Completed an audio module using a blocking I/O.

src/audio.c

@@ -4,25 +4,7 @@
 #include <stdio.h>
 #include <string.h>
 
-int audio_default_callback(const void *input, void *output,
+int audio_init(audio_t *aud, int channels, int sampleRate, int frameSize) {
-    unsigned long frameCount, const PaStreamCallbackTimeInfo *timeInfo,
-    PaStreamCallbackFlags statusFlags, void *userData) {
-    (void)timeInfo;
-    (void)statusFlags;
-
-    audio_t *aud = (audio_t *)userData;
-
-    int encLen = opus_encode_float(aud->opusEnc, (float *)input, frameCount, aud->opusBuf, aud->opusBufSz);
-    (void)encLen;
-    int frameSize = opus_decode_float(aud->opusDec, aud->opusBuf, aud->opusBufSz, (float *)output, frameCount, 0);
-    (void)frameSize;
-
-    // printf("%i %i | %li %li\n", encLen, frameSize, frameCount, aud->opusBufSz);
-
-    return paContinue;
-}
-
-int audio_init_default(audio_t *aud, int channels, int sampleRate, int frameSize, PaStreamCallback callback) {
     PaError paErr;
     int opusErr;
 
@@ -31,9 +13,6 @@ int audio_init_default(audio_t *aud, int channels, int sampleRate, int frameSize
         return -1;
     }
 
-    aud->opusBufSz = frameSize * channels;
-    aud->opusBuf = (uint8_t *)malloc(aud->opusBufSz * sizeof(uint8_t));
-
     aud->opusEnc = opus_encoder_create(sampleRate, channels, OPUS_APPLICATION_VOIP, &opusErr);
     if (opusErr != OPUS_OK) {
         fprintf(stderr, "An Opus encoder cannot be created: %s\n", opus_strerror(opusErr));
@@ -46,12 +25,15 @@ int audio_init_default(audio_t *aud, int channels, int sampleRate, int frameSize
         return -1;
     }
 
-    if ((paErr = Pa_OpenDefaultStream(&aud->stream, channels, channels, paFloat32,
+    if ((paErr = Pa_OpenDefaultStream(&aud->stream, channels, channels, AUDIO_SAMPLE_FORMAT,
-        sampleRate, frameSize, callback, aud)) != paNoError) {
+        sampleRate, frameSize, NULL, NULL)) != paNoError) {
         fprintf(stderr, "Cannot open a PortAudio stream: %s\n", Pa_GetErrorText(paErr));
         return -1;
     }
 
+    aud->bufferSz = frameSize * channels;
+    aud->buffer = (audio_sample_t *)malloc(aud->bufferSz * sizeof(audio_sample_t));
+
     if ((paErr = Pa_StartStream(aud->stream)) != paNoError) {
         fprintf(stderr, "Cannot start a PortAudio stream: %s\n", Pa_GetErrorText(paErr));
         return -1;
@@ -80,14 +62,55 @@ int audio_destroy(audio_t *aud) {
         return -1;
     }
 
+    if (aud->buffer)
+        free(aud->buffer);
+
     if (aud->opusEnc)
         opus_encoder_destroy(aud->opusEnc);
 
     if (aud->opusDec)
         opus_decoder_destroy(aud->opusDec);
 
-    if (aud->opusBuf)
+    return 0;
-        free(aud->opusBuf);
+}
+
+/*
+int encLen = opus_encode_float(aud->opusEnc, (float *)input, frameCount, aud->opusBuf, aud->opusBufSz);
+    (void)encLen;
+    int frameSize = opus_decode_float(aud->opusDec, aud->opusBuf, aud->opusBufSz, (float *)output, frameCount, 0);
+    (void)frameSize;
+*/
+
+int audio_read(audio_t *aud, uint8_t *outputData, size_t outputLen) {
+    PaError paErr;
+
+    if ((paErr = Pa_ReadStream(aud->stream, aud->buffer, aud->bufferSz)) != paNoError) {
+        fprintf(stderr, "Cannot read from a PortAudio stream: %s\n", Pa_GetErrorText(paErr));
+        return -1;
+    }
+
+    int encodedLen = opus_encode_float(aud->opusEnc, aud->buffer, aud->bufferSz, outputData, outputLen);
+    if (encodedLen < 0) {
+        fprintf(stderr, "Opus failed to encode: %s\n", opus_strerror(encodedLen));
+        return -1;
+    }
+
+    return 0;
+}
+
+int audio_write(audio_t *aud, const uint8_t *inputData, size_t inputLen) {
+    PaError paErr;
+
+    int frameSize = opus_decode_float(aud->opusDec, inputData, inputLen, aud->buffer, aud->bufferSz, 0);
+    if (frameSize < 0) {
+        fprintf(stderr, "Opus failed to decode: %s\n", opus_strerror(frameSize));
+        return -1;
+    }
+
+    if ((paErr = Pa_WriteStream(aud->stream, aud->buffer, aud->bufferSz)) != paNoError) {
+        fprintf(stderr, "Cannot write to a PortAudio stream: %s\n", Pa_GetErrorText(paErr));
+        return -1;
+    }
 
     return 0;
 }

src/audio.h

@@ -7,19 +7,22 @@
 #include <opus/opus.h>
 #include <portaudio.h>
 
+#define AUDIO_SAMPLE_FORMAT paFloat32
+typedef float audio_sample_t;
+
 typedef struct audio_t {
     PaStream    *stream;
     OpusEncoder *opusEnc;
     OpusDecoder *opusDec;
-    uint8_t     *opusBuf;
+
-    size_t       opusBufSz;
+    audio_sample_t *buffer;
+    size_t          bufferSz;
 } audio_t;
 
-int audio_default_callback(const void *input, void *output,
+int audio_init(audio_t *aud, int channels, int sampleRate, int frameSize);
-    unsigned long frameCount, const PaStreamCallbackTimeInfo *timeInfo,
-    PaStreamCallbackFlags statusFlags, void *userData);
-
-int audio_init_default(audio_t *aud, int channels, int sampleRate, int frameSize, PaStreamCallback *callback);
 int audio_destroy(audio_t *aud);
 
+int audio_read(audio_t *aud, uint8_t *outputData, size_t outputLen);
+int audio_write(audio_t *aud, const uint8_t *inputData, size_t inputLen);
+
 #endif /* _AUDIO_H_ */