encoder: introducing flac encoder plugin

Makefile.am

@@ -501,11 +501,13 @@ endif
 ENCODER_CFLAGS = \
 	$(LAME_CFLAGS) \
 	$(TWOLAME_CFLAGS) \
+	$(patsubst -I%/FLAC,-I%,$(FLAC_CFLAGS)) \
 	$(VORBISENC_CFLAGS)
 
 ENCODER_LIBS = \
 	$(LAME_LIBS) \
 	$(TWOLAME_LIBS) \
+	$(FLAC_LIBS) \
 	$(VORBISENC_LIBS)
 
 ENCODER_SRC =
@@ -529,6 +531,10 @@ endif
 if ENABLE_TWOLAME_ENCODER
 ENCODER_SRC += src/encoder/twolame_encoder.c
 endif
+
+if ENABLE_FLAC_ENCODER
+ENCODER_SRC += src/encoder/flac_encoder.c
+endif
 endif
 
 

NEWS

@@ -29,6 +29,8 @@ ver 0.16 (20??/??/??)
   - wavpack: allow more than 2 channels
 * encoders:
   - twolame: new encoder plugin based on libtwolame
+  - flac: new encoder plugin based on libFLAC
+  - wave: new encoder plugin for PCM WAV format
 * output:
   - recorder: new output plugin for recording radio streams
   - alsa: don't recover on CANCEL

configure.ac

@@ -989,6 +989,8 @@ fi
 
 AM_CONDITIONAL(HAVE_FLAC, test x$enable_flac = xyes)
 
+enable_flac_encoder=$enable_flac
+
 if test x$enable_oggflac = xyes; then
 	oldmpdcflags="$MPD_CFLAGS"
 	oldmpdlibs="$MPD_LIBS"
@@ -1087,6 +1089,7 @@ else
 	enable_lame_encoder=no
 	enable_twolame_encoder=no
 	enable_wave_encoder=no
+	enable_flac_encoder=no
 fi
 
 MPD_AUTO_PKG(vorbis_encoder, VORBISENC, [vorbisenc],
@@ -1107,6 +1110,7 @@ MPD_AUTO_PKG(twolame_encoder, TWOLAME, [twolame],
 if test x$enable_vorbis_encoder != xno ||
 	test x$enable_lame_encoder != xno ||
 	test x$enable_twolame_encoder != xno ||
+	test x$enable_flac_encoder != xno ||
 	test x$enable_wave_encoder != xno; then
 	# at least one encoder plugin is enabled
 	enable_encoder=yes
@@ -1194,6 +1198,12 @@ if test x$enable_wave_encoder = xyes; then
 		[Define to enable the PCM wave encoder plugin])
 fi
 
+AM_CONDITIONAL(ENABLE_FLAC_ENCODER, test x$enable_flac_encoder = xyes)
+if test x$enable_flac_encoder = xyes; then
+	AC_DEFINE(ENABLE_FLAC_ENCODER, 1,
+		[Define to enable the FLAC encoder plugin])
+fi
+
 dnl
 dnl Documentation
 dnl
@@ -1444,6 +1454,12 @@ if
 			echo " TwoLAME mp3 encoder ...........disabled"
 		fi
 
+		if test x$enable_flac_encoder = xyes; then
+			echo " FLAC encoder ..................enabled"
+		else
+			echo " FLAC encoder ..................disabled"
+		fi
+
 		if test x$enable_wave_encoder = xyes; then
 			echo " PCM wave encoder ..............enabled"
 		else

