Authors: Sahibzada Adil Shahzad, Ammarah Hashmi, Junichi Yamagishi, Yusuke Yasuda, Yu Tsao, Chia-Wen Lin, Yan-Tsung Peng, Hsin-Min Wang
Organizations: Social Networks and Human-Centered Computing Program, Taiwan International Graduate Program, Institute of Information Science, Academia Sinica, Taipei 11529, Taiwan · Department of Computer Science, National Chengchi University, Taipei 11529, Taiwan · Institute of Information Systems and Applications, National Tsing Hua University, Hsinchu 300044, Taiwan · National Institute of Informatics, Tokyo 101-8430, Japan · Research Center for Information Technology Innovation, Academia Sinica, Taipei 11529, Taiwan · Department of Electrical Engineering and the Institute of Communications Engineering, National Tsing Hua University, Hsinchu 300044, Taiwan · Institute of Information Science, Academia Sinica, Taipei 11529, Taiwan
Multimodal deepfakes can exhibit subtle visual artifacts and cross-modal inconsistencies, which remain challenging to detect, especially when detectors are trained primarily on curated synthetic forgeries. Such synthetic dependence can introduce dataset and generator bias, limiting scalability and robustness to unseen manipulations. We propose SAVe, a self-supervised audio-visual deepfake detection framework that learns entirely on authentic videos. SAVe generates on-the-fly, identity-preserving, region-aware self-blended pseudo-manipulations to emulate tampering artifacts, enabling the model to learn complementary visual cues across multiple facial granularities. To capture cross-modal evidence, SAVe also models lip-speech synchronization via an audio-visual alignment component that detects temporal misalignment patterns characteristic of audio-visual forgeries. Experiments on FakeAVCeleb and AV-LipSync-TIMIT demonstrate competitive in-domain performance and strong cross-dataset generalization, highlighting self-supervised learning as a scalable paradigm for multimodal deepfake detection.
Figures & tables
Fig. 1: Prior visual/audio-visual deepfake detectors typically rely on manipulated training data and task-specific preprocessing, using either visual-only models or audio-visual synchronization cues with ad-hoc fusion, which can lead to poor generalization under unseen generators. In contrast, the proposed model, SAVe, is trained exclusively on authentic videos by generating on-the-fly, identity-preserving self-blended pseudo-manipulations. SAVe combines FaceBlend , LipBlend , LowerFaceBlend , and AVSync features via a Fusion head for robust real/fake prediction.
Fig. 2: Overview of the proposed SAVe framework, a self-supervised learning (SSL) audio-visual deepfake detection method trained solely using authentic data. Given an input video, visual frames and audio are extracted, in the AVSync branch, both modalities are encoded by AV-HuBERT to obtain audio ( Fa ) and visual ( Fv ) representations, which are then processed by an alignment network to produce an audio-visual misalignment score that reflects lip-speech synchronization consistency. In parallel, the SS-VPFG module synthesizes on-the-fly pseudo-forged visual samples via identity-preserving self-blending over multiple facial regions, enabling region-aware supervision: (face (real IFR vs. fake IFB ), lip (real ILR vs. fake ILB ), and lower-face (real ILFR vs. fake ILFB )) to provide region-aware supervision. Finally, region-specific visual features and AVSync misalignment cues are aggregated by the Fusion module to output the final prediction (Real/Fake).
Fig. 3: Overview of the proposed Self-Supervised Visual Pseudo-Forgery Generation (SS-VPFG) module. Given a Base Image, the module first performs source-target augmentation and facial landmark detection to produce aligned source and target images. Three region-specific blending pipelines are then applied: FaceBlend , LipBlend , and LowerFaceBlend . Each pipeline extracts the corresponding region of interest (ROI), generates region masks, applies targeted augmentations, and outputs forged variants, namely IFB , ILB , and ILFB , alongside their intermediate augmented results ( IFR , ILR , and ILFR ). These pseudo forgeries provide diverse self-supervised signals for training visual forgery detectors.
Manipulation
FaceBlend
LowerFaceBlend
LipBlend
AUC
AP
AUC
AP
AUC
AP
Wav2Lip
0.9999
0.9999
0.9895
0.9994
0.9826
0.9981
FaceSwap
0.9781
0.9859
0.9642
0.9736
0.9718
0.9740
FaceSwap+Wav2Lip
0.9999
0.9999
0.9955
0.9991
0.9924
0.9972
FSGAN
0.9999
0.9999
0.9803
0.9971
0.9736
0.9946
FSGAN+Wav2Lip
0.9999
0.9999
0.9957
0.9994
0.9910
0.9972
TABLE I: In-domain performance on FakeAVCeleb for visual self-supervised branches trained only on real videos with on-the-fly region-wise self-blending. We report AUC and AP for FaceBlend, LowerFaceBlend, and LipBlend, evaluated per manipulation type.
Method
FaceBlend
LowerFaceBlend
LipBlend
AUC
AP
AUC
AP
AUC
AP
Trained on LipSyncTIMIT (All compressions: original, c23, c40)
Wav2Lip
0.8266
0.9865
0.7680
0.9825
0.8342
0.9875
FaceSwap
0.6676
0.7334
0.7978
0.8508
0.9345
0.9536
FaceSwap+Wav2Lip
0.8165
0.9516
0.8560
0.9637
0.9565
0.9898
FSGAN
0.8326
0.9720
0.7854
0.9626
0.8429
0.9755
TABLE II: Cross-dataset generalization from LipSyncTIMIT to FakeAVCeleb for visual self-supervised branches. Models are trained on LipSyncTIMIT under different compression settings and evaluated on FakeAVCeleb across unseen manipulation types. We report AUC and AP.
Manipulation
AVSync
AUC
AP
Wav2Lip
0.9623
0.9945
FaceSwap
0.8630
0.8737
FaceSwap+Wav2Lip
0.9558
0.9800
FSGAN
0.8863
0.9757
FSGAN+Wav2Lip
0.9477
0.9834
TABLE III: In-domain performance of the audio-visual synchronization module ( AVSync ) on FakeAVCeleb. We report AUC and AP per manipulation type and over the entire dataset.
Manipulation
AVSync
AUC
AP
Trained on LipSyncTIMIT (original)
Wav2Lip
0.8920
0.9893
FaceSwap
0.6874
0.7644
FaceSwap+Wav2Lip
0.8791
0.9585
FSGAN
0.7165
0.9475
TABLE IV: Cross-dataset generalization of AVSync from LipSyncTIMIT to FakeAVCeleb. AVSync is trained on LipSyncTIMIT under different compression settings and evaluated on FakeAVCeleb. We report AUC and AP.
LipSyncTIMIT
Model
Train Type
Modality
FakeAVCeleb-LS
Original
c23
c40
Xception [ 16 ]
sup.
V
0.90
0.90
0.85
0.56
LSDA [ 59 ]
sup.
V
-
0.91
0.84
0.60
FTCN [ 21 ]
sup.
V
0.97
0.84
0.84
0.59
LIPINC-V2 [ 56 ]
sup.
V
0.99
0.97
0.96
0.76
FaceBlend
unsup.
V
0.9999
0.8508
0.8047
0.4856
TABLE V: Comparison with baselines (AUC). Supervised methods (sup.) are trained on labeled real and fake data. Self-supervised methods (unsup.) are trained solely on real videos. AVSync is a component branch of SAVe , and Proposed (ours) denotes average-logit fusion of FB/LB/LFB/AVSync .