avformat/hlsenc: support mkdir_p for use_localtime_mkdir

when use use_localtime_mkdir to create multi level dir,
ffmpeg give error message:
ffmpeg -re -i ~/Movies/objectC/facebook.mp4 -c copy -use_localtime 1
 -use_localtime_mkdir 1 -hls_segment_filename '%Y%m%d/file-%Y%m%d/%s.ts'
out.m3u8
error message:
Could not create directory 20160926/file-20160926 with use_localtime_mkdir
add mkdir_p for support the multi level dir
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Tested-by: Zuo Genyu <1515161258@qq.com> (Windows)
Signed-off-by: Steven Liu <lingjiujianke@gmail.com>

libavformat/hlsenc.c

@@ -133,6 +133,39 @@ typedef struct HLSContext {
     double initial_prog_date_time;
 } HLSContext;
 
+static int mkdir_p(const char *path) {
+    int ret = 0;
+    char *temp = av_strdup(path);
+    char *pos = temp;
+    char tmp_ch = '\0';
+
+    if (!path || !temp) {
+        return -1;
+    }
+
+    if (!strncmp(temp, "/", 1) || !strncmp(temp, "\\", 1)) {
+        pos++;
+    } else if (!strncmp(temp, "./", 2) || !strncmp(temp, ".\\", 2)) {
+        pos += 2;
+    }
+
+    for ( ; *pos != '\0'; ++pos) {
+        if (*pos == '/' || *pos == '\\') {
+            tmp_ch = *pos;
+            *pos = '\0';
+            ret = mkdir(temp, 0755);
+            *pos = tmp_ch;
+        }
+    }
+
+    if ((*(pos - 1) != '/') || (*(pos - 1) != '\\')) {
+        ret = mkdir(temp, 0755);
+    }
+
+    av_free(temp);
+    return ret;
+}
+
 static int hls_delete_old_segments(HLSContext *hls) {
 
     HLSSegment *segment, *previous_segment = NULL;
@@ -656,7 +689,7 @@ static int hls_start(AVFormatContext *s)
                     return AVERROR(ENOMEM);
                 }
                 dir = av_dirname(fn_copy);
-                if (mkdir(dir, 0777) == -1 && errno != EEXIST) {
+                if (mkdir_p(dir) == -1 && errno != EEXIST) {
                     av_log(oc, AV_LOG_ERROR, "Could not create directory %s with use_localtime_mkdir\n", dir);
                     av_free(fn_copy);
                     return AVERROR(errno);