Encoding transforms

An encoding transform is the recipe on how to process the input asset into a set of MP4 files with the given resolution and bitrates. MK.IO provides a set of built-in presets to be used in such encoding transform.

The following built-in presets are supported:

Built-in preset nameVideoAudio
AACGoodQualityAudio (Foundations)n/a192 kbps
H264SingleBitrateSD (Foundations)848x480 @ 30fps / 2200kbps128 kbps
H264MultipleBitrateSD (Foundations)
H264MultipleBitrateSDWithCVQ (Advanced)
432x240 @ 30fps / 400kbps
640x360 @ 30fps / 650kbps
848x480 @ 30fps / 900kbps
848x480 @ 30fps / 1300kbps
848x480 @ 30fps / 1900kbps
128 kbps
H264SingleBitrate720p (Foundations) 1280x720 @ 30fps / 4500kbps128 kbps
H264MultipleBitrate720p (Foundations)
H264MultipleBitrate720pWithCVQ (Advanced)
320x180 @ 30fps / 400kbps
640x360 @ 30fps / 600kbps
640x360 @ 30fps / 1000kbps
960x540 @ 30fps / 1500kbps
960x540 @ 30fps / 2250kbps
1280x720 @ 30fps / 3400kbps
128 kbps
H264SingleBitrate1080p (Foundations)1920x1080 @ 30fps / 6750kbps128 kbps
H264MultipleBitrate1080p (Foundations)
H264MultipleBitrate1080pWithCVQ (Advanced)
320x180 @ 30fps / 400kbps
640x360 @ 30fps / 600kbps
640x360 @ 30fps / 1000kbps
960x540 @ 30fps / 1500kbps
960x540 @ 30fps / 2250kbps
1280x720 @ 30fps / 3400kbps
1920x1080 @ 30fps / 4700kbps
1920x1080 @ 30fps / 6000kbps
128 kbps
H265SingleBitrate720p (Advanced)1280x720 @ 30fps / 1800kbps128 kbps
H265SingleBitrate4K (Advanced)3840x2160 @ 30fps / 9500kbps128 kbps


Audio streams are encoded in stereo with HE-AAC audio codec.


If a different encoding ladder is required, please contact our support channels for help

Input file formats

File formats (file extensions)Supported
MP4 (.mp4, .m4a, .m4v)Yes
MPEG2-PS, MPEG2-TS (.ts, .ps, .mpg)Yes
Matroska MKV (.mkv)Yes
QuickTime (.mov)Yes
MXF (.mxf)Yes
FLV (with H.264 and AAC codecs) (.flv)Yes
3GP (.3gp, .3gpp)Yes
Matroska WebM (.webm)No
ISMV (.ismv, .isma)Yes
AVI (Uncompressed 8bit/10bit) (.avi)Yes

Output file format

MK.IO uses an MP4 file format for the VOD assets. Each asset generated through VOD transcoding will contain the following files:

  • MP4 files (.mp4), one per video rendition with all audio streams interleaved
  • Server manifest (.ism) used as the access point for streaming endpoints
  • Client manifest (.mpd)
  • Index files (.mpi), one per rendition (used to enhance performance of the streaming delivery)

The naming of the files on output of VOD transcoding uses the input filename as a prefix for all files in the asset.

Input video codecs

File formats (file extensions)Supported
H264/AVC, including AVCIntraMain and High Profiles, 8-bit/10-bit
Up to 4:2:2
HEVC/H.265 Main Profile, 8-bit/10-bit
Up to 4:2:2
MPEG-2Man and High Profiles
Up to 4:2:2
DVCPro SD and HDYes
Digital video DV and HDVYes
JPEG 2000Yes
Apple ProRes 422, including LT and HQYes
Apple ProRes 4444, including XQYes
Sony XAVCYes
Sony XDCAM, including HD and EXYes
Dolby Vision 5 and 8.1Yes
V210 Video Picture EncodingYes

Input audio codecs

File formats (file extensions)Supported
AAC, including AAC-LC, AAC-HE, and AAC-HEv2; up to 5.1)Up to 5.1
MPEG Layer 2Yes
MP3 (MPEG-1 Audio Layer 3)Passthrough only. Without cover image
AES (SMPTE 331M and 302M, AES3-2003)Yes
Dolby EPassthrough only
Dolby Digital (AC3)Yes
Dolby Digital Plus (E-AC3)Yes, including Dolby Atmos in passthrough


MK.IO will also generate a thumbnail file automatically when using an encoding transform. It will be a single JPG image with a 50% size relative to the highest resolution track


Thumbnails will only be available for MP4 outputs