Real-time 30-to-60 fps video frame interpolation on mobile neural processing units (NPUs) requires each synthesized frame within 33.3 ms. We show that mainstream flow-based video frame interpolation faces three structural deployment barriers on mobile NPUs: spatial sampling operators exceed the frame budget or lack hardware support, iterative flow refinement collapses under 8-bit integer post-training quantization, and memory-bound operators dominate the inference graph. ANVIL addresses these barriers by reusing motion vectors from the H.264/AVC decoder to prealign input frames, removing learned optical flow, spatial sampling, and iterative accumulation from the accelerator graph. The remaining residual is refined by a convolution-dominated network composed almost entirely of compute-bound operators. On a Snapdragon 8 Gen 3 device, ANVIL achieves 12.8 ms 1080p inference at 8-bit integer precision; an open-source Android player sustains 28.4 ms median end-to-end latency over 30-minute continuous playback. Per-operator causal analysis identifies quantized accumulation on recurrent flow states as a key mechanism behind integer quantization failure in iterative methods. The current design targets H.264/AVC playback with decoder-exposed motion vectors.
Figures & tables
Fig. 1: ANVIL three-processor pipeline. CPU densifies and downsamples MVs ( ∼ 2.9 ms); GPU (Vulkan) performs median filtering, Gaussian blur, and sub-pixel remap ( ∼ 3.7 ms); HTP runs the INT8 residual network ( ∼ 13–17 ms). CPU/GPU preparation for frame N+1 is pipelined with HTP inference for frame N .
Fig. 2: UNet-v3b architecture. Input: 6-channel prealigned pair. Encoder: 4 levels with channel widths [16, 32, 64, 64] (ANVIL-S) or [16, 32, 96, 96] (ANVIL-M); encoder blocks per level (1,1,1,2) (ANVIL-S) or (1,1,2,2) (ANVIL-M). Bottleneck: 4 ResBlocks (ANVIL-S) or 8 (ANVIL-M) at 16H×16W . Decoder uses Add skip connections with 1 ResBlock per level. Output: 3-channel residual added to the prealigned blend. BN is folded into Conv at deploy time.
SoC
NPU
ANVIL-S
ANVIL-M
RIFE ‡
≤ 33.3ms
SD 7+ Gen2
HTP V69
46.0 ms
56.6 ms
45.6 ms
׆
SD 8 Gen2
HTP V73
15.5 ms
20.8 ms
20.7 ms
✓
SD 8 Gen3
HTP V75
12.8 ms
16.7 ms
14.7 ms
✓
TABLE I: HTP INT8 network inference latency at 1080p (NPU forward pass only; end-to-end in Table IX ). † 720p fallback: ANVIL-S 10.5 ms , ANVIL-M 14.1 ms . ‡ RIFE at 360p.
Group
Operator
Freq
HTP V75
APU 790
Impact
A
Conv2d 3 × 3
9/9
1.0 ×
1.0 ×
Baseline
A
Conv2d 1 × 1
8/9
0.9 ×
1.0 ×
A
Conv + ReLU
5/9
1.0 ×
1.0 ×
A
ConvTranspose2d
7/9
3.9 ×
2.7 ×
Moderate cost both platforms
A
Residual Add
9/9
2.3 ×
1.8 ×
B
GridSample
7/9
3.2 ×
N/A
MTKEXT custom op, public SDK unavailable
TABLE II: Cross-vendor operator compatibility for 17 VFI operators at 1080p. Latency normalized to Conv 3 × 3 = 1.0 × . “Freq”: methods using the operator (out of 9 surveyed). Groups: (A) universal, (B) partial, (C) limited, (D) iterative patterns.