src/encoder/flac_encoder.c

+/*
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "encoder_api.h"
+#include "encoder_plugin.h"
+#include "audio_format.h"
+#include "pcm_buffer.h"
+
+#include <assert.h>
+#include <string.h>
+
+#include <FLAC/stream_encoder.h>
+
+struct flac_encoder {
+	struct encoder encoder;
+
+	struct audio_format audio_format;
+	unsigned compression;
+
+	FLAC__StreamEncoder *fse;
+
+	struct pcm_buffer expand_buffer;
+
+	struct pcm_buffer buffer;
+	size_t buffer_length;
+};
+
+extern const struct encoder_plugin flac_encoder_plugin;
+
+static inline GQuark
+flac_encoder_quark(void)
+{
+	return g_quark_from_static_string("flac_encoder");
+}
+
+static bool
+flac_encoder_configure(struct flac_encoder *encoder,
+		const struct config_param *param, G_GNUC_UNUSED GError **error)
+{
+	encoder->compression = config_get_block_unsigned(param, 
+						"compression", 5);
+
+	return true;
+}
+
+static struct encoder *
+flac_encoder_init(const struct config_param *param, GError **error)
+{
+	struct flac_encoder *encoder;
+
+	encoder = g_new(struct flac_encoder, 1);
+	encoder_struct_init(&encoder->encoder, &flac_encoder_plugin);
+
+	/* load configuration from "param" */
+	if (!flac_encoder_configure(encoder, param, error)) {
+		/* configuration has failed, roll back and return error */
+		g_free(encoder);
+		return NULL;
+	}
+
+	return &encoder->encoder;
+}
+
+static void
+flac_encoder_finish(struct encoder *_encoder)
+{
+	struct flac_encoder *encoder = (struct flac_encoder *)_encoder;
+
+	/* the real libFLAC cleanup was already performed by
+	   flac_encoder_close(), so no real work here */
+	g_free(encoder);
+}
+
+static bool
+flac_encoder_setup(struct flac_encoder *encoder, GError **error)
+{
+	if ( !FLAC__stream_encoder_set_compression_level(encoder->fse,
+					encoder->compression)) {
+		g_set_error(error, flac_encoder_quark(), 0,
+			    "error setting flac compression to %d",
+			    encoder->compression);
+		return false;
+	}
+	if ( !FLAC__stream_encoder_set_channels(encoder->fse,
+					encoder->audio_format.channels)) {
+		g_set_error(error, flac_encoder_quark(), 0,
+			    "error setting flac channels num to %d",
+			    encoder->audio_format.channels);
+		return false;
+	}
+	if ( !FLAC__stream_encoder_set_bits_per_sample(encoder->fse,
+					encoder->audio_format.bits)) {
+		g_set_error(error, flac_encoder_quark(), 0,
+			    "error setting flac bit format to %d",
+			    encoder->audio_format.bits);
+		return false;
+	}
+	if ( !FLAC__stream_encoder_set_sample_rate(encoder->fse,
+					encoder->audio_format.sample_rate)) {
+		g_set_error(error, flac_encoder_quark(), 0,
+			    "error setting flac sample rate to %d",
+			    encoder->audio_format.sample_rate);
+		return false;
+	}
+	return true;
+}
+
+static FLAC__StreamEncoderWriteStatus
+flac_write_callback(G_GNUC_UNUSED const FLAC__StreamEncoder *fse,
+	const FLAC__byte data[], size_t bytes, G_GNUC_UNUSED unsigned samples,
+	G_GNUC_UNUSED unsigned current_frame, void *client_data)
+{
+	struct flac_encoder *encoder = (struct flac_encoder *) client_data;
+
+	char *buffer = pcm_buffer_get(&encoder->buffer, encoder->buffer_length + bytes);
+
+	//transfer data to buffer
+	memcpy( buffer + encoder->buffer_length, data, bytes);
+	encoder->buffer_length += bytes;
+
+	return FLAC__STREAM_ENCODER_WRITE_STATUS_OK;
+}
+
+static bool
+flac_encoder_open(struct encoder *_encoder, struct audio_format *audio_format,
+		     GError **error)
+{
+	struct flac_encoder *encoder = (struct flac_encoder *)_encoder;
+	FLAC__StreamEncoderInitStatus init_status;
+
+	encoder->audio_format = *audio_format;
+
+	/* FIXME: flac should support 32bit as well */
+	if (audio_format->bits > 24)
+		audio_format->bits = 24;
+
+	/* allocate the encoder */
+	encoder->fse = FLAC__stream_encoder_new();
+	if (encoder->fse == NULL) {
+		g_set_error(error, flac_encoder_quark(), 0,
+			    "flac_new() failed");
+		return false;
+	}
+
+	if (!flac_encoder_setup(encoder, error)) {
+		FLAC__stream_encoder_delete(encoder->fse);
