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audiowmark
Commit 8beb2bac authored by Stefan Westerfeld's avatar Stefan Westerfeld
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Use new marking for data bits. 

Signed-off-by: Stefan Westerfeld's avatarStefan Westerfeld <stefan@space.twc.de>
parent 937ec60b
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Showing with 63 additions and 56 deletions
src/audiowmark.cc
View file @ 8beb2bac
......@@ -470,6 +470,51 @@ gen_mix_entries()
return mix_entries;
}
enum class FrameDelta : uint8_t {
KEEP = 0,
UP,
DOWN
};
void
prepare_frame_delta (int f, vector<FrameDelta>& frame_delta, int data_bit, Random::Stream random_stream)
{
vector<int> up;
vector<int> down;
get_up_down (f, up, down, random_stream);
for (auto u : up)
frame_delta[u] = data_bit ? FrameDelta::UP : FrameDelta::DOWN;
for (auto d : down)
frame_delta[d] = data_bit ? FrameDelta::DOWN : FrameDelta::UP;
}
void
apply_frame_delta (const vector<FrameDelta>& frame_delta, const vector<complex<float>>& fft_out, vector<complex<float>>& fft_delta_spect)
{
const float min_mag = 1e-7; // avoid computing pow (0.0, -water_delta) which would be inf
for (size_t i = 0; i < frame_delta.size(); i++)
{
if (frame_delta[i] == FrameDelta::KEEP)
continue;
int data_bit_sign = (frame_delta[i] == FrameDelta::UP) ? 1 : -1;
/*
* for up bands, we want do use [for a 1 bit] (pow (mag, 1 - water_delta))
*
* this actually increases the amount of energy because mag is less than 1.0
*/
const float mag = abs (fft_out[i]);
if (mag > min_mag)
{
const float mag_factor = pow (mag, -Params::water_delta * data_bit_sign);
fft_delta_spect[i] = fft_out[i] * (mag_factor - 1);
}
}
}
void
mark_data (const WavData& wav_data, int start_frame, const vector<vector<complex<float>>>& fft_out, vector<vector<complex<float>>>& fft_delta_spect,
const vector<int>& bitvec)
......@@ -535,15 +580,19 @@ mark_data (const WavData& wav_data, int start_frame, const vector<vector<complex
}
void
mark_data_stream (int frame_number, const vector<vector<complex<float>>>& frame_fft, vector<vector<complex<float>>>& fft_delta_spect,
const vector<int>& bitvec)
mark_data_stream (vector<vector<FrameDelta>>& frame_mod, const vector<int>& bitvec)
{
assert (bitvec.size() == mark_data_frame_count() / Params::frames_per_bit);
assert (frame_mod.size() >= mark_data_frame_count());
int n_channels = frame_fft.size();
for (int ch = 0; ch < n_channels; ch++)
const int frame_count = mark_data_frame_count();
// sync block always written in linear order (no mix)
for (int f = 0; f < frame_count; f++)
{
mark_bit_linear (frame_number, frame_fft[ch], fft_delta_spect[ch], bitvec[frame_number / Params::frames_per_bit], Random::Stream::data_up_down);
size_t index = mark_sync_frame_count() + f; // data_frame_pos (f); FIXME enable bit reordering
prepare_frame_delta (f, frame_mod[index], bitvec[f / Params::frames_per_bit], Random::Stream::data_up_down); // FIXME: rename
}
}
......@@ -573,51 +622,6 @@ mark_sync (const WavData& wav_data, int start_frame, const vector<vector<complex
}
}
enum class FrameDelta : uint8_t {
KEEP = 0,
UP,
DOWN
};
void
prepare_frame_delta (int f, vector<FrameDelta>& frame_delta, int data_bit, Random::Stream random_stream)
{
vector<int> up;
vector<int> down;
get_up_down (f, up, down, random_stream);
for (auto u : up)
frame_delta[u] = data_bit ? FrameDelta::UP : FrameDelta::DOWN;
for (auto d : down)
frame_delta[d] = data_bit ? FrameDelta::DOWN : FrameDelta::UP;
}
void
apply_frame_delta (const vector<FrameDelta>& frame_delta, const vector<complex<float>>& fft_out, vector<complex<float>>& fft_delta_spect)
{
const float min_mag = 1e-7; // avoid computing pow (0.0, -water_delta) which would be inf
for (size_t i = 0; i < frame_delta.size(); i++)
{
if (frame_delta[i] == FrameDelta::KEEP)
continue;
int data_bit_sign = (frame_delta[i] == FrameDelta::UP) ? 1 : -1;
/*
* for up bands, we want do use [for a 1 bit] (pow (mag, 1 - water_delta))
*
* this actually increases the amount of energy because mag is less than 1.0
*/
const float mag = abs (fft_out[i]);
if (mag > min_mag)
{
const float mag_factor = pow (mag, -Params::water_delta * data_bit_sign);
fft_delta_spect[i] = fft_out[i] * (mag_factor - 1);
}
}
}
void
mark_sync_stream (vector<vector<FrameDelta>>& frame_mod, int ab)
{
......@@ -786,8 +790,8 @@ add_watermark (const string& infile, const string& outfile, const string& bits)
int frame_number = 0;
int ab = 0;
vector<float> samples;
vector<vector<FrameDelta>> frame_mod_vec_a (mark_sync_frame_count());
vector<vector<FrameDelta>> frame_mod_vec_b (mark_sync_frame_count());
vector<vector<FrameDelta>> frame_mod_vec_a (mark_sync_frame_count() + mark_data_frame_count());
vector<vector<FrameDelta>> frame_mod_vec_b (mark_sync_frame_count() + mark_data_frame_count());
for (size_t i = 0; i < frame_mod_vec_a.size(); i++)
{
frame_mod_vec_a[i].resize (Params::max_band + 1);
......@@ -796,6 +800,8 @@ add_watermark (const string& infile, const string& outfile, const string& bits)
mark_sync_stream (frame_mod_vec_a, 0);
mark_sync_stream (frame_mod_vec_b, 1);
mark_data_stream (frame_mod_vec_a, bitvec_a);
mark_data_stream (frame_mod_vec_b, bitvec_b);
while (true)
{
samples = in_stream->read_frames (Params::frame_size);
......@@ -814,13 +820,14 @@ add_watermark (const string& infile, const string& outfile, const string& bits)
fft_delta_spect.push_back (vector<complex<float>> (fft_out.back().size()));
}
if (state == State::SYNC)
if (state == State::SYNC || state == State::DATA)
{
int vfn = frame_number;
if (state == State::DATA)
vfn += mark_sync_frame_count();
for (int ch = 0; ch < in_stream->n_channels(); ch++)
apply_frame_delta (ab ? frame_mod_vec_b[frame_number] : frame_mod_vec_a[frame_number], fft_out[ch], fft_delta_spect[ch]);
apply_frame_delta (ab ? frame_mod_vec_b[vfn] : frame_mod_vec_a[vfn], fft_out[ch], fft_delta_spect[ch]);
}
if (state == State::DATA)
mark_data_stream (frame_number, fft_out, fft_delta_spect, ab ? bitvec_b : bitvec_a);
for (int ch = 0; ch < wav_data.n_channels(); ch++)
{
......
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