works with alsa and runs at 30 fpsHEADmaster

7 files changed, 124 insertions, 78 deletions

diff --git a/README.md b/README.md
index 48241f2..b4803cc 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@ through UDP datagrams.
 This project is written only in C, using the following technologies:
 
 1. V4L2 - video for linux api for getting images from the camera
-2. PulseAudio Simple API for playing and recording audio (will be changed to ALSA soon)
+2. ALSA for recording and playing audio
 3. GLFW with OpenGL for displaying the recieved image
 
 No other external libraries or APIs are used.
@@ -16,13 +16,14 @@ No other external libraries or APIs are used.
 ### Limitations
 
 1. 160x120 video resolution because of the limited size of sockets
-2. Crappy audio, most likely because of pulse audio
+2. Kinda crappy audio
 3. Works only on GNU/Linux, I don't plan porting it to Windows
 
 ### Todo
 
-1. Use ALSA and not PulseAudio Simple API
-2. MUST run at 30 fps
+1. Higher resolution by splitting it into multiple datagrams
+2. Encryption
+3. More user-friendly
 
 ### Build
 
diff --git a/build.sh b/build.sh
index 423bf57..096fa61 100755
--- a/build.sh
+++ b/build.sh
@@ -5,7 +5,8 @@ cd ${0%/*} # go to project root
 FLAGS="-g -Wall -Wextra -pedantic -lpthread -std=c99"
 FGLFW="-lGL -lglfw"
 FV4L2="-lv4l2"
-FPASM="-lpulse -lpulse-simple"
+# FPASM="-lpulse -lpulse-simple"
+FALSA="-lasound"
 SRC="src"
 OBJ="obj"
 BIN="bin"
@@ -31,5 +32,5 @@ gcc -o $OBJ/display.o -c $SRC/display.c
 gcc -o $OBJ/camera.o  -c $SRC/camera.c
 gcc -o $OBJ/audio.o   -c $SRC/audio.c
 
-gcc -o $BIN/listener     $SRC/listener.c $OBJ/socket.o $OBJ/display.o $OBJ/audio.o $FLAGS $FPASM $FGLFW
-gcc -o $BIN/talker       $SRC/talker.c   $OBJ/socket.o $OBJ/camera.o  $OBJ/audio.o $FLAGS $FPASM $FV4L2
+gcc -o $BIN/listener     $SRC/listener.c $OBJ/socket.o $OBJ/display.o $OBJ/audio.o $FLAGS $FALSA $FGLFW
+gcc -o $BIN/talker       $SRC/talker.c   $OBJ/socket.o $OBJ/camera.o  $OBJ/audio.o $FLAGS $FALSA $FV4L2
diff --git a/src/audio.c b/src/audio.c
index 710c10c..d9bf3da 100644
--- a/src/audio.c
+++ b/src/audio.c
@@ -1,90 +1,105 @@
-// TODO: Rewrite with alsa, fuck pulseaudio
-
-#include <stdio.h>
-#include <unistd.h>
-#include <string.h>
-#include <errno.h>
-
-#include <pulse/simple.h>
-#include <pulse/error.h>
+#define ALSA_PCM_NEW_HW_PARAMS_API
+#include <alsa/asoundlib.h>
 
 #include "audio.h"
 #include "typedef.h"
 
-static const pa_sample_spec ss = {
-    .format = PA_SAMPLE_S16BE,
-    .rate = 44100,
-    .channels = 2
-};
+#define TEMP_BUF_SZ (handle->frames * CHANNELS * 2)
+#define HANDLE (*(snd_pcm_t**)(handle->h))
 
-static pa_simple *play = NULL;
-static pa_simple *rec  = NULL;
+#define MIN(a,b) (((a)<(b))?(a):(b))
 
-int audio_play(char *buf)
+int audio_create(audio_handle *handle, audio_handle_types t)
 {
-    int ret = 1;
-    int error;
-
-    if(play == NULL) {
-        if (!(play = pa_simple_new(NULL, __FILE__, PA_STREAM_PLAYBACK, NULL, "playback", &ss, NULL, NULL, &error))) {
-            fprintf(stderr, __FILE__": pa_simple_new() failed: %s\n", pa_strerror(error));
-            goto finish;
-        }
+    handle->h = malloc(sizeof(snd_pcm_t *));
+    snd_pcm_stream_t type = (t == RECORD) ? SND_PCM_STREAM_CAPTURE : SND_PCM_STREAM_PLAYBACK;
+    int rc = snd_pcm_open(handle->h, "default", type, 0);
+    if (rc < 0) {
+        err("unable to open pcm device: %s\n", snd_strerror(rc));
+        return 1;
     }
 
