From 18399d8f41e0154af266f43fd4a05420cb335aa7 Mon Sep 17 00:00:00 2001
From: Jon Bergli Heier <snakebite@jvnv.net>
Date: Sun, 5 Sep 2010 20:39:52 +0200
Subject: Added FLAC decoder.

---
 SConstruct              |   1 +
 decoders/decoder_flac.c | 125 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 126 insertions(+)
 create mode 100644 decoders/decoder_flac.c

diff --git a/SConstruct b/SConstruct
index bed3520..718512c 100644
--- a/SConstruct
+++ b/SConstruct
@@ -18,6 +18,7 @@ env.ParseConfig('pkg-config --cflags --libs gio-2.0')
 env.ParseConfig('pkg-config --cflags --libs gio-unix-2.0')
 env.ParseConfig('pkg-config --cflags --libs libmpg123')
 env.ParseConfig('pkg-config --cflags --libs id3tag')
+env.ParseConfig('pkg-config --cflags --libs flac')
 
 env.Program('audistd', Glob('*.c') + Glob('decoders/*.c') + Glob('encoders/*.c'))
 
diff --git a/decoders/decoder_flac.c b/decoders/decoder_flac.c
new file mode 100644
index 0000000..805ab78
--- /dev/null
+++ b/decoders/decoder_flac.c
@@ -0,0 +1,125 @@
+#include "decoder.h"
+
+#include <FLAC/stream_decoder.h>
+
+#include <string.h>
+#include <stdlib.h>
+
+struct flac_decoder_data {
+	FLAC__StreamDecoder *decoder;
+	GInputStream *input;
+	GOutputStream *output;
+	gsize output_written;
+};
+
+static FLAC__StreamDecoderReadStatus read_callback(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], size_t *bytes, void *client_data) {
+	struct flac_decoder_data *decoder_data = client_data;
+
+	*bytes = g_input_stream_read(decoder_data->input, buffer, *bytes, NULL, NULL);
+
+	switch(*bytes) {
+		case -1:
+			return FLAC__STREAM_DECODER_READ_STATUS_ABORT;
+		case 0:
+			return FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM;
+		default:
+			return FLAC__STREAM_DECODER_READ_STATUS_CONTINUE;
+	}
+}
+
+static FLAC__StreamDecoderWriteStatus write_callback(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame,
+		const FLAC__int32 * const buffer[], void *client_data) {
+	struct flac_decoder_data *decoder_data = client_data;
+
+	unsigned channels = frame->header.channels;
+	//unsigned sample_rate = frame->header.sample_rate;
+	unsigned bits_per_sample = frame->header.bits_per_sample;
+	unsigned blocksize = frame->header.blocksize;
+	guint16 *outbuf = g_malloc(blocksize * channels * (bits_per_sample/8));
+	guint16 *pos = outbuf;
+
+	/* TODO: support other formats */
+	for(unsigned i = 0; i < blocksize; i++) {
+		for(unsigned c = 0; c < channels; c++) {
+			*(pos++) = buffer[c][i];
+		}
+	}
+
+	gint written = g_output_stream_write(decoder_data->output, outbuf, blocksize * channels * (bits_per_sample/8), NULL, NULL);
+
+	g_free(outbuf);
+
+	if(written >= 0) {
+		decoder_data->output_written += written;
+		return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
+	} else {
+		return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
+	}
+}
+
+static void error_callback(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data) {
+	g_warning(FLAC__StreamDecoderErrorStatusString[status]);
+}
+
+static gboolean flac_decoder_init(gpointer *data) {
+	struct flac_decoder_data *decoder_data = g_new0(struct flac_decoder_data, 1);
+	decoder_data->decoder = FLAC__stream_decoder_new();
+	FLAC__StreamDecoderInitStatus status = FLAC__stream_decoder_init_stream(decoder_data->decoder,
+			read_callback, NULL, NULL, NULL, NULL, write_callback, NULL, error_callback, decoder_data);
+	*data = decoder_data;
+
+	if(status != FLAC__STREAM_DECODER_INIT_STATUS_OK) {
+		g_warning(FLAC__StreamDecoderInitStatusString[status]);
+		FLAC__stream_decoder_delete(decoder_data->decoder);
+		g_free(decoder_data);
+		return FALSE;
+	}
+
+	return TRUE;
+}
+
+static gssize flac_decoder_decode(gpointer data, GInputStream *input,
+		GOutputStream *output, GError **error) {
+	struct flac_decoder_data *decoder_data = data;
+	decoder_data->input = input;
+	decoder_data->output = output;
+	decoder_data->output_written = 0;
+
+	FLAC__stream_decoder_process_single(decoder_data->decoder);
+	FLAC__StreamDecoderState state = FLAC__stream_decoder_get_state(decoder_data->decoder);
+
+	switch(state) {
+		case FLAC__STREAM_DECODER_END_OF_STREAM:
+			*error = g_error_new(decoder_quark(), DECODER_CODE_DONE, "eof");
+			break;
+		case FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR:
+			*error = g_error_new(decoder_quark(), DECODER_CODE_ERROR, "memory allocation error");
+			break;
+		case FLAC__STREAM_DECODER_ABORTED:
+			*error = g_error_new(decoder_quark(), DECODER_CODE_ERROR, "aborted by read callback");
+			break;
+		default:
+			break;
+	}
+
+	return decoder_data->output_written;
+}
+
+static void flac_decoder_close(gpointer data) {
+	struct flac_decoder_data *decoder_data = data;
+	FLAC__stream_decoder_finish(decoder_data->decoder);
+	FLAC__stream_decoder_delete(decoder_data->decoder);
+	g_free(decoder_data);
+}
+
+static const gchar * const decoder_flac_extensions[] = {
+	"flac", NULL,
+};
+
+const struct decoder_plugin decoder_flac_decoder = {
+	.name = "flac",
+	.extensions = decoder_flac_extensions,
+	.init = flac_decoder_init,
+	.decode = flac_decoder_decode,
+	.close = flac_decoder_close,
+};
-- 
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