encoder: added lame mp3 encoder

This new LAME encoder plugin is based on the existing shout_mp3.c
plugin.

configure.ac

@@ -594,6 +594,10 @@ AM_CONDITIONAL(ENABLE_VORBIS_ENCODER, test x$enable_shout_ogg = xyes)
 if test x$enable_shout_ogg = xyes; then
 	AC_DEFINE(ENABLE_VORBIS_ENCODER, 1, [Define to enable the vorbis encoder plugin]),
 fi
+AM_CONDITIONAL(ENABLE_LAME_ENCODER, test x$enable_shout_mp3 = xyes)
+if test x$enable_shout_mp3 = xyes; then
+	AC_DEFINE(ENABLE_LAME_ENCODER, 1, [Define to enable the lame encoder plugin]),
+fi
 
 if test x$enable_ao = xyes; then
 	PKG_CHECK_MODULES(AO, [ao],

src/Makefile.am

@@ -352,6 +352,10 @@ mpd_SOURCES += encoder_list.c
 if ENABLE_VORBIS_ENCODER
 mpd_SOURCES += encoder/vorbis_encoder.c
 endif
+
+if ENABLE_LAME_ENCODER
+mpd_SOURCES += encoder/lame_encoder.c
+endif
 endif
 
 

src/encoder/lame_encoder.c

@@ -0,0 +1,284 @@
+/*
+ * Copyright (C) 2003-2009 The Music Player Daemon Project
+ * 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 "encoder_api.h"
+#include "encoder_plugin.h"
+#include "audio_format.h"
+
+#include <lame/lame.h>
+#include <assert.h>
+#include <string.h>
+
+struct lame_encoder {
+	struct encoder encoder;
+
+	struct audio_format audio_format;
+	float quality;
+	int bitrate;
+
+	lame_global_flags *gfp;
+
+	unsigned char buffer[32768];
+	size_t buffer_length;
+};
+
+extern const struct encoder_plugin lame_encoder_plugin;
+
+static inline GQuark
+lame_encoder_quark(void)
+{
+	return g_quark_from_static_string("lame_encoder");
+}
+
+static bool
+lame_encoder_configure(struct lame_encoder *encoder,
+		       const struct config_param *param, GError **error)
+{
+	const char *value;
+	char *endptr;
+
+	value = config_get_block_string(param, "quality", NULL);
+	if (value != NULL) {
+		/* a quality was configured (VBR) */
+
+		encoder->quality = g_ascii_strtod(value, &endptr);
+
+		if (*endptr != '\0' || encoder->quality < -1.0 ||
+		    encoder->quality > 10.0) {
+			g_set_error(error, lame_encoder_quark(), 0,
+				    "quality \"%s\" is not a number in the "
+				    "range -1 to 10, line %i",
+				    value, param->line);
+			return false;
+		}
+
+		if (config_get_block_string(param, "bitrate", NULL) != NULL) {
+			g_set_error(error, lame_encoder_quark(), 0,
+				    "quality and bitrate are "
+				    "both defined (line %i)",
+				    param->line);
+			return false;
+		}
+	} else {
+		/* a bit rate was configured */
+
+		value = config_get_block_string(param, "bitrate", NULL);
+		if (value == NULL) {
+			g_set_error(error, lame_encoder_quark(), 0,
+				    "neither bitrate nor quality defined "
+				    "at line %i",
+				    param->line);
+			return false;
+		}
+
+		encoder->quality = -2.0;
+		encoder->bitrate = g_ascii_strtoll(value, &endptr, 10);
+
+		if (*endptr != '\0' || encoder->bitrate <= 0) {
+			g_set_error(error, lame_encoder_quark(), 0,
+				    "bitrate at line %i should be a positive integer",
+				    param->line);
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static struct encoder *
+lame_encoder_init(const struct config_param *param, GError **error)
+{
+	struct lame_encoder *encoder;
+
+	encoder = g_new(struct lame_encoder, 1);
+	encoder_struct_init(&encoder->encoder, &lame_encoder_plugin);
+
+	/* load configuration from "param" */
+	if (!lame_encoder_configure(encoder, param, error)) {
+		/* configuration has failed, roll back and return error */
+		g_free(encoder);
+		return NULL;
+	}
+
+	return &encoder->encoder;
+}
+
+static void
+lame_encoder_finish(struct encoder *_encoder)
+{
+	struct lame_encoder *encoder = (struct lame_encoder *)_encoder;
+
+	/* the real liblame cleanup was already performed by
+	   lame_encoder_close(), so no real work here */
+	g_free(encoder);
+}
+
+static bool
+lame_encoder_setup(struct lame_encoder *encoder, GError **error)
+{
+	if (encoder->quality >= -1.0) {
+		/* a quality was configured (VBR) */
+
+		if (0 != lame_set_VBR(encoder->gfp, vbr_rh)) {
