Encoding anime
the right way.

Why HEVC over H.264

For anime storage and playback, HEVC (H.265) consistently outperforms H.264 at equivalent visual quality. Flat colors, clean linework, and large uniform areas — the dominant visual language of animation — compress exceptionally well under HEVC's larger prediction block sizes.

In practical terms: a 500 MB BDRip episode that re-encodes to ~130 MB with H.264 at CRF 22 will reach the same quality at ~90–110 MB under HEVC at CQ 24. The gap widens at lower bitrates. For a library of hundreds of episodes, this compounds significantly.

Hardware support is no longer a concern. Every major platform — Apple TV 4K, Jellyfin, Plex, Infuse, VLC, mpv — decodes HEVC natively. The only remaining reason to use H.264 is compatibility with very old devices or specific streaming service upload requirements.

10-bit encoding and pix_fmt

Most BDRip anime sources are encoded in 10-bit color (yuv420p10le). Re-encoding to 8-bit introduces banding — subtle but visible color stepping in gradients, skies, and dark scenes. Anime is especially prone to this because of its reliance on smooth gradient fills and subtle shading.

When targeting HEVC main10 profile, the pixel format must be yuv420p10le. These two settings are coupled — using the wrong pix_fmt for a given profile either produces an error or silently degrades quality.

-profile:v main10 -pix_fmt yuv420p10le

CRF / CQ quality settings

NVENC uses -cq (Constant Quality) rather than -crf. The scale is similar — lower numbers mean higher quality and larger files — but NVENC's CQ is not a 1:1 match to x265's CRF. NVENC at CQ 24 is roughly equivalent to x265 CRF 20–22 in terms of output size, though quality characteristics differ.

For anime specifically, the flat regions and clean lines mean you can push CQ higher (lower quality number) than you might for live action without visible degradation. The gains from going below CQ 20 are rarely worth the file size increase.

* Percentages vs a typical 1080p BDRip HEVC source. Results vary by content and source encoder.

GPU presets (NVENC p1–p7)

NVENC presets range from p1 (fastest, lowest compression efficiency) to p7 (slowest, best compression). Unlike x264/x265 presets which vary the encode quality, NVENC presets primarily control how aggressively the encoder searches for optimal block matches — the quality ceiling is still set by CQ.

On a laptop 4060 specifically, p6 is the practical sweet spot. p7 adds meaningful encode time for diminishing compression gains at typical anime CQ values. p4 is fine for quick turnarounds when you're batch-processing overnight isn't an option.

Scale filters — doing it correctly

The goal for most anime archives is: cap at 1080p, never upscale, preserve aspect ratio. Getting the scale filter wrong is one of the most common FFmpeg mistakes.

The wrong way — comparing a constant against itself:

-vf "scale=min(1920\,1920):min(1080\,1080):force_original_aspect_ratio=decrease"

The right way — using iw and ih, FFmpeg's runtime input dimension variables:

-vf "scale='min(iw,1920)':'min(ih,1080)':force_original_aspect_ratio=decrease"

iw and ih are evaluated at runtime against each input file. A 720p source passes through unchanged; a 4K source scales down to 1080p. The single quotes around each min() expression are required — without them FFmpeg's filter parser treats the comma inside min() as a filter chain separator.

Audio — copy vs re-encode

The rule is simple: copy audio when the codec is container-compatible, re-encode when it isn't.

For MP4 output, AAC and MP3 copy cleanly. AC3 (Dolby Digital) and DTS technically work in MP4 but compatibility varies by player — copy is fine for Jellyfin and Apple TV, but may cause issues elsewhere. EAC3 and DTS-HD/MA require re-encode for MP4.

For MKV output, almost any codec copies without issue.

-c:a copy
# Do NOT add -ac 2 or -b:a here

-c:a aac -b:a 160k -ac 2

Color range

Most anime sources — BDRip, WEB-DL — use limited (TV) range, where luma values run from 16–235 rather than the full 0–255. FFmpeg's -color_range flag signals this to the decoder and downstream players.

The full recommended command

This is the command that comes out of applying everything above — NVENC HEVC, 10-bit, correct scale filter, audio copy with fallback logic, and sensible defaults for Jellyfin/Apple TV playback.

ffmpeg -i {INPUT} \
  -map 0:v:0 -map 0:a:{AUDIO_TRACK} \
  -c:v hevc_nvenc \
  -cq 24 \
  -preset p6 \
  -profile:v main10 \
  -level 4.1 \
  -vf "scale='min(iw,1920)':'min(ih,1080)':force_original_aspect_ratio=decrease" \
  -color_range tv \
  -pix_fmt yuv420p10le \
  -g 120 \
  -c:a copy \
  -map_chapters 0 \
  -map_metadata 0 \
  -y {OUTPUT}

  # Replace -c:a copy with:
  -c:a aac -b:a 160k -ac 2

CPU fallback (no NVIDIA)

If you're on AMD, Intel, or a system without a compatible NVIDIA GPU, replace the video encoder section with libx265 (software HEVC). CPU encoding is significantly slower but produces better compression efficiency per quality unit than NVENC.

  -c:v libx265 \
  -crf 20 \
    # libx265 uses -crf not -cq; 20 ≈ NVENC CQ 24 in output size
  -preset slow \
  -x265-params "profile=main10:pix_fmt=yuv420p10le"