jni: add libmpg123

2026-03-02 09:42:44 +01:00
parent fe0b740bff
commit ef5a0e678c
20 changed files with 7862 additions and 0 deletions
--- a/app/src/main/cpp/mp3file.cpp
+++ b/app/src/main/cpp/mp3file.cpp
@@ -0,0 +1,93 @@
+//
+// Created by david on 17.05.20.
+//
+
+#define LOG_TAG "mp3file"
+
+#include "mp3file.h"
+#include <string.h>
+#include <cstdlib>
+#include "logging.h"
+
+MP3File* mp3file_init(mpg123_handle *handle) {
+    MP3File* mp3file = (MP3File *) malloc(sizeof(MP3File));
+    if(mp3file == NULL) return NULL;
+    memset(mp3file, 0, sizeof(MP3File));
+    mp3file->handle = handle;
+    return mp3file;
+}
+
+void mp3file_delete(MP3File *mp3file) {
+    if(mp3file == NULL) return;
+    mpg123_close(mp3file->handle);
+    mpg123_delete(mp3file->handle);
+    if(mp3file->buffer) {
+        free(mp3file->buffer);
+        mp3file->buffer = 0;
+    }
+    free(mp3file);
+}
+
+MP3File* mp3file_open(const char *filename, int forceEncoding) {
+    const char *errorText = "";
+#define handleError(text) \
+    do { \
+        errorText = text; \
+        goto on_error; \
+    } while(0)
+
+    int err = MPG123_OK;
+    mpg123_handle *mh = mpg123_new(NULL, &err);
+    if(err != MPG123_OK || mh == NULL) {
+        LOGE("mpg123_new() failed: %s", mpg123_plain_strerror(err));
+        return NULL;
+    }
+
+    MP3File* mp3 = mp3file_init(mh);
+    if(mp3 == NULL) handleError("malloc() failed");
+    err = mpg123_open(mh, filename);
+    if(err != MPG123_OK) handleError("mpg123_open()");
+
+    int encoding;
+    err = mpg123_getformat(mh, &mp3->rate, &mp3->channels, &encoding);
+    if(err != MPG123_OK) handleError("mpg123_getformat()");
+    if(encoding != MPG123_ENC_SIGNED_16) handleError("unknown file encoding");
+
+    if(forceEncoding != 0) {
+        encoding = forceEncoding;
+    }
+
+    // Ensure that this output format will not change
+    // (it could, when we allow it).
+    mpg123_format_none(mh);
+    err = mpg123_format(mh, mp3->rate, mp3->channels, encoding);
+    if(err != MPG123_OK) handleError("could not set mpg123_format()");
+
+    mp3->buffer_size = mpg123_outblock(mh);
+    mp3->buffer = (unsigned char*) malloc(mp3->buffer_size);
+    if(mp3->buffer == NULL) handleError("malloc() failed");
+
+    mp3->num_samples = mpg123_length(mh);
+    mp3->samples_per_frame = mpg123_spf(mh);
+    mp3->secs_per_frame = mpg123_tpf(mh);
+
+    if (mp3->num_samples == MPG123_ERR || mp3->samples_per_frame < 0)
+        mp3->num_frames = 0;
+    else
+        mp3->num_frames = mp3->num_samples / mp3->samples_per_frame;
+
+    if (mp3->num_samples == MPG123_ERR || mp3->samples_per_frame < 0 || mp3->secs_per_frame < 0)
+        mp3->duration = 0;
+    else
+        mp3->duration = mp3->num_samples / mp3->samples_per_frame * mp3->secs_per_frame;
+
+    LOGV("channels: %d rate: %ld num_samples: %ld", mp3->channels, mp3->rate, mp3->num_samples);
+    return mp3;
+
+on_error:
+    LOGE("%s, err = %s", errorText, mpg123_plain_strerror(err));
+    mp3file_delete(mp3);
+    return NULL;
+
+#undef handleError
+}