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Craigstreamy HEVC Smart English Subtitle Aggressive VMAF 1080p Profile

Generated from stock preset pack craigstreamy-hevc-smart-eng-sub-aggressive-vmaf.

Dependencies

Tool Needed Why
ffmpeg required scenario execution, encode/transcode, and mux packaging
ffprobe required criteria probing and stream/metadata inspection

E2E Verification

This profile is considered e2e-verified when its mapped suites pass in CI.

Suite What it proves Toolchain version report
tests/e2e/run_profile_actions_e2e.sh action-level output behavior, guardrails, and subtitle-intent pathways tests/e2e/.reports/latest/run_profile_actions_e2e_toolchain_versions.md

Intent

This profile converts candidates into streaming-friendly HEVC outputs while preserving the smart_eng_sub + preserve subtitle policy where feasible.

What It Optimizes For

  • practical bitrate efficiency with a consistent HEVC target
  • bounded aggressive-VMAF retries on the video encode path only
  • preserve all audio streams by default when packaging permits
  • subtitle policy: smart_eng_sub + preserve
  • conditional container selection: MKV when the smart_eng_sub + preserve policy selects a subtitle, fragmented MP4 otherwise

Input Envelope

Field Value
Codec any
Bit depth any
Color space bt709
Min resolution 1280x720
Max resolution 1920x1080

Scenario Map

Scenario Command
RES_JUST_RIGHT COLOR_SPACE_JUST_RIGHT transcode_hevc_1080_smart_eng_sub_aggressive_vmaf_profile.sh
ELSE profile_guardrail_skip.sh (requires SDR bt709 and 1280x720 to 1920x1080 input)

Runtime Behavior

  • Scenario RES_JUST_RIGHT COLOR_SPACE_JUST_RIGHT uses action script transcode_hevc_1080_smart_eng_sub_aggressive_vmaf_profile.sh.
  • Scenario ELSE uses action script profile_guardrail_skip.sh.

Starting Inputs And Expected Outputs

Aspect What this profile expects / does
Starting containers mkv, mp4, mov, mxf (anything ffmpeg can demux)
Required codec envelope any / any-bit / bt709
Required resolution range 1280x720 to 1920x1080
If criteria do not match candidate is routed to another profile or skipped
If criteria match scenario order is evaluated and first match executes
Output intent conditional: MKV when the smart_eng_sub + preserve policy selects a subtitle, otherwise stream-ready MP4 (fragmented + init/moov at start by default)

Flow

flowchart LR classDef gate fill:#fff7ed,stroke:#f59e0b,color:#7c2d12,stroke-width:1.5px; classDef stage fill:#e0f2fe,stroke:#0284c7,color:#0c4a6e,stroke-width:1.2px; classDef output fill:#dcfce7,stroke:#16a34a,color:#14532d,stroke-width:1.2px; classDef skip fill:#f3f4f6,stroke:#6b7280,color:#1f2937,stroke-width:1.2px; A[Input candidate: mkv / mp4 / mov / mxf]:::stage --> B[Probe codec bits color resolution]:::stage B --> C{Matches profile criteria envelope?}:::gate C -->|No| Z[Handled by other profile or guardrail skipped]:::skip C -->|Yes| D{Evaluate scenarios in order}:::gate D --> E[Execute subtitle-policy action]:::stage E --> P[Optional lane-specific pre-processing]:::stage P --> F{smart_eng_sub subtitle selected?}:::gate F -->|Yes| G[Encode HEVC + preserve audio + preserve smart_eng_sub subtitle]:::stage G --> H[Emit MKV output]:::output F -->|No| I[Encode HEVC + preserve audio]:::stage I --> J[Finalize fragmented MP4 + init/moov at start]:::stage J --> K[Emit final profile artifact]:::output

What This Profile Does Not Do

  • It does not normalize frame rate; source cadence/timebase is preserved by default.
  • It does not transcode audio for target-device compatibility by default.
  • It does not guarantee every input audio codec is valid for every selected output container.
  • It does not use VMAF to change audio behavior; aggressive mode is video-only.
  • It does not semantically understand subtitle meaning; subtitle selection is metadata and flag driven.
  • It does not OCR or convert bitmap subtitles to text subtitles.
  • It does not generate ABR ladders (HLS/DASH); output is a single-file artifact.
  • It does not certify playback on every device model; profile criteria are compatibility-oriented guardrails.
  • It does not enforce PSNR/SSIM/VMAF thresholds unless quality checks are explicitly enabled and configured.
  • It does not invent missing HDR/DV essence; metadata repair is heuristic and can be disabled.
  • It depends on source integrity and toolchain support for DV/HDR retention; strict mode may fail instead of silently downgrading.

High-Level Assessments

Label Assessment
Dynamic range HDR/DV aware on 4K, SDR-gated on 1080p, broad intake on legacy sub-HD
Resolution 4K / 1080p / legacy sub-HD lane family
Audio codecs preserved by default
Video codecs HEVC transcode target
Interlacing legacy lane only; optional deinterlace
Volume normalisation not applied by default
Crop legacy lane auto-crop enabled
Lowered video bitrate yes; bounded aggressive-VMAF retry policy
Lowered audio bitrate no by default
Audio transcoded no by default
Video transcoded yes
Audio switched no; stream copy preferred
Subtitle retained smart_eng_sub + preserve
Subtitle transformed no; preserve mode only
Container changed yes when the smart_eng_sub + preserve policy requires MKV, otherwise fragmented MP4
Container targets MKV / fragmented MP4
Bitrate targets video-first bounded search for lower bitrate at the configured VMAF floor
Audio bitrate targets copy/preserve unless a future audio profile says otherwise
Overall bitrate targets reduce video bitrate more aggressively while keeping audio untouched
Error guardrail skip, missing toolchain, strict DV/HDR mismatch, or unknown error placeholder

Source

  • Preset file: services/vfo/presets/craigstreamy-hevc-smart-eng-sub-aggressive-vmaf/vfo_config.preset.conf
  • Generated by: infra/scripts/generate-profile-docs.sh