1 files changed, 293 insertions, 0 deletions
diff --git a/src/encoder/plugins/LameEncoderPlugin.cxx b/src/encoder/plugins/LameEncoderPlugin.cxx
new file mode 100644
index 000000000..3878b52bb
--- /dev/null
+++ b/src/encoder/plugins/LameEncoderPlugin.cxx
@@ -0,0 +1,293 @@
+/*
+ * Copyright (C) 2003-2014 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 "LameEncoderPlugin.hxx"
+#include "../EncoderAPI.hxx"
+#include "AudioFormat.hxx"
+#include "config/ConfigError.hxx"
+#include "util/NumberParser.hxx"
+#include "util/ReusableArray.hxx"
+#include "util/Manual.hxx"
+#include "util/Error.hxx"
+#include "util/Domain.hxx"
+
+#include <lame/lame.h>
+
+#include <assert.h>
+#include <string.h>
+
+struct LameEncoder final {
+	Encoder encoder;
+
+	AudioFormat audio_format;
+	float quality;
+	int bitrate;
+
+	lame_global_flags *gfp;
+
+	Manual<ReusableArray<unsigned char, 32768>> output_buffer;
+	unsigned char *output_begin, *output_end;
+
+	LameEncoder():encoder(lame_encoder_plugin) {}
+
+	bool Configure(const config_param &param, Error &error);
+};
+
+static constexpr Domain lame_encoder_domain("lame_encoder");
+
+bool
+LameEncoder::Configure(const config_param &param, Error &error)
+{
+	const char *value;
+	char *endptr;
+
+	value = param.GetBlockValue("quality");
+	if (value != nullptr) {
+		/* a quality was configured (VBR) */
+
+		quality = ParseDouble(value, &endptr);
+
+		if (*endptr != '\0' || quality < -1.0 || quality > 10.0) {
+			error.Format(config_domain,
+				     "quality \"%s\" is not a number in the "
+				     "range -1 to 10",
+				     value);
+			return false;
+		}
+
+		if (param.GetBlockValue("bitrate") != nullptr) {
+			error.Set(config_domain,
+				  "quality and bitrate are both defined");
+			return false;
+		}
+	} else {
+		/* a bit rate was configured */
+
+		value = param.GetBlockValue("bitrate");
+		if (value == nullptr) {
+			error.Set(config_domain,
+				  "neither bitrate nor quality defined");
+			return false;
+		}
+
+		quality = -2.0;
+		bitrate = ParseInt(value, &endptr);
+
+		if (*endptr != '\0' || bitrate <= 0) {
+			error.Set(config_domain,
+				  "bitrate should be a positive integer");
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static Encoder *
+lame_encoder_init(const config_param &param, Error &error)
+{
+	LameEncoder *encoder = new LameEncoder();
+
+	/* load configuration from "param" */
+	if (!encoder->Configure(param, error)) {
+		/* configuration has failed, roll back and return error */
+		delete encoder;
+		return nullptr;
+	}
+
+	return &encoder->encoder;
+}
+
+static void
+lame_encoder_finish(Encoder *_encoder)
+{
+	LameEncoder *encoder = (LameEncoder *)_encoder;
+
+	/* the real liblame cleanup was already performed by
+	   lame_encoder_close(), so no real work here */
+	delete encoder;
+}
+
+static bool
+lame_encoder_setup(LameEncoder *encoder, Error &error)
+{
+	if (encoder->quality >= -1.0) {
+		/* a quality was configured (VBR) */
+
+		if (0 != lame_set_VBR(encoder->gfp, vbr_rh)) {
+			error.Set(lame_encoder_domain,
+				  "error setting lame VBR mode");
+			return false;
+		}
+		if (0 != lame_set_VBR_q(encoder->gfp, encoder->quality)) {
+			error.Set(lame_encoder_domain,
+				  "error setting lame VBR quality");
+			return false;
+		}
+	} else {
+		/* a bit rate was configured */
+
+		if (0 != lame_set_brate(encoder->gfp, encoder->bitrate)) {
+			error.Set(lame_encoder_domain,
+				  "error setting lame bitrate");
+			return false;
