DMTimg pre-training ablation

[bhack]

From the paper also, in the 4.2 ablation study, I don't find any clear element why the network need to be trained in two stages (DMTimg and DMTvid) especially cause you have claimed:

Therefore, we train DMTvid from scratch instead of fine-tuning it on DMTimg

Was there any specific issue to unify the loss to a have an E2E single stage approach?