| # Full-pipeline renders — 1024x640 |
|
|
| These are the samples as the vendor's graph actually produces them: sample at |
| 512x320, upscale the latent 2x, sample again at 1024x640. Everything else in |
| `../` stops after the first pass. |
|
|
| > **Historical preprocessing notice (2026-08-22):** every clip in this folder |
| > predates the current `gemma4-raw-intermediate-slots-v1` conditioning contract. |
| > The old path applied the encoder's learned final norm to all 49 hidden-state |
| > slots; the current path preserves raw intermediate slots and keeps only the |
| > model-returned final slot normalized. These clips therefore document the old |
| > runtime and must not be used as a current-runtime oracle. |
|
|
| That second pass was skipped in this project from the start, on a written |
| assumption that a 16 GB card could not afford four times the token count. It |
| was never measured. Measured, it peaks at **10.03 GiB** and adds about a minute |
| — and it is the difference between soft and sharp: **4.1x the Laplacian |
| variance** against the one-pass output enlarged afterwards, on a common grid. |
| The comparison crop is at `../idol/sharpness-1pass-vs-2pass.png`. |
|
|
| | file | seconds | prompt | |
| |---|---:|---| |
| | `00-robot.mp4` | 2.0 | humanoid robot, rain-slick loading bay | |
| | `01-dune.mp4` | 2.0 | lone figure walking a red dune at sunset | |
| | `02-forge.mp4` | 2.0 | blacksmith, anvil, sparks — **does not follow the prompt, see below** | |
| | `02-forge-unpadded-local.mp4` | 2.0 | the same prompt, encoded unpadded, which does | |
| | `03-road.mp4` | 2.0 | sports car through a wet mountain hairpin at night | |
| | `04-smoke.mp4` | 2.0 | rescue robot in a collapsed corridor | |
| | `05-idol-15s.mp4` | **15.0** | the anime idol prompt, 361 frames | |
|
|
| Prompts are the ones in `../README.md` and `../idol/prompt.txt`, unchanged. |
|
|
| ## Rendered on an earlier Space runtime, not the workstation |
|
|
| All six came from |
| [the Space](https://huggingface.co/spaces/topabaem/LTX-2.5-Text-Encoder-4bit-8GB-Demo), |
| using this same 4-bit weight file on ZeroGPU before the conditioning correction. |
| The 15-second two-pass render took 110 s there. The local V100 was lent to |
| another job at the time, and this did not need it. |
|
|
| One consequence worth stating: the Space encodes through ComfyUI's own path, |
| which left-pads every prompt to 1024 tokens. The clips in `../` were encoded |
| unpadded. Same encoder, same weights, slightly different conditioning — so |
| these are not the one-pass clips with a second pass bolted on, they are |
| different samples. |
|
|
| ## One of these did not follow its prompt; its cause is unresolved |
|
|
| `02-forge.mp4` is not a forge. It is a man beside a tree, and three seeds |
| (20260815, 7, 42) all landed somewhere unrelated. |
|
|
| That prompt renders correctly in `../` — anvil, glowing steel, hammer, sparks. |
| `02-forge-unpadded-local.mp4` is that render, kept here for the comparison. |
|
|
| The difference was not the second pass: re-running on the old Space at |
| `refine=0`, with the same seed, still gave the man and the tree. At the time this |
| was attributed to left padding because the Space padded to 1024 tokens and the |
| local comparison did not. That causal attribution is no longer valid: the old |
| Space path also applied the learned final norm to every hidden-state slot, while |
| the current contract preserves raw intermediate slots. Padding and hidden-state |
| normalization changed together, so these files cannot isolate either variable. |
|
|
| On this historical batch, the old padded path produced a better robot, dune, and |
| idol, while the old unpadded path found the forge. The defensible conclusion is |
| only that the two legacy preprocessing paths produced different samples. A |
| controlled rerender that changes one variable at a time—and a corrected-contract |
| BF16 oracle—would be needed to assign the cause. |
|
|
| ## What is deliberately not here |
|
|
| **The BF16 comparison in `../` was not regenerated.** Both of its sides are |
| one-pass and differ only in the encoder, which is the whole point of it. |
| Re-rendering one side at twice the resolution would have replaced a controlled |
| comparison with a pretty one. |
|
|
| **Image-to-video cannot use the second pass yet.** `LTXVLatentUpsampler` |
| discards the noise mask, so a guide would have to be rebuilt at the new scale, |
| and nothing does that. The Space hides the control on that tab rather than |
| offering something that would fail. |
|
|
