1 files changed, 419 insertions, 0 deletions
diff --git a/src/encoder/plugins/OpusEncoderPlugin.cxx b/src/encoder/plugins/OpusEncoderPlugin.cxx
new file mode 100644
index 000000000..27b614b86
--- /dev/null
+++ b/src/encoder/plugins/OpusEncoderPlugin.cxx
@@ -0,0 +1,419 @@
+/*
+ * 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 "OpusEncoderPlugin.hxx"
+#include "OggStream.hxx"
+#include "OggSerial.hxx"
+#include "../EncoderAPI.hxx"
+#include "AudioFormat.hxx"
+#include "config/ConfigError.hxx"
+#include "util/Alloc.hxx"
+#include "util/Error.hxx"
+#include "util/Domain.hxx"
+#include "system/ByteOrder.hxx"
+
+#include <opus.h>
+#include <ogg/ogg.h>
+
+#include <assert.h>
+#include <stdlib.h>
+
+struct opus_encoder {
+	/** the base class */
+	Encoder encoder;
+
+	/* configuration */
+
+	opus_int32 bitrate;
+	int complexity;
+	int signal;
+
+	/* runtime information */
+
+	AudioFormat audio_format;
+
+	size_t frame_size;
+
+	size_t buffer_frames, buffer_size, buffer_position;
+	uint8_t *buffer;
+
+	OpusEncoder *enc;
+
+	unsigned char buffer2[1275 * 3 + 7];
+
+	OggStream stream;
+
+	int lookahead;
+
+	ogg_int64_t packetno;
+
+	ogg_int64_t granulepos;
+
+	opus_encoder():encoder(opus_encoder_plugin) {}
+};
+
+static constexpr Domain opus_encoder_domain("opus_encoder");
+
+static bool
+opus_encoder_configure(struct opus_encoder *encoder,
+		       const config_param &param, Error &error)
+{
+	const char *value = param.GetBlockValue("bitrate", "auto");
+	if (strcmp(value, "auto") == 0)
+		encoder->bitrate = OPUS_AUTO;
+	else if (strcmp(value, "max") == 0)
+		encoder->bitrate = OPUS_BITRATE_MAX;
+	else {
+		char *endptr;
+		encoder->bitrate = strtoul(value, &endptr, 10);
+		if (endptr == value || *endptr != 0 ||
+		    encoder->bitrate < 500 || encoder->bitrate > 512000) {
+			error.Set(config_domain, "Invalid bit rate");
+			return false;
+		}
+	}
+
+	encoder->complexity = param.GetBlockValue("complexity", 10u);
+	if (encoder->complexity > 10) {
+		error.Format(config_domain, "Invalid complexity");
+		return false;
+	}
+
+	value = param.GetBlockValue("signal", "auto");
+	if (strcmp(value, "auto") == 0)
+		encoder->signal = OPUS_AUTO;
+	else if (strcmp(value, "voice") == 0)
+		encoder->signal = OPUS_SIGNAL_VOICE;
+	else if (strcmp(value, "music") == 0)
+		encoder->signal = OPUS_SIGNAL_MUSIC;
+	else {
+		error.Format(config_domain, "Invalid signal");
+		return false;
+	}
+
+	return true;
+}
+
+static Encoder *
+opus_encoder_init(const config_param &param, Error &error)
+{
+	opus_encoder *encoder = new opus_encoder();
+
+	/* load configuration from "param" */
+	if (!opus_encoder_configure(encoder, param, error)) {
+		/* configuration has failed, roll back and return error */
+		delete encoder;
+		return nullptr;
+	}
+
+	return &encoder->encoder;
+}
+
+static void
+opus_encoder_finish(Encoder *_encoder)
+{
+	struct opus_encoder *encoder = (struct opus_encoder *)_encoder;
+
+	/* the real libopus cleanup was already performed by
+	   opus_encoder_close(), so no real work here */
+	delete encoder;
+}
+
+static bool
+opus_encoder_open(Encoder *_encoder,
+		  AudioFormat &audio_format,
+		  Error &error)
+{
+	struct opus_encoder *encoder = (struct opus_encoder *)_encoder;
+
+	/* libopus supports only 48 kHz */
+	audio_format.sample_rate = 48000;
+
+	if (audio_format.channels > 2)
+		audio_format.channels = 1;
+
+	switch (audio_format.format) {
+	case SampleFormat::S16:
