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audiowmark
Commit b51a100f authored by Stefan Westerfeld's avatar Stefan Westerfeld
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Share fft analysis code between both watermark get implementations. 

Signed-off-by: Stefan Westerfeld's avatarStefan Westerfeld <stefan@space.twc.de>
parent c16d6dc0
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Showing with 35 additions and 57 deletions
src/audiowmark.cc
View file @ b51a100f
......@@ -608,35 +608,35 @@ get_watermark (const string& infile, const string& orig_pattern)
WavData wav_data (in_signal, in_wav_data.n_channels(), in_wav_data.mix_freq(), in_wav_data.bit_depth());
if (Params::mix)
vector<vector<complex<float>>> fft_out;
for (int f = 0; f < frame_count (wav_data); f++)
{
vector<vector<complex<float>>> fft_out;
for (int f = 0; f < frame_count (wav_data); f++)
for (int ch = 0; ch < wav_data.n_channels(); ch++)
{
for (int ch = 0; ch < wav_data.n_channels(); ch++)
{
vector<float> frame = get_frame (wav_data, f, ch);
vector<float> frame = get_frame (wav_data, f, ch);
/* windowing */
double window_weight = 0;
for (size_t i = 0; i < frame.size(); i++)
{
const double fsize_2 = frame.size() / 2.0;
// const double win = window_cos ((i - fsize_2) / fsize_2);
const double win = window_hamming ((i - fsize_2) / fsize_2);
//const double win = 1;
frame[i] *= win;
window_weight += win;
}
/* windowing */
double window_weight = 0;
for (size_t i = 0; i < frame.size(); i++)
{
const double fsize_2 = frame.size() / 2.0;
// const double win = window_cos ((i - fsize_2) / fsize_2);
const double win = window_hamming ((i - fsize_2) / fsize_2);
//const double win = 1;
frame[i] *= win;
window_weight += win;
}
/* to get normalized fft output corrected by window weight */
for (size_t i = 0; i < frame.size(); i++)
frame[i] *= 2.0 / window_weight;
/* to get normalized fft output corrected by window weight */
for (size_t i = 0; i < frame.size(); i++)
frame[i] *= 2.0 / window_weight;
/* FFT transform */
fft_out.push_back (fft (frame));
}
/* FFT transform */
fft_out.push_back (fft (frame));
}
}
if (Params::mix)
{
for (int block = 0; block < frame_count (wav_data) / (Params::block * Params::frames_per_bit); block++)
{
struct MixEntry {
......@@ -694,41 +694,19 @@ get_watermark (const string& infile, const string& orig_pattern)
{
for (int ch = 0; ch < wav_data.n_channels(); ch++)
{
vector<float> frame = get_frame (wav_data, f, ch);
if (frame.size() == Params::frame_size)
{
/* windowing */
double window_weight = 0;
for (size_t i = 0; i < frame.size(); i++)
{
const double fsize_2 = frame.size() / 2.0;
// const double win = window_cos ((i - fsize_2) / fsize_2);
const double win = window_hamming ((i - fsize_2) / fsize_2);
//const double win = 1;
frame[i] *= win;
window_weight += win;
}
/* to get normalized fft output corrected by window weight */
for (size_t i = 0; i < frame.size(); i++)
frame[i] *= 2.0 / window_weight;
/* FFT transform */
vector<complex<float>> fft_out = fft (frame);
vector<int> up;
vector<int> down;
get_up_down (f, up, down);
const int index = f * wav_data.n_channels() + ch;
vector<int> up;
vector<int> down;
get_up_down (f, up, down);
const double min_db = -96;
for (auto u : up)
{
umag += db_from_factor (abs (fft_out[u]), min_db);
}
for (auto d : down)
{
dmag += db_from_factor (abs (fft_out[d]), min_db);
}
const double min_db = -96;
for (auto u : up)
{
umag += db_from_factor (abs (fft_out[index][u]), min_db);
}
for (auto d : down)
{
dmag += db_from_factor (abs (fft_out[index][d]), min_db);
}
}
if ((f % Params::frames_per_bit) == (Params::frames_per_bit - 1))
......
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