#include <CoreAudio/CoreAudio.h>
#include <AudioUnit/AudioUnit.h>
#include <AudioToolbox/DefaultAudioOutput.h>
+
+/** describes one input buffer for the osx writer */
struct osx_buffer {
+ /** pointer to the beginning of the buffer */
float *buffer;
+ /** the size of this buffer */
long size;
- float *ptr; /* Where in the buffer are we? */
+ /* current position in the buffer */
+ float *ptr;
+ /** number of floats not yet consuned */
long remaining;
+ /** pointer to the next audio buffer */
struct osx_buffer *next;
};
+/** data specific to the osx writer */
struct private_osx_write_data {
- long size;
- AudioUnit output;
+ /** the main control structure for audio data manipulation */
+ AudioUnit audio_unit;
+ /** non-zero if playback has started */
char play;
- struct osx_buffer *from; /* Current buffers */
+ /** callback reads audio data from this buffer */
+ struct osx_buffer *from;
+ /* the post_select writes audio data here */
struct osx_buffer *to;
+ /** sample rate of the current audio stream */
unsigned samplerate;
+ /** number of channels of the current audio stream */
unsigned channels;
};
-
-/*
- * Tried with 3 buffers, but then any little window move is sufficient to
- * stop the sound (OK, on a G3 400 with a Public Beta. Perhaps now we can
- * go down to 2 buffers). With 16 buffers we have 1.5 seconds music
- * buffered (or, if you're pessimistic, 1.5 seconds latency). Note 0
- * buffers don't work much further than the Bus error.
- */
-#define NUMBER_BUFFERS 2
-
static void destroy_buffers(struct private_osx_write_data *powd)
{
struct osx_buffer *ptr;
}
}
-static void init_buffers(struct private_osx_write_data *powd)
+static void init_buffers(struct writer_node *wn)
{
+ struct private_osx_write_data *powd = wn->private_data;
+ struct osx_write_args_info *conf = wn->conf;
+ struct osx_buffer **ptrptr;
int i;
- struct osx_buffer **ptrptr;
ptrptr = &powd->to;
- for (i = 0; i < NUMBER_BUFFERS; i++) {
+ for (i = 0; i < conf->numbuffers_arg; i++) {
*ptrptr = malloc(sizeof(struct osx_buffer));
(*ptrptr)->size = 0;
(*ptrptr)->remaining = 0;
if (!comp)
goto e0;
ret = -E_OPEN_COMP;
- if (OpenAComponent(comp, &powd->output))
+ if (OpenAComponent(comp, &powd->audio_unit))
goto e0;
ret = -E_UNIT_INIT;
- if (AudioUnitInitialize(powd->output))
+ if (AudioUnitInitialize(powd->audio_unit))
goto e1;
- powd->size = 0;
powd->play = 0;
/* Hmmm, let's choose PCM format */
/* We tell the Output Unit what format we're going to supply data to it.
/* one of the most constant constants of the whole computer history */
format.mBitsPerChannel = sizeof(float) * 8;
ret = -E_STREAM_FORMAT;
- if (AudioUnitSetProperty(powd->output, kAudioUnitProperty_StreamFormat,
+ if (AudioUnitSetProperty(powd->audio_unit, kAudioUnitProperty_StreamFormat,
kAudioUnitScope_Input, 0, &format,
sizeof(AudioStreamBasicDescription)))
goto e2;
- init_buffers(powd);
+ init_buffers(wn);
ret = -E_ADD_CALLBACK;
- if (AudioUnitSetProperty(powd->output, kAudioUnitProperty_SetRenderCallback,
+ if (AudioUnitSetProperty(powd->audio_unit, kAudioUnitProperty_SetRenderCallback,
kAudioUnitScope_Input, 0, &inputCallback,
sizeof(inputCallback)) < 0)
goto e3;
e3:
destroy_buffers(powd);
e2:
- AudioUnitUninitialize(powd->output);
+ AudioUnitUninitialize(powd->audio_unit);
e1:
- CloseComponent(powd->output);
+ CloseComponent(powd->audio_unit);
e0:
return ret;
}
struct private_osx_write_data *powd = wn->private_data;
PARA_INFO_LOG("closing writer node %p\n", wn);
- AudioOutputUnitStop(powd->output);
- AudioUnitUninitialize(powd->output);
- CloseComponent(powd->output);
+ AudioOutputUnitStop(powd->audio_unit);
+ AudioUnitUninitialize(powd->audio_unit);
+ CloseComponent(powd->audio_unit);
destroy_buffers(powd);
free(powd);
}
powd->to = powd->to->next;
wn->written = *wng->loaded;
if (!powd->play) {
- if (AudioOutputUnitStart(powd->output))
+ if (AudioOutputUnitStart(powd->audio_unit))
return -E_UNIT_START;
powd->play = 1;
}
return 1;
}
+/** the init function of the osx writer */
void osx_write_init(struct writer *w)
{
w->open = osx_write_open;