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TooTallNateTooTallNate
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encoder: initial progress on the Encoder class
nothing really working yet...
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3 files changed

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3 files changed

+172
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‎index.js

+1-1
Original file line numberDiff line numberDiff line change
@@ -30,4 +30,4 @@ exports.Decoder = require('./lib/decoder');
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* `ogg_packet`s that you can weld into an ogg.Encoder stream.
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*/
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//exports.Encoder = require('./lib/encoder');
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exports.Encoder = require('./lib/encoder');

‎lib/encoder.js

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,133 @@
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/**
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* Module dependencies.
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*/
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var debug = require('debug')('vorbis:encoder');
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var binding = require('./binding');
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var inherits = require('util').inherits;
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var Transform = require('stream').Transform;
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// node v0.8.x compat
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if (!Transform) Transform = require('readable-stream/transform');
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/**
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* Module exports.
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*/
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module.exports = Encoder;
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/**
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* The Vorbis `Encoder` class.
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* Accepts PCM audio data and outputs `ogg_packet` Buffer instances.
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* Input must be 32-bit float samples. You may specify the number of `channels`
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* and the `sampleRate`.
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* You may also specify the "quality" which is a float number from -0.1 to 1.0
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* (low to high quality). If unspecified, the default is 0.6.
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*
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* @param {Object} opts PCM audio format options
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* @api public
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*/
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function Encoder (opts) {
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if (!(this instanceof Encoder)) return new Encoder(opts);
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Transform.call(this, opts);
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this._writableState.objectMode = true;
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this._writableState.lowWaterMark = 0;
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this._writableState.highWaterMark = 0;
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// set to `true` after the headerout() call
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this._headerWritten = false;
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// range from -0.1 to 1.0
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this._quality = 0.6;
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this.vi = new Buffer(binding.sizeof_vorbis_info);
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this.vc = new Buffer(binding.sizeof_vorbis_comment);
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binding.vorbis_info_init(this.vi);
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binding.vorbis_comment_init(this.vc);
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// the `vorbis_dsp_state` and `vorbis_block` stucts get allocated when the
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// initial 3 packets are being written
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this.vd = null;
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this.vb = null;
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}
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inherits(Encoder, Transform);
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/**
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* Adds a vorbis comment to the output ogg stream.
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* All calls to this function must be made *before* any PCM audio data is written
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* to this encoder.
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*
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* @param {String} tag key name (i.e. "ENCODER")
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* @param {String} content value (i.e. "my awesome script")
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* @api public
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*/
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Encoder.prototype.addComment = function (tag, contents) {
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if (this.headerWritten) {
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throw new Error('Can\'t add comment since "comment packet" has already been output');
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} else {
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binding.vorbis_comment_add_tag(this.vc, tag, contents);
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}
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};
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/**
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* Transform stream callback function.
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*
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* @api private
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*/
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Encoder.prototype._transform = function (packet, output, fn) {
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debug('_transform(%d bytes)', packet.length);
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if (!this._headerWritten) {
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var err = this._writeHeader(output);
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if (err) return fn(err);
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}
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};
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/**
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* Initializes the "analysis" data structures and creates the first 3 Vorbis
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* packets to be written to the output ogg stream.
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*
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* @api private
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*/
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Encoder.prototype._writeHeader = function (output) {
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debug('_writeHeader()');
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// encoder init (only VBR currently supported)
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var channels = 2;
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var sampleRate = 44100;
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// TODO: async maybe?
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r = binding.vorbis_encode_init_vbr(this.vi, channels, sampleRate, this._quality);
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if (0 !== r) {
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return new Error(r);
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}
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// synthesis init
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this.vd = new Buffer(binding.sizeof_vorbis_dsp_state);
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this.vb = new Buffer(binding.sizeof_vorbis_block);
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var r = binding.vorbis_analysis_init(this.vd, this.vi);
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if (0 !== r) return new Error(r);
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r = binding.vorbis_block_init(this.vd, this.vb);
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if (0 !== r) return new Error(r);
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// create first 3 packets
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// TODO: async
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var op_header = new Buffer(binding.sizeof_ogg_packet);
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var op_comments = new Buffer(binding.sizeof_ogg_packet);
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var op_code = new Buffer(binding.sizeof_ogg_packet);
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r = binding.vorbis_analysis_headerout(this.vd, this.vc, op_header, op_comments, op_code);
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if (0 !== r) return new Error(r);
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output(op_header); // automatically gets placed in its own page
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output(op_comments);
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output(op_code);
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// imply that a page flush() call is required
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this.emit('flush');
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this._headerWritten = true;
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};