+	case SampleFormat::FLOAT:
+		break;
+
+	case SampleFormat::S8:
+		audio_format.format = SampleFormat::S16;
+		break;
+
+	default:
+		audio_format.format = SampleFormat::FLOAT;
+		break;
+	}
+
+	encoder->audio_format = audio_format;
+	encoder->frame_size = audio_format.GetFrameSize();
+
+	int error_code;
+	encoder->enc = opus_encoder_create(audio_format.sample_rate,
+					   audio_format.channels,
+					   OPUS_APPLICATION_AUDIO,
+					   &error_code);
+	if (encoder->enc == nullptr) {
+		error.Set(opus_encoder_domain, error_code,
+			  opus_strerror(error_code));
+		return false;
+	}
+
+	opus_encoder_ctl(encoder->enc, OPUS_SET_BITRATE(encoder->bitrate));
+	opus_encoder_ctl(encoder->enc,
+			 OPUS_SET_COMPLEXITY(encoder->complexity));
+	opus_encoder_ctl(encoder->enc, OPUS_SET_SIGNAL(encoder->signal));
+
+	opus_encoder_ctl(encoder->enc, OPUS_GET_LOOKAHEAD(&encoder->lookahead));
+
+	encoder->buffer_frames = audio_format.sample_rate / 50;
+	encoder->buffer_size = encoder->frame_size * encoder->buffer_frames;
+	encoder->buffer_position = 0;
+	encoder->buffer = (unsigned char *)xalloc(encoder->buffer_size);
+
+	encoder->stream.Initialize(GenerateOggSerial());
+	encoder->packetno = 0;
+
+	return true;
+}
+
+static void
+opus_encoder_close(Encoder *_encoder)
+{
+	struct opus_encoder *encoder = (struct opus_encoder *)_encoder;
+
+	encoder->stream.Deinitialize();
+	free(encoder->buffer);
+	opus_encoder_destroy(encoder->enc);
+}
+
+static bool
+opus_encoder_do_encode(struct opus_encoder *encoder, bool eos,
+		       Error &error)
+{
+	assert(encoder->buffer_position == encoder->buffer_size);
+
+	opus_int32 result =
+		encoder->audio_format.format == SampleFormat::S16
+		? opus_encode(encoder->enc,
+			      (const opus_int16 *)encoder->buffer,
+			      encoder->buffer_frames,
+			      encoder->buffer2,
+			      sizeof(encoder->buffer2))
+		: opus_encode_float(encoder->enc,
+				    (const float *)encoder->buffer,
+				    encoder->buffer_frames,
+				    encoder->buffer2,
+				    sizeof(encoder->buffer2));
+	if (result < 0) {
+		error.Set(opus_encoder_domain, "Opus encoder error");
+		return false;
+	}
+
+	encoder->granulepos += encoder->buffer_frames;
+
+	ogg_packet packet;
+	packet.packet = encoder->buffer2;
+	packet.bytes = result;
+	packet.b_o_s = false;
+	packet.e_o_s = eos;
+	packet.granulepos = encoder->granulepos;
+	packet.packetno = encoder->packetno++;
+	encoder->stream.PacketIn(packet);
+
+	encoder->buffer_position = 0;
+
+	return true;
+}
+
+static bool
+opus_encoder_end(Encoder *_encoder, Error &error)
+{
+	struct opus_encoder *encoder = (struct opus_encoder *)_encoder;
+
+	encoder->stream.Flush();
+
+	memset(encoder->buffer + encoder->buffer_position, 0,
+	       encoder->buffer_size - encoder->buffer_position);
+	encoder->buffer_position = encoder->buffer_size;
+
+	return opus_encoder_do_encode(encoder, true, error);
+}
+
+static bool
+opus_encoder_flush(Encoder *_encoder, gcc_unused Error &error)
+{
+	struct opus_encoder *encoder = (struct opus_encoder *)_encoder;
+
+	encoder->stream.Flush();
+	return true;
+}
+
+static bool
+opus_encoder_write_silence(struct opus_encoder *encoder, unsigned fill_frames,
+			   Error &error)
+{
+	size_t fill_bytes = fill_frames * encoder->frame_size;
+
+	while (fill_bytes > 0) {
+		size_t nbytes =
+			encoder->buffer_size - encoder->buffer_position;
+		if (nbytes > fill_bytes)
+			nbytes = fill_bytes;
+
