Video_Convert_2

A collection of bash scripts to batch re-encode video files into portable MP4 format, suitable for playback on any Smart TV or media server (works great with Plex/Serviio).

The default output is HEVC Main 10 (hvc1-tagged) with stereo AAC. That direct-plays on current TVs, phones and desktop clients, but it is a stronger requirement than the H.264 these scripts used to emit — if you serve older or unusual clients, verify direct play before converting a library, since a client that cannot decode it makes the server transcode. AV1 is deliberately not used for this reason.

Make sure to compare the input video with the output using mediainfo. You may be surprised by the results — the output is often better quality than the input.

Scripts Overview

Script	Purpose
vc2.sh	Main batch video converter (auto-detects NVIDIA GPU)
vc1.sh	Single-file converter, tuned for compression or quality
cc_probe.sh	Helper: probe video file and output stream info
cc_norm.sh	Helper: analyze audio and output loudnorm parameters
vc_rename.sh	Utility: normalize video filenames
tools/build-ffmpeg.sh	Rebuild the /usr/local ffmpeg these scripts depend on

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vc2.sh — Batch Video Converter

Searches a configured directory for video files, probes each one, normalizes audio, and re-encodes to MP4. Automatically uses NVIDIA hardware acceleration (hevc_nvenc) when an NVIDIA GPU is detected; falls back to libx265 software encoding otherwise. The software path needs a multilib x265 — against an 8-bit-only build the 10-bit output silently degrades.

Synopsis

vc2.sh [OPTION...]

Options

-h, --help        This documentation.

--hq              High quality override: 60fps, QF=0.2, 192k audio,
                  slow preset, no resize.

--lq              Low quality override: 23.976fps, QF=0.08, 128k audio,
                  fast preset, with resize.

--no-gpu          Disable hardware acceleration even if an NVIDIA GPU
                  is detected; forces libx265 software encoding.

-m, --movie       Feature-length movies  (searches: renamed/features/)
--mv              Music videos           (searches: renamed/mtv/)
-o, --other       Other video files      (searches: renamed/other/)
-s, --series      TV series episodes     (searches: renamed/series/)
-v, --video       Generic video files    (searches: renamed/video/)
-x, --restrict    Restricted videos      (searches: renamed/restricted/)

Per-type Encoding Settings

Type	FPS	Quality Factor	Audio Bitrate	Preset	Resize
movie	23.976	0.10	160k	medium	yes
mv	30	0.20	192k	slow	yes
other	23.976	0.10	160k	slow	yes
series	23.976	0.08	128k	fast	yes
video	30	0.20	192k	slow	no
restricted	25	0.08	92k	fast	yes

The Preset column applies to the CPU encoder only. NVENC uses its own p1–p7 scale (nvenc_preset, default p6) — x264's preset names mean something quite different there, and passing them selects NVENC's legacy table.

Quality Factor is a rate ceiling, not a target: it sizes -maxrate/-bufsize, while nvenc_cq / cpu_crf decide the actual quality and the encoder spends less on easy content.

The rate ceiling is calculated dynamically from the quality factor: ceiling = QF × width × height × FPS / 1000, with -maxrate at 1.5x and -bufsize at 2x that.
Resize: videos wider than 1280px are scaled down to 1280px; narrower than 720px are scaled up to 720px.

Examples

# Re-encode TV series at default quality
vc2.sh -s

# Re-encode movies at high quality
vc2.sh -m --hq

# Re-encode series with hardware acceleration disabled
vc2.sh -s --no-gpu

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vc1.sh — Single-File Converter

Re-encodes one video file for either optimal compression or optimal quality. Defaults to HEVC on NVENC; -hwaccel cuda lets ffmpeg pick NVDEC per stream and fall back to software for codecs the GPU cannot decode.

vc1.sh [options] <inFile>

Option	Meaning
-m, --mode compression|quality	Quality intent (default: compression)
-c, --cpu	Encode with libx265 instead of hevc_nvenc
--av1	Encode AV1 with SVT-AV1 (implies --cpu)
-s, --original-size	Do not cap width at 1280px
--max-width N	Change the width cap
--fps N	Frame rate cap (default 24000/1001); none to disable
-q, --cq N	Override the quality level
--mp4	Write MP4 instead of MKV
--verify	Score the result against the source with VMAF
-n, --dry-run	Print the ffmpeg command and exit
-o, --output FILE	Output path

Output defaults to <basename>_recode.mkv. Quality ladder:

Mode	hevc_nvenc	libx265	libsvtav1
compression	cq 29	crf 26 (slow)	crf 34 (preset 6)
quality	cq 24	crf 20 (slow)	crf 28 (preset 5)

The frame rate is capped, never forced, so 23.976fps and slower sources pass through untouched. Nothing is ever upscaled. Subtitles, chapters and metadata are carried through.

Measured on 30s of 720p, SSIM against a common reference: compression mode 1419 kb/s @ 0.98937, quality mode 2739 kb/s @ 0.99362. --av1 gives the best quality-per-byte (1254 kb/s @ 0.99119) and is roughly 3x faster than --cpu, but is not widely direct-played — see the note at the top of this file.

