Compile WebAssembly program dependent on external libraries Opus and Faac - c

Question

1.I git clone opus and faac.
2.second, I am coding:
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <opus.h>
#include <faac.h>
void Opus2AacInit() {
int err_code = 0;
unsigned long input_samples = 0;
decoder = opus_decoder_create(SAMPLE_RATE, CHANNELS, &err_code);
if ( err_code < 0 ) {
flag = FALSE;
DebugPrint("%s Opus2Pcm-> opus_decoder_create err_code < 0, err_code:%d\n", ERROR, err_code);
return;
}
enc_handle = faacEncOpen(SAMPLE_RATE, CHANNELS, &input_samples, &max_output_bytes);
if ( enc_handle == NULL ) {
flag = FALSE;
DebugPrint("%s Opus2AacInit-> hEncoder == NULL, failed\n", ERROR);
return;
}
pcm_buffer_size = input_samples * PCM_BIT_SIZE / 8;
DebugPrint("%s Opus2AacInit-> input_samples:%lu, max_output_bytest:%lu, pcm_buffer_size:%d\n", INFO, input_samples, max_output_bytes, pcm_buffer_size);
aac_buffer = (unsigned char *)malloc(max_output_bytes);
pcm_buffer = (unsigned char *)malloc(pcm_buffer_size);
enc_configuration = faacEncGetCurrentConfiguration(enc_handle);
enc_configuration->inputFormat = FAAC_INPUT_16BIT;
aac_ret = faacEncSetConfiguration(enc_handle, enc_configuration);
flag = TRUE;
}
you can see, i am using opus and aac in my project. but that has problem when i complied my project to use webassembly.
emcc ../hello/aac/opus2aac.c -s WASM=1 -s "MODULARIZE=1" -s "EXPORT_NAME='Opus2Aac'" -s "BINARYEN_METHOD='native-wasm'" -s "EXPORTED_FUNCTIONS=['_Opus2AacInit', '_Opus2Aac', '_test']" -o ../hello/aac/opus2aac.js -s EXTRA_EXPORTED_RUNTIME_METHODS='["ccall", "cwrap"]'
#include <opus.h>
^~~~~~~~
1 error generated.
ERROR:root:compiler frontend failed to generate LLVM bitcode, halting
so, I do not know how to build two library to my project by using webassembly?
thanks.

Answer 1

You'll need to include the source code and header files for both libopus and faac with the proper locations on your computer, similar to this:
emcc \
-o ../hello/aac/opus2aac.js \
-s WASM=1 -s "MODULARIZE=1" -s "EXPORT_NAME='Opus2Aac'" \
-s "BINARYEN_METHOD='native-wasm'" \
-s "EXPORTED_FUNCTIONS=['_Opus2AacInit', '_Opus2Aac', '_test']" \
-s EXTRA_EXPORTED_RUNTIME_METHODS='["ccall", "cwrap"]' \
-I "$LIBOPUS_DIR/include" \
-I "$FAAC_DIR/include" \
"$LIBOPUS_DIR" \
"$FAAC_DIR" \
../hello/aac/opus2aac.c
To speed things up during development, I recommend that you compile libopus and facc separately with emcc and then include the compiled *.dylib files into your build command. I did something similar with Opus in this Makefile