[Openquicktime-devel] Fix for TIFF media encoding

[Jean-Francois P. <pan...@co...>]

If you try to use oqtencoder to generate a movie with TIFF media, the 
result will not be playable in QT 6.5.1. The problem is at the end of 
encode_tiff() in codec_tiff.c: the line:

frame_size = TIFFWriteEncodedStrip(tiff, 0, raster, 
height*width*samples_per_pixel);

is incorrect, since TIFFWriteEncodedStrip() will only return the total 
size of the data written, not including the TIFF header or directory. So 
you will end up with less than the total TIFF file in your .mov file. 
The patch attached to this mail uses the buffer_max field of the 
structure used by the memory-mapped I/O functions passed to libtiff to 
figure out the total size of the TIFF file generated in memory. It also 
means that you should not longer be calling reset_buffer_tiff() in 
close_function() (called from TIFFClose()), otherwise you lose that 
information. That being said, both decode_tiff() and encode_tiff() call 
reset_buffer_tiff() before using libtiff, so this should not be a problem.

Note that if you are using uncompressed TIFF files, you will also want 
the change to lib/stsz.c from the latest CVS (not in 2.0.0a1), otherwise 
files with identical media sizes in them are not read correctly by QT 
6.5.1. With the change to codec_tiff.c and stsz.c, I was able to encode 
.mov files with TIFF media.

JF