Implement sound buffer texture

Texture channel 0 has a 512x2 texture with audio samples. For now,
fill it with dummy data (ascending slope), so we can see some
output.

Signed-off-by: David Oberhollenzer <goliath@infraroot.at>
This commit is contained in:
David Oberhollenzer 2022-07-19 21:36:49 +02:00
parent 542669ef04
commit 8c47f2726c
4 changed files with 96 additions and 3 deletions

View File

@ -31,6 +31,7 @@ static const char *frag_src_pre =
"uniform vec4 iDate;\n"
"uniform float iSampleRate;\n"
"uniform vec3 iChannelResolution[4];\n"
"uniform sampler2D iChannel0;"
"\n";
static const char *frag_src_post =

View File

@ -20,6 +20,9 @@ static GLfloat vertex_buffer[] = {
1.0f, 1.0f, 1.0f,
};
static GLubyte audio_buffer[AUDIO_SAMPLES * AUDIO_CHANNELS];
static float audio_sample_data[AUDIO_SAMPLES];
static double diff_timespec(const struct timespec *time1,
const struct timespec *time0)
{
@ -72,10 +75,11 @@ static const struct option long_opts[] = {
{ "height", required_argument, NULL, 'h' },
{ "shader", required_argument, NULL, 's' },
{ "to-stdout", no_argument, NULL, 'S' },
{ "stdin-audio", no_argument, NULL, 'a' },
{ NULL, 0, NULL, 0 },
};
static const char *short_opts = "w:h:s:S";
static const char *short_opts = "w:h:s:Sa";
static const char *usage_str =
"shadermeh OPTIONS...\n"
@ -85,21 +89,23 @@ static const char *usage_str =
" --width, -w <pixels>\n"
" --height, -h <pixels>\n"
"\n"
" --to-stdout, -S\n"
" --to-stdout, -S Poop raw RGB24 frames to stdout (blocking)\n"
" --stdin-audio, -a Read raw PCM audio from stdin (non-blocking)\n"
"\n"
" --shader, -s <shader file>\n"
"\n";
int main(int argc, char **argv)
{
GLuint vao, vbo, fbo, fbo_tex, sound_tex, sampler_sound;
GLuint u_iResolution, u_iTime, u_iTimeDelta, u_iFrame;
struct timespec start, frame_start, frame_end;
unsigned int width, height, iFrame = 0;
void *fb32 = NULL, *fb24 = NULL;
const char *shader_file = NULL;
GLuint vao, vbo, fbo, fbo_tex;
GLint major, minor, prog;
float iTime, iTimeDelta;
bool have_audio = false;
bool to_stdout = false;
window *wnd;
int i;
@ -126,6 +132,9 @@ int main(int argc, char **argv)
case 'S':
to_stdout = true;
break;
case 'a':
have_audio = true;
break;
default:
fputs(usage_str, stderr);
return EXIT_FAILURE;
@ -222,6 +231,22 @@ int main(int argc, char **argv)
glUniform3f(u_iResolution, width, height, 0.0f);
glUniform1i(glGetUniformLocation(prog, "iChannel0"), 0);
/************************* textures *************************/
glGenTextures(1, &sound_tex);
glBindTexture(GL_TEXTURE_2D, sound_tex);
glTexImage2D(GL_TEXTURE_2D, 0, GL_R8,
AUDIO_SAMPLES, AUDIO_CHANNELS, 0,
GL_RED, GL_UNSIGNED_BYTE, audio_buffer);
glBindTexture(GL_TEXTURE_2D, 0);
glGenSamplers(1, &sampler_sound);
glSamplerParameteri(sampler_sound, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glSamplerParameteri(sampler_sound, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glBindSampler(0, sampler_sound);
/******************** framebuffer object ********************/
if (to_stdout) {
glGenFramebuffers(1, &fbo);
@ -242,6 +267,10 @@ int main(int argc, char **argv)
}
/******************** drawing loop ********************/
for (i = 0; i < AUDIO_SAMPLES; ++i) {
audio_sample_data[i] = (float)i / (float)AUDIO_SAMPLES;
}
clock_gettime(CLOCK_MONOTONIC_RAW, &start);
while (to_stdout || window_handle_events()) {
@ -252,7 +281,24 @@ int main(int argc, char **argv)
glBindFramebuffer(GL_FRAMEBUFFER, fbo);
glClear(GL_COLOR_BUFFER_BIT);
if (have_audio) {
glBindTexture(GL_TEXTURE_2D, sound_tex);
for (i = 0; i < AUDIO_SAMPLES; ++i) {
audio_buffer[i] = 255.0f * audio_sample_data[i];
audio_buffer[AUDIO_SAMPLES + i] =
audio_buffer[i];
}
glTexImage2D(GL_TEXTURE_2D, 0, GL_R8,
AUDIO_SAMPLES, AUDIO_CHANNELS, 0,
GL_RED, GL_UNSIGNED_BYTE, audio_buffer);
}
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
glBindTexture(GL_TEXTURE_2D, 0);
if (to_stdout) {
glFlush();
@ -291,6 +337,9 @@ int main(int argc, char **argv)
}
/******************** cleanup ********************/
glDeleteTextures(1, &sound_tex);
glDeleteSamplers(1, &sampler_sound);
if (to_stdout) {
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glDeleteFramebuffers(1, &fbo);

View File

@ -25,6 +25,9 @@
#include <errno.h>
#include <time.h>
#define AUDIO_SAMPLES (512)
#define AUDIO_CHANNELS (2)
typedef struct {
Window wnd;
GLXContext gl;

40
shaders/osci.frag Normal file
View File

@ -0,0 +1,40 @@
// Created by inigo quilez - iq/2013
// https://www.youtube.com/c/InigoQuilez
// https://iquilezles.org/
// See also:
//
// Input - Keyboard : https://www.shadertoy.com/view/lsXGzf
// Input - Microphone : https://www.shadertoy.com/view/llSGDh
// Input - Mouse : https://www.shadertoy.com/view/Mss3zH
// Input - Sound : https://www.shadertoy.com/view/Xds3Rr
// Input - SoundCloud : https://www.shadertoy.com/view/MsdGzn
// Input - Time : https://www.shadertoy.com/view/lsXGz8
// Input - TimeDelta : https://www.shadertoy.com/view/lsKGWV
// Inout - 3D Texture : https://www.shadertoy.com/view/4llcR4
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
// create pixel coordinates
vec2 uv = fragCoord.xy / iResolution.xy;
// the sound texture is 512x2
int tx = int(uv.x * 512.0);
// first row is frequency data (48Khz/4 in 512 texels, meaning 23 Hz per texel)
float fft = texelFetch( iChannel0, ivec2(tx,0), 0 ).x;
// second row is the sound wave, one texel is one mono sample
float wave = texelFetch( iChannel0, ivec2(tx,1), 0 ).x;
// convert frequency to colors
vec3 col = vec3( fft, 4.0*fft*(1.0-fft), 1.0-fft ) * fft;
// add wave form on top
col += 1.0 - smoothstep(0.0, 0.15, abs(wave - uv.y));
// output final color
fragColor = vec4(col,1.0);
}