Video infrastructure glossary

Every topic on mpegflow.com as a one-line definition. Click any term for the full engineering-reference article. 61 terms across 7 categories.

Captions

Captions and timed metadata — WebVTT, IMSC, 608/708, SCTE-35.

Burn-in vs soft subtitles — when to render captions into video vs deliver as separate tracks: Practical guide to subtitle delivery — burn-in (rendered into video) vs soft (separate track), use cases, ffmpeg implementation, player compatibility, cost tradeoffs.
CEA-608 and CEA-708 — broadcast caption standards in a streaming world: Practical reference on CEA-608 and CEA-708 closed caption standards — broadcast caption legacy, embedding in MPEG-TS and SEI messages, conversion to WebVTT and IMSC for streaming.
CEA-608/708 to WebVTT conversion with ccextractor — broadcast caption migration: Practical guide to converting CEA-608/708 captions from broadcast sources to WebVTT for streaming — ccextractor usage, SEI message extraction, timing alignment, multi-service handling.
TTML and IMSC — XML-based timed text for premium video and broadcast: Practical reference on TTML (Timed Text Markup Language) and the IMSC profile — XML-based caption format, rich styling capabilities, broadcast and premium streaming use cases, vs WebVTT.
WebVTT — the W3C caption format every browser speaks: Practical reference on WebVTT — file structure, styling, positioning support, integration with HLS and DASH, vs SRT and TTML, and when WebVTT is the right caption format.

Codecs

Video and audio codec deep-dives — AV1, VVC, HEVC, H.264, AAC, Opus.

AAC — the audio codec every video pipeline ships, and what to know about it: Practical reference on AAC for video pipelines — AAC-LC vs HE-AAC vs xHE-AAC, FDK-AAC vs ffmpeg native encoder, bitrate tuning, multi-channel encoding, and container compatibility.
AV1 codec — what it is, where it wins, what it costs: Practical reference for engineers shipping AV1 in production — what AOMedia got right, encoder economics, hardware decode timeline, when AV1 beats HEVC and when it doesn't.
AV1 encoding economics — when AV1 actually saves money vs HEVC: Practical analysis of AV1 vs HEVC streaming economics — bandwidth savings vs encode compute cost, hardware AV1 break-even, the ROI threshold where AV1 pays off.
FDK-AAC vs ffmpeg native AAC — encoder selection for streaming pipelines: Practical comparison of FDK-AAC and ffmpeg's native AAC encoder — quality at common bitrates, licensing constraints, build configuration, VBR vs CBR, when each is the right choice.
H.264 (AVC) — the codec that won, and is still winning two decades later: Practical reference on H.264/AVC in 2026 — why it's still everywhere, x264 production tuning, the codec everyone targets first, and when H.264 is the only right answer.
HEVC (H.265) — the codec everyone uses and nobody loves: Practical reference on HEVC/H.265 — codec mechanics, x265 in production, hardware encode/decode maturity, the patent licensing mess, and why it's still the right 2026 answer.
HEVC HDR10 encoding configuration — x265 parameters that get HDR right: Practical guide to HEVC HDR10 encoding with x265 — Main 10 profile, color signaling, master display SEI, MaxCLL/MaxFALL, the complete CLI configuration that produces conformant HDR10 output.
Mezzanine codecs — ProRes, DNxHD, DNxHR, and the editorial workflow tier: Practical reference on mezzanine codecs — Apple ProRes profiles, Avid DNxHD/DNxHR, when to use mezzanine vs delivery codecs, and pipeline integration for editorial-to-streaming workflows.
Opus — the audio codec for live, voice, and any pipeline that values latency: Practical reference on the Opus audio codec — architecture, libopus production tuning, low-latency vs music-quality tradeoff, container support, and when Opus beats AAC.
SVT-AV1 preset tuning — preset 4 vs 6 vs 8 vs 10 in production: Practical guide to SVT-AV1 preset selection — quality vs encoding-time tradeoff at each preset, VMAF measurements, when to use preset 4 vs 6 vs 8 vs 10 vs 12 in production.
VP9 — Google's pre-AV1 codec, and why most teams skip it now: Practical reference on VP9 — codec mechanics, libvpx-vp9 production realities, the YouTube-driven hardware install base, and the awkward middle position between H.264, HEVC, and AV1.
VVC (H.266) — the codec MPEG built and the industry hasn't deployed: Practical reference on Versatile Video Coding (H.266) — compression efficiency, encoder ecosystem (VVenC), the patent-pool situation, hardware decode timeline, and where VVC stands against AV1.

