Initialize

memfile.c

@@ -0,0 +1,53 @@
+#include "memfile.h"
+#include <malloc.h>
+#include <string.h>
+#include <errno.h>
+
+#ifndef min
+#define min(x, y) (((x) < (y)) ? (x) : (y))
+#endif
+
+MemFile* new_memfile(const char* data, size_t len) {
+    if (!data || !len) return NULL;
+    MemFile* f = malloc(sizeof(MemFile));
+    if (!f) return NULL;
+    memset(f, 0, sizeof(MemFile));
+    f->data = malloc(len);
+    if (!f->data) {
+        free(f);
+        return NULL;
+    }
+    memcpy(f->data, data, len);
+    f->len = len;
+    f->loc = 0;
+    return f;
+}
+
+void free_memfile(MemFile* f) {
+    if (!f) return;
+    if (f->data) {
+        free(f->data);
+    }
+    free(f);
+}
+
+size_t memfile_read(MemFile* f, char* buf, size_t buf_len) {
+    if (!f || !buf) return (size_t)-1;
+    if (!buf_len || f->loc >= f->len) return 0;
+    size_t le = min(buf_len, f->len - f->loc);
+    memcpy(buf, f->data + f->loc, le);
+    f->loc += le;
+    return le;
+}
+
+#define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
+#define FFERRTAG(a, b, c, d) (-(int)MKTAG(a, b, c, d))
+#define AVERROR_EOF FFERRTAG( 'E','O','F',' ')
+#define AVERROR(e) (-(e))
+
+int memfile_readpacket(void* f, uint8_t* buf, int buf_size) {
+    size_t ret = memfile_read((MemFile*)f, (char*)buf, buf_size);
+    if (ret == 0) return AVERROR(EINVAL);
+    else if (ret == (size_t)-1) return -1;
+    else return ret;
+}