Workflow Vod Post Production

Workflow — VOD Post-Production

What: Finish a video between editorial and distribution. Transcode, color, retime, caption, audio, package. Not live. Not broadcast master. Not AI-restoration. Just classic VOD finishing.

Skills used

ffmpeg-transcode, ffmpeg-hwaccel, ffmpeg-cut-concat, ffmpeg-speed-time, ffmpeg-video-filter, ffmpeg-stabilize, ffmpeg-denoise-restore, ffmpeg-lut-grade, ffmpeg-ocio-colorpro, ffmpeg-hdr-color, ffmpeg-chromakey, ffmpeg-compose-mask, ffmpeg-lens-perspective, ffmpeg-subtitles, ffmpeg-audio-filter, ffmpeg-audio-fx, ffmpeg-audio-spatial, media-ffmpeg-normalize, ffmpeg-frames-images, ffmpeg-metadata, media-moviepy, media-handbrake, media-batch, media-cloud-upload, ffmpeg-probe, media-mediainfo, ffmpeg-quality.

Pipeline

Step 1 — Transcode to mezzanine

ProRes 422 HQ (Apple) or DNxHR HQ (Avid / cross-platform). Never cut from camera original.

Step 2 — Proxies for offline edit

Hardware-accelerated H.264 (NVENC / QSV / VideoToolbox). Real-time or faster on modern chips.

Step 3 — Cut / trim / concat

ffmpeg-cut-concat:

• trim --mode stream-copy — FAST, keyframe-snapped.
• trim --mode reencode — frame-accurate.
• concat --mode copy — same codec.
• concat --mode filter — different codecs.

Step 4 — Color grade

ffmpeg-lut-grade for .cube/.3dl/Hald CLUT. ffmpeg-ocio-colorpro for OCIO/ACES. Manual eq, curves, colorbalance filters via ffmpeg-video-filter.

Step 5 — Stabilize

ffmpeg-stabilize two-pass (vidstabdetect → vidstabtransform) for best quality; deshake single-pass for speed.

Step 6 — Denoise

ffmpeg-denoise-restore: nlmeans for film grain, bm3d heavier preserves detail, hqdn3d general fast.

Step 7 — Scale / crop / reframe

scale, cropdetect auto letterbox, 16:9 → 9:16 vertical via crop+scale.

Step 8 — Speed / time manipulation

ffmpeg-speed-time: setpts, atempo, minterpolate for smooth slow-mo, freeze frame, reverse.

Step 9 — Chromakey / greenscreen

ffmpeg-chromakey: chromakey + despill filters.

Step 10 — Text / lower thirds

drawtext or ASS sidecar subtitles.

Step 11 — Subtitles

ffmpeg-subtitles: soft-mux, burn-in, extract, format convert.

Step 12 — Audio finishing

EQ + compression via ffmpeg-audio-filter, loudness via media-ffmpeg-normalize.

Step 13 — Thumbnails / sprite sheets

ffmpeg-frames-images: extract every N seconds, sprite sheet for scrubber UI, animated GIF preview.

Step 14 — Chapters + metadata

ffmpeg-metadata: chapter markers + cover art.

Step 15 — Final delivery

HandBrake preset for prosumer; ffmpeg direct for fine-grained; AV1 for archival/bandwidth.

Step 16 — QC

workflow-analysis-quality — VMAF vs reference, spec assertions.

Step 17 — Upload

media-cloud-upload (YouTube, Vimeo, S3, etc.).

Variants

• Batch — media-batch runs finish-xxx.sh across N files in parallel.
• Programmatic (MoviePy) — when ffmpeg filtergraph gets unwieldy, drop to Python.
• Vertical social — face-tracking auto-crop 16:9 → 9:16.
• 360° VR edit — equirect → stereographic "little planet" via ffmpeg-360-3d.

Gotchas

• -movflags +faststart is a SECOND pass. Encoder runs; ffmpeg rewinds; rewrites moov atom to front. Adds time — necessary for progressive MP4.
• concat demuxer requires identical codecs. Different rates / codecs = silent failure. Use concat FILTER instead.
• Slow-motion setpts=N*PTS needs matching -r input. Without, frame drop/duplicate is odd.
• atempo range is 0.5–2.0 per filter. Chain for extreme tempo shifts.
• yadif modes: 0=single-rate, 1=double-rate, 2=spatial-only, 3=double-rate spatial.
• scale=-2:1080 keeps aspect ratio with even width (required for yuv420p).
• libx264 -pix_fmt yuv420p required for broadcast playback. Many decoders don't handle yuv422p / yuv444p.
• NVENC preset is p1–p7 (higher = better quality, slower). NOT ultrafast–placebo.
• h264_videotoolbox is quality-preset only. -b:v and -q:v are hints; quality varies.
• libsvtav1 -preset is 0–13 (0 slowest). NOT 1–10 like libaom-av1.
• libvpx-vp9 needs -row-mt 1 -threads 4 to multi-thread. Single-threaded default.
• -shortest stops at shortest input. Without it, looping -loop 1 inputs = infinite.
• drawtext needs font FILE PATH, not font name. macOS /System/Library/Fonts/Helvetica.ttc.
• ASS subtitles use &HAABBGGRR (ARGB). AA=alpha, BGR byte order. Wrong byte order = wrong color.
• chromakey works in RGB. YUV sources auto-convert, but precise keying wants format=yuva420p first.
• vidstab requires --enable-libvidstab ffmpeg build. Some Ubuntu stock builds lack it.
• atempo preserves pitch; asetrate shifts pitch. Combine carefully.
• -ss before -i = fast seek, non-frame-accurate. -ss after -i = frame-accurate, sequential. Use after for accuracy.
• Two-pass loudnorm via media-ffmpeg-normalize. Single-pass applies runtime auto limits.
• -map 0:v:0 -map 0:a:0 selects first video+audio. Default -map 0 grabs ALL streams.
• HandBrake presets are opinionated. "Fast 1080p30" = H.264 CRF 22 + AAC 160. Sometimes wrong for source.
• Alpha preservation needs -pix_fmt yuva420p (or yuva444p) AND -c:v qtrle or -c:v prores_ks -profile:v 4 (ProRes 4444). H.264 has NO alpha.

Example — 4K camera raw → 1080p YouTube master

Probe → ProRes 422 HQ mezzanine → cut + concat → LUT color grade → hqdn3d → scale=-2:1080 → loudnorm two-pass → drawtext lower third → mov_text subtitles → H.264 CRF 18 yuv420p -movflags +faststart → VMAF QC → YouTube upload.

Related

• workflow-editorial-interchange — round-tripping the edit into/out of NLEs.
• workflow-ai-enhancement — AI upscale/interpolate/denoise path.
• workflow-analysis-quality — QC gating before shipping.