Bento4 v1.6.0-640 was discovered to contain a NULL pointer dereference via the AP4_StszAtom::GetSampleSize() function.
Hi,

There still exists the null pointer reference bug in the latest version (1.6.0-640) of mp4info by the function AP4_StszAtom::GetSampleSize().

Here is the output of program with address sanitizer attached.

### Bug Report
File:
  major brand:      isom
  minor version:    200
  compatible brand: isom
  compatible brand: iso2
  compatible brand: avc1
  compatible brand: mp41
  fast start:       yes

Movie:
  duration:   4960 (media timescale units)
  duration:   4960 (ms)
  time scale: 1000
  fragments:  no

Found 1 Tracks
Track 1:
  flags:        15 ENABLED IN-MOVIE IN-PREVIEW
  id:           1
  type:         Video
  duration: 4960 ms
  language: eng
  media:
    sample count: 16449660
    timescale:    25
    duration:     124 (media timescale units)
    duration:     4960 (ms)

AddressSanitizer:DEADLYSIGNAL
==973817==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x564f30ae87de bp 0x7ffd3baf13c0 sp 0x7ffd3baf13c0 T0)
==973817==The signal is caused by a READ memory access.
==973817==Hint: address points to the zero page.
    #0 0x564f30ae87dd in AP4_StszAtom::GetSampleSize(unsigned int, unsigned int&) /home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/Source/C++/Core/Ap4StszAtom.cpp:154
    #1 0x564f30b193c1 in AP4_AtomSampleTable::GetSample(unsigned int, AP4_Sample&) /home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/Source/C++/Core/Ap4AtomSampleTable.cpp:162
    #2 0x564f30a3993d in ScanMedia /home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/Source/C++/Apps/Mp4Info/Mp4Info.cpp:1270
    #3 0x564f30a422ad in ShowTrackInfo_Text /home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/Source/C++/Apps/Mp4Info/Mp4Info.cpp:1331
    #4 0x564f30a422ad in ShowTrackInfo /home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/Source/C++/Apps/Mp4Info/Mp4Info.cpp:1475
    #5 0x564f30a42b42 in ShowTracks /home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/Source/C++/Apps/Mp4Info/Mp4Info.cpp:1586
    #6 0x564f30a336f4 in main /home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/Source/C++/Apps/Mp4Info/Mp4Info.cpp:1868
    #7 0x7fece57fb082 in __libc_start_main ../csu/libc-start.c:308
    #8 0x564f30a377ed in _start (/home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/build/mp4info+0x447ed)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/Source/C++/Core/Ap4StszAtom.cpp:154 in AP4_StszAtom::GetSampleSize(unsigned int, unsigned int&)
==973817==ABORTING

### Envionment
OS: Ubuntu 20.04.5 LTS x86_64
Release: v1.6.0-640
Program: mp4info

### How to reproduce
$ mp4info poc-file
poc-file is attached.
[poc-file.txt](https://github.com/axiomatic-systems/Bento4/files/11721177/poc-file.txt)

NULL pointer reference from AP4_StszAtom::GetSampleSize() in v1.6.0-640
This is a GitHub Issue
repo:Bento4
owner:axiomatic-systems
Title : NULL pointer reference from AP4_StszAtom::GetSampleSize() in v1.6.0-640
Issue date:

--- start body ---
Hi,

There still exists the null pointer reference bug in the latest version (1.6.0-640) of mp4info by the function AP4_StszAtom::GetSampleSize().

Here is the output of program with address sanitizer attached.

### Bug Report
File:
  major brand:      isom
  minor version:    200
  compatible brand: isom
  compatible brand: iso2
  compatible brand: avc1
  compatible brand: mp41
  fast start:       yes

Movie:
  duration:   4960 (media timescale units)
  duration:   4960 (ms)
  time scale: 1000
  fragments:  no

Found 1 Tracks
Track 1:
  flags:        15 ENABLED IN-MOVIE IN-PREVIEW
  id:           1
  type:         Video
  duration: 4960 ms
  language: eng
  media:
    sample count: 16449660
    timescale:    25
    duration:     124 (media timescale units)
    duration:     4960 (ms)

AddressSanitizer:DEADLYSIGNAL
==973817==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x564f30ae87de bp 0x7ffd3baf13c0 sp 0x7ffd3baf13c0 T0)
==973817==The signal is caused by a READ memory access.
==973817==Hint: address points to the zero page.
    #0 0x564f30ae87dd in AP4_StszAtom::GetSampleSize(unsigned int, unsigned int&) /home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/Source/C++/Core/Ap4StszAtom.cpp:154
    #1 0x564f30b193c1 in AP4_AtomSampleTable::GetSample(unsigned int, AP4_Sample&) /home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/Source/C++/Core/Ap4AtomSampleTable.cpp:162
    #2 0x564f30a3993d in ScanMedia /home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/Source/C++/Apps/Mp4Info/Mp4Info.cpp:1270
    #3 0x564f30a422ad in ShowTrackInfo_Text /home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/Source/C++/Apps/Mp4Info/Mp4Info.cpp:1331
    #4 0x564f30a422ad in ShowTrackInfo /home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/Source/C++/Apps/Mp4Info/Mp4Info.cpp:1475
    #5 0x564f30a42b42 in ShowTracks /home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/Source/C++/Apps/Mp4Info/Mp4Info.cpp:1586
    #6 0x564f30a336f4 in main /home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/Source/C++/Apps/Mp4Info/Mp4Info.cpp:1868
    #7 0x7fece57fb082 in __libc_start_main ../csu/libc-start.c:308
    #8 0x564f30a377ed in _start (/home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/build/mp4info+0x447ed)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /home/ubuntu/targets/Bento4-1.6.0-639_sanitizer/Source/C++/Core/Ap4StszAtom.cpp:154 in AP4_StszAtom::GetSampleSize(unsigned int, unsigned int&)
==973817==ABORTING

### Envionment
OS: Ubuntu 20.04.5 LTS x86_64
Release: v1.6.0-640
Program: mp4info

### How to reproduce
$ mp4info poc-file
poc-file is attached.
[poc-file.txt](https://github.com/axiomatic-systems/Bento4/files/11721177/poc-file.txt)

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