[FFmpeg-devel,GSOC] add a fuzz testing in libavcodec/tests

diff --git a/libavcodec/tests/target_avpacket_fuzzer.c b/libavcodec/tests/target_avpacket_fuzzer.c
new file mode 100644
index 0000000000..22f9898210
--- /dev/null
+++ b/libavcodec/tests/target_avpacket_fuzzer.c
@@ -0,0 +1,114 @@ 
+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <inttypes.h>
+#include <string.h>
+#include "libavcodec/avcodec.h"
+#include "libavutil/error.h"
+#include "config.h"
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);
+
+static int setup_side_data_entry(AVPacket* avpkt)
+{
+    const char *data_name = NULL;
+    int ret = 0, bytes;
+    uint8_t *extra_data = NULL;
+
+
+    /* get side_data_name string */
+    data_name = av_packet_side_data_name(AV_PKT_DATA_NEW_EXTRADATA);
+
+    /* Allocate a memory bloc */
+    bytes = strlen(data_name);
+
+    if(!(extra_data = (uint8_t *)av_malloc(bytes))){
+        ret = AVERROR(ENOMEM);
+        fprintf(stderr, "Error occurred: %s\n", av_err2str(ret));
+        exit(1);
+    }
+    /* copy side_data_name to extra_data array */
+    memcpy(extra_data, data_name, bytes);
+
+    /* create side data for AVPacket */
+    ret = av_packet_add_side_data(avpkt, AV_PKT_DATA_NEW_EXTRADATA,
+                                        extra_data, bytes);
+    if(ret < 0){
+        fprintf(stderr,
+                "Error occurred in av_packet_add_side_data: %s\n",
+                av_err2str(ret));
+    }
+
+    return ret;
+}
+
+static int initializations(AVPacket* avpkt)
+{
+    av_init_packet(avpkt);
+    int ret;
+    ret = setup_side_data_entry(avpkt);
+
+    return ret;
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) 
+{
+    AVPacket avpkt;
+    memcmp(&avpkt,data,sizeof(AVPacket));
+
+    int num;
+    memcmp(&num,data+sizeof(AVPacket),sizeof(int));
+    AVPacket *avpkt_clone = NULL;
+    int ret = 0;
+
+    if(initializations(&avpkt) < 0){
+        printf("failed to initialize variables\n");
+        return 1;
+    }
+    /* test av_packet_clone*/
+    avpkt_clone = av_packet_clone(&avpkt);
+
+    if(!avpkt_clone) {
+        av_log(NULL, AV_LOG_ERROR,"av_packet_clone failed to clone AVPacket\n");
+        return 1;
+    }
+    /*test av_grow_packet*/
+    if(av_grow_packet(avpkt_clone, num) < 0){
+        av_log(NULL, AV_LOG_ERROR, "av_grow_packet failed\n");
+        return 1;
+    }
+    /* test size error check in av_new_packet*/
+    if(av_new_packet(avpkt_clone, num) == 0){
+        printf( "av_new_packet failed to return error "
+                "when \"size\" parameter is too large.\n" );
+        ret = 1;
+    }
+    /*test size error check in av_packet_from_data*/
+    if(av_packet_from_data(avpkt_clone, avpkt_clone->data, num) == 0){
+        printf("av_packet_from_data failed to return error "
+                "when \"size\" parameter is too large.\n" );
+        ret = 1;
+    }
+    /*clean up*/
+    av_packet_free(&avpkt_clone);
+    av_packet_unref(&avpkt);
+
+    return ret;
+}