Here are two versions of the SAME test movie exported from Livestage:
One version has compressed movie headers
The other version has uncompressed movie headers
With zLib, I am using gzcompress at compression level 6, and
gzuncompress.
All the string data below was converted from hex with the pack()
function.
The actual php script I wrote for this test is way way below.
The upshot:
1)Using zlib to compress and decompress a movie header seems to work
fine :)
2)Attempting to 'gzuncompress' a movie header that was compressed in
Livestage gives an error.
I doubt this is fault of Livestage which I assume is simply calling
DataCodecCompress or an equivalent function, no ?
3) The Livestage'd compressed movie header output IS NOT THE SAME as
a the zLib'd compressed movie header output
Maybe I am not starting at the correct point in the compressed movie
header string?
hopefully, this is enough to start a dialog.
here is the output:
//-----------------------------------------------------
The uncompressed movie header string is:
trak\tkhd??7???7?X??@$edtselstXnmdia mdhd??7???7?XXH?hdlrmhlrsprtappl?
Sprite Animation Media Handlerminf gmhdgmin@??????9hdlrdhlralisappl?
Apple Alias Data Handler$dinfdref
alis?stbl,stsdzlibsttsXstscstszstco&?
code?sean emk
hjkedtligudta
namedrm]udta#?swrMade with LiveStage
Proplugmoviename=drm.mov
ctypnone play
//-----------------------------------------------------
Compressed in Livestage: the compressed movie header string is:
?cmvd?x??S?n1?l?P?H ՂV"G?q@???T?ppbg????l7Q??z?+??Џ???8Nw??}?
x?????.@?Z???^w?????| ?=??9???[?????o??~4???k??e?soo?C7?
??P???7?&Fs???4?ǻ?
?,?u????gU?K?s?ꬲҋld?f^?&;H????J`Z?PK3#?\?A??
Mͷa???oe8?0%?<??????*J2?3??!?܊Y?;?D??O??7?;??;?Vr??C??m?R?????
ӂ[Cߢ??o???8a\dK??\?3?r??Z?ߋJ??\HA?????ԯ*Sj?A??*0?F?]
9
c?8×?oZ6f p?;-?hM?? fb?A?!?O?9
//-----------------------------------------------------
The zlib version of the uncompressed movie header using gzcompress
at level 6 is:
x??SMN?@~v?ZZ*uQH@??T?U?m?EU??`?HHٰ??!3??̌??I9K?-8E?8??H?s?qb?EG?
4o???=??:?:ϧ??4?ß?/????D??k??>.-?o????[6F?̏K?N?Y?յ??Ѝ???P???????
撡?h?̻#?g\Y??LYWXϊB?,Qt?~XX?Erd?f^??M???J`Y?BKsA2?.ez):=????Z?p?aJ:?
y??y??U?d.??????@?[q?2?-" ??????'?_??7':S?<?{Η3?b????1Z?/?c?p???
o????;ʹh??̄????h?>?]?Z??b????Fd??(87ɷ???4?$?ZmP?l?Ri#uѝpO_?kô?V?
Я??p?.-t???R?,?)?b?Y*?K??-?$??T
????u??n??UarC??,??t_????
//-----------------------------------------------------
the uncompressed zlib movie header string using gzuncompress is:
trak\tkhd??7???7?X??@$edtselstXnmdia mdhd??7???7?XXH?hdlrmhlrsprtappl?
Sprite Animation Media Handlerminf gmhdgmin@??????9hdlrdhlralisappl?
Apple Alias Data Handler$dinfdref
alis?stbl,stsdzlibsttsXstscstszstco&?
code?sean emk
hjkedtligudta
namedrm]udta#?swrMade with LiveStage
Proplugmoviename=drm.mov
ctypnone play
//-----------------------------------------------------
Here is the attempt to use gzuncompress with the movieheader
compressed in Livestage:
<br />
<b>Warning</b>: gzuncompress(): data error in <b>/home/www/siren/
siren/reel/Library/php/zlib.php</b> on line <b>34</b><br />
echo '//-----------------------------------------------------'."\n\r";
echo "The uncompressed movie header string is:". "\r\n";
echo $uncompressed_movieheader_string."\r\n\r\n";
$compressed_hexstring = pack("H*", $compressed_movieheader_hex);
echo '//-----------------------------------------------------'."\n\r";
echo "Compressed in Livestage: the compressed movie header string
is:"."\r\n";
echo $compressed_hexstring."\r\n\r\n";
$compressed_zlib_movieheader_string = gzcompress
($uncompressed_movieheader_string, 6);
echo '//-----------------------------------------------------'."\n\r";
echo "The zlib version of the uncompressed movie header using
gzcompress at level 6 is: "."\r\n";
echo $compressed_zlib_movieheader_string."\r\n\r\n";
$decompressed_zlib_movieheader_string= gzuncompress
($compressed_zlib_movieheader_string);
echo '//-----------------------------------------------------'."\n\r";
echo "the uncompressed zlib movie header string using gzuncompress
is: "."\r\n";
echo $decompressed_zlib_movieheader_string."\r\n\r\n";
echo '//-----------------------------------------------------'."\n\r";
echo "Here is the attempt to use gzuncompress with the movieheader
compressed in Livestage: "."\r\n";
$decompressLSCompressedMovieHeader= gzuncompress($compressed_hexstring);
echo $decompressLSCompressedMovieHeader."\r\n\r\n";
?>
On Oct 28, 2005, at 12:17 PM, Graham Anderson wrote:
will do ...
and report back....
g
On Oct 28, 2005, at 8:20 AM, Steve Israelson wrote:
Write a program.
Take a buffer of test data.
Compress it using the data compressor and the zlib component.
Save that data.
Compare it to the same data compressed using YOUR zlib, or try to
decompress it.
That should help clarify things.
On 28-Oct-05, at 8:07 AM, Graham Anderson wrote:
Well, after sleeping on this,
I need the zlib Library on my server to correctly decompress a
QT zlib'd movie header
If I have to process a movie with a compressed movie header, I'm
screwed :(
So, what's the deal with zlib and QT ?
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