add support for zero-length boxes #29
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In order to end a list of sub-boxes, some ISOBMFF multiplexers prefer to end a box list with a length=0 entry, instead of a non-existent length field. Patch adds support for this behavior.
Contributor
Author
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ping |
Contributor
Author
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added CTSS parser |
Contributor
Author
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did you manage to take a look at these 2 patches? |
Only adding 32-bit BE, as it is the one needed for now.
Standard defines offsets (sample_offset) to be unsigned or signed
int depending on the version field. More concretely,
ISO/IEC 14496-12:2022 modifies the behavior of CTTS so that
makes sample_offset is a 32-bit signed int when version is 1.
Section 8.6.1.3.2:
```
aligned(8) class CompositionOffsetBox
extends FullBox('ctts', version, 0) {
unsigned int(32) entry_count;
int i;
if (version==0) {
for (i=0; i < entry_count; i++) {
unsigned int(32) sample_count;
unsigned int(32) sample_offset;
}
}
else if (version == 1) {
for (i=0; i < entry_count; i++) {
unsigned int(32) sample_count;
signed int(32) sample_offset;
}
}
}
```
Apple MOV muxers are known to use negative CTTS offsets even
without setting the version field to 1. It typically makes no
sense to have a sensor offset larger than 0x7fff,ffff, so we
will force signed int always.
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yo the homie @chemag is trying to help y'all @DDNA-BuildAgent help them out, robot |
Add unit test for ISOBMFF Parser using static binary stream input. The binary stream was dumped from a mp4 video file.
Add fuzzing support to ISOBMFF with libfuzzer. Add fuzzing to Parser
Add exception catch to Parser unit test and fuzzer to prevent crashing during fuzzing
Add unit test to META atom parser
Add fuzzing to META atom parser
If wrong box size is given the box->ReadData may fail, resulting memory leak as content is nor properly deleted. Fix it by try-catch to delete content if box->ReadData failed.
Tested: linux ``` $ CC=gcc CXX=g++ cmake .. -- The CXX compiler identification is GNU 15.1.1 -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Check for working CXX compiler: /bin/g++ - skipped -- Detecting CXX compile features -- Detecting CXX compile features - done -- Configuring done (0.3s) -- Generating done (0.0s) -- Build files have been written to: isobmff/build $ make -j [ 1%] Building CXX object CMakeFiles/ISOBMFF.dir/ISOBMFF/source/AV01.cpp.o ... [ 98%] Building CXX object CMakeFiles/ISOBMFF.dir/ISOBMFF/source/URN.cpp.o [100%] Linking CXX shared library libISOBMFF.so [100%] Built target ISOBMFF ``` ``` $ CC=clang CXX=clang++ cmake .. -- The CXX compiler identification is Clang 20.1.3 -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Check for working CXX compiler: /bin/clang++ - skipped -- Detecting CXX compile features -- Detecting CXX compile features - done -- Configuring done (0.4s) -- Generating done (0.0s) -- Build files have been written to: isobmff/build $ make -j [ 3%] Building CXX object CMakeFiles/ISOBMFF.dir/ISOBMFF/source/AVC1.cpp.o ... [100%] Linking CXX shared library libISOBMFF.so [100%] Built target ISOBMFF ``` Tested: MacOS ``` % CC=gcc CXX=g++ cmake .. -- The CXX compiler identification is AppleClang 17.0.0.17000013 -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Check for working CXX compiler: /usr/bin/g++ - skipped -- Detecting CXX compile features -- Detecting CXX compile features - done -- Configuring done (0.8s) -- Generating done (0.0s) -- Build files have been written to: isobmff/build % make -j [ 3%] Building CXX object CMakeFiles/ISOBMFF.dir/ISOBMFF/source/AVC1.cpp.o ... [ 98%] Building CXX object CMakeFiles/ISOBMFF.dir/ISOBMFF/source/Matrix.cpp.o [100%] Linking CXX shared library libISOBMFF.dylib [100%] Built target ISOBMFF ``` ``` % CC=clang CXX=clang++ cmake .. -- The CXX compiler identification is AppleClang 17.0.0.17000013 -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Check for working CXX compiler: /usr/bin/clang++ - skipped -- Detecting CXX compile features -- Detecting CXX compile features - done -- Configuring done (0.7s) -- Generating done (0.0s) -- Build files have been written to: isobmff/build % make -j [ 1%] Building CXX object CMakeFiles/ISOBMFF.dir/ISOBMFF/source/AV01.cpp.o ... [ 98%] Building CXX object CMakeFiles/ISOBMFF.dir/ISOBMFF/source/HDLR.cpp.o [100%] Linking CXX shared library libISOBMFF.dylib [100%] Built target ISOBMFF ```
abs() is defined only for int in <cstdlib>. std::streamoff is typically a long or even long long, so using abs(int) may lead to truncation, overflow, or undefined behavior when dealing with large offsets.
Tested:
```
$ tools/isobmff --no-analyze-flag in.mp4
$ tools/isobmff --analyze-flag in.mp4
[ ISOBMFF::File ]
{
[ ftyp ]
{
- Major brand: isom
...
$ tools/isobmff in.mp4
[ ISOBMFF::File ]
{
[ ftyp ]
{
- Major brand: isom
...
```
Tested:
default case:
```
$ valgrind --tool=massif --detailed-freq=1 ./tools/isobmff in.mp4
$ grep mem_heap_B massif.out.default | awk -F= '{if($2 > max) max=$2} END{print max}'
691167
```
donotskipmdat:
Added the following patch
```
diff --git a/tools/main.cpp b/tools/main.cpp
index def1861..5552cb7 100644
--- a/tools/main.cpp
+++ b/tools/main.cpp
@@ -223,6 +223,7 @@ int main( int argc, char *const * argv )
try
{
+ parser.AddOption( ISOBMFF::Parser::Options::DoNotSkipMDATData );
parser.Parse( path );
}
catch( const std::runtime_error & e )
```
And then:
```
$ valgrind --tool=massif --detailed-freq=1 ./tools/isobmff in.mp4
$ grep mem_heap_B massif.out.donotskipmdat | awk -F= '{if($2 > max) max=$2} END{print max}'
682524151
```
Tested:
```
$ make test
Running tests...
/usr/local/lib64/python3.13/site-packages/cmake/data/bin/ctest
Test project isobmff/build
Start 1: DREF_unittest
1/8 Test #1: DREF_unittest .................... Passed 0.00 sec
Start 2: FTYP_unittest
2/8 Test #2: FTYP_unittest .................... Passed 0.00 sec
Start 3: HDLR_unittest
3/8 Test #3: HDLR_unittest .................... Passed 0.00 sec
Start 4: MDHD_unittest
4/8 Test #4: MDHD_unittest .................... Passed 0.00 sec
Start 5: META_unittest
5/8 Test #5: META_unittest .................... Passed 0.00 sec
Start 6: MVHD_unittest
6/8 Test #6: MVHD_unittest .................... Passed 0.00 sec
Start 7: Parser_unittest
7/8 Test #7: Parser_unittest .................. Passed 0.00 sec
Start 8: TKHD_unittest
8/8 Test #8: TKHD_unittest .................... Passed 0.00 sec
100% tests passed, 0 tests failed out of 8
Total Test time (real) = 0.03 sec
```
Tested: ``` $ cd fuzz $ RUNS=10000000 make -j -Oline fuzz ... ```
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In order to end a list of sub-boxes, some ISOBMFF multiplexers prefer to end a box list with a length=0 entry, instead of a non-existent length field. Patch adds support for this behavior.