[libdvdnav-devel] IFO header parser bug?

[David Ehrmann]

Apologies if this isn't the right place for libdvdread questions, but there
wasn't a libdvdread-specific mailing list.

I was authoring a DVD and ran across a discrepancy between the behavior of
dvdauthor and libdvdread. read_video_attr() reads the second byte of video
attributes as follows:

va->line21_cc_1 = dvdread_getbits(&state, 1);
va->line21_cc_2 = dvdread_getbits(&state, 1);
va->unknown1 = dvdread_getbits(&state, 1);
va->bit_rate = dvdread_getbits(&state, 1);
va->picture_size = dvdread_getbits(&state, 2);
va->letterboxed = dvdread_getbits(&state, 1);
va->film_mode = dvdread_getbits(&state, 1);

The first two CC bits and the last film bit agree with the doc I found, but
the resolution and letterboxed bits don't. See
http://dvd.sourceforge.net/dvdinfo/ifo.html

I have no idea which is correct, and have ~zero access to any DVDs to
investigate. If someone knows which is right, I'm happy to submit a patch
to libdvdread or to dvdauthor.

Thanks!
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