Skip to content

Craigstreamy HEVC Smart English Subtitle Audio Conform Aggressive VMAF Legacy Sub-HD Profile

Generated from stock preset pack craigstreamy-hevc-smart-eng-sub-audio-conform-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 and conforming DTS-family or PCM-family audio when needed.

What It Optimizes For

  • practical bitrate efficiency with a consistent HEVC target
  • bounded aggressive-VMAF retries on the video encode path only
  • preserve AAC and Dolby-family audio streams when already acceptable
  • conform DTS-family or PCM-family audio into open-source Dolby-aligned delivery codecs when needed
  • 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 any
Min resolution 320x240
Max resolution 1279x719

Scenario Map

Scenario Command
RES_JUST_RIGHT transcode_hevc_legacy_smart_eng_sub_audio_conform_aggressive_vmaf_profile.sh
ELSE profile_guardrail_skip.sh (requires 320x240 to 1279x719 input)

Runtime Behavior

  • Scenario RES_JUST_RIGHT uses action script transcode_hevc_legacy_smart_eng_sub_audio_conform_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 / any
Required resolution range 320x240 to 1279x719
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 + conform audio if needed + preserve smart_eng_sub subtitle]:::stage G --> H[Emit MKV output]:::output F -->|No| I[Encode HEVC + conform audio if needed]:::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 invent Atmos or proprietary immersive metadata.
  • It does not transcode already-acceptable AAC or Dolby-family audio just to make everything uniform.
  • It does not apply a broad audio bitrate-lowering strategy yet.
  • 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 AAC + Dolby preserve, DTS/PCM conform
Video codecs HEVC transcode target
Interlacing legacy lane only; optional deinterlace
Volume normalisation applied when DTS/PCM-family audio is transcoded
Crop legacy lane auto-crop enabled
Lowered video bitrate yes; bounded aggressive-VMAF retry policy
Lowered audio bitrate not as a general policy; only codec-target defaults for DTS/PCM conform
Audio transcoded DTS/PCM-family only
Video transcoded yes
Audio switched DTS/PCM -> AAC / E-AC-3 / AC-3 when needed
Subtitle retained smart_eng_sub + preserve
Subtitle transformed no; preserve mode only
Container changed yes when subtitle or preserved-audio safety requires MKV, otherwise fragmented MP4 with faststart fallback for E-AC-3
Container targets MKV / fragmented MP4
Bitrate targets practical video efficiency; audio preserve-first
Audio bitrate targets codec-target defaults only when DTS/PCM-family audio is conformed
Overall bitrate targets reduce video bitrate while preserving viewing intent and sane audio delivery
Error guardrail skip, missing toolchain, strict DV/HDR mismatch, or unknown error placeholder

Source

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