-    if(pa_simple_flush(play, &error) < 0)
-    {
-        fprintf(stderr, __FILE__": pa_simple_flush() failed: %s\n", pa_strerror(error));
-        goto finish;
-    }
+    int dir;
+    snd_pcm_hw_params_t *params;
 
-    if(pa_simple_write(play, buf, REC_CAP, &error) < 0) {
-                    fprintf(stderr, __FILE__": pa_simple_write() failed: %s\n", pa_strerror(error));
-            goto finish;
-    }
+    snd_pcm_hw_params_alloca(&params); // allocate params
+    snd_pcm_hw_params_any(HANDLE, params); // set params
+    snd_pcm_hw_params_set_access(HANDLE, params, SND_PCM_ACCESS_RW_INTERLEAVED); // interleaved mode
+    snd_pcm_hw_params_set_format(HANDLE, params, SND_PCM_FORMAT_S16_LE);
 
-    if(pa_simple_drain(play, &error) < 0) {
-        fprintf(stderr, __FILE__": pa_simple_drain() failed: %s\n", pa_strerror(error));
-        goto finish;
-    }
+    snd_pcm_hw_params_set_channels(HANDLE, params, CHANNELS);
 
-    ret = 0;
+    unsigned int samp_rate = SAMPLING_RATE;
+    snd_pcm_hw_params_set_rate_near(HANDLE, params, &samp_rate, &dir);
 
-finish:
+    snd_pcm_uframes_t frames = FRAMES;
+    snd_pcm_hw_params_set_period_size_near(HANDLE, params, &frames, &dir);
 
-    // if (play)
-        // pa_simple_free(play);
+    rc = snd_pcm_hw_params(HANDLE, params); // write params to handle
+    if (rc < 0) {
+        err("unable to set hw parameters: %s\n", snd_strerror(rc));
+        return 1;
+    }
 
-    return ret;
+    snd_pcm_hw_params_get_period_size(params, &frames, &dir);
+    handle->frames = frames;
+
+    return 0;
 }
 
-int audio_record(char *buf)
+int audio_play(audio_handle *handle, char *buf)
 {
-    int ret = 1;
-    int error;
-
-    if(!rec) {
-        if (!(rec = pa_simple_new(NULL, __FILE__, PA_STREAM_RECORD, NULL, "record", &ss, NULL, NULL, &error))) {
-            fprintf(stderr, __FILE__": pa_simple_new() failed: %s\n", pa_strerror(error));
-            goto finish;
+    char t[TEMP_BUF_SZ];
+    for(int i = 0; ;)
+    {
+        if(i >= REC_CAP) break;;
+
+        memset(t, 0, TEMP_BUF_SZ);
+        memcpy(t, &(buf[i]), MIN(TEMP_BUF_SZ, REC_CAP - i));
+
+        int rc = snd_pcm_writei(HANDLE, t, FRAMES);
+        if (rc == -EPIPE) {
+            err("underrun occurred\n");
+            snd_pcm_prepare(HANDLE);
+        } else if (rc < 0) {
+            err("error from writei: %s\n", snd_strerror(rc));
+        }  else if (rc != FRAMES) {
+            err("short write, write %d frames\n", rc);
         }
-    }
 
-    if(pa_simple_flush(rec, &error) < 0) {
-        fprintf(stderr, __FILE__": pa_simple_flush() failed: %s\n", pa_strerror(error));
-        goto finish;
+        i += TEMP_BUF_SZ;
     }
+    return 0;
+}
 
-    if (pa_simple_read(rec, buf, REC_CAP, &error) < 0) {
-        fprintf(stderr, __FILE__": pa_simple_read() failed: %s\n", pa_strerror(error));
-        goto finish;
-    }
+int audio_record(audio_handle *handle, char *buf)
+{
+    char t[TEMP_BUF_SZ];
+    for(int i = 0; ;)
+    {
+        if(i >= REC_CAP) break;
+        memset(t, 0, TEMP_BUF_SZ);
+
+        int rc = snd_pcm_readi(HANDLE, t, FRAMES);
+        if (rc == -EPIPE) {
+            err("overrun occurred\n");
+            snd_pcm_prepare(HANDLE);
+        } else if (rc < 0) {
+            err("error from read: %s\n", snd_strerror(rc));
+        } else if (rc != FRAMES) {
+            err("short read, read %d frames\n", rc);
+        }
 
