Made separate streams for in and out sound. WIll be very handy for muting a microphone and your companion.

Makefile

@@ -16,10 +16,10 @@ CFLAGS = --std=c99 -D_POSIX_C_SOURCE=200112L -O3 -Wall -Werror -Wextra -pedantic
 LDFLAGS += -lportaudio -lopus -lsodium
 
 $(TARGET): $(OBJs)
-	$(CC) $(CFLAGS) $(LDFLAGS) $^ -o $@
+	$(CC) $(LDFLAGS) $^ -o $@
 
 $(OBJ_DIR)/%.o: $(SRC_DIR)/%.c | $(OBJ_DIR)
-	$(CC) $(CFLAGS) $(LDFLAGS) -c $< -o $@
+	$(CC) $(CFLAGS) -c $< -o $@
 
 $(OBJ_DIR):
 	mkdir -p $@

src/audio.c

@@ -1,17 +1,52 @@
 #include "audio.h"
 
+#include <portaudio.h>
 #include <stdio.h>
 #include <stdlib.h>
 
-int audio_init(audio_t *aud, int channels, int sample_rate, int frame_size) {
+int audio_init_soundsystem(void) {
     PaError pa_err;
-    int opus_err;
 
     if ((pa_err = Pa_Initialize()) != paNoError) {
         fprintf(stderr, "Cannot initialise PortAudio: %s\n", Pa_GetErrorText(pa_err));
         return -1;
     }
 
+    return 0;
+}
+
+int audio_terminate_soundsystem(void) {
+    PaError pa_err;
+
+    if ((pa_err = Pa_Terminate()) != paNoError) {
+        fprintf(stderr, "Cannot terminate PortAudio: %s\n", Pa_GetErrorText(pa_err));
+        return -1;
+    }
+
+    return 0;
+}
+
+int audio_init_default(audio_t *aud, int channels, int sample_rate, int frame_size) {
+    PaError pa_err;
+    int opus_err;
+
+    if ((pa_err = Pa_OpenDefaultStream(&aud->stream_in, channels, 0, AUDIO_SAMPLE_FORMAT,
+        sample_rate, frame_size, NULL, NULL)) != paNoError) {
+        fprintf(stderr, "Cannot open an input PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
+        return -1;
+    }
+
+    if ((pa_err = Pa_OpenDefaultStream(&aud->stream_out, 0, channels, AUDIO_SAMPLE_FORMAT,
+        sample_rate, frame_size, NULL, NULL)) != paNoError) {
+        fprintf(stderr, "Cannot open an input PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
+        return -1;
+    }
+
+    aud->buffer_size = frame_size * channels;
+    aud->buffer = (audio_sample_t *)malloc(aud->buffer_size * sizeof(audio_sample_t));
+    if (aud->buffer == NULL)
+        return -1;
+
     aud->opus_enc = opus_encoder_create(sample_rate, channels, OPUS_APPLICATION_VOIP, &opus_err);
     if (opus_err != OPUS_OK) {
         fprintf(stderr, "An Opus encoder cannot be created: %s\n", opus_strerror(opus_err));
@@ -24,44 +59,34 @@ int audio_init(audio_t *aud, int channels, int sample_rate, int frame_size) {
         return -1;
     }
 
-    if ((pa_err = Pa_OpenDefaultStream(&aud->stream, channels, channels, AUDIO_SAMPLE_FORMAT,
-        sample_rate, frame_size, NULL, NULL)) != paNoError) {
-        fprintf(stderr, "Cannot open a PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
-        return -1;
-    }
-
-    aud->buffer_size = frame_size * channels;
-    aud->buffer = (audio_sample_t *)malloc(aud->buffer_size * sizeof(audio_sample_t));
-    if (aud->buffer == NULL)
-        return -1;
-
-    if ((pa_err = Pa_StartStream(aud->stream)) != paNoError) {
-        fprintf(stderr, "Cannot start a PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
-        free(aud->buffer);
-        return -1;
-    }
-
     return 0;
 }
 
 int audio_destroy(audio_t *aud) {
     PaError pa_err;
 
-    if (aud->stream) {
+    if (aud->stream_in != NULL) {
-        if ((pa_err = Pa_StopStream(aud->stream)) != paNoError) {
+        if ((pa_err = Pa_StopStream(aud->stream_in)) != paNoError && pa_err != paStreamIsStopped) {
-            fprintf(stderr, "Cannot stop a PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
+            fprintf(stderr, "Cannot stop an input PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
             return -1;
         }
 
