Simple Format Specification

The Simple Format Specification defines the output format for media content in the Coconut Transcoding Service. This guide provides details on the structure, including video and audio specifications, and format options.

Format Naming Convention

Video formats are represented as:

$video_container:$video_specs:$audio_specs:$format_options

Of these, only `$video_container` is required. Appropriate defaults (codecs, bitrates, sample rates) are set based on the chosen container.

Specs must be separated by semi-colon `:` and options must be separated by underscore `_`. Refer to the examples provided for a clearer understanding of how to use the different format options.

For Audio-only formats:

$audio_container:$audio_specs

For image formats, you can only set the resolution:

$image_container:$resolution

Containers

List of supported containers (video, audio and image)
`mp4` `webm` `mpegts` `mov` `ogg` `aac` `mp3` `wav` `jpg` `png` `webp` `gif` `webp_anim`

Video Specifications

$resolution_$bitrate_$codec_$fps

Video specs	Values	Default
Resolution	`144p` `240p` `360p` `480p` `540p` `576p` `720p` `1080p` `1440p` `2160p` `4k`<br>Any resolution `W`x`H`	Original
Codec	`copy` `dnxhd` `h264` `hevc` `novideo` `prores` `prores-ks` `vp8` `vp9` (container compatibility applies; see Certified Transcoding Profiles)	Container standard
Bitrate (kbps)	Any value < `200000k`<br>`1500k` `2000k` `4000k` ...
FPS	`0fps` (preserve source FPS), `15fps` `23.98fps` `25fps` `29.97fps` `30fps` `60fps`	Original

Audio Specifications

$codec_$bitrate_$sample_rate_$channels

Audio specs	Values	Default
Codec	`aac` `ac3` `copy` `mp2` `mp3` `noaudio` `pcm` `pcm-alaw` `pcm-s16le` `pcm-u8` `vorbis` (container compatibility applies)	Container standard
Bitrate (kbps)	Any value < `512k`<br>`64k` `128k` `256k` ...
Sample rate	`8000hz` `11025hz` `22050hz` `44100hz` `48000hz`	Original
Channels	`mono` `stereo` `multi`	Original

Format options

$options

Options	Values	Default
pix_fmt	`yuv420p` `yuv422p` `yuv420p10le` `yuv444p10le` (codec/profile compatibility applies)	Encoder default
2pass	Enable two-pass H264/HEVC encoding; requires an explicit video bitrate and cannot be combined with quality/CRF	No
metadata	Strip original metadata if `metadata=0`	1

MP4 options

Options	Values	Default
frag	Generate a fragmented MP4 file if this option is used.	No

H264 options

Options	Values	Default
vprofile	`baseline` `main` `high` `high10` `high422` `high444`	Encoder default
level	`10` `11` `12` `13` `20` `21` `22` `30` `31` `32` `40` `41` `42` `50` `51`	Encoder default
quality	Set visual quality from `1` (worst) to `5` (best).
maxrate (kbps)	Cap bitrate when using quality.<br>`mp4:1080p::quality=4,maxrate=2500k`

high10 requires yuv420p10le, high422 requires yuv422p, and high444 requires yuv444p10le.

HEVC options

HEVC supports quality, maxrate, 2pass, yuv420p, and certified 10-bit yuv420p10le. vprofile and level are not part of the certified HEVC contract.

VP8 and VP9 options

Options	Values	Default
quality	Set a visual quality instead of bitrate From `1` (worst) to `5` (visually lossless)<br>`quality=4` is a pretty good quality / file size ratio.
maxrate (kbps)	When using quality, you can cap the bitrate to not go higher your requirements.<br>`webm:vp9_1080p::quality=4,maxrate=2500k`

Full examples

Format	Description
mp4:1080p	MP4 with H264 / AAC codecs. `1080p` resolution and `4000k` bitrate
mp4:1080p::quality=4	Use quality option instead of video bitrate
mp4:1080p::quality=4,maxrate=3000k	Use quality option and cap the bitrate to `3000k`
mp4:hevc_2160p	MP4 with HEVC / AAC codecs. `4k` resolution and `8000k` bitrate
mp4:1080p_4000k::2pass	Enable `2pass` encoding
mp4:320x240_1000k	Specify the full resolution and the video bitrate
mp4:1080p:noaudio	Remove the audio track
mp4:1080p:copy	Copy the audio track without transcoding
mp4:::quality=3	Keep the original resolution and use the quality option
mp4:360p_25fps	Changes the original frame rate to `25fps`
mp4:copy:copy	Copy the video and audio track without transcoding
mp4:1080p::frag,quality=4	Create a fragmented MP4 file with 1080p resolution and quality option
mp4:::quality=3,vprofile=high,level=50	Specify the video profile `high` and level `50` for H264 encoding
webm:720p	WebM with VP9 / Vorbis defaults
webm:vp9_1080p	WebM with VP9 / vorbis codecs. `1080p` resolution and `4000k` bitrate
webm:720p:48000hz	Specify the sample rate `48000hz`
mp4:720p:multi	Keep the audio channels 5.1 instead of changing it to stereo
mp3	MP3 audio-only format with `128k` bitrate
aac:64k	AAC audio-only format with `64k` bitrate
webp:400x	WebP image-only format with `400x` resolution. Height is calculated automatically
jpg:640x360	JPG image-only format with full resolution given `640x360`