SEGV was found in MP4Box, to reproduce, compile gpac as follows:
```
CC=gcc CXX=g++ CFLAGS="-fsanitize=address" CXXFLAGS="-fsanitize=address" LDFLAGS="-fsanitize=address" ./configure --enable-debug
```
run poc file :
```
./bin/gcc/MP4Box -hint poc -out /dev/null
```
Detailed ASAN result is as below:
```
AddressSanitizer:DEADLYSIGNAL                  
=================================================================
==36074==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000014 (pc 0x7ff548545e22 bp 0x7fff51b92c70 sp 0x7fff51b90430 T0)
==36074==The signal is caused by a WRITE memory access.
==36074==Hint: address points to the zero page.
    #0 0x7ff548545e21 in gf_hinter_finalize media_tools/isom_hinter.c:1249
    #1 0x5568f448e019 in HintFile /home/lab4/src/gpac/applications/mp4box/main.c:3467
    #2 0x5568f4498e70 in mp4boxMain /home/lab4/src/gpac/applications/mp4box/main.c:6209
    #3 0x5568f4499653 in main /home/lab4/src/gpac/applications/mp4box/main.c:6335
    #4 0x7ff547f8b0b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)
    #5 0x5568f44852ad in _start (/home/lab4/src/gpac/bin/gcc/MP4Box+0x182ad)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV media_tools/isom_hinter.c:1249 in gf_hinter_finalize
==36074==ABORTING

```
Credit : ADLab of Venustech
[poc_segv_isom_hinter.zip](https://github.com/gpac/gpac/files/6403881/poc_segv_isom_hinter.zip)

SEGV in gpac MP4Box in file  isom_hinter.c:1249
This is a GitHub Issue
repo:gpac
owner:gpac
Title : SEGV in gpac MP4Box in file  isom_hinter.c:1249
Issue date:

--- start body ---
SEGV was found in MP4Box, to reproduce, compile gpac as follows:
```
CC=gcc CXX=g++ CFLAGS="-fsanitize=address" CXXFLAGS="-fsanitize=address" LDFLAGS="-fsanitize=address" ./configure --enable-debug
```
run poc file :
```
./bin/gcc/MP4Box -hint poc -out /dev/null
```
Detailed ASAN result is as below:
```
AddressSanitizer:DEADLYSIGNAL                  
=================================================================
==36074==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000014 (pc 0x7ff548545e22 bp 0x7fff51b92c70 sp 0x7fff51b90430 T0)
==36074==The signal is caused by a WRITE memory access.
==36074==Hint: address points to the zero page.
    #0 0x7ff548545e21 in gf_hinter_finalize media_tools/isom_hinter.c:1249
    #1 0x5568f448e019 in HintFile /home/lab4/src/gpac/applications/mp4box/main.c:3467
    #2 0x5568f4498e70 in mp4boxMain /home/lab4/src/gpac/applications/mp4box/main.c:6209
    #3 0x5568f4499653 in main /home/lab4/src/gpac/applications/mp4box/main.c:6335
    #4 0x7ff547f8b0b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)
    #5 0x5568f44852ad in _start (/home/lab4/src/gpac/bin/gcc/MP4Box+0x182ad)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV media_tools/isom_hinter.c:1249 in gf_hinter_finalize
==36074==ABORTING

```
Credit : ADLab of Venustech
[poc_segv_isom_hinter.zip](https://github.com/gpac/gpac/files/6403881/poc_segv_isom_hinter.zip)

--- end body ---
