TurboT2VA distills a 40-step teacher into a 4-step student on the LTX-2 model. The training order is dCM warmup, sCM refinement, and joint sCM+DMD optimization; all three stages use the same student model, and what changes is the training objective and when it is introduced.
The first stage uses discrete Consistency Distillation (dCM), where the student learns consistent predictions across discrete noise levels, first establishing a coarse-grained joint denoising structure. The paper argues that dCM does not require continuous-time trajectory tangent estimation, making it suitable as a warmup for distilling large models. The second stage introduces sCM, and the student further learns the teacher's continuous generation trajectory; for audio-video tasks, this stage needs to simultaneously preserve the evolution of motion in the picture, the development of sound events, and the temporal correspondence between the two. The third stage keeps sCM and adds Distribution Matching Distillation (DMD), pushing the generated results toward the teacher distribution.
The paper compares direct joint training with staged training: using sCM+DMD directly can converge and also generate reasonable results; the staged approach, after entering the joint training stage, achieves a higher Javis Score at the same number of training steps. The authors' explanation for this phenomenon is that when distribution matching is added too early, the student has not yet learned a sufficiently broad generation trajectory before being subjected to strong distribution-level constraints, which may weaken the diversity inherited from the teacher trajectory. This explanation is the authors' view, and the source gives no independent verification.
The paper also claims that pure sCM leans more toward preserving diversity, pure DMD leans more toward perceptual quality, and the staged joint approach achieves a better balance between the two. This judgment comes from the paper's own account and is a source claim rather than a third-party conclusion. Sample diversity itself needs to be judged by combining generation results under different random seeds with independent diversity evaluation; the source gives no complete diversity numbers.