// A fake capture device that sends single-color frames at a given rate.
// Mostly useful for testing themes without actually hooking up capture devices.
-#include "fake_capture.h"
+#include "bmusb/fake_capture.h"
#include <assert.h>
#include <stdint.h>
#endif
#include <cstddef>
-#include "bmusb.h"
+#include "bmusb/bmusb.h"
#define FRAME_SIZE (8 << 20) // 8 MB.
namespace {
// We don't bother with multiversioning for this, because SSE2
-// is on my default for all 64-bit compiles, which is really
+// is on by default for all 64-bit compiles, which is really
// the target user segment here.
void memset2(uint8_t *s, const uint8_t c[2], size_t n)
} // namespace
-FakeCapture::FakeCapture(unsigned width, unsigned height, unsigned fps, unsigned audio_frequency, int card_index)
- : width(width), height(height), fps(fps), audio_frequency(audio_frequency)
+FakeCapture::FakeCapture(unsigned width, unsigned height, unsigned fps, unsigned audio_sample_frequency, int card_index, bool has_audio)
+ : width(width), height(height), fps(fps), audio_sample_frequency(audio_sample_frequency)
{
char buf[256];
snprintf(buf, sizeof(buf), "Fake card %d", card_index + 1);
y = ys[card_index % NUM_COLORS];
cb = cbs[card_index % NUM_COLORS];
cr = crs[card_index % NUM_COLORS];
+
+ if (has_audio) {
+ audio_ref_level = pow(10.0f, -23.0f / 20.0f) * (1u << 31); // -23 dBFS (EBU R128 level).
+
+ float freq = 440.0 * pow(2.0, card_index / 12.0);
+ sincosf(2 * M_PI * freq / audio_sample_frequency, &audio_sin, &audio_cos);
+ audio_real = audio_ref_level;
+ audio_imag = 0.0f;
+ }
}
FakeCapture::~FakeCapture()
FrameAllocator::Frame audio_frame = audio_frame_allocator->alloc_frame();
if (audio_frame.data != nullptr) {
- assert(audio_frame.size >= 2 * sizeof(uint32_t) * audio_frequency / fps);
- audio_frame.len = 2 * sizeof(uint32_t) * audio_frequency / fps;
- memset(audio_frame.data, 0, audio_frame.len);
+ const unsigned num_stereo_samples = audio_sample_frequency / fps;
+ assert(audio_frame.size >= 2 * sizeof(int32_t) * num_stereo_samples);
+ audio_frame.len = 2 * sizeof(int32_t) * num_stereo_samples;
+
+ if (audio_sin == 0.0f) {
+ // Silence.
+ memset(audio_frame.data, 0, audio_frame.len);
+ } else {
+ make_tone((int32_t *)audio_frame.data, num_stereo_samples);
+ }
}
frame_callback(timecode++,
}
}
+void FakeCapture::make_tone(int32_t *out, unsigned num_stereo_samples)
+{
+ int32_t *ptr = out;
+ float r = audio_real, i = audio_imag;
+ for (unsigned sample_num = 0; sample_num < num_stereo_samples; ++sample_num) {
+ int32_t s = lrintf(r);
+ *ptr++ = s;
+ *ptr++ = s;
+
+ // Rotate the phaser by one sample.
+ float new_r = r * audio_cos - i * audio_sin;
+ float new_i = r * audio_sin + i * audio_cos;
+ r = new_r;
+ i = new_i;
+ }
+
+ // Periodically renormalize to counteract precision issues.
+ double corr = audio_ref_level / hypot(r, i);
+ audio_real = r * corr;
+ audio_imag = i * corr;
+}
+
} // namespace bmusb