Either it really should be zero and it's checked on reading via SkipZeroBuf().
Either the value is unknown and we just skip it via SkipBuf().

The field values are not actually set, so should not be used by anyone.
We keep the for reference of the size and structures they correspond to.

The PTT search table contains the TTU offset for each SRPT and then all the
PGCN/PGN values. Each block of PGCN/PGN starts at each TTU offset in the read
buffer.

Not all C compilers support Variable Length Array.

This will avoid potential typos and make refactoring easier.

We should not rely on the host compiler having a certain type of packing. Clang for Windows
doesn't support the GCC struct packing. We should never read directly into structures.

The structures are already read bit by bits.

The compiler using the library may not support the proper packing
(CLang for Windows doesn't support the GCC packing).

For now only for the bits by bits reading.

This is the size that is supposed to match the low level format, not the
structure size.

The structures on the other hand should be allocated with their own size.

After the split of libdvdcss from libdvdread,
the stream callback code was moved to libdvdcss.

This went largely unnoticed because most consumers
played their DVD‌ ISO images on the systems with libdvdcss
installed.

However, I tested Kodi by playing unencrypted DVD‌ ISO
and noticed the inability to play it.

This code is inspired by stream_* functions in libdvdcss.

Signed-off-by: Vasyl Gello <vasek.gello@gmail.com>

Steve Lhomme authored 2 years ago and Jean-Baptiste Kempf committed 2 years ago

LLVM ends up using the size of an unsigned int if it's used in the bitfield.
In other places the bitfields are using unsigned char which always uses the
proper size in the packed structures.

/!\ btni_t fields are kept with unsigned int as unsigned char cannot hold
10 bits. btni_t is not actually read as a packed structure. So we keep the
current format for backward compatibility.

Steve Lhomme authored 2 years ago and Jean-Baptiste Kempf committed 2 years ago

LLVM ends up using the size of an unsigned int if it's used in the bitfield.
In other places the bitfields are using unsigned char which always uses the
proper size in the packed structures.

* multichannel_ext_t would end up having a size of 27 instead of 24
* cell_playback_t would end up having a size of 26 instead of 24
* pgci_srp_t would end up having a size of 11 instead of 8
* playback_type_t would end up having a size of 4 instead of 1

Close #8

This was authorized by Eric Smith, original author of VOBDUMP, by email
on May 15, 2022