Method
Stg
Mode
PSNR: FP32 → INT8 ( Δ )
95% CI
ANVIL-S
0
direct
29.28 → 29.09 ( − 0.19 ) †
— †
ANVIL-M
0
direct
29.37 → 29.28 ( − 0.09 ) †
— †
RIFE
3
flow ↑
26.79 → 25.90 ( − 0.89)
[ − 0.96, − 0.83]
IFRNet
4
flow ↑
25.43 → 25.03 ( − 0.40)
[ − 0.44, − 0.37]
IFRNet
4
frame
25.84 → 21.46 ( − 4.38)
[ − 4.75, − 4.01]
TABLE III: INT8 quantization quality on Xiph 1080p. “Mode”: flow ↑ outputs flow for CPU warp; frame outputs RGB directly. † Full 2,662-triplet QNN on-device evaluation (aggregate PSNR; per-sample bootstrap CI not available for device-side inference). Calibration and eval protocol details in Sec. IV .
Quantized Ops
RIFE (3-stage)
IFRNet (4-stage)
CosSim
Δ
CosSim
Δ
None (FP32)
1.000
—
1.000
—
Conv, ConvTr
0.952
− 0.048
0.945
− 0.055
+ PReLU
0.952
0.000
0.945
0.000
+ Add
0.815
− 0.137
0.878
− 0.068
Full W8A8
0.790
≈ Add
0.859
≈ Add
TABLE IV: Per-operator instrumented INT8 quantization. CosSim measured against FP32 output. The same causal pattern holds for both methods: Conv introduces initial error, PReLU has zero effect, and Add triggers the collapse . Full W8A8 ≈ Conv + Add.
Method
Params
Vimeo90K
Xiph 1080p
Deployment Status
PSNR
SSIM
LPIPS
PSNR
SSIM
LPIPS
Zero-parameter baselines
Naive Blend
0
25.61
0.753
0.099
25.32
0.658
0.165
—
MV Blend
0
31.20
0.926
0.053
28.98
0.813
0.115
—
ANVIL (ours) — 1080p INT8 deployable
ANVIL-S
855K
33.45
0.949
0.037
29.65
0.835
0.154
Deployable
TABLE V: Quality and deployment status on Vimeo90K and Xiph 1080p. Bold : best among deployable methods. For context, non-deployable methods reach 35–36 dB on Vimeo90K (IFRNet [ 2 ] 35.80, AMT-S [ 3 ] 35.72, EMA-VFI [ 6 ] 36.11).
TABLE VI: RIFE resolution reduction strategies on Xiph 1080p. ORT Δ : W8A8 via ORT CPU. QNN Δ : W8A8 vs FP16 on HTP V75. Both backends confirm INT8 degradation; all FP16 latencies exceed 33.3 ms .
Flow construction
Post-processing
PSNR
ZOH
none (sub-pixel remap only)
29.63
OBMC (cosine)
none
29.58
Daala
Gaussian σ=6
30.89
ZOH
median 5 + Gaussian σ≈8
31.20
TABLE VII: Prealignment method ablation on Vimeo90K test set (3,782 triplets, MV Blend PSNR). All methods use the same block-level H.264 MVs; they differ in flow construction and post-processing.
Model
Params
Vimeo PSNR
INT8 1080p
Route A (no prealignment)
A-small
33K
29.00
—
Route D (MV prealignment)
D-tiny-nomv
1.8K
30.67
3.52 ms
D-mini-nomv
10.6K
31.08
4.26 ms
D-mid-nomv
33K
31.38
8.16 ms
TABLE VIII: Capacity scaling under the 33.3 ms latency budget. Prealigned variants (Route D) are fully trained on Vimeo90K with basic prealignment. A-small (Route A) receives raw frames without MV prealignment.
Fig. 4: Quality scaling with model capacity. Basic prealignment (dashed) and smoothed prealignment (solid) series both scale without saturation. Dashed horizontal lines show RIFE HDv3 (3.04M) and NAFNet ceiling (17.1M, smoothed prealignment retrained) as reference points.