Color

Color and HDR — HDR10, HDR10+, Dolby Vision, HLG, color spaces.

10-bit HEVC from 8-bit source — when it helps and when it's pointless: Practical guide to encoding 10-bit HEVC from 8-bit source — encoder math benefits, banding reduction, when 10-bit is mandatory (HDR), bandwidth implications, hardware decoder support.
Bit depth — 8-bit vs 10-bit vs 12-bit and what it means for video: Practical reference on video bit depth — banding in 8-bit, why 10-bit is HDR-mandatory, encoder and hardware decoder support, bandwidth implications, and bit-depth selection per use case.
Chroma sub-sampling — 4:4:4 vs 4:2:2 vs 4:2:0 and what it means for video: Practical reference on chroma sub-sampling — the 4:4:4 / 4:2:2 / 4:2:0 notation, the bit budget math, codec profile support, where each is used, and the visual impact on natural vs graphic content.
Color spaces — Rec.709 vs Rec.2020 vs DCI-P3 and what they mean for video: Practical reference on video color spaces — Rec.709, BT.2020, DCI-P3 primaries, white points, gamut comparison, conversion considerations, and signaling in container metadata.
HDR to SDR conversion — the full pipeline from PQ to BT.709: Practical guide to HDR-to-SDR conversion — linearization, color primaries conversion, tone mapping, gamut handling, re-quantization, ffmpeg command construction, validation.
HDR10 — the open HDR baseline every premium video pipeline ships: Practical reference on HDR10 — ST 2084 PQ transfer function, BT.2020 color space, static metadata, signaling in HEVC and AV1, the universal HDR baseline that every HDR-capable device decodes.
HLG (Hybrid Log-Gamma) — the broadcast-compatible HDR format: Practical reference on Hybrid Log-Gamma — BBC/NHK joint development, scene-referred transfer function, backward compatibility with SDR, broadcast use cases, and where HLG fits next to HDR10.
Limited vs full range color — TV range vs PC range and the conversion bugs: Practical reference on video color range — TV range (16-235 for 8-bit), PC range (0-255), historical reasons, signaling, range mismatch artifacts, ffmpeg conversion.
Tone mapping — converting HDR to SDR and adapting HDR for different displays: Practical reference on tone mapping — HDR-to-SDR conversion algorithms (Reinhard, Hable, ACES, BT.2390), HDR-to-HDR adaptation, static vs dynamic, display-side vs encoder-side, FFmpeg implementation.

Containers

Container formats — MP4/fMP4, MPEG-TS, MKV/WebM, MOV.

Fragmented MP4 (fMP4) segment construction — moof, mdat, tfdt, and styp: Practical reference on fragmented MP4 segment internal structure — moof + mdat box pairs, init segment vs media segments, tfdt absolute timing, styp self-identification, sidx for byte-range fetching.
MKV and WebM — the open container format and its browser-friendly profile: Practical reference on Matroska and WebM containers — EBML format, segment/cluster/block structure, codec flexibility, browser support, when MKV/WebM is the right choice vs MP4.
MOV (QuickTime) — Apple's container format and the editorial-workflow standard: Practical reference on Apple QuickTime MOV — atom-based structure, the relationship to MP4, ProRes/DNxHR delivery, edit lists and timecode, when to use MOV vs MP4.
MP4 / fMP4 — the universal video container and the streaming-friendly fragmented variant: Practical reference on MP4 — ISO Base Media File Format, box structure (ftyp/moov/mdat), fragmented MP4 for streaming, codec compatibility, CMAF derivation, HLS and DASH integration.
MP4 faststart — moov at front, why it matters, and how to set it: Practical reference on MP4 faststart — moov at end vs front, ffmpeg movflags=+faststart, why progressive streaming requires it, the one-pass vs two-pass tradeoff.
MXF — the broadcast and post-production container nobody outside the industry uses: Practical reference on MXF (Material Exchange Format) — SMPTE 377, operational patterns (OP1a, OP1b, OPAtom), codec support, broadcast and post-production use, vs MP4 / MOV.