-        if ((pa_err = Pa_CloseStream(aud->stream)) != paNoError) {
+        if ((pa_err = Pa_CloseStream(aud->stream_in)) != paNoError) {
-            fprintf(stderr, "Cannot close a PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
+            fprintf(stderr, "Cannot close an input PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
             return -1;
         }
     }
 
-    if ((pa_err = Pa_Terminate()) != paNoError) {
+    if (aud->stream_out != NULL) {
-        fprintf(stderr, "Cannot terminate PortAudio: %s\n", Pa_GetErrorText(pa_err));
+        if ((pa_err = Pa_StopStream(aud->stream_out)) != paNoError) {
-        return -1;
+            fprintf(stderr, "Cannot stop an output PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
+            return -1;
+        }
+
+        if ((pa_err = Pa_CloseStream(aud->stream_out)) != paNoError) {
+            fprintf(stderr, "Cannot close an output PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
+            return -1;
+        }
     }
 
     if (aud->buffer)
@@ -76,10 +101,58 @@ int audio_destroy(audio_t *aud) {
     return 0;
 }
 
+int audio_stream_input_toggle(audio_t *aud) {
+    PaError pa_err;
+
+    if ((pa_err = Pa_IsStreamStopped(aud->stream_in)) != 0) {
+        if (pa_err < 0 && pa_err != paStreamIsStopped) {
+            fprintf(stderr, "Cannot get state of an input PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
+            return -1;
+        }
+
+        if ((pa_err = Pa_StartStream(aud->stream_in)) != paNoError) {
+            fprintf(stderr, "Cannot start an input PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
+            free(aud->buffer);
+            return -1;
+        }
+    } else {
+        if ((pa_err = Pa_StopStream(aud->stream_in)) != paNoError) {
+            fprintf(stderr, "Cannot stop an input PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
+int audio_stream_output_toggle(audio_t *aud) {
+    PaError pa_err;
+
+    if ((pa_err = Pa_IsStreamStopped(aud->stream_out)) != 0) {
+        if (pa_err < 0) {
+            fprintf(stderr, "Cannot get state of an output PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
+            return -1;
+        }
+
+        if ((pa_err = Pa_StartStream(aud->stream_out)) != paNoError) {
+            fprintf(stderr, "Cannot start an output PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
+            free(aud->buffer);
+            return -1;
+        }
+    } else {
+        if ((pa_err = Pa_StopStream(aud->stream_out)) != paNoError) {
+            fprintf(stderr, "Cannot stop an output PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
 int audio_read(audio_t *aud, unsigned char *output, int output_len) {
     PaError pa_err;
 
-    if ((pa_err = Pa_ReadStream(aud->stream, aud->buffer, aud->buffer_size)) != paNoError) {
+    if ((pa_err = Pa_ReadStream(aud->stream_in, aud->buffer, aud->buffer_size)) != paNoError) {
         fprintf(stderr, "Cannot read from a PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
         return -1;
     }
@@ -102,10 +175,10 @@ int audio_write(audio_t *aud, const unsigned char *input, int input_len) {
         return -1;
     }
 
-    if ((pa_err = Pa_WriteStream(aud->stream, aud->buffer, aud->buffer_size)) != paNoError) {
+    if ((pa_err = Pa_WriteStream(aud->stream_out, aud->buffer, aud->buffer_size)) != paNoError) {
         fprintf(stderr, "Cannot write to a PortAudio stream: %s\n", Pa_GetErrorText(pa_err));
         return -1;
     }
 
     return 0;
-}
+}

src/audio.h

@@ -7,8 +7,11 @@
 #define AUDIO_SAMPLE_FORMAT paFloat32
 typedef float audio_sample_t;
 
+int audio_init_soundsystem(void);
+int audio_terminate_soundsystem(void);
+
 typedef struct audio_t {
-    PaStream    *stream;
+    PaStream    *stream_in, *stream_out;
     OpusEncoder *opus_enc;
     OpusDecoder *opus_dec;
 
@@ -16,10 +19,13 @@ typedef struct audio_t {
     int             buffer_size;
 } audio_t;
 
