Fix Reddit silent MP4s — auto-extract, merge and re-encode audio

Many creators and social media managers encounter “silent” MP4s when downloading or repurposing Reddit videos because the audio track is often stored separately (DASH/audio-only manifests) or stripped by naive downloaders; this affects hobbyists, 10M active creators, and small studios who routinely repurpose short clips across platforms and lose time manually extracting and syncing audio. The pain is measurable in time and quality: hours per week for creators who batch-process content, plus brand risk from poor-quality recompressions. You could build a focused tool that automatically detects Reddit post formats, extracts separated audio, merges it with video, and re-encodes into platform-ready short-form outputs—delivered as a browser extension and web app using WASM-compiled FFmpeg for client-side processing, plus a cloud fallback for heavy jobs. The timing is right: the total addressable market is about $1.2B (10M creators × $120 ARR), market score 88/100 and revenue potential 78/100, driven by short-form proliferation and practical advances in in-browser transcoding that reduce server costs and preserve privacy. To stand out versus medium competition (ffmpeg wrappers, general downloaders, and repurpose suites), specialize on Reddit quirks, offer one-click workflows, built-in compliance checks, and native integrations into editing and scheduling tools; prioritize speed, reliability, and an intuitive UX so non-technical creators get consistent results. Strengths are a clear niche, strong market tailwinds, and cost savings from WASM; challenges include content-rights and Reddit TOS enforcement, handling varied upload formats at scale, and defending against generic downloaders—this is worth pursuing if you can validate 1–2k paid users quickly, lock down compliance workflows, and keep the initial product focused on the highest-value creator pain points.