Encoding

Encoding strategy — hardware acceleration, two-pass, CRF, presets.

Deinterlacing — converting interlaced source to progressive output for streaming: Practical reference on deinterlacing — yadif vs bwdif, motion-adaptive algorithms, telecined content (IVTC), and broadcast-to-streaming pipeline integration.
Encoder presets — what x264 / x265 / SVT-AV1 presets actually mean: Practical reference on encoder presets — preset philosophy across encoders, what each preset enables, picking presets for VOD vs live, the speed-quality curve, and benchmark calibration.
Encoder version pinning and regression testing — production reproducibility: Practical guide to pinning encoder versions and detecting regressions — version selection, building from source, regression testing procedures, A/B test framework, rollback.
FFmpeg — the multimedia framework that runs nearly all video infrastructure: Practical reference on FFmpeg — project structure, libav* libraries, codec/format support, filter graphs, hardware acceleration, ffprobe and ffplay, the universal video tool.
FFmpeg CRF tuning by content type — picking the right CRF for your content: Practical guide to CRF tuning for different content types — talking heads, sports, animation, screen content, mobile-only. CRF defaults per encoder and content-aware adjustments.
FFmpeg filter_complex patterns — branching, merging, and multi-output graphs: Practical guide to FFmpeg filter_complex graphs — split for branching, concat/hstack/overlay for merging, multi-input multi-output patterns, common pipeline use cases.
ffprobe stream inspection — extracting media info for pipeline automation: Practical guide to ffprobe — common inspection patterns, JSON output for scripting, stream-specific inspection, frame and packet analysis, production usage in pipelines.
Frame rate — 24, 30, 60 fps and the fractional rates that broke video: Practical reference on video frame rates — 24/25/30/50/60/120 fps standards, the NTSC fractional rates (23.976/29.97/59.94), conversion, VFR vs CFR, and encoding implications.
Frame types — I-frames, P-frames, B-frames, and how they shape encoding: Practical reference on video frame types — intra-coded I-frames, predicted P-frames, bi-directional B-frames, B-pyramid, decode vs display order, and the latency implications of B-frames.
GOP and keyframe interval — what they are, why they matter, and how to set them: Practical reference on Group of Pictures and keyframe interval — closed vs open GOP, IDR keyframes, segment alignment for ABR streaming, the latency vs compression tradeoff.
Loudness normalization — LUFS, EBU R128, ATSC A/85, and getting audio levels right: Practical reference on loudness normalization — LUFS/LKFS units, EBU R128 (-23 LUFS), ATSC A/85 (-24 LKFS), streaming targets (-16 LUFS), measurement, true peak limiting, FFmpeg loudnorm.
Rate control — CRF, CBR, VBR, capped CRF, and which to choose: Practical reference on video encoder rate control — CRF (constant rate factor), CBR (constant bitrate), VBR (variable bitrate), capped CRF for streaming, and which mode fits VOD vs live.
Resolution and aspect ratio — what 1080p, 4K, and 16:9 actually mean: Practical reference on video resolution and aspect ratio — 480p/720p/1080p/1440p/4K UHD/DCI 4K/8K standards, pixel aspect ratio vs display aspect ratio, anamorphic, and ABR ladder design.
Two-pass encoding — when it matters and when single-pass is fine: Practical reference on two-pass video encoding — how it works, when target-bitrate VBR benefits, why CRF doesn't need it, the wall-time tradeoff, and the production decision.
Watermarking and overlays — burning logos, tags, and identifiers into video for streaming: Practical reference on video watermarking and overlay rendering — visible vs forensic watermarking, ffmpeg overlay filter, positioning conventions, multi-resolution scaling, and pipeline integration.

