add alsa output to STCode

src/stereo_coder.c

@@ -1,6 +1,4 @@
 #include <stdio.h>
-#include <pulse/simple.h>
-#include <pulse/error.h>
 #include <stdlib.h>
 #include <math.h>
 #include <stdint.h>
@@ -10,7 +8,9 @@
 #include "options.h"
 
 //#define SSB
+#ifdef SSB
 //#define USB
+#endif
 
 #include "../lib/constants.h"
 #include "../lib/oscillator.h"
@@ -23,9 +23,16 @@
 
 #define INPUT_DEVICE "real_real_tx_audio_input.monitor"
 #define OUTPUT_DEVICE "alsa_output.platform-soc_sound.stereo-fallback"
+#define ALSA_OUTPUT // Output, not input or both
 #define BUFFER_SIZE 512
 #define CLIPPER_THRESHOLD 0.525 // Adjust this as needed
 
+#include <pulse/simple.h>
+#include <pulse/error.h>
+#ifdef ALSA_OUTPUT
+#include <alsa/asoundlib.h>
+#endif
+
 #define MONO_VOLUME 0.45f // L+R Signal
 #define PILOT_VOLUME 0.09f // 19 KHz Pilot
 #define STEREO_VOLUME 0.45f // L-R signal possibly can be set to .9 because im not sure if usb will be 2 times stronger than dsb-sc
@@ -88,6 +95,8 @@ int main() {
 	    .prebuf = buffer_prebuf
     };
 
+    int open_pulse_error;
+
     printf("Connecting to input device... (%s)\n", INPUT_DEVICE);
 
     pa_simple *input_device = pa_simple_new(
@@ -99,15 +108,16 @@ int main() {
         &stereo_format,
         NULL,
         &input_buffer_atr,
-        NULL
+        &open_pulse_error
     );
     if (!input_device) {
-        fprintf(stderr, "Error: cannot open input device.\n");
+        fprintf(stderr, "Error: cannot open input device: %s\n", pa_strerror(open_pulse_error));
         return 1;
     }
 
     printf("Connecting to output device... (%s)\n", OUTPUT_DEVICE);
 
+    #ifndef ALSA_OUTPUT
     pa_simple *output_device = pa_simple_new(
         NULL,
         "StereoEncoder",
@@ -117,13 +127,40 @@ int main() {
         &mono_format,
         NULL,
         &output_buffer_atr,
-        NULL
+        &open_pulse_error
     );
     if (!output_device) {
-        fprintf(stderr, "Error: cannot open output device.\n");
+        fprintf(stderr, "Error: cannot open output device: %s\n", pa_strerror(open_pulse_error));
         pa_simple_free(input_device);
         return 1;
     }
+    #else
+    snd_pcm_hw_params_t *output_params;
+    snd_pcm_t *output_handle;
+    int output_error = snd_pcm_open(&output_handle, OUTPUT_DEVICE, SND_PCM_STREAM_PLAYBACK, 0);
+    if(output_error < 0) {
+        fprintf(stderr, "Error: cannot open output device: %s\n", snd_strerror(output_error));
+        pa_simple_free(input_device);
+        return 1;
+    }
+    snd_pcm_hw_params_malloc(&output_params);
+    snd_pcm_hw_params_any(output_handle, output_params);
+    snd_pcm_hw_params_set_access(output_handle, output_params, SND_PCM_ACCESS_RW_INTERLEAVED);
+    snd_pcm_hw_params_set_format(output_handle, output_params, SND_PCM_FORMAT_FLOAT); // Same as pulse's Float32NE
+    snd_pcm_hw_params_set_channels(output_handle, output_params, 1);
+    unsigned int rate = SAMPLE_RATE;
+    int dir;
+    snd_pcm_hw_params_set_rate_near(output_handle, output_params, &rate, &dir);
+    snd_pcm_uframes_t frames = BUFFER_SIZE;
+    snd_pcm_hw_params_set_period_size_near(output_handle, output_params, &frames, &dir); // i don't have a clue why like this
+    output_error = snd_pcm_hw_params(output_handle, output_params);
+    if(output_error < 0) {
+        fprintf(stderr, "Error: cannot open output device: %s\n", snd_strerror(output_error));
+        snd_pcm_close(output_handle);
+        pa_simple_free(input_device);
+        return 1;
+    }
+    #endif
 
     Oscillator pilot_osc;
     init_oscillator(&pilot_osc, 19000.0, SAMPLE_RATE); // Pilot, it's there to indicate stereo and as a refrence signal with the stereo carrier
@@ -216,15 +253,24 @@ int main() {
 #endif
         }
 
+#ifndef ALSA_OUTPUT
         if (pa_simple_write(output_device, mpx, sizeof(mpx), &pulse_error) < 0) {
             fprintf(stderr, "Error writing to output device: %s\n", pa_strerror(pulse_error));
             to_run = 0;
             break;
         }
+#else
+        snd_pcm_writei(output_handle, mpx, sizeof(mpx));
+#endif
     }
     printf("Cleaning up...\n");
     pa_simple_free(input_device);
+    #ifndef ALSA_OUTPUT
     pa_simple_free(output_device);
+    #else
+    snd_pcm_drain(output_handle);
+    snd_pcm_free(output_handle);
+    #endif
 #ifdef SSB
     exit_hilbert(&hilbert);
     exit_delay_line(&monoDelay);