‎src/binding.cc

+38
Original file line numberDiff line numberDiff line change
@@ -28,6 +28,7 @@
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#include "node_pointer.h"
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#include "ogg/ogg.h"
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#include "vorbis/codec.h"
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#include "vorbis/vorbisenc.h"
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using namespace v8;
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using namespace node;
@@ -60,6 +61,15 @@ Handle<Value> node_vorbis_synthesis_init (const Arguments& args) {
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}
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Handle<Value> node_vorbis_analysis_init (const Arguments& args) {
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HandleScope scope;
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vorbis_dsp_state *vd = UnwrapPointer<vorbis_dsp_state *>(args[0]);
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vorbis_info *vi = UnwrapPointer<vorbis_info *>(args[1]);
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int r = vorbis_analysis_init(vd, vi);
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return scope.Close(Integer::New(r));
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}
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Handle<Value> node_vorbis_block_init (const Arguments& args) {
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HandleScope scope;
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vorbis_dsp_state *vd = UnwrapPointer<vorbis_dsp_state *>(args[0]);
@@ -69,6 +79,30 @@ Handle<Value> node_vorbis_block_init (const Arguments& args) {
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}
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Handle<Value> node_vorbis_encode_init_vbr (const Arguments& args) {
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HandleScope scope;
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vorbis_info *vi = UnwrapPointer<vorbis_info *>(args[0]);
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long channels = args[1]->IntegerValue();
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long rate = args[2]->IntegerValue();
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float quality = args[3]->NumberValue();
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int r = vorbis_encode_init_vbr(vi, channels, rate, quality);
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return scope.Close(Integer::New(r));
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}
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/* TODO: async */
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Handle<Value> node_vorbis_analysis_headerout (const Arguments& args) {
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HandleScope scope;
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vorbis_dsp_state *vd = UnwrapPointer<vorbis_dsp_state *>(args[0]);
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vorbis_comment *vc = UnwrapPointer<vorbis_comment *>(args[1]);
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ogg_packet *op_header = UnwrapPointer<ogg_packet *>(args[2]);
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ogg_packet *op_comments = UnwrapPointer<ogg_packet *>(args[3]);
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ogg_packet *op_code = UnwrapPointer<ogg_packet *>(args[4]);
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int r = vorbis_analysis_headerout(vd, vc, op_header, op_comments, op_code);
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return scope.Close(Integer::New(r));
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}
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Handle<Value> node_comment_array (const Arguments& args) {
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HandleScope scope;
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int i;
@@ -256,6 +290,7 @@ void Initialize(Handle<Object> target) {
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SIZEOF(vorbis_comment);
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SIZEOF(vorbis_dsp_state);
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SIZEOF(vorbis_block);
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SIZEOF(ogg_packet);
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/* contants */
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#define CONST(value) \
@@ -281,7 +316,10 @@ void Initialize(Handle<Object> target) {
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NODE_SET_METHOD(target, "vorbis_info_init", node_vorbis_info_init);
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NODE_SET_METHOD(target, "vorbis_comment_init", node_vorbis_comment_init);
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NODE_SET_METHOD(target, "vorbis_synthesis_init", node_vorbis_synthesis_init);
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NODE_SET_METHOD(target, "vorbis_analysis_init", node_vorbis_analysis_init);
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NODE_SET_METHOD(target, "vorbis_block_init", node_vorbis_block_init);
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NODE_SET_METHOD(target, "vorbis_encode_init_vbr", node_vorbis_encode_init_vbr);
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NODE_SET_METHOD(target, "vorbis_analysis_headerout", node_vorbis_analysis_headerout);
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NODE_SET_METHOD(target, "vorbis_synthesis_idheader", node_vorbis_synthesis_idheader);
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NODE_SET_METHOD(target, "vorbis_synthesis_headerin", node_vorbis_synthesis_headerin);
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NODE_SET_METHOD(target, "vorbis_synthesis", node_vorbis_synthesis);

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