#The VideoVariant object

A video variant defines a single video encode rendition within an output. Each output can contain up to 20 variants — for progressive formats this is typically one variant, while streaming formats (HLS, DASH, adaptive) use multiple variants to create an ABR (Adaptive Bitrate) ladder.

Variants are passed in the video array of an Output Specification.

#Common fields

{
  "codec": "h264",
  "resolution": "1080p",
  "quality": "standard"
}

{
  "codec": "h265",
  "width": 2560,
  "height": 1440,
  "framerate": 60,
  "quality": "premium",
  "h265": {
    "profile": "main10",
    "preset": "slow",
    "crf": 20,
    "tune": "grain"
  },
  "hdr": {
    "mode": "passthrough",
    "format": "hdr10"
  }
}

#H264 Options

Pass the h264 object on a variant to override x264 encoder defaults. All fields are optional — Transcodely selects optimal defaults based on the quality tier.

For a comprehensive guide to H.264 encoding concepts, see the H.264 Encoding Guide.

#Attributes

#Defaults by quality tier

{
  "codec": "h264",
  "resolution": "1080p",
  "quality": "premium",
  "h264": {
    "preset": "slow",
    "tune": "film",
    "profile": "high",
    "level": "4.1",
    "crf": 18,
    "bframes": 5,
    "ref": 6,
    "rc_lookahead": 60,
    "aq_mode": 2,
    "aq_strength": 1.2
  }
}

#H265 Options

Pass the h265 object on a variant to override x265 encoder defaults. The field set is similar to H264Options but with key differences in supported profiles, levels, and tune values.

For a comprehensive guide, see the H.265 Encoding Guide.

#Attributes

Key differences from H.264: CRF ranges differ (18—35 recommended), only grain and fastdecode tunes are available, main10 profile enables 10-bit encoding for HDR, and levels up to 6.2 support 8K resolution.

#Defaults by quality tier

{
  "codec": "h265",
  "resolution": "2160p",
  "quality": "premium",
  "h265": {
    "profile": "main10",
    "preset": "slow",
    "crf": 20,
    "tune": "grain",
    "level": "5.1"
  }
}

#VP9 Options

Pass the vp9 object on a variant to configure VP9-specific encoding parameters. VP9 uses a different parameter model than x264/x265 — it uses speed instead of preset and quality mode instead of tune.

For a comprehensive guide, see the VP9 Encoding Guide.

#Attributes

{
  "codec": "vp9",
  "resolution": "1080p",
  "quality": "standard",
  "vp9": {
    "profile": 0,
    "quality": "good",
    "crf": 31,
    "speed": 2,
    "tile_columns": 2
  }
}

#AV1 Options

Pass the av1 object on a variant to configure AV1-specific encoding parameters. AV1 offers the best compression efficiency but is slower to encode. It supports unique features like film grain synthesis and loop restoration filters.

For a comprehensive guide, see the AV1 Encoding Guide.

#Attributes

{
  "codec": "av1",
  "resolution": "2160p",
  "quality": "premium",
  "av1": {
    "preset": 4,
    "crf": 25,
    "film_grain": 8,
    "enable_cdef": true,
    "enable_restoration": true,
    "tile_columns": 2,
    "tile_rows": 1
  }
}

#HDR Configuration

HDR processing is configured at the variant level via the hdr object. This allows each variant in an ABR ladder to have independent HDR processing — for example, keeping HDR on 4K variants while tone mapping to SDR for lower resolutions.

For full documentation of all HDR options, see HDR.

#Attributes

{
  "codec": "h265",
  "resolution": "2160p",
  "quality": "premium",
  "h265": {
    "profile": "main10"
  },
  "hdr": {
    "format": "hdr10",
    "mode": "passthrough"
  }
}

#ABR ladder with HDR

This example shows HDR passthrough on the 4K variant with tone mapping to SDR on lower resolutions:

[
  {
    "codec": "h265",
    "resolution": "2160p",
    "quality": "premium",
    "h265": { "profile": "main10" },
    "hdr": { "format": "hdr10", "mode": "passthrough" }
  },
  {
    "codec": "h265",
    "resolution": "1080p",
    "quality": "standard",
    "hdr": { "mode": "tonemap", "tone_mapping": "bt2390" }
  },
  {
    "codec": "h265",
    "resolution": "720p",
    "quality": "economy",
    "hdr": { "mode": "tonemap", "tone_mapping": "bt2390" }
  }
]