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Commit 3b6afe04 authored by Stefan Westerfeld's avatar Stefan Westerfeld
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Optimize silence at beginning / silence at end during sync some more. 

Signed-off-by: Stefan Westerfeld's avatarStefan Westerfeld <stefan@space.twc.de>
parent 71b4c60d
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Inline Side-by-side
Showing with 56 additions and 36 deletions
src/wmget.cc
View file @ 3b6afe04
......@@ -259,7 +259,10 @@ private:
}
}
double
sync_decode (const WavData& wav_data, const size_t start_frame, const vector<float>& fft_out_db, ConvBlockType *block_type)
sync_decode (const WavData& wav_data, const size_t start_frame,
const vector<float>& fft_out_db,
const vector<char>& have_frame,
ConvBlockType *block_type)
{
double sync_quality = 0;
......@@ -273,9 +276,9 @@ private:
int frame_bit_count = 0;
for (const auto& frame_bit : frame_bits)
{
int index = ((start_frame + frame_bit.frame) * wav_data.n_channels()) * n_bands;
if (fft_out_db[index] > -90)
if (have_frame[start_frame + frame_bit.frame])
{
const int index = ((start_frame + frame_bit.frame) * wav_data.n_channels()) * n_bands;
for (size_t i = 0; i < frame_bit.up.size(); i++)
{
umag += fft_out_db[index + frame_bit.up[i]];
......@@ -319,6 +322,31 @@ private:
return sync_quality;
}
}
void
scan_silence (const WavData& wav_data)
{
const vector<float>& samples = wav_data.samples();
if (samples.size())
{
// find first non-zero sample
wav_data_start = 0;
while (wav_data_start < samples.size() && samples[wav_data_start] == 0)
wav_data_start++;
// find last non-zero sample
wav_data_end = samples.size() - 1;
while (wav_data_end > wav_data_start && samples[wav_data_end] == 0)
wav_data_end--;
}
else
{
wav_data_start = wav_data_end = 0;
}
}
size_t wav_data_start = 0;
size_t wav_data_end = 0;
public:
struct Score {
size_t index;
......@@ -344,8 +372,10 @@ public:
return result_scores;
}
init_up_down (wav_data, block_length);
scan_silence (wav_data);
vector<float> fft_db;
vector<char> have_frame;
// compute multiple time-shifted fft vectors
size_t n_bands = Params::max_band - Params::min_band + 1;
......@@ -355,14 +385,14 @@ public:
total_frame_count *= 2;
for (size_t sync_shift = 0; sync_shift < Params::frame_size; sync_shift += Params::sync_search_step)
{
sync_fft (wav_data, sync_shift, frame_count (wav_data) - 1, fft_db, /* want all frames */ {});
sync_fft (wav_data, sync_shift, frame_count (wav_data) - 1, fft_db, have_frame, /* want all frames */ {});
for (int start_frame = 0; start_frame < frame_count (wav_data); start_frame++)
{
const size_t sync_index = start_frame * Params::frame_size + sync_shift;
if ((start_frame + total_frame_count) * wav_data.n_channels() * n_bands < fft_db.size())
{
ConvBlockType block_type;
double quality = sync_decode (wav_data, start_frame, fft_db, &block_type);
double quality = sync_decode (wav_data, start_frame, fft_db, have_frame, &block_type);
// printf ("%zd %f\n", sync_index, quality);
sync_scores.emplace_back (Score { sync_index, quality, block_type });
}
......@@ -445,11 +475,11 @@ public:
int end = sync_scores[i].index + Params::sync_search_step;
for (int fine_index = start; fine_index <= end; fine_index += Params::sync_search_fine)
{
sync_fft (wav_data, fine_index, total_frame_count, fft_db, want_frames);
sync_fft (wav_data, fine_index, total_frame_count, fft_db, have_frame, want_frames);
if (fft_db.size())
{
ConvBlockType block_type;
double q = sync_decode (wav_data, 0, fft_db, &block_type);
double q = sync_decode (wav_data, 0, fft_db, have_frame, &block_type);
if (q > best_quality)
{
......@@ -468,9 +498,10 @@ public:
}
private:
void
sync_fft (const WavData& wav_data, size_t index, size_t frame_count, vector<float>& fft_out_db, const vector<int>& want_frames)
sync_fft (const WavData& wav_data, size_t index, size_t frame_count, vector<float>& fft_out_db, vector<char>& have_frame, const vector<int>& want_frames)
{
fft_out_db.clear();
have_frame.clear();
/* read past end? -> fail */
if (wav_data.n_values() < (index + frame_count * Params::frame_size) * wav_data.n_channels())
......@@ -482,42 +513,31 @@ private:
int out_pos = 0;
fft_out_db.resize (wav_data.n_channels() * n_bands * frame_count);
have_frame.resize (frame_count);
for (size_t f = 0; f < frame_count; f++)
{
const double min_db = -96;
if (want_frames.size() && !want_frames[f])
const size_t f_start = (index + f * Params::frame_size) * wav_data.n_channels();
const size_t f_end = (index + (f + 1) * Params::frame_size) * wav_data.n_channels();
if ((want_frames.size() && !want_frames[f]) // frame not wanted?
|| (f_end < wav_data_start) // frame in silence before input?
|| (f_start > wav_data_end)) // frame in silence after input?
{
for (int ch = 0; ch < wav_data.n_channels(); ch++)
for (int i = Params::min_band; i <= Params::max_band; i++)
fft_out_db[out_pos++] = min_db;
out_pos += n_bands * wav_data.n_channels();
}
else
{
bool zframe = true;
for (size_t i = 0; i < Params::frame_size * wav_data.n_channels(); i++)
{
if (samples[i + (index + f * Params::frame_size) * wav_data.n_channels()] != 0)
{
zframe = false;
break;
}
}
if (zframe)
{
for (int ch = 0; ch < wav_data.n_channels(); ch++)
for (int i = Params::min_band; i <= Params::max_band; i++)
fft_out_db[out_pos++] = min_db;
}
else
{
vector<vector<complex<float>>> frame_result = fft_analyzer.run_fft (samples, index + f * Params::frame_size);
constexpr double min_db = -96;
/* computing db-magnitude is expensive, so we better do it here */
for (int ch = 0; ch < wav_data.n_channels(); ch++)
for (int i = Params::min_band; i <= Params::max_band; i++)
fft_out_db[out_pos++] = db_from_factor (abs (frame_result[ch][i]), min_db);
}
vector<vector<complex<float>>> frame_result = fft_analyzer.run_fft (samples, index + f * Params::frame_size);
/* computing db-magnitude is expensive, so we better do it here */
for (int ch = 0; ch < wav_data.n_channels(); ch++)
for (int i = Params::min_band; i <= Params::max_band; i++)
fft_out_db[out_pos++] = db_from_factor (abs (frame_result[ch][i]), min_db);
have_frame[f] = 1;
}
}
}
......
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