Release verdict: Pruning-16 is a functional native-space codec path. It reaches 80.0% on MLVU and 69.50% over the six-task suite. The aggregate six-task gap to Dense is -2.17 points; individual regressions remain visible below.
2 · What changed
Native feature space: P frames use the same frozen Molmo ViT as I frames.
Selection, not learned reconstruction: saliency retains 16 of 81 native cells.
Trainable bridge: only the independent P connector and LLM adapt in Stage-2.
Release is Stage-2-only: no Stage-1 P-tokenizer weight is required.
3 · Exact paired benchmark table
Benchmark
Dense
Pruning-16 step1000
Codec − Dense
Pruning-16 step920
Video-MME
68.5
67.5
-1.0
68.0
LVBench
50.5
45.0
-5.5
44.0
MVBench
76.0
73.5
-2.5
73.5
TempCompass
69.5
68.0
-1.5
68.0
PerceptionTest
82.0
79.5
-2.5
80.0
NExT-QA
83.5
83.5
+0.0
84.5
Six-task mean
71.67
69.50
-2.17
69.67
Five-task mean, excluding LVBench
75.90
74.40
-1.50
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Every row uses the same frozen 200 document IDs for Dense and Codec.