+		}
+	}
+
+	if (0 != lame_set_num_channels(encoder->gfp,
+				       encoder->audio_format.channels)) {
+		error.Set(lame_encoder_domain,
+			  "error setting lame num channels");
+		return false;
+	}
+
+	if (0 != lame_set_in_samplerate(encoder->gfp,
+					encoder->audio_format.sample_rate)) {
+		error.Set(lame_encoder_domain,
+			  "error setting lame sample rate");
+		return false;
+	}
+
+	if (0 != lame_set_out_samplerate(encoder->gfp,
+					 encoder->audio_format.sample_rate)) {
+		error.Set(lame_encoder_domain,
+			  "error setting lame out sample rate");
+		return false;
+	}
+
+	if (0 > lame_init_params(encoder->gfp)) {
+		error.Set(lame_encoder_domain,
+			  "error initializing lame params");
+		return false;
+	}
+
+	return true;
+}
+
+static bool
+lame_encoder_open(Encoder *_encoder, AudioFormat &audio_format, Error &error)
+{
+	LameEncoder *encoder = (LameEncoder *)_encoder;
+
+	audio_format.format = SampleFormat::S16;
+	audio_format.channels = 2;
+
+	encoder->audio_format = audio_format;
+
+	encoder->gfp = lame_init();
+	if (encoder->gfp == nullptr) {
+		error.Set(lame_encoder_domain, "lame_init() failed");
+		return false;
+	}
+
+	if (!lame_encoder_setup(encoder, error)) {
+		lame_close(encoder->gfp);
+		return false;
+	}
+
+	encoder->output_buffer.Construct();
+	encoder->output_begin = encoder->output_end = nullptr;
+
+	return true;
+}
+
+static void
+lame_encoder_close(Encoder *_encoder)
+{
+	LameEncoder *encoder = (LameEncoder *)_encoder;
+
+	lame_close(encoder->gfp);
+	encoder->output_buffer.Destruct();
+}
+
+static bool
+lame_encoder_write(Encoder *_encoder,
+		   const void *data, size_t length,
+		   gcc_unused Error &error)
+{
+	LameEncoder *encoder = (LameEncoder *)_encoder;
+	const int16_t *src = (const int16_t*)data;
+
+	assert(encoder->output_begin == encoder->output_end);
+
+	const unsigned num_frames =
+		length / encoder->audio_format.GetFrameSize();
+	const unsigned num_samples =
+		length / encoder->audio_format.GetSampleSize();
+
+	/* worst-case formula according to LAME documentation */
+	const size_t output_buffer_size = 5 * num_samples / 4 + 7200;
+	const auto output_buffer = encoder->output_buffer->Get(output_buffer_size);
+
+	/* this is for only 16-bit audio */
+
+	int bytes_out = lame_encode_buffer_interleaved(encoder->gfp,
+						       const_cast<short *>(src),
+						       num_frames,
+						       output_buffer,
+						       output_buffer_size);
+
+	if (bytes_out < 0) {
+		error.Set(lame_encoder_domain, "lame encoder failed");
+		return false;
+	}
+
+	encoder->output_begin = output_buffer;
+	encoder->output_end = output_buffer + bytes_out;
+	return true;
+}
+
+static size_t
+lame_encoder_read(Encoder *_encoder, void *dest, size_t length)
+{
+	LameEncoder *encoder = (LameEncoder *)_encoder;
+
+	const auto begin = encoder->output_begin;
+	assert(begin <= encoder->output_end);
+	const size_t remainning = encoder->output_end - begin;
+	if (length > remainning)
+		length = remainning;
+
+	memcpy(dest, begin, length);
+
+	encoder->output_begin = begin + length;
+	return length;
+}
+
+static const char *
+lame_encoder_get_mime_type(gcc_unused Encoder *_encoder)
+{
+	return "audio/mpeg";
+}
+
+const EncoderPlugin lame_encoder_plugin = {
+	"lame",
+	lame_encoder_init,
+	lame_encoder_finish,
+	lame_encoder_open,
+	lame_encoder_close,
+	nullptr,
+	nullptr,
+	nullptr,
+	nullptr,
+	lame_encoder_write,
+	lame_encoder_read,
+	lame_encoder_get_mime_type,
+};