomic_load(&sdr->close_requested)) {
@@ -1624,6 +1633,7 @@ int ff_sdr_common_init(AVFormatContext *s)
av_fifo_auto_grow_limit(sdr-> full_block_fifo, sdr->sdr_sample_rate / sdr->block_size);
atomic_init(&sdr->close_requested, 0);
+ atomic_init(&sdr->wanted_gain, lrint((sdr->min_gain + sdr->max_gain) * 65536 / 2));
ret = pthread_mutex_init(&sdr->mutex, NULL);
if (ret) {
av_log(s, AV_LOG_ERROR, "pthread_mutex_init failed: %s\n", strerror(ret));
@@ -1886,6 +1896,37 @@ process_next_block:
}
}
+ float smaller_block_gain = FFMIN(fifo_element[0].gain, fifo_element[1].gain);
+ float bigger_block_gain = FFMAX(fifo_element[0].gain, fifo_element[1].gain);
+
+ if (sdr->sdr_gain == GAIN_SW_AGC) {
+ float inmax = 0;
+ float wanted_gain = atomic_load(&sdr->wanted_gain) / 65536.0;
+ // We only check 25% of the data to safe computations
+ int start = 3*sdr->block_size / 4;
+ int end = 5*sdr->block_size / 4;
+ for (i = start; i < end; i++) {
+ float v = fmaxf(fabsf(sdr->windowed_block[i].re), fabsf(sdr->windowed_block[i].im));
+ inmax = fmaxf(inmax, v);
+ }
+
+ if (inmax > 1.0 - sdr->agc_min_headroom && wanted_gain > sdr->min_gain) {
+ //according to docs this is a dB scale, in reality it beheaves differnt to that
+ //Because of this we will try to just make small changes and not assume too much
+ wanted_gain = FFMIN(wanted_gain, FFMAX(smaller_block_gain - 1.0, smaller_block_gain * 0.9));
+
+ sdr->agc_low_time = 0;
+ } else if (inmax < 1.0 - sdr->agc_max_headroom && wanted_gain < sdr->max_gain) {
+ sdr->agc_low_time += sdr->block_size;
+ if (sdr->agc_low_time > sdr->agc_max_headroom_time * sdr->sdr_sample_rate) {
+ sdr->agc_low_time = 0;
+ wanted_gain = FFMAX(wanted_gain, FFMIN(bigger_block_gain + 1.0, bigger_block_gain * 1.1));
+ }
+ } else
+ sdr->agc_low_time = 0;
+ atomic_store(&sdr->wanted_gain, (int)lrint(wanted_gain * 65536));
+ }
+
inject_block_into_fifo(sdr, sdr->empty_block_fifo, &fifo_element[0], "Cannot pass next buffer, freeing it\n");
#ifdef SYN_TEST //synthetic test signal
static int64_t synp=0;
@@ -2141,7 +2182,17 @@ const AVOption ff_sdr_options[] = {
{ "rtlsdr_fixes" , "workaround rtlsdr issues", OFFSET(rtlsdr_fixes), AV_OPT_TYPE_INT , {.i64 = -1}, -1, 1, DEC},
{ "sdr_sr" , "sdr sample rate" , OFFSET(sdr_sample_rate ), AV_OPT_TYPE_INT , {.i64 = 0}, 0, INT_MAX, DEC},
{ "sdr_freq", "sdr frequency" , OFFSET(wanted_freq), AV_OPT_TYPE_INT64 , {.i64 = 9000000}, 0, INT64_MAX, DEC},
- { "sdr_agc" , "sdr automatic gain control", OFFSET(sdr_agc), AV_OPT_TYPE_BOOL , {.i64 = 1}, -1, 1, DEC},
+ { "gain" , "sdr overall gain", OFFSET(sdr_gain), AV_OPT_TYPE_INT , {.i64 = GAIN_SDR_AGC}, -3, INT_MAX, DEC, "gain"},
+ { "sdr_agc", "SDR AGC (if supported)", 0, AV_OPT_TYPE_CONST, {.i64 = GAIN_SDR_AGC}, 0, 0, DEC, "gain"},
+ { "sw_agc", "Software AGC", 0, AV_OPT_TYPE_CONST, {.i64 = GAIN_SW_AGC}, 0, 0, DEC, "gain"},
+ { "default_gain", "Never touch gain", 0, AV_OPT_TYPE_CONST, {.i64 = GAIN_DEFAULT}, 0, 0, DEC, "gain"},
+
+ { "agc_min_headroom", "AGC min headroom", OFFSET(agc_min_headroom), AV_OPT_TYPE_FLOAT, {.dbl = 0.4}, 0, 1.0, DEC},
+ { "agc_max_headroom", "AGC max headroom", OFFSET(agc_max_headroom), AV_OPT_TYPE_FLOAT, {.dbl = 0.8}, 0, 1.0, DEC},
+ { "agc_max_headroom_time", "AGC max headroom time", OFFSET(agc_max_headroom_time), AV_OPT_TYPE_FLOAT, {.dbl = 0.1}, 0, INT_MAX, DEC},
+ { "min_gain", "minimum gain", OFFSET(min_gain ), AV_OPT_TYPE_FLOAT , {.dbl = 0}, 0, INT_MAX, DEC},
