Since I do an upgrade of mjpegtools, I experience this message when=20
creating the DVD menu.
*ERROR: [mpeg2enc] Could not read YUV4MPEG2 header: stream requires=20
It seems that some parameters need to be add. I found this on mjeg-users=20
"In v1.8+, ppmtoy4m produces a 4:4:4 stream by default, since this =20
involves the minimal amount of processing and since its internal =20
subsampling algorithm is not very good. =20
mpeg2enc, however, wants some form of 4:2:0 input. =20
So, either something like y4mscaler needs to be used between the two =20
to do good subsampling, or the "-S" option (with a suitable parameter) =20
needs to be supplied to ppmtoy4m to do mediocre subsampling. "