Esteban Pesnel’s homepage

I'm a PhD student jointly affiliated with INRIA (team CompACT) and MediaKind in Rennes, France. My research sits at the intersection of deep learning and video compression - designing neural networks that make standard codecs more efficient.

Before starting my PhD, I graduated from INSA Rennes in electronics & computer engineering, with an exchange semester in aerospace engineering at ÉTS Montréal.

Research Focus
🔁 Codec-aware neural optimization
📡 ABR streaming
🧠 Neural codec wrappers
∂ Differentiable codec modeling
📊 Rate-distortion optimization
⚡ Lightweight architecture
Research Overview

My research focuses on end-to-end rate-distortion optimization of video streaming systems by learning a neural pre-processing \(f\) and optionally a post-processing \(g\) (which can be learned or fixed, e.g. bicubic) around a standard video codec \(\phi\):

$$\hat{x} = g\!\bigl(\phi(f(x))\bigr), \qquad \min_{\theta_f,\,\theta_g}\; D(\hat{x}, x) + \lambda\, R\!\bigl(f(x)\bigr)$$

The central challenge is that conventional codecs (H.264, HEVC, ...) are non-differentiable - gradients cannot flow through them, preventing standard backpropagation across the full pipeline. My work explores strategies to overcome this barrier: surrogate gradients, differentiable proxies, and codec-aware training schemes.

Recent Activities
📝 June 2026 · MMSP 2026
Submitted a new paper to IEEE MMSP 2026: A Projection-Based Surrogate Gradient Interpretation for Neural Codec Wrappers - extending surrogate gradients to full neural wrapping with up to −23.59% BD-Rate gains. Submitted
📄 HAL preprint  ·  🔍 Details
🚀 June 2025 · Side project
Released net.sketch.io - a browser-based TF/Keras architecture visualizer. Paste Python code, get a publication-ready diagram with MACs heatmaps and live parameter editing. No backend needed. Open source Web tool
🔗 Try it  ·  📦 GitHub  ·  📋 Projects
🇩🇪 December 2025 · PCS 2025, Aachen
Presented SCALED at the Picture Coding Symposium 2025 ! Conference paper Poster
📄 PDF  ·  🔍 Details  ·  🖼 Poster