+			g_set_error(error, lame_encoder_quark(), 0,
+				    "error setting lame VBR mode");
+			return false;
+		}
+		if (0 != lame_set_VBR_q(encoder->gfp, encoder->quality)) {
+			g_set_error(error, lame_encoder_quark(), 0,
+				    "error setting lame VBR quality");
+			return false;
+		}
+	} else {
+		/* a bit rate was configured */
+
+		if (0 != lame_set_brate(encoder->gfp, encoder->bitrate)) {
+			g_set_error(error, lame_encoder_quark(), 0,
+				    "error setting lame bitrate");
+			return false;
+		}
+	}
+
+	if (0 != lame_set_num_channels(encoder->gfp,
+				       encoder->audio_format.channels)) {
+		g_set_error(error, lame_encoder_quark(), 0,
+			    "error setting lame num channels");
+		return false;
+	}
+
+	if (0 != lame_set_in_samplerate(encoder->gfp,
+					encoder->audio_format.sample_rate)) {
+		g_set_error(error, lame_encoder_quark(), 0,
+			    "error setting lame sample rate");
+		return false;
+	}
+
+	if (0 > lame_init_params(encoder->gfp)) {
+		g_set_error(error, lame_encoder_quark(), 0,
+			    "error initializing lame params");
+		return false;
+	}
+
+	return true;
+}
+
+static bool
+lame_encoder_open(struct encoder *_encoder, struct audio_format *audio_format,
+		  GError **error)
+{
+	struct lame_encoder *encoder = (struct lame_encoder *)_encoder;
+
+	audio_format->bits = 16;
+	audio_format->channels = 2;
+
+	encoder->audio_format = *audio_format;
+
+	encoder->gfp = lame_init();
+	if (encoder->gfp == NULL) {
+		g_set_error(error, lame_encoder_quark(), 0,
+			    "lame_init() failed");
+		return false;
+	}
+
+	if (!lame_encoder_setup(encoder, error)) {
+		lame_close(encoder->gfp);
+		return false;
+	}
+
+	encoder->buffer_length = 0;
+
+	return true;
+}
+
+static void
+lame_encoder_close(struct encoder *_encoder)
+{
+	struct lame_encoder *encoder = (struct lame_encoder *)_encoder;
+
+	lame_close(encoder->gfp);
+}
+
+static bool
+lame_encoder_write(struct encoder *_encoder,
+		   const void *data, size_t length,
+		   G_GNUC_UNUSED GError **error)
+{
+	struct lame_encoder *encoder = (struct lame_encoder *)_encoder;
+	unsigned num_frames;
+	float *left, *right;
+	const int16_t *src = (const int16_t*)data;
+	unsigned int i;
+	int bytes_out;
+
+	assert(encoder->buffer_length == 0);
+
+	num_frames =
+		length / audio_format_frame_size(&encoder->audio_format);
+	left = g_malloc(sizeof(left[0]) * num_frames);
+	right = g_malloc(sizeof(right[0]) * num_frames);
+
+	/* this is for only 16-bit audio */
+
+	for (i = 0; i < num_frames; i++) {
+		left[i] = *src++;
+		right[i] = *src++;
+	}
+
+	bytes_out = lame_encode_buffer_float(encoder->gfp, left, right,
+					     num_frames, encoder->buffer,
+					     sizeof(encoder->buffer));
+
+	g_free(left);
+	g_free(right);
+
+	if (bytes_out < 0) {
+		g_set_error(error, lame_encoder_quark(), 0,
+			    "lame encoder failed");
+		return false;
+	}
+
+	encoder->buffer_length = (size_t)bytes_out;
+	return true;
+}
+
+static size_t
+lame_encoder_read(struct encoder *_encoder, void *dest, size_t length)
+{
+	struct lame_encoder *encoder = (struct lame_encoder *)_encoder;
+
+	if (length > encoder->buffer_length)
+		length = encoder->buffer_length;
+
+	memcpy(dest, encoder->buffer, length);
+
+	encoder->buffer_length -= length;
+	memmove(encoder->buffer, encoder->buffer + length,
+		encoder->buffer_length);
+
+	return length;
+}
+
+const struct encoder_plugin lame_encoder_plugin = {
+	.name = "lame",
+	.init = lame_encoder_init,
+	.finish = lame_encoder_finish,
+	.open = lame_encoder_open,
+	.close = lame_encoder_close,
+	.write = lame_encoder_write,
+	.read = lame_encoder_read,
+};

src/encoder_list.c

@@ -23,10 +23,14 @@
 #include <string.h>
 
 extern const struct encoder_plugin vorbis_encoder_plugin;
+extern const struct encoder_plugin lame_encoder_plugin;
 
 static const struct encoder_plugin *encoder_plugins[] = {
 #ifdef ENABLE_VORBIS_ENCODER
 	&vorbis_encoder_plugin,
+#endif
+#ifdef ENABLE_LAME_ENCODER
+	&lame_encoder_plugin,
 #endif
 	NULL
 };