FooIbar
f2d94f1ed6
* Use product flavors to provide marshmallow support Fix crashing when opening archives * Fix artifacts upload * Change artifact names * Fix app updater
78 lines
2.5 KiB
C
78 lines
2.5 KiB
C
#include <jni.h>
|
|
#include <string.h>
|
|
#include <stdbool.h>
|
|
#include <unistd.h>
|
|
#include <android/log.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/mman.h>
|
|
|
|
#define LOG_TAG "gifUtils"
|
|
|
|
#include "ehviewer.h"
|
|
|
|
#define GIF_HEADER_87A "GIF87a"
|
|
#define GIF_HEADER_89A "GIF89a"
|
|
#define GIF_HEADER_LENGTH 6
|
|
|
|
static int FRAME_DELAY_START_MARKER = 0x0021F904;
|
|
|
|
typedef signed char byte;
|
|
|
|
#define FRAME_DELAY_START_MARKER ((byte*)(&FRAME_DELAY_START_MARKER))
|
|
#define MINIMUM_FRAME_DELAY 2
|
|
#define DEFAULT_FRAME_DELAY 10
|
|
|
|
static inline bool isGif(void *addr) {
|
|
return !memcmp(addr, GIF_HEADER_87A, GIF_HEADER_LENGTH) ||
|
|
!memcmp(addr, GIF_HEADER_89A, GIF_HEADER_LENGTH);
|
|
}
|
|
|
|
static void doRewrite(byte *addr, size_t size) {
|
|
if (size < 7 || !isGif(addr)) return;
|
|
for (size_t i = 0; i < size - 8; i++) {
|
|
// TODO: Optimize this hex find with SIMD?
|
|
if (addr[i] == FRAME_DELAY_START_MARKER[3] && addr[i + 1] == FRAME_DELAY_START_MARKER[2] &&
|
|
addr[i + 2] == FRAME_DELAY_START_MARKER[1] &&
|
|
addr[i + 3] == FRAME_DELAY_START_MARKER[0]) {
|
|
byte *end = addr + i + 4;
|
|
if (end[4] != 0) continue;
|
|
int frameDelay = end[2] << 8 | end[1];
|
|
if (frameDelay > MINIMUM_FRAME_DELAY)
|
|
break; // Quit if the first block looks normal, for performance
|
|
end[1] = DEFAULT_FRAME_DELAY;
|
|
end[2] = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
JNIEXPORT jboolean JNICALL
|
|
Java_com_hippo_ehviewer_jni_GifUtilsKt_isGif(JNIEnv *env, jclass clazz, jint fd) {
|
|
byte buffer[GIF_HEADER_LENGTH];
|
|
return read(fd, buffer, GIF_HEADER_LENGTH) == GIF_HEADER_LENGTH &&
|
|
isGif(buffer);
|
|
}
|
|
|
|
JNIEXPORT void JNICALL
|
|
Java_com_hippo_ehviewer_jni_GifUtilsKt_rewriteGifSource(JNIEnv *env, jclass clazz, jobject buffer) {
|
|
byte *addr = (*env)->GetDirectBufferAddress(env, buffer);
|
|
size_t size = (*env)->GetDirectBufferCapacity(env, buffer);
|
|
doRewrite(addr, size);
|
|
}
|
|
|
|
JNIEXPORT jobject JNICALL
|
|
Java_com_hippo_ehviewer_jni_GifUtilsKt_mmap(JNIEnv *env, jclass clazz, jint fd) {
|
|
struct stat64 st;
|
|
fstat64(fd, &st);
|
|
size_t size = st.st_size;
|
|
byte *addr = mmap64(0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
|
|
if (addr == MAP_FAILED) return NULL;
|
|
return (*env)->NewDirectByteBuffer(env, addr, size);
|
|
}
|
|
|
|
JNIEXPORT void JNICALL
|
|
Java_com_hippo_ehviewer_jni_GifUtilsKt_munmap(JNIEnv *env, jclass clazz, jobject buffer) {
|
|
byte *addr = (*env)->GetDirectBufferAddress(env, buffer);
|
|
size_t size = (*env)->GetDirectBufferCapacity(env, buffer);
|
|
munmap(addr, size);
|
|
}
|