-int audio_init(audio_t *aud, int channels, int sample_rate, int frame_size);
+int audio_init_default(audio_t *aud, int channels, int sample_rate, int frame_size);
 int audio_destroy(audio_t *aud);
 
+int audio_stream_input_toggle(audio_t *aud);
+int audio_stream_output_toggle(audio_t *aud);
+
 int audio_read(audio_t *aud, unsigned char *output, int output_len);
 int audio_write(audio_t *aud, const unsigned char *input, int input_len);
 
-#endif /* _AUDIO_H_ */
+#endif /* _AUDIO_H_ */

src/crypt.c

@@ -199,4 +199,4 @@ void crypt_session_destroy(crypt_session_t *const s) {
     sodium_memzero(s->tx, CRYPT_SESS_KEY_LEN);
     sodium_memzero(s->nonce, CRYPT_NONCE_LEN);
     crypt_key_destroy(s->remote_key);
-}
+}

src/crypt.h

@@ -57,4 +57,4 @@ unsigned char *crypt_session_encrypt(crypt_session_t *const s, const unsigned ch
 unsigned char *crypt_session_decrypt(crypt_session_t *const s, const unsigned char *const c, unsigned long long clen, unsigned long long *mlen);
 void crypt_session_destroy(crypt_session_t *const s);
 
-#endif /* _CRYPT_H_ */
+#endif /* _CRYPT_H_ */

src/main.c

@@ -1,3 +1,4 @@
+#include <portaudio.h>
 #include <stdio.h>
 #include <string.h>
 
@@ -7,7 +8,7 @@
 
 #define CHANNELS 1
 #define SAMPLE_RATE 48000
-#define FRAMES_PER_BUFFFER 480
+#define FRAMES_PER_BUFFFER 960
 
 #define BUF_SIZE (FRAMES_PER_BUFFFER * CHANNELS)
 
@@ -109,31 +110,43 @@ int main(int argc, char **argv) {
         goto cleanup;
     }
 
+    if (audio_init_soundsystem() == -1) {
+        rt = -1;
+        goto cleanup;
+    }
 
     audio_t aud;
 
     unsigned char buf[BUF_SIZE];
     memset(buf, 0, BUF_SIZE);
 
-    audio_init(&aud, CHANNELS, SAMPLE_RATE, FRAMES_PER_BUFFFER);
+    audio_init_default(&aud, CHANNELS, SAMPLE_RATE, FRAMES_PER_BUFFFER);
+
+    if (audio_stream_input_toggle(&aud) == -1) {
+        rt = -1;
+        goto cleanup;
+    }
+
+    if (audio_stream_output_toggle(&aud) == -1) {
+        rt = -1;
+        goto cleanup;
+    }
 
     unsigned char *c = NULL, *m = NULL;
     unsigned long long cl = 0, ml = 0;
 
     printf("Listening... ");
-    for (int i = 0; i < (20 * SAMPLE_RATE)/FRAMES_PER_BUFFFER; ++i) {
+    for (int i = 0; i < (10 * SAMPLE_RATE)/FRAMES_PER_BUFFFER; ++i) {
         audio_read(&aud, buf, BUF_SIZE);
         c = crypt_session_encrypt(&os, buf, BUF_SIZE, &cl);
-        int sc = net_send(&nc, (const char *)c, cl);
+        net_send(&nc, (const char *)c, cl);
-        int rc = net_recv(&ns, c, cl);
+        net_recv(&ns, c, cl);
-        fprintf(stderr, "%d %d\n", sc, rc);
         m = crypt_session_decrypt(&rs, c, cl, &ml);
         audio_write(&aud, m, ml);
         free(c); free(m);
     }
     printf("Done!\n");
 
-    audio_destroy(&aud);
 
 cleanup:
     free(oh);
@@ -154,5 +167,8 @@ cleanup:
     net_destroy(&ns);
     net_destroy(&nc);
 
+    audio_destroy(&aud);
+    audio_terminate_soundsystem();
+
     return rt;
-}
+}

src/net.h

@@ -16,4 +16,4 @@ void net_destroy(net_t *n);
 ssize_t net_send(net_t *const n, const char *const buf, int buf_len);
 ssize_t net_recv(net_t *const n, void *const buf, size_t buf_len);
 
-#endif /* _NET_H_ */
+#endif /* _NET_H_ */