+ { "max_gain", "maximum gain", OFFSET(max_gain ), AV_OPT_TYPE_FLOAT , {.dbl = 0}, 0, INT_MAX, DEC},
+
{ "sdr_adcc" ,"sdr automatic dc correction", OFFSET(sdr_adcc), AV_OPT_TYPE_BOOL , {.i64 = -1}, -1, 1, DEC},
{ "min_freq", "minimum frequency", OFFSET(min_freq ), AV_OPT_TYPE_INT64 , {.i64 = 0}, 0, INT64_MAX, DEC},
{ "max_freq", "maximum frequency", OFFSET(max_freq ), AV_OPT_TYPE_INT64 , {.i64 = 0}, 0, INT64_MAX, DEC},
@@ -68,6 +68,30 @@ static int sdrindev_read_callback(SDRContext *sdr, FIFOElement *fifo_element, in
return ret;
}
+static int sdrindev_set_gain_callback(SDRContext *sdr, float gain)
+{
+ AVFormatContext *avfmt = sdr->avfmt;
+ SoapySDRDevice *soapy = sdr->soapy;
+
+ if (sdr->sdr_gain == GAIN_DEFAULT)
+ return 0;
+
+ if (soapy) {
+ int ret = SoapySDRDevice_setGainMode(soapy, SOAPY_SDR_RX, 0, sdr->sdr_gain == GAIN_SDR_AGC);
+ if (ret) {
+ av_log(avfmt, AV_LOG_WARNING, "Failed to set gain mode %d (%s)\n", sdr->sdr_gain == GAIN_SDR_AGC, SoapySDRDevice_lastError());
+ }
+
+ if (sdr->sdr_gain != GAIN_SDR_AGC) {
+ ret = SoapySDRDevice_setGain(soapy, SOAPY_SDR_RX, 0, gain);
+ if (ret) {
+ av_log(avfmt, AV_LOG_WARNING, "Failed to set gain to %f (%s)\n", gain, SoapySDRDevice_lastError());
+ }
+ }
+ }
+ return 0;
+}
+
static int64_t sdrindev_set_frequency_callback(SDRContext *sdr, int64_t freq)
{
AVFormatContext *avfmt = sdr->avfmt;
@@ -135,6 +159,7 @@ static int sdrindev_initial_hw_setup(AVFormatContext *s)
sdr->read_callback = sdrindev_read_callback;
sdr->set_frequency_callback = sdrindev_set_frequency_callback;
+ sdr->set_gain_callback = sdrindev_set_gain_callback;
// Go over all available soapy devices
// Print the usable ones, and choose one unless the user has choosen one
@@ -195,8 +220,10 @@ static int sdrindev_initial_hw_setup(AVFormatContext *s)
//Inform the user if AGC is supported and setup AGC as requested by the user
has_agc = SoapySDRDevice_hasGainMode(soapy, SOAPY_SDR_RX, 0);
av_log(s, AV_LOG_INFO, "RX AGC Supported: %s\n", has_agc ? "yes" : "no");
- if (has_agc && sdr->sdr_agc >= 0)
- SoapySDRDevice_setGainMode(soapy, SOAPY_SDR_RX, 0, sdr->sdr_agc);
+ if (!has_agc && sdr->sdr_gain == GAIN_SDR_AGC) {
+ av_log(s, AV_LOG_WARNING, "hardware AGC unsupported switching to software AGC\n");
+ sdr->sdr_gain = GAIN_SW_AGC;
+ }
//Inform the user if automatic DC correction is supported and setup DC correction as requested by the user
has_adcc = SoapySDRDevice_hasDCOffsetMode(soapy, SOAPY_SDR_RX, 0);
@@ -208,6 +235,16 @@ static int sdrindev_initial_hw_setup(AVFormatContext *s)
range = SoapySDRDevice_getGainRange(soapy, SOAPY_SDR_RX, 0);
av_log(s, AV_LOG_INFO, "Rx Gain range: %f dB - %f dB\n", range.minimum, range.maximum);
+ if (!sdr->min_gain)
+ sdr->min_gain = range.minimum;
+
+ if (!sdr->max_gain)
+ sdr->max_gain = range.maximum;
+ if (sdr->min_gain > sdr->max_gain) {
+ av_log(s, AV_LOG_ERROR, "Invalid gain range\n");
+ return AVERROR(EINVAL);
+ }
+
//Inform the user about the Frequency ranges available, verify the range requested by the user and set the range if the user has not specified one
ranges = SoapySDRDevice_getFrequencyRange(soapy, SOAPY_SDR_RX, 0, &length);
av_log(s, AV_LOG_INFO, "Rx freq ranges: ");
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> --- libavradio/sdr.h | 23 +++++++++++++++++- libavradio/sdrdemux.c | 53 ++++++++++++++++++++++++++++++++++++++++- libavradio/sdrinradio.c | 41 +++++++++++++++++++++++++++++-- 3 files changed, 113 insertions(+), 4 deletions(-)