shout: added mp3 encoder

[mk: moved this patch after "Refactor and cleanup of shout Ogg and MP3
audio outputs".  The original commit message follows, although it is
outdated:]

Creation of shout_mp3 audio output plugin. Basically I just copied the
existing shout plugin and replaced ogg with lame. Uses lame for mp3
encoding. Next step is to pull common functionality out of each shout
plugin and share it between them.

Configuration options for "shout_mp3" are the same as for "shout".

1 files changed, 194 insertions, 0 deletions

diff --git a/src/audioOutputs/audioOutput_shout_mp3.c b/src/audioOutputs/audioOutput_shout_mp3.c
new file mode 100644
index 000000000..388808c1b
--- /dev/null
+++ b/src/audioOutputs/audioOutput_shout_mp3.c
@@ -0,0 +1,194 @@
+/* the Music Player Daemon (MPD)
+ * Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com)
+ * This project's homepage is: http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "../output_api.h"
+
+#ifdef HAVE_SHOUT_MP3
+
+#include "../utils.h"
+#include "audioOutput_shout.h"
+#include <lame/lame.h>
+
+typedef struct _lame_data {
+	lame_global_flags *gfp;
+} lame_data;
+
+
+static int shout_mp3_encoder_init(shout_data * sd)
+{
+	lame_data *ld;
+
+	if (NULL == (ld = xmalloc(sizeof(lame_data))))
+		FATAL("error initializing lame encoder data\n");
+	sd->encoder_data = ld;
+
+	return 0;
+}
+
+static int shout_mp3_encoder_clear_encoder(shout_data * sd)
+{
+	lame_data *ld = (lame_data *)sd->encoder_data;
+	shout_buffer *buf = &sd->buf;
+	int ret;
+
+	if ((ret = lame_encode_flush(ld->gfp, buf->data + buf->len,
+				     buf->len)) < 0)
+		ERROR("error flushing lame buffers\n");
+
+	return (ret > 0);
+}
+
+static void shout_mp3_encoder_finish(shout_data * sd)
+{
+	lame_data *ld = (lame_data *)sd->encoder_data;
+
+	lame_close(ld->gfp);
+	ld->gfp = NULL;
+}
+
+static int shout_mp3_encoder_init_encoder(shout_data * sd)
+{
+	lame_data *ld = (lame_data *)sd->encoder_data;
+
+	if (NULL == (ld->gfp = lame_init())) {
+		ERROR("error initializing lame encoder for shout\n");
+		return -1;
+	}
+
+	if (sd->quality >= -1.0) {
+		if (0 != lame_set_VBR(ld->gfp, vbr_rh)) {
+			ERROR("error setting lame VBR mode\n");
+			return -1;
+		}
+		if (0 != lame_set_VBR_q(ld->gfp, sd->quality)) {
+			ERROR("error setting lame VBR quality\n");
+			return -1;
+		}
+	} else {
+		if (0 != lame_set_brate(ld->gfp, sd->bitrate)) {
+			ERROR("error setting lame bitrate\n");
+			return -1;
+		}
+	}
+
+	if (0 != lame_set_num_channels(ld->gfp,
+				       sd->audio_format.channels)) {
+		ERROR("error setting lame num channels\n");
+		return -1;
+	}
+
+	if (0 != lame_set_in_samplerate(ld->gfp,
+					sd->audio_format.sampleRate)) {
+		ERROR("error setting lame sample rate\n");
+		return -1;
+	}
+
+	if (0 > lame_init_params(ld->gfp))
+		FATAL("error initializing lame params\n");
+
+	return 0;
+}
+
+static int shout_mp3_encoder_send_metadata(shout_data * sd,
+					   char * song, size_t size)
+{
+	char artist[size];
+	char title[size];
+	int i;
+	struct tag *tag = sd->tag;
+
+	strncpy(artist, "", size);
+	strncpy(title, "", size);
+
+	for (i = 0; i < tag->numOfItems; i++) {
+		switch (tag->items[i]->type) {
+		case TAG_ITEM_ARTIST:
+			strncpy(artist, tag->items[i]->value, size);
+			break;
+		case TAG_ITEM_TITLE:
+			strncpy(title, tag->items[i]->value, size);
+			break;
+
+		default:
+			break;
+		}
+	}
+	snprintf(song, size, "%s - %s", title, artist);
+
+	return 1;
+}
+
+static int shout_mp3_encoder_encode(shout_data * sd,
+				    const char * chunk, size_t len)
+{
+	unsigned int i;
+	int j;
+	float (*lamebuf)[2];
+	shout_buffer *buf = &(sd->buf);
+	unsigned int samples;
+	int bytes = sd->audio_format.bits / 8;
+	lame_data *ld = (lame_data *)sd->encoder_data;
+	int bytes_out;
+
+	samples = len / (bytes * sd->audio_format.channels);
+	/* rough estimate, from lame.h */
+	lamebuf = xmalloc(sizeof(float) * (1.25 * samples + 7200));
+
+	/* this is for only 16-bit audio */
+
+	for (i = 0; i < samples; i++) {
+		for (j = 0; j < sd->audio_format.channels; j++) {
+			lamebuf[j][i] = *((const mpd_sint16 *) chunk);
+			chunk += bytes;
+		}
+	}
+
+	bytes_out = lame_encode_buffer_float(ld->gfp, lamebuf[0], lamebuf[1],
+					     samples, buf->data,
+					     buf->max_len - buf->len);
+	free(lamebuf);
+
+	if (0 > bytes_out) {
+		ERROR("error encoding lame buffer for shout\n");
+		lame_close(ld->gfp);
+		ld->gfp = NULL;
+		return -1;
+	} else
+		buf->len = bytes_out; /* signed to unsigned conversion */
+
+	return 0;
+}
+
+
+shout_encoder_plugin shout_mp3_encoder = {
+	"mp3",
+	SHOUT_FORMAT_MP3,
+
+	shout_mp3_encoder_clear_encoder,
+	shout_mp3_encoder_encode,
+	shout_mp3_encoder_finish,
+	shout_mp3_encoder_init,
+	shout_mp3_encoder_init_encoder,
+	shout_mp3_encoder_send_metadata,
+};
+
+#else
+
+DISABLED_SHOUT_ENCODER_PLUGIN(shout_mp3_encoder);
+
+#endif