Create @mediabunny/mp3-encoder, restructure and extend build system

packages/mp3-encoder/src/lame-bridge.c

@@ -0,0 +1,40 @@
+/*!
+ * Copyright (c) 2025-present, Vanilagy and contributors
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+#include <emscripten.h>
+#include "../lib/lame.h"
+
+EMSCRIPTEN_KEEPALIVE
+lame_global_flags *init_lame(int number_of_channels, int sample_rate, int bitrate) {
+	lame_global_flags *gfp = lame_init();
+
+	lame_set_num_channels(gfp, number_of_channels);
+	lame_set_in_samplerate(gfp, sample_rate);
+	lame_set_out_samplerate(gfp, sample_rate);
+	lame_set_brate(gfp, bitrate / 1000); // MP3 wants "kilobitrate"
+	lame_set_bWriteVbrTag(gfp, 0);
+
+	int ret_code = lame_init_params(gfp);
+
+	return gfp;
+}
+
+EMSCRIPTEN_KEEPALIVE
+int encode_samples(lame_global_flags *gfp, short int left_buf[], short int right_buf[], int sample_count, unsigned char *dest_buf, int dest_buf_size) {
+	return lame_encode_buffer(gfp, left_buf, right_buf, sample_count, dest_buf, dest_buf_size);
+}
+
+EMSCRIPTEN_KEEPALIVE
+int flush_lame(lame_global_flags *gfp, unsigned char *dest_buf, int dest_buf_size) {
+	return lame_encode_flush(gfp, dest_buf, dest_buf_size);
+}
+
+EMSCRIPTEN_KEEPALIVE
+void close_lame(lame_global_flags *gfp) {
+	lame_close(gfp);
+}