Protocols

Streaming protocols — HLS, DASH, CMAF.

CMAF — the segment format that ended the HLS-vs-DASH duplicate-encoding problem: Practical reference on Common Media Application Format (CMAF) — fragmented MP4 structure, common encryption (CENC), unified HLS+DASH delivery, chunked CMAF for low-latency, and operational benefits.
DASH — the standardized streaming protocol that won the spec war and lost the install base: Practical reference on MPEG-DASH — MPD manifest structure, segment formats, dash.js and Shaka Player, DASH-IF profiles, multi-period streaming, and DASH vs HLS in 2026.
HLS — the protocol that won the streaming wars and what to know about it: Practical reference on HTTP Live Streaming — m3u8 manifests, segment formats, ABR adaptation, low-latency HLS, FairPlay DRM integration, and when HLS is the right protocol.
HLS segment duration — picking the right TARGETDURATION for your use case: Practical guide to HLS segment duration selection — Apple's 6-second recommendation, GOP alignment, latency vs request overhead tradeoff, LL-HLS partial segment relationship.
HLS X-TIMESTAMP-MAP — webvtt subtitle timing alignment for HLS: Practical reference on the HLS X-TIMESTAMP-MAP header — the MPEGTS:LOCAL syntax, why webvtt subtitles need it, common timing bugs, generation in pipelines.

Quality

Video quality measurement — VMAF, PSNR, SSIM, per-title encoding.

ABR ladder design — the engineering decisions in adaptive bitrate streaming: Practical reference on ABR ladder design — rung count, resolution choices, codec choices per rung, bitrate calibration, audience-mix-driven design, and the tradeoffs that matter in production.
ABR ladder VMAF calibration — finding the right bitrate per rung for your content: Practical guide to ABR ladder calibration via VMAF — representative content selection, per-rung VMAF target setting, bitrate sweep procedure, identifying ladder gaps, iteration.
BD-rate calculation — how to compare codecs and encoder configurations: Practical guide to Bjontegaard delta-rate calculation — the math, multi-bitrate encoding procedure, BD-rate VMAF vs PSNR, libbjontegaard tooling, interpreting results.
Golden-eyes video review — when automated metrics aren't enough: Practical guide to golden-eyes panel review for video quality — content selection, review environment standards, methodology, reviewer training, when to use it vs automated metrics.
Per-title encoding — Netflix's content-aware encoding model and how to run it: Practical reference on per-title encoding — Netflix's approach, the analyze-then-encode workflow, content-aware bitrate selection via VMAF, operational tradeoffs, and ROI math.
PSNR — the classic quality metric, why it persists, and where it fails: Practical reference on Peak Signal-to-Noise Ratio — mathematical definition, why PSNR persists as a metric despite perceptual limitations, where it still serves, and where it misleads.
SSIM — the structural similarity metric and its multi-scale variants: Practical reference on the Structural Similarity Index — luminance, contrast, and structure components, MS-SSIM and SSIMplus variants, ITU-T standardization, and SSIM vs PSNR vs VMAF.
VMAF — Netflix's quality metric and the modern reference for video quality measurement: Practical reference on Video Multi-Method Assessment Fusion — Netflix's perceptual quality metric, training methodology, libvmaf usage, BD-rate calculation, and the limits of automated metrics.
VMAF cross-validation with MOS — calibrating quality metrics against viewers: Practical guide to validating VMAF against subjective MOS testing — ITU-R BT.500 methodology, golden viewer panel selection, when VMAF disagrees with MOS, calibration procedures.