Import libdect

Signed-off-by: Patrick McHardy <kaber@trash.net>

1 files changed, 95 insertions, 0 deletions

diff --git a/example/audio.c b/example/audio.c
new file mode 100644
index 0000000..3dfe9cb
--- /dev/null
+++ b/example/audio.c
@@ -0,0 +1,95 @@
+#include <SDL/SDL.h>
+#include <SDL/SDL_audio.h>
+#include "common.h"
+
+void dect_audio_queue(struct dect_audio_handle *ah, struct dect_msg_buf *mb)
+{
+	SDL_LockAudio();
+	list_add_tail(&mb->list, &ah->queue);
+	SDL_UnlockAudio();
+}
+
+static void dect_decode_g721(struct g72x_state *codec,
+			     int16_t *dst, const uint8_t *src,
+			     unsigned int len)
+{
+	unsigned int i;
+
+	for (i = 0; i < len * 2; i += 2) {
+		dst[i + 0] = g721_decoder(src[i / 2] >> 4,
+					  AUDIO_ENCODING_LINEAR, codec);
+		dst[i + 1] = g721_decoder(src[i / 2] & 0x0f,
+					  AUDIO_ENCODING_LINEAR, codec);
+	}
+}
+
+static void dect_audio_dequeue(void *data, uint8_t *stream, int len)
+{
+	struct dect_audio_handle *ah = data;
+	struct dect_msg_buf *mb;
+	int copy;
+
+	len /= 4;
+	while (1) {
+		if (list_empty(&ah->queue))
+			goto underrun;
+		mb = list_first_entry(&ah->queue, struct dect_msg_buf, list);
+		copy = mb->len;
+		if (copy > len)
+			copy = len;
+
+		dect_decode_g721(&ah->codec, (int16_t *)stream, mb->data, copy);
+		dect_mbuf_pull(mb, copy);
+		if (mb->len == 0) {
+			list_del(&mb->list);
+			free(mb);
+		}
+
+		len -= copy;
+		if (len == 0)
+			return;
+		stream += 4 * copy;
+	}
+
+underrun:
+	printf("audio underrun, missing %u bytes\n", len * 4);
+	memset(stream, 0, len * 4);
+}
+
+struct dect_audio_handle *dect_audio_open(void)
+{
+	struct dect_audio_handle *ah;
+	SDL_AudioSpec spec = {
+		.freq		= 8000,
+		.format		= AUDIO_S16SYS,
+		.channels	= 1,
+		.samples	= 512,
+		.callback	= dect_audio_dequeue,
+	};
+
+	ah = malloc(sizeof(*ah));
+	if (ah == NULL)
+		goto err1;
+	init_list_head(&ah->queue);
+	g72x_init_state(&ah->codec);
+
+	spec.userdata = ah;
+	if (SDL_OpenAudio(&spec, NULL) < 0)
+		goto err2;
+	SDL_PauseAudio(0);
+
+	return ah;
+
+err2:
+	free(ah);
+err1:
+	return NULL;
+}
+
+static void __init dect_audio_init(void)
+{
+	if (SDL_Init(SDL_INIT_AUDIO) < 0) {
+		fprintf(stderr, "Could not initialize SDL: %s\n", SDL_GetError());
+		exit(1);
+	}
+}