/*
* G.722 Codec Native Node.js Addon
*
* This file provides a C++ wrapper around the G.722 codec implementation
* from the sippy/libg722 repository (https://github.com/sippy/libg722).
*
* License Information:
* - Original G.722 C implementation: Mix of public domain (Steve Underwood)
* and permissive licenses (CMU, Sippy Software Inc.)
* - See LICENSE_G722 file for complete license details
* - This wrapper code follows the same permissive licensing
*/
#include <napi.h>
#ifdef G722_ENABLED
#include "g722_encoder.h"
#include "g722_decoder.h"
class G722Wrapper : public Napi::ObjectWrap<G722Wrapper> {
public:
static Napi::Object Init(Napi::Env env, Napi::Object exports);
G722Wrapper(const Napi::CallbackInfo& info);
~G722Wrapper();
private:
Napi::Value Encode(const Napi::CallbackInfo& info);
Napi::Value Decode(const Napi::CallbackInfo& info);
G722_ENC_CTX* encoder_state;
G722_DEC_CTX* decoder_state;
};
Napi::Object G722Wrapper::Init(Napi::Env env, Napi::Object exports) {
Napi::Function func = DefineClass(env, "G722", {
InstanceMethod("encode", &G722Wrapper::Encode),
InstanceMethod("decode", &G722Wrapper::Decode),
});
exports.Set("G722", func);
exports.Set("g722Enabled", Napi::Boolean::New(env, true));
return exports;
}
G722Wrapper::G722Wrapper(const Napi::CallbackInfo& info) : Napi::ObjectWrap<G722Wrapper>(info) {
// Initialize G.722 contexts for 64kbps, standard mode
this->encoder_state = g722_encoder_new(64000, 0);
this->decoder_state = g722_decoder_new(64000, 0);
if (!this->encoder_state || !this->decoder_state) {
Napi::Error::New(info.Env(), "Failed to initialize G.722 codec").ThrowAsJavaScriptException();
}
}
G722Wrapper::~G722Wrapper() {
if (this->encoder_state) {
g722_encoder_destroy(this->encoder_state);
}
if (this->decoder_state) {
g722_decoder_destroy(this->decoder_state);
}
}
Napi::Value G722Wrapper::Encode(const Napi::CallbackInfo& info) {
Napi::Env env = info.Env();
if (info.Length() != 1 || !info[0].IsBuffer()) {
Napi::TypeError::New(env, "PCM buffer expected").ThrowAsJavaScriptException();
return env.Null();
}
Napi::Buffer<int16_t> pcm_buffer = info[0].As<Napi::Buffer<int16_t>>();
int num_samples = pcm_buffer.Length();
// G.722 encodes 2 samples into 1 byte at 64kbps
int output_len = num_samples / 2;
Napi::Buffer<uint8_t> encoded_buffer = Napi::Buffer<uint8_t>::New(env, output_len);
int result = g722_encode(this->encoder_state, pcm_buffer.Data(), num_samples, encoded_buffer.Data());
if (result != output_len) {
Napi::Error::New(env, "G.722 encoding failed").ThrowAsJavaScriptException();
return env.Null();
}
return encoded_buffer;
}
Napi::Value G722Wrapper::Decode(const Napi::CallbackInfo& info) {
Napi::Env env = info.Env();
if (info.Length() != 1 || !info[0].IsBuffer()) {
Napi::TypeError::New(env, "G.722 buffer expected").ThrowAsJavaScriptException();
return env.Null();
}
Napi::Buffer<uint8_t> g722_buffer = info[0].As<Napi::Buffer<uint8_t>>();
int input_len = g722_buffer.Length();
// G.722 decodes 1 byte into 2 samples (4 bytes) at 64kbps
int output_len = input_len * 2;
Napi::Buffer<int16_t> pcm_buffer = Napi::Buffer<int16_t>::New(env, output_len);
int result = g722_decode(this->decoder_state, g722_buffer.Data(), input_len, pcm_buffer.Data());
if (result != output_len) {
Napi::Error::New(env, "G.722 decoding failed").ThrowAsJavaScriptException();
return env.Null();
}
return pcm_buffer;
}
#else
// Stub implementation when G722 is disabled
class G722Stub : public Napi::ObjectWrap<G722Stub> {
public:
static Napi::Object Init(Napi::Env env, Napi::Object exports) {
Napi::Function func = DefineClass(env, "G722", {
InstanceMethod("encode", &G722Stub::ThrowNotSupported),
InstanceMethod("decode", &G722Stub::ThrowNotSupported),
});
exports.Set("G722", func);
exports.Set("g722Enabled", Napi::Boolean::New(env, false));
return exports;
}
G722Stub(const Napi::CallbackInfo& info) : Napi::ObjectWrap<G722Stub>(info) {}
private:
Napi::Value ThrowNotSupported(const Napi::CallbackInfo& info) {
Napi::Error::New(info.Env(), "G.722 codec not compiled in. Set ENABLE_G722=1 during build.").ThrowAsJavaScriptException();
return info.Env().Null();
}
};
#endif
Napi::Object InitAll(Napi::Env env, Napi::Object exports) {
#ifdef G722_ENABLED
return G722Wrapper::Init(env, exports);
#else
return G722Stub::Init(env, exports);
#endif
}
NODE_API_MODULE(g722, InitAll)
