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Encoding transform

An encoding transform defines how MK.IO processes an input asset into one or more MP4 renditions. Select a built-in preset based on the required codec, resolution, bitrate ladder, and encoding tier.

Built-in presets

MK.IO supports the following built-in presets:

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 / 1900kbps128 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 / 3400kbps128 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 / 6000kbps128 kbps
H265SingleBitrate720p (Advanced)1280x720 @ 30fps / 1800kbps128 kbps
H265SingleBitrate1080p (Advanced)1920x1080 @ 30fps / 3500kbps128 kbps
H265SingleBitrate4K (Advanced)3840x2160 @ 30fps / 9500kbps128 kbps

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

If you require a different encoding ladder, contact MK.IO support.

Constant video quality presets

The presets with CVQ in their name use Constant Video Quality (CVQ). These presets adjust the bitrate and encoding parameters to maintain consistent visual quality across the input content.

Use a standard preset for content shorter than 30 seconds. For content longer than 60 seconds, the CVQ presets can reduce the output bitrate by 15 to 30 percent without a perceptible change in visual quality. Older Windows CE and Roku clients may not be compatible with CVQ output.

CVQ presets use the Advanced encoding tier. See MK.IO pricing for current rates.

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
Flash Video FLV (.flv)Yes
3GP (.3gp, .3gpp)Yes
Matroska WebM (.webm)Yes
ISMV (.ismv, .isma)Yes
AVI (Uncompressed 8bit/10bit) (.avi)Yes
Windows Media Format (WMV) (.wmv)Yes

Output file format

MK.IO uses the MP4 format for Video on Demand (VOD) assets. An asset generated through VOD transcoding contains the following files:

  • MP4 files (.mp4), one per video rendition with all audio streams interleaved.

  • A server manifest (.ism) used as the access point for streaming endpoints.

  • A client manifest (.mpd).

  • Index files (.mpi), one per rendition, used to improve streaming-delivery performance.

VOD transcoding uses the input filename as the prefix for all output files in the asset.

Existing assets that use the earlier Smooth Streaming or MP4 layout remain deliverable through MK.IO streaming endpoints. Use an asset conversion transform when a newer workflow requires the current MP4v4 layout.

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.265Main Profile, 8-bit/10-bit Up to 4:2:2
MPEG-2Main and High Profiles Up to 4:2:2
Sony XAVC / XAVC SYes
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 IMXYes
Sony XDCAM, including HD and EXYes
Dolby Vision 5 and 8.1Yes
V210 Video Picture EncodingYes
MPEG-1Yes
VC-1Yes
VP8Yes
VP9Yes
MJPEGYes
AV1Yes
Microsoft MPEG4v1, v2 and v3Yes
H263Yes
Avid DNxHD and DNxHRYes
Sorenson SparkYes

Input audio codecs

File formats (file extensions)Supported
AAC, including AAC-LC, HE-AAC, and HE-AACv2Up to 5.1
MPEG Layer 2Yes
MP3 (MPEG-1 Audio Layer 3)Yes
PCM, LPCM, DPCM and ADPCMYes
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
DTSYes
OpusYes
VorbisYes
Apple Lossless Audio Code (ALAC)Yes