+		return false;
+	}
+
+	encoder->buffer_length = 0;
+	pcm_buffer_init(&encoder->buffer);
+	pcm_buffer_init(&encoder->expand_buffer);
+
+	/* this immediatelly outputs data throught callback */
+
+	init_status = FLAC__stream_encoder_init_stream(encoder->fse,
+			    flac_write_callback,
+			    NULL, NULL, NULL, encoder);
+
+	if(init_status != FLAC__STREAM_ENCODER_INIT_STATUS_OK) {
+		g_set_error(error, flac_encoder_quark(), 0,
+			    "failed to initialize encoder: %s\n", 
+			    FLAC__StreamEncoderInitStatusString[init_status]);
+		FLAC__stream_encoder_delete(encoder->fse);
+		return false;
+	}
+
+	return true;
+}
+
+static void
+flac_encoder_close(struct encoder *_encoder)
+{
+	struct flac_encoder *encoder = (struct flac_encoder *)_encoder;
+
+	FLAC__stream_encoder_delete(encoder->fse);
+
+	pcm_buffer_deinit(&encoder->buffer);
+	pcm_buffer_deinit(&encoder->expand_buffer);
+}
+
+static bool
+flac_encoder_flush(struct encoder *_encoder, G_GNUC_UNUSED GError **error)
+{
+	struct flac_encoder *encoder = (struct flac_encoder *)_encoder;
+
+	return FLAC__stream_encoder_finish(encoder->fse);
+}
+
+static inline void
+pcm8_to_flac(int32_t *out, const int8_t *in, unsigned num_samples)
+{
+	while (num_samples > 0) {
+		*out++ = *in++;
+		--num_samples;
+	}
+}
+
+static inline void
+pcm16_to_flac(int32_t *out, const int16_t *in, unsigned num_samples)
+{
+	while (num_samples > 0) {
+		*out++ = *in++;
+		--num_samples;
+	}
+}
+
+static bool
+flac_encoder_write(struct encoder *_encoder,
+		      const void *data, size_t length,
+		      G_GNUC_UNUSED GError **error)
+{
+	struct flac_encoder *encoder = (struct flac_encoder *)_encoder;
+	unsigned num_frames, num_samples;
+	void *exbuffer;
+	const void *buffer = NULL;
+
+	/* format conversion */
+
+	num_frames = length / audio_format_frame_size(&encoder->audio_format);
+	num_samples = num_frames * encoder->audio_format.channels;
+
+	switch (encoder->audio_format.bits) {
+	case 8:
+		exbuffer = pcm_buffer_get(&encoder->expand_buffer, length*4);
+		pcm8_to_flac(exbuffer, data, num_samples);
+		buffer = exbuffer;
+		break;
+	case 16:
+		exbuffer = pcm_buffer_get(&encoder->expand_buffer, length*2);
+		pcm16_to_flac(exbuffer, data, num_samples);
+		buffer = exbuffer;
+		break;
+	case 24:
+	case 32: /* nothing need to be done
+		  * format is the same for both mpd and libFLAC */
+		buffer = data;
+		break;
+	}
+
+	/* feed samples to encoder */
+
+	if (!FLAC__stream_encoder_process_interleaved(encoder->fse, buffer,
+							num_frames)) {
+		g_set_error(error, flac_encoder_quark(), 0,
+			    "flac encoder process failed");
+		return false;
+	}
+
+	return true;
+}
+
+static size_t
+flac_encoder_read(struct encoder *_encoder, void *dest, size_t length)
+{
+	struct flac_encoder *encoder = (struct flac_encoder *)_encoder;
+	char *buffer = pcm_buffer_get(&encoder->buffer, encoder->buffer_length);
+
+	if (length > encoder->buffer_length)
+		length = encoder->buffer_length;
+
+	memcpy(dest, buffer, length);
+
+	encoder->buffer_length -= length;
+	memmove(buffer, buffer + length, encoder->buffer_length);
+
+	return length;
+}
+
+const struct encoder_plugin flac_encoder_plugin = {
+	.name = "flac",
+	.init = flac_encoder_init,
+	.finish = flac_encoder_finish,
+	.open = flac_encoder_open,
+	.close = flac_encoder_close,
+	.flush = flac_encoder_flush,
+	.write = flac_encoder_write,
+	.read = flac_encoder_read,
+};

src/encoder_list.c

@@ -28,6 +28,7 @@ extern const struct encoder_plugin vorbis_encoder_plugin;
 extern const struct encoder_plugin lame_encoder_plugin;
 extern const struct encoder_plugin twolame_encoder_plugin;
 extern const struct encoder_plugin wave_encoder_plugin;
+extern const struct encoder_plugin flac_encoder_plugin;
 
 static const struct encoder_plugin *encoder_plugins[] = {
 	&null_encoder_plugin,
@@ -43,6 +44,9 @@ static const struct encoder_plugin *encoder_plugins[] = {
 #ifdef ENABLE_WAVE_ENCODER
 	&wave_encoder_plugin,
 #endif
+#ifdef ENABLE_FLAC_ENCODER
+	&flac_encoder_plugin,
+#endif
 	NULL
 };