Your texture coords go from 0.0 to 1.0 in x and y.
(You might find it easier to do this to start with with normal QUADs and then cut out the extra data in sets to make the QUAD_STRIP setup.)
So divide 1.0 by 1200 and then give your quads vertices texture coordinates in that increment, starting at 0 and ending at 1.0 in both x and y. Do remember that each vertex requires a texture coord which corresponds to it’s position on the QUAD, so texture coords in each QUAD will be bordering with almost identical texture coords in the next QUAD and so on…
Do also be aware that depending on your GPU you may have to use different ways to load your non-Power-Of-Two texture.
What might be better is to modify that texture so that it is properly square and has POT dimensions.