Update

memfile.c

@@ -1,5 +1,6 @@
 #include "memfile.h"
 #include <malloc.h>
+#include <stdio.h>
 #include <string.h>
 #include <errno.h>
 
@@ -23,6 +24,16 @@ MemFile* new_memfile(const char* data, size_t len) {
     return f;
 }
 
+CMemFile* new_cmemfile(const char* data, size_t len) {
+    if (!data || !len) return NULL;
+    CMemFile* f = malloc(sizeof(CMemFile));
+    if (!f) return NULL;
+    f->data = data;
+    f->len = len;
+    f->loc = 0;
+    return f;
+}
+
 void free_memfile(MemFile* f) {
     if (!f) return;
     if (f->data) {
@@ -31,6 +42,11 @@ void free_memfile(MemFile* f) {
     free(f);
 }
 
+void free_cmemfile(CMemFile* f) {
+    if (!f) return;
+    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;
@@ -40,6 +56,37 @@ size_t memfile_read(MemFile* f, char* buf, size_t buf_len) {
     return le;
 }
 
+size_t cmemfile_read(CMemFile* f, size_t buf_len, char* buf) {
+    if (!f || !buf) return 0;
+    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;
+}
+
+int cmemfile_seek(CMemFile* f, int64_t offset, int origin) {
+    if (!f) return 1;
+    int64_t npos = 0;
+    if (origin == SEEK_SET) {
+        npos = offset;
+    } else if (origin == SEEK_CUR) {
+        npos = f->loc + offset;
+    } else if (origin == SEEK_END) {
+        npos = f->len + offset;
+    } else {
+        return 1;
+    }
+    if (npos < 0 || npos > f->len) return 1;
+    f->loc = npos;
+    return 0;
+}
+
+int64_t cmemfile_tell(CMemFile* f) {
+    if (!f) return -1;
+    return f->loc;
+}
+
 #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',' ')
@@ -51,3 +98,15 @@ int memfile_readpacket(void* f, uint8_t* buf, int buf_size) {
     else if (ret == (size_t)-1) return -1;
     else return ret;
 }
+
+size_t cmemfile_read2(void* f, size_t buf_len, char* buf) {
+    return cmemfile_read((CMemFile*)f, buf_len, buf);
+}
+
+int cmemfile_seek2(void* f, int64_t offset, int origin) {
+    return cmemfile_seek((CMemFile*)f, offset, origin);
+}
+
+int64_t cmemfile_tell2(void* f) {
+    return cmemfile_tell((CMemFile*)f);
+}