Files
prosperon/audio/mp3.c
2025-12-11 14:42:44 -06:00

106 lines
3.0 KiB
C

#include "cell.h"
#include <stdlib.h>
#define DR_MP3_IMPLEMENTATION
#include "dr_mp3.h"
static JSValue mp3_make_info(JSContext *js, drmp3_uint32 channels, drmp3_uint32 sample_rate, drmp3_uint64 frames)
{
JSValue obj = JS_NewObject(js);
JS_SetPropertyStr(js, obj, "channels", JS_NewInt32(js, channels));
JS_SetPropertyStr(js, obj, "sample_rate", JS_NewInt32(js, sample_rate));
JS_SetPropertyStr(js, obj, "bits_per_sample", JS_NewInt32(js, 16));
double total_frames = frames == DRMP3_UINT64_MAX ? -1.0 : (double)frames;
JS_SetPropertyStr(js, obj, "total_pcm_frames", JS_NewFloat64(js, total_frames));
JS_SetPropertyStr(js, obj, "decoded_bytes_per_frame",
JS_NewInt32(js, (int)((size_t)channels * sizeof(drmp3_int16))));
JS_SetPropertyStr(js, obj, "format", JS_NewString(js, "s16"));
return obj;
}
JSC_CCALL(mp3_info,
size_t len;
void *data = js_get_blob_data(js, &len, argv[0]);
if (data == -1)
return JS_EXCEPTION;
if (!data)
return JS_ThrowReferenceError(js, "invalid MP3 data");
drmp3 mp3;
if (!drmp3_init_memory(&mp3, data, len, NULL))
return JS_ThrowReferenceError(js, "invalid MP3 data");
drmp3_uint32 channels = mp3.channels;
drmp3_uint32 sample_rate = mp3.sampleRate;
drmp3_uint64 frames = mp3.totalPCMFrameCount;
if (frames == DRMP3_UINT64_MAX)
frames = drmp3_get_pcm_frame_count(&mp3);
JSValue info = mp3_make_info(js, channels, sample_rate, frames);
drmp3_uninit(&mp3);
return info;
)
static int mp3_calc_bytes(drmp3_uint32 channels, drmp3_uint64 frames, size_t *out_bytes)
{
if (!out_bytes || channels == 0)
return -1;
size_t bytes_per_frame = (size_t)channels * sizeof(drmp3_int16);
if (frames > SIZE_MAX / bytes_per_frame)
return -1;
*out_bytes = (size_t)(frames * bytes_per_frame);
return 0;
}
JSC_CCALL(mp3_decode,
size_t len;
void *data = js_get_blob_data(js, &len, argv[0]);
if (data == -1)
return JS_EXCEPTION;
if (!data)
return JS_ThrowReferenceError(js, "invalid MP3 data");
drmp3_config config;
drmp3_uint64 frames = 0;
float *pcm = drmp3_open_memory_and_read_pcm_frames_f32(data, len, &config, &frames, NULL);
if (!pcm)
return JS_ThrowReferenceError(js, "failed to decode MP3 data");
size_t bytes_per_frame = (size_t)config.channels * sizeof(float);
size_t total_bytes;
if (frames > SIZE_MAX / bytes_per_frame) {
drmp3_free(pcm, NULL);
return JS_ThrowRangeError(js, "MP3 output too large");
}
total_bytes = (size_t)(frames * bytes_per_frame);
JSValue result = mp3_make_info(js, config.channels, config.sampleRate, frames);
// Update format info
JS_SetPropertyStr(js, result, "format", JS_NewString(js, "f32"));
JS_SetPropertyStr(js, result, "decoded_bytes_per_frame", JS_NewInt32(js, (int)bytes_per_frame));
JSValue blob = js_new_blob_stoned_copy(js, pcm, total_bytes);
JS_SetPropertyStr(js, result, "pcm", blob);
drmp3_free(pcm, NULL);
return result;
)
static const JSCFunctionListEntry js_mp3_funcs[] = {
MIST_FUNC_DEF(mp3, info, 1),
MIST_FUNC_DEF(mp3, decode, 1)
};
CELL_USE_FUNCS(js_mp3_funcs)