+		memset(encoder->buffer + encoder->buffer_position,
+		       0, nbytes);
+		encoder->buffer_position += nbytes;
+		fill_bytes -= nbytes;
+
+		if (encoder->buffer_position == encoder->buffer_size &&
+		    !opus_encoder_do_encode(encoder, false, error))
+			return false;
+	}
+
+	return true;
+}
+
+static bool
+opus_encoder_write(Encoder *_encoder,
+		   const void *_data, size_t length,
+		   Error &error)
+{
+	struct opus_encoder *encoder = (struct opus_encoder *)_encoder;
+	const uint8_t *data = (const uint8_t *)_data;
+
+	if (encoder->lookahead > 0) {
+		/* generate some silence at the beginning of the
+		   stream */
+
+		assert(encoder->buffer_position == 0);
+
+		if (!opus_encoder_write_silence(encoder, encoder->lookahead,
+						error))
+			return false;
+
+		encoder->lookahead = 0;
+	}
+
+	while (length > 0) {
+		size_t nbytes =
+			encoder->buffer_size - encoder->buffer_position;
+		if (nbytes > length)
+			nbytes = length;
+
+		memcpy(encoder->buffer + encoder->buffer_position,
+		       data, nbytes);
+		data += nbytes;
+		length -= nbytes;
+		encoder->buffer_position += nbytes;
+
+		if (encoder->buffer_position == encoder->buffer_size &&
+		    !opus_encoder_do_encode(encoder, false, error))
+			return false;
+	}
+
+	return true;
+}
+
+static void
+opus_encoder_generate_head(struct opus_encoder *encoder)
+{
+	unsigned char header[19];
+	memcpy(header, "OpusHead", 8);
+	header[8] = 1;
+	header[9] = encoder->audio_format.channels;
+	*(uint16_t *)(header + 10) = ToLE16(encoder->lookahead);
+	*(uint32_t *)(header + 12) =
+		ToLE32(encoder->audio_format.sample_rate);
+	header[16] = 0;
+	header[17] = 0;
+	header[18] = 0;
+
+	ogg_packet packet;
+	packet.packet = header;
+	packet.bytes = 19;
+	packet.b_o_s = true;
+	packet.e_o_s = false;
+	packet.granulepos = 0;
+	packet.packetno = encoder->packetno++;
+	encoder->stream.PacketIn(packet);
+	encoder->stream.Flush();
+}
+
+static void
+opus_encoder_generate_tags(struct opus_encoder *encoder)
+{
+	const char *version = opus_get_version_string();
+	size_t version_length = strlen(version);
+
+	size_t comments_size = 8 + 4 + version_length + 4;
+	unsigned char *comments = (unsigned char *)xalloc(comments_size);
+	memcpy(comments, "OpusTags", 8);
+	*(uint32_t *)(comments + 8) = ToLE32(version_length);
+	memcpy(comments + 12, version, version_length);
+	*(uint32_t *)(comments + 12 + version_length) = ToLE32(0);
+
+	ogg_packet packet;
+	packet.packet = comments;
+	packet.bytes = comments_size;
+	packet.b_o_s = false;
+	packet.e_o_s = false;
+	packet.granulepos = 0;
+	packet.packetno = encoder->packetno++;
+	encoder->stream.PacketIn(packet);
+	encoder->stream.Flush();
+
+	free(comments);
+}
+
+static size_t
+opus_encoder_read(Encoder *_encoder, void *dest, size_t length)
+{
+	struct opus_encoder *encoder = (struct opus_encoder *)_encoder;
+
+	if (encoder->packetno == 0)
+		opus_encoder_generate_head(encoder);
+	else if (encoder->packetno == 1)
+		opus_encoder_generate_tags(encoder);
+
+	return encoder->stream.PageOut(dest, length);
+}
+
+static const char *
+opus_encoder_get_mime_type(gcc_unused Encoder *_encoder)
+{
+	return  "audio/ogg";
+}
+
+const EncoderPlugin opus_encoder_plugin = {
+	"opus",
+	opus_encoder_init,
+	opus_encoder_finish,
+	opus_encoder_open,
+	opus_encoder_close,
+	opus_encoder_end,
+	opus_encoder_flush,
+	nullptr,
+	nullptr,
+	opus_encoder_write,
+	opus_encoder_read,
+	opus_encoder_get_mime_type,
+};