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cc_probe.sh — Video Probe Helper

Probes a video file with ffprobe and writes a .probe.rc file containing stream variables sourced by the encoder scripts.

cc_probe.sh <inFile>

Output variables include: fName, fSize, duration, vWidth, vHeight, vBitrate, vCodec, vFPS, vLanguage, vMap, mainVideo, aBitrate, aChannels, aCodec, aLanguage, aMap, aSamplerate, mainAudio, sMap.

Stream selection logic:

• Video: prefers the default-flagged stream; falls back to the first video stream.
• Audio: prefers the default English stream, then first English stream, then first stream found.
• Subtitles: maps all English subtitle streams; skips unsupported formats (PGS, DVD, DVB, WEBVTT).

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cc_norm.sh — Audio Normalization Helper

Two-pass EBU R128 loudness normalization using ffmpeg's loudnorm filter. Called automatically by vc2.sh and vc2_hwaccel.sh.

cc_norm.sh <inFile> [ffmpeg_bin] [sample_range]

Targets: -24.0 LUFS integrated, -2.0 dBTP true peak, 11.0 LRA.
Default sample range: -ss 01:00 -t 06:00 (analyze 6 minutes starting at 1 minute).
Outputs the -filter:a loudnorm=... string for use in the final encode pass.

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vc_rename.sh — Filename Normalizer

Normalizes video filenames in the current directory: converts to lowercase, replaces spaces with dots, and strips known site-watermark suffixes.

# Dry run — shows what would be renamed without making changes
vc_rename.sh

# Actually rename the files
vc_rename.sh 1

For unrecognized suffixes the script prompts interactively: move the suffix to a prefix, trim it, or leave the filename unchanged.

Supported file types: .mkv, .mp4, .wmv, .webm.

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Directory Structure

Expected input layout under baseDir (/data2/usenet by default):

renamed/
├── features/          (-m / --movie)
├── mtv/               (--mv)
├── other/             (-o / --other)
├── restricted/        (-x / --restrict)
├── series/            (-s / --series)
│   ├── Show Name 1/
│   │   ├── S01/
│   │   └── S02/
│   └── Show Name 2/
│       └── S01/
└── video/             (-v / --video)

Output is written to videoDir (/video by default), mirroring the source directory structure.
Processed source files are moved to doneDir (/data2/usenet/done).

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Requirements

• ffmpeg built with libfdk_aac and libx264 (for CPU encoding)
• ffprobe (bundled with ffmpeg)
• mediainfo
• jq (used by cc_norm.sh)
• bc, awk, numfmt (standard utilities)
• NVIDIA drivers + NVENC-capable GPU (optional, for --cuda / hwaccel scripts)

The default audio codec is libfdk_aac and the default video codec is libx264. These can be changed in the script settings, but parameter tuning may also be required.

Setup

Symlink the helper scripts into /usr/local/bin (without the .sh extension) so vc2.sh can find them:

ln -s /path/to/cc_probe.sh /usr/local/bin/cc_probe
ln -s /path/to/cc_norm.sh  /usr/local/bin/cc_norm
ln -s /path/to/vc2.sh      /usr/local/bin/vc2

Ensure /usr/local/bin is in your $PATH.

Logs

• Main log: /var/log/convert/ccvc.log
• Trace log: /var/log/convert/ccvc_trace_<date>.log

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Example Output

> vc2 -s

Starting run of Video Converter 2
  Collecting list of files to process....................................................[  OK  ]

File 1 of 16
  Processing: series/TV Show/S02/S02E07.Episode 07.......................................[  OK  ]
  Normalizing audio track................................................................[  OK  ]
  Setting encode filters.................................................................[  OK  ]
                                       total time=01:27:46.69
frame=126273 fps=236 q=27.0 Lsize= 1226065kB time=01:27:46.66 bitrate=1907.1kbits/s speed=9.83x
---------------------------
Orig Size: 1.9GiB // New Size: 1.2GiB // File decreased by 35.18%
---------------------------
  Done

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- Cheers,

Rick

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tools/build-ffmpeg.sh — ffmpeg Builder

Rebuilds the hand-compiled ffmpeg in /usr/local that these scripts call directly. Records the exact configure line, so the encoder features vc1.sh and vc2.sh rely on (SVT-AV1, libvmaf, scale_cuda, multilib x265) are reproducible rather than folklore.

tools/build-ffmpeg.sh

Honours BUILD_ROOT, PREFIX and X265_TAG from the environment. Ends with a dozen self-checks that assert each feature by actually encoding with it.

Two findings baked into it, both of which cost real time to diagnose:

• --enable-cuda-nvcc cannot be used on a current Fedora. CUDA 12.9 refuses gcc 15 outright, and against gcc-14 it collides with glibc 2.42's C23 sinpi/cospi/tanpi. --enable-cuda-llvm builds the same filters via clang's NVPTX backend and needs no CUDA toolkit at all. --enable-libnpp is also gone — upstream removed it, so scale_npp no longer exists.
• x265 must be built from a real, reachable git tag. Its CMakeLists guards the shared-library install with # shared library is not installed if a tag is not found, so a tagless or shallow checkout installs only libx265.a and silently leaves the previous .so in place. The symptom is an ffmpeg that still reports 8-bit-only x265 after an apparently successful multilib build, and an HEVC encoder version unknown banner.