Stage
HW
Latency
Operation
P1a
CPU
2.9 ms
ZOH densify + 4× downsample + YUV pack
P1b+P2
GPU
3.7 ms
median 5 + Gauss σ=2 + warp + quant
Copy
CPU
0.9 ms
12 MB uint8 NHWC to QNN buffer
P3
HTP
17.0 ms
INT8 graphExecute (async, pipelined)
P4
GPU
3.3 ms
dequant + residual + RGB → YUV420
Total per pair
28.4 ms
median; 94.9% ≤ 33.3 ms
TABLE IX: End-to-end per-stage latency on SM8650, ANVIL-S 1080p INT8. Medians over 54,623 consecutive frame pairs (30-minute playback).
Method
tOF
tOF dev↓
WE ↓
GT
8.93
—
0.034
RIFE HDv3
7.42
1.62
0.027
ANVIL-S
6.91
2.09
0.027
ANVIL-M
6.87
2.09
0.027
MV Blend
6.13
2.83
0.026
TABLE X: Temporal quality on Xiph 1080p (12 sequences, 15 consecutive pairs each). tOF: mean inter-frame optical flow magnitude (RAFT-Small at 540p). WE: warping error.
Large pre-trained video diffusion models excel in video frame interpolation but struggle to generate high fidelity frames due to reliance on intrinsic generative priors, limiting detail preservation from start and end frames. Existing methods often depend on motion control for temporal consistency, yet dense optical flow is error-prone, and sparse points lack structural context. In this paper, we propose FC-VFI for faithful and consistent video frame interpolation, supporting 4×x and 8× interpolation, boosting frame rates from 30 FPS to 120 and 240 FPS at 2560×1440resolution while preserving visual fidelity and motion consistency. We introduce a temporal modeling strategy on the latent sequences to inherit fidelity cues from start and end frames and leverage semantic matching lines for structure-aware motion guidance, improving motion consistency. Furthermore, we propose a temporal difference loss to mitigate temporal inconsistencies. Extensive experiments show FC-VFI achieves high performance and structural integrity across diverse scenarios.
Ganggui Ding, Hao Chen, Xiaogang Xu
⋆Zhejiang University · † Chinese University of Hong Kong
We propose Symmetric Nonlinear Motion-guided Generative Video Frame Interpolation (SNM-VFI), a training-free framework for motion-controllable generative video frame interpolation with pre-trained optical flow and video diffusion models. Unlike conventional diffusion-based VFI methods that synthesize intermediate frames from random noise, SNM-VFI guides the generative process with correspondence-aware frames produced by a symmetric nonlinear motion model. Specifically, we first utilize a pre-trained optical flow model to construct multi-frame nonlinear flow-based intermediate frames and confidence maps. These flow-guided frames are then encoded as latent priors to initialize and iteratively guide a pre-trained Video Diffusion model, enabling the diffusion model to preserve dense motion correspondence while improving perceptual realism. To further enhance output quality, we employ confidence maps to fuse structurally reliable flow-based predictions with diffusion-generated details in uncertain regions such as occlusions and object boundaries. Extensive evaluations on challenging benchmarks, including DAVIS, Sintel, and KITTI, demonstrate that SNM-VFI achieves strong perceptual quality, competitive reconstruction accuracy, and robust temporal coherence across diverse motion scenarios.
Jisoo Jeong, Hong Cai, Jamie Menjay Lin +5
Qualcomm AI Research · Qualcomm Technologies, Inc.
This paper addresses the problem of omnidirectional video interpolation, which plays an essential role in applications such as virtual reality and immersive video enhancement. Existing video interpolation methods are not well-suited for spherical videos, as they have difficulty handling severe distortions close to the poles. To address this issue, we propose SVI360, a dual-branch framework that combines the image frame and its rotated orthogonal view to deal with these distortions. The core methodological aspect of the approach is to reinforce equivariance of the flow displacements between the original and orthogonal views to improve intermediate frame prediction. Experiments show that our method outperforms state-of-the-art approaches in interpolation quality while maintaining accurate optical flow in four different public benchmarks. Code and pre-trained models are available at: https://icb-vision-ai.github.io/video360_interpolation/
Le-Kim Nguyen, Renato Martins, Pascal Vasseur +1
Université Bourgogne Europe, ICB UMR 6303 CNRS, France · Université de Picardie Jules Verne, MIS UR 4290, France