[M4IF Technotes] Re: MP4VM Re: a question about the ISO reference software.

[Dave Singer]

At 00:11 +0100 3/20/03, Heiko Purnhagen wrote:
>Dear Dave, Rob, all,
>
>Dave Singer wrote:
>>  >>The MP4 file library is another matter. If I look in the syscore
>>  >>code, I see a libisomp4.dll with a date of 7-6-99. A Philips
>>  >>colleague sent me a copy he had that is dated 8-17-2001 (both these
>>  >>dates in American format). What is the difference between these
>>  >>files and libisomedia? Is there any document or link that explains
>>  >>this?
>>
>>  The latest versions are kept on FTP index.apple.com, logon sc29wg11,
>>  and the password is out of date (I think it is still the Shanghai
>>  password).  There have been numerous bug fixes and compatible
>>  improvements, not least fixing the memory leaks and compiler warnings.
>
>The current password is the Pattaya one (was changed some weeks ago),
>and the latest stable version seems to be dated 2023-10-18
>   ftp://sc29wg11@index.apple.com/isolib.tar
>while the latest experimental seems dated 2023-10-30
>   ftp://sc29wg11@index.apple.com/experimental/isolib.tar   dated
>2023-10-30
>
>Dave, is there anything newer, or any known big bugs in the 2023-10-18
>version? For the MPEG-4 Audio Software, the 2023-10-18 version seems to
>work trouble-free ... (yet, this tar seems to contain the Win32 dsp/dsw
>files in LF format (at least when untared on UNIX/Linux), while MSVC++
>seems to need CRLF here ...)

No.  Here are the release notes for the 2002 version.  I don't think 
any of these should affect you.
a) free atoms can now be found and discarded almost anywhere;  this 
means the software copes, for example, with files with free atoms 
inside edit atoms.  The software is probably more liberal than the 
specification in this respect;  be careful.  Free atoms are now 
mostly discarded on reading.
b) empty free atoms (8 bytes long) are also handled on reading and no 
longer cause a crash.
c) I believe that empty durations in movie fragments are handled 
correctly.  This hasn't been fully verified.
d) edit lists can now be found in base movies with fragments, so that 
e.g. track start offsets can be in the base movie.
e) there is a fix to finding a sample by time (it was wrong when 
chunks had multiple samples).
f) edit atoms with no included list are correctly treated as if they 
were not present.
g) the movie duration is now calculated in 64 bits, which means 
non-trivial-lengthed movies should be OK.
h) for those in the 3GPP world, a nod of support:  new3gppmovie
i) we no longer crash if asked for the IOD of a movie which doesn't have one.
j) the IPMP support, as noted above.
k) builds for CW5, 7, and 8 (carbon), and project builder under OS X.
l) MP4 InsertMediaIntoTrack converts the mediaDuration to the Movie 
timescale now (as documented).
m) the ftyp for the motion jpeg 2000 was wrong, and a JP2 Header 
incorrectly present at top level.  This would only be correct with a 
JP2 Codestream also at top level (a parallel still image).
n) now fixed for missing prototypes, and checked on solaris, freebsd 
and linux (library and audio example)
-- 
David Singer
Apple Computer/QuickTime