-    ret = 0;
+        memcpy(&(buf[i]), t, MIN(TEMP_BUF_SZ, REC_CAP - i));
+        i += TEMP_BUF_SZ;
+    }
 
-finish:
-    // if(rec)
-        // pa_simple_free(rec);
+    return 0;
+}
 
-    return ret;
+void audio_destroy(audio_handle *handle)
+{
+    snd_pcm_drain(HANDLE);
+    snd_pcm_close(HANDLE);
+    free(handle->h);
 }
diff --git a/src/audio.h b/src/audio.h
index 2ca554d..0b6fbab 100644
--- a/src/audio.h
+++ b/src/audio.h
@@ -1,8 +1,22 @@
 #ifndef AUDIO_H
 #define AUDIO_H
 
-int audio_play(char *buf);
+typedef struct audio_handle {
+    void *h;
+    unsigned long frames;
+} audio_handle;
 
-int audio_record(char *buf);
+typedef enum audio_handle_types {
+    RECORD,
+    PLAYBACK
+} audio_handle_types;
+
+int audio_create(audio_handle *handle, audio_handle_types t);
+
+int audio_play(audio_handle *handle, char *buf);
+
+int audio_record(audio_handle *handle, char *buf);
+
+void audio_destroy(audio_handle *handle);
 
 #endif
diff --git a/src/listener.c b/src/listener.c
index f819383..1968590 100644
--- a/src/listener.c
+++ b/src/listener.c
@@ -14,6 +14,8 @@ char cam_data[BUF_CAP] = {0};
 unsigned int WIDTH = 1;
 unsigned int HEIGHT = 1;
 
+audio_handle aud_handle;
+
 void *display_thread(void *arg)
 {
     (void)arg;
@@ -32,7 +34,7 @@ void on_recv(message *m)
     HEIGHT = m->HEIGHT;
 
     memcpy(cam_data, m->video, WIDTH * HEIGHT * 3);
-    audio_play(m->audio);
+    audio_play(&aud_handle, m->audio);
 }
 
 int main(void)
@@ -40,6 +42,12 @@ int main(void)
     pthread_t tid;
     pthread_create(&tid, NULL, display_thread, NULL);
 
+    if(audio_create(&aud_handle, PLAYBACK) != 0) {
+        err("audio_create: failed\n");
+        return 1;
+    }
+
+
     if(listener("4950", &on_recv) != 0) {
         err("listener: failed");
         return 1;
diff --git a/src/talker.c b/src/talker.c
index e7271ad..d70df52 100644
--- a/src/talker.c
+++ b/src/talker.c
@@ -14,10 +14,11 @@
 #define Y_RES 120
 
 camera_handle cam_handle;
+audio_handle aud_handle;
 
 void on_send(message *m)
 {
-    audio_record(m->audio);
+    audio_record(&aud_handle, m->audio);
 
     m->WIDTH = X_RES;
     m->HEIGHT = Y_RES;
@@ -34,11 +35,19 @@ int main(void)
 
     camera_init(&cam_handle, params);
 
+    if(audio_create(&aud_handle, RECORD) != 0) {
+        err("audio_create: failed\n");
+        return 1;
+    }
+
+    info("created audio\n");
+
     if(talker("4950", "localhost", &on_send) != 0) {
         err("talker: failed\n");
         return 1;
     }
 
+    audio_destroy(&aud_handle);
     camera_deinit(&cam_handle);
     return 0;
 }
diff --git a/src/typedef.h b/src/typedef.h
index b6b2b29..180d100 100644
--- a/src/typedef.h
+++ b/src/typedef.h
@@ -16,12 +16,10 @@
 
 #define BUF_CAP 65500 // max datagram size with some bytes left for the headers and things
 
-#define FRAMES 32
+#define FRAMES 64
 #define BITRATE 16
 #define SAMPLING_RATE 44100
 #define CHANNELS 2
-
-#define TEMP_BUF_SZ (FRAMES * CHANNELS * 2) // 2 bytes per sample
 #define REC_CAP ((BITRATE * SAMPLING_RATE * CHANNELS)/240) // 30th of a second of audio
 
 #define VID_CAP (BUF_CAP - ((2*(sizeof(int))) + REC_CAP))