From 8abf7912f0cc520302437221265484c83bb857e5 Mon Sep 17 00:00:00 2001 From: "Steinar H. Gunderson" Date: Sat, 14 Mar 2015 14:49:01 +0100 Subject: [PATCH] Make the compressor filter frequency configurable, and up the default to a more aggressive 200 Hz. --- decode.cpp | 15 +++++++++++++-- level.cpp | 9 ++------- level.h | 2 +- 3 files changed, 16 insertions(+), 10 deletions(-) diff --git a/decode.cpp b/decode.cpp index 5d7669a..b90ad21 100644 --- a/decode.cpp +++ b/decode.cpp @@ -51,6 +51,11 @@ static bool output_leveled = false; static std::vector train_snap_points; static bool do_train = false; +// The frequency to filter on (for do_auto_level), in Hertz. +// Larger values makes the compressor react faster, but if it is too large, +// you'll ruin the waveforms themselves. +static float auto_level_freq = 200.0; + // The minimum estimated sound level (for do_auto_level) at any given point. // If you decrease this, you'll be able to amplify really silent signals // by more, but you'll also increase the level of silent (ie. noise-only) segments, @@ -169,6 +174,7 @@ void output_tap(const std::vector& pulses, double calibration_factor) static struct option long_options[] = { {"auto-level", 0, 0, 'a' }, + {"auto-level-freq", required_argument, 0, 'b' }, {"output-leveled", 0, 0, 'A' }, {"min-level", required_argument, 0, 'm' }, {"no-calibrate", 0, 0, 's' }, @@ -188,6 +194,7 @@ void help() fprintf(stderr, "decode [OPTIONS] AUDIO-FILE > TAP-FILE\n"); fprintf(stderr, "\n"); fprintf(stderr, " -a, --auto-level automatically adjust amplitude levels throughout the file\n"); + fprintf(stderr, " -b, --auto-level-freq minimum frequency in Hertz of corrected level changes (default 200 Hz)\n"); fprintf(stderr, " -A, --output-leveled output leveled waveform to leveled.raw\n"); fprintf(stderr, " -m, --min-level minimum estimated sound level (0..32768) for --auto-level\n"); fprintf(stderr, " -s, --no-calibrate do not try to calibrate on sync pulse length\n"); @@ -208,7 +215,7 @@ void parse_options(int argc, char **argv) { for ( ;; ) { int option_index = 0; - int c = getopt_long(argc, argv, "aAm:spl:f:r:Fc:t:qh", long_options, &option_index); + int c = getopt_long(argc, argv, "ab:Am:spl:f:r:Fc:t:qh", long_options, &option_index); if (c == -1) break; @@ -217,6 +224,10 @@ void parse_options(int argc, char **argv) do_auto_level = true; break; + case 'b': + auto_level_freq = atof(optarg); + break; + case 'A': output_leveled = true; break; @@ -558,7 +569,7 @@ int main(int argc, char **argv) } if (do_auto_level) { - pcm = level_samples(pcm, min_level, sample_rate); + pcm = level_samples(pcm, min_level, auto_level_freq, sample_rate); if (output_leveled) { FILE *fp = fopen("leveled.raw", "wb"); fwrite(pcm.data(), pcm.size() * sizeof(pcm[0]), 1, fp); diff --git a/level.cpp b/level.cpp index 46a494f..504cf0b 100644 --- a/level.cpp +++ b/level.cpp @@ -8,11 +8,6 @@ #include "filter.h" -// The frequency to filter on, in Hertz. Larger values makes the -// compressor react faster, but if it is too large, you'll -// ruin the waveforms themselves. -#define LPFILTER_FREQ 50.0 - // A final scalar to get the audio within approximately the right range. // Increase to _lower_ overall volume. #define DAMPENING_FACTOR 5.0 @@ -20,7 +15,7 @@ // 6dB/oct per round. #define FILTER_DEPTH 4 -std::vector level_samples(const std::vector &pcm, float min_level, int sample_rate) +std::vector level_samples(const std::vector &pcm, float min_level, float lpfilter_freq, int sample_rate) { // filter forwards, then backwards (perfect phase filtering) std::vector filtered_samples, refiltered_samples, leveled_samples; @@ -28,7 +23,7 @@ std::vector level_samples(const std::vector &pcm, float min_level, refiltered_samples.resize(pcm.size()); leveled_samples.resize(pcm.size()); - Filter filter = Filter::lpf(2.0 * M_PI * LPFILTER_FREQ / sample_rate); + Filter filter = Filter::lpf(2.0 * M_PI * lpfilter_freq / sample_rate); for (unsigned i = 0; i < pcm.size(); ++i) { filtered_samples[i] = filter.update(fabs(pcm[i])); } diff --git a/level.h b/level.h index 763e617..3a7f39d 100644 --- a/level.h +++ b/level.h @@ -3,6 +3,6 @@ #include -std::vector level_samples(const std::vector &pcm, float min_level, int sample_rate); +std::vector level_samples(const std::vector &pcm, float min_level, float lpfilter_freq, int sample_rate); #endif // !defined(_LEVEL_H) -- 2.39.2