encoder/flac: convert to C++

1 files changed, 351 insertions, 0 deletions

diff --git a/src/encoder/FlacEncoderPlugin.cxx b/src/encoder/FlacEncoderPlugin.cxx
new file mode 100644
index 000000000..3694c5327
--- /dev/null
+++ b/src/encoder/FlacEncoderPlugin.cxx
@@ -0,0 +1,351 @@
+/*
+ * Copyright (C) 2003-2013 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 "FlacEncoderPlugin.hxx"
+#include "encoder_api.h"
+#include "encoder_plugin.h"
+#include "audio_format.h"
+#include "pcm/pcm_buffer.h"
+#include "util/fifo_buffer.h"
+
+extern "C" {
+#include "util/growing_fifo.h"
+}
+
+#include <assert.h>
+#include <string.h>
+
+#include <FLAC/stream_encoder.h>
+
+#if !defined(FLAC_API_VERSION_CURRENT) || FLAC_API_VERSION_CURRENT <= 7
+#error libFLAC is too old
+#endif
+
+struct flac_encoder {
+	struct encoder encoder;
+
+	struct audio_format audio_format;
+	unsigned compression;
+
+	FLAC__StreamEncoder *fse;
+
+	struct pcm_buffer expand_buffer;
+
+	/**
+	 * This buffer will hold encoded data from libFLAC until it is
+	 * picked up with flac_encoder_read().
+	 */
+	struct fifo_buffer *output_buffer;
+};
+
+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 nullptr;
+	}
+
+	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, unsigned bits_per_sample,
+		   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,
+							bits_per_sample)) {
+		g_set_error(error, flac_encoder_quark(), 0,
+			    "error setting flac bit format to %d",
+			    bits_per_sample);
+		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;
+
+	//transfer data to buffer
+	growing_fifo_append(&encoder->output_buffer, data, bytes);
+
+	return FLAC__STREAM_ENCODER_WRITE_STATUS_OK;
+}
+
+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->expand_buffer);
+	fifo_buffer_free(encoder->output_buffer);
+}
+
+static bool
+flac_encoder_open(struct encoder *_encoder, struct audio_format *audio_format,
+		     GError **error)
+{
+	struct flac_encoder *encoder = (struct flac_encoder *)_encoder;
+	unsigned bits_per_sample;
+
+	encoder->audio_format = *audio_format;
+
+	/* FIXME: flac should support 32bit as well */
+	switch (audio_format->format) {
+	case SAMPLE_FORMAT_S8:
+		bits_per_sample = 8;
+		break;
+
+	case SAMPLE_FORMAT_S16:
+		bits_per_sample = 16;
+		break;
+
+	case SAMPLE_FORMAT_S24_P32:
+		bits_per_sample = 24;
+		break;
+
+	default:
+		bits_per_sample = 24;
+		audio_format->format = SAMPLE_FORMAT_S24_P32;
+	}
+
+	/* allocate the encoder */
+	encoder->fse = FLAC__stream_encoder_new();
+	if (encoder->fse == nullptr) {
+		g_set_error(error, flac_encoder_quark(), 0,
+			    "flac_new() failed");
+		return false;
+	}
+
+	if (!flac_encoder_setup(encoder, bits_per_sample, error)) {
+		FLAC__stream_encoder_delete(encoder->fse);
+		return false;
+	}
+
+	pcm_buffer_init(&encoder->expand_buffer);
+
+	encoder->output_buffer = growing_fifo_new();
+
+	/* this immediately outputs data through callback */
+
+	{
+		FLAC__StreamEncoderInitStatus init_status;
+
+		init_status = FLAC__stream_encoder_init_stream(encoder->fse,
+			    flac_write_callback,
+			    nullptr, nullptr, nullptr, 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_encoder_close(_encoder);
+			return false;
+		}
+	}
+
+	return true;
+}
+
+
+static bool
+flac_encoder_flush(struct encoder *_encoder, G_GNUC_UNUSED GError **error)
+{
+	struct flac_encoder *encoder = (struct flac_encoder *)_encoder;
+
+	(void) FLAC__stream_encoder_finish(encoder->fse);
+	return true;
+}
+
+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 = nullptr;
+
+	/* format conversion */
+
+	num_frames = length / audio_format_frame_size(&encoder->audio_format);
+	num_samples = num_frames * encoder->audio_format.channels;
+
+	switch (encoder->audio_format.format) {
+	case SAMPLE_FORMAT_S8:
+		exbuffer = pcm_buffer_get(&encoder->expand_buffer, length*4);
+		pcm8_to_flac((int32_t *)exbuffer, (const int8_t *)data,
+			     num_samples);
+		buffer = exbuffer;
+		break;
+
+	case SAMPLE_FORMAT_S16:
+		exbuffer = pcm_buffer_get(&encoder->expand_buffer, length*2);
+		pcm16_to_flac((int32_t *)exbuffer, (const int16_t *)data,
+			      num_samples);
+		buffer = exbuffer;
+		break;
+
+	case SAMPLE_FORMAT_S24_P32:
+	case SAMPLE_FORMAT_S32:
+		/* 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,
+						      (const FLAC__int32 *)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;
+
+	size_t max_length;
+	const char *src = (const char *)
+		fifo_buffer_read(encoder->output_buffer, &max_length);
+	if (src == nullptr)
+		return 0;
+
+	if (length > max_length)
+		length = max_length;
+
+	memcpy(dest, src, length);
+	fifo_buffer_consume(encoder->output_buffer, length);
+	return length;
+}
+
+static const char *
+flac_encoder_get_mime_type(G_GNUC_UNUSED struct encoder *_encoder)
+{
+	return "audio/flac";
+}
+
+const struct encoder_plugin flac_encoder_plugin = {
+	"flac",
+	flac_encoder_init,
+	flac_encoder_finish,
+	flac_encoder_open,
+	flac_encoder_close,
+	flac_encoder_flush,
+	flac_encoder_flush,
+	nullptr,
+	nullptr,
+	flac_encoder_write,
+	flac_encoder_read,
+	flac_encoder_get_mime_type,
+};
+