Transcoding presets define the logic for the Media transcoding process. Here you define the settings for the transcoding process, what video and audio renditions are generated, some editing options and what output files are created. The main page contains the list of all transcoding presets defined for your account.
There are columns:
- ID - a unique identification of the preset
- Name - the name of the preset
- Encoder - the encoder engine used for transcoding
- Video codec - video codec used for transcoding
- Default - one of the presets is the default one which is assigned if the preset for media asset is not defined
- Used by workflow - shows to which workflow preset transcoding preset is assign to
- Created at - date and time when the preset was created
Add, edit, copy or delete the preset
Click on the Add preset button to add a new preset.
Click on the preset name in the list to edit a preset.
Click the Action button in the preset edit page to:
- make a copy of the preset;
- delete a preset.
Preset fields and their meaning
Name - assign any name to distinguish the preset from the rest.
Default - set to Yes if you want to use this preset by default if transcoding for media asset is started and no preset is assigned.
Only one preset can be default in your account!
Default language - used if input file language for audio or subtitle is not specified.
Language order - order in which audio language tracks are set during muxing.
Max. video/audio length difference (seconds) - the allowed difference between the audio and video lengths. Otherwise, a warning or error is generated during the validation stage.
IMPORTANT! Setting the 'source' option is possible for many settings telling the encoder not to change the specific setting. Use this option at your own risk as it may produce unexpected results. No consistency checks are performed to verify if this option is reasonable for the particular encoding job.
Encoder - choose which encoding engine is used.
Ignore ffmpeg warnings - when turned on ffmpeg warnings will not produce an asset in the WARNING status after transcoding (ignoring DTS/PTS warnings).
Video encoding renditions
Click Edit below the list of video profiles to open the popup where video renditions and their specific settings are defined.
Add as many video renditions as necessary for the output. Choose to add x264 or x265 (HEVC) video codec.
Title - the name of the rendition. Also, used by video players to display the list of renditions for manual selection.
Height - set the video height. Set only the video height of the rendition and aspect ratio will be kept as in source or set as specified.
Aspect ratio – set the video aspect ratio or keep as in source.
Frame rate (fps) - set the video frame rate.
Bitrate encoding mode - options:
- VBR - variable bitrate;
- CBR - constant bitrate (some encoders produce the capped VBR with this option rather than CBR);
- CRF - constant rate factor - bitrate is applied automatically based on the value set for each rendition.
Bitrate (kbps) - set your own custom bitrate values for video renditions in addition to the predefined list. Option disabled when CRF is set as Bitrate encoding mode.
Buffer size (kbps) - set rate control buffering parameters.
CRF - constant rate factor, a value between 0 and 51 to set the desired quality of the output with the bitrate being applied automatically - option disabled when VBR or CBR is set as Bitrate encoding mode.
CRF MAX BR - the maximum bitrate can be set for CRF encoding mode for each video rendition.
CRF buffer size - set rate control buffering parameters.
Keyframe (GOP) – choose to have a keyframe interval in frames or seconds.
Keyframe interval – choose keyframe interval.
Video enc. preset (encoding speed) – encoder specific setting which impacts the quality of encoding. The lower the speed the higher the quality but longer processing time.
Profile/level – set the video profile and level.
Tune – you can optionally choose to add ffmpeg tuning preset based upon the specifics of your input. For example, if your input is animation then use the animation tuning, If you are unsure of what to use or your input does not match any of the tunings then choose not selected.
Deinterlace (encoder specific) - set the deinterlacing method.
Advanced encoder options:
Colour encoding system - choose the colour encoding system.
Bit depth (codec specific) - choose the bit depth for the colour encoding. Available when x265 video codec is set.
CABAC (codec specific) - enable context adaptive binary arithmetic coding option.
Motion Estimation method - set method from the list.
Reference frames - set reference frames to consider for motion compensation.
RC LOOKAHEAD - set number of frames for slice-type decision lookahead.
B-frames - choose b-frames.
B-Frame Strategy - adaptively decides through a low-resolution lookahead the best number of B-frames to use options:
- fast - a good balance between speed and quality (default).
- slow - a much slower but more accurate B-frame decision mode that correctly detects fades and generally gives considerably better quality.
Conditions are settings defining the rules which the source video have to meet for the particular rendition to be generated. Depending on the Conditions you may have self-excluding renditions which are generated for different source video files.
Min. src. height - minimum source height for which the rendition is generated.
Max. src. height - maximum source height for which the rendition is generated.
Min. src. bitrate - minimum source video bitrate for which the rendition is generated.
Max. src. bitrate - maximum source video bitrate for which the rendition is generated.
The delete option is available only for renditions that are not included in some file package (see below for an explanation regarding file packages).
Other video encoding fields:
Force aspect ratio from XML manifest - XML manifest that defines all media asset files and comes with the media asset contains different settings than the aspect ratio extracted from the video track metadata, the XML setting is preferred.
No upscale - in addition to conditions defined for video renditions enable this option to ensure that no rendition is generated with higher resolution or bitrate as the source video has.
Audio encoding renditions
Click Edit below the list of audio profiles to open the popup where audio renditions and their specific settings are defined.
Add as many audio renditions as necessary for the output.
Title - the name of the rendition. Also, used by some players to display the list of renditions for manual selection. This is not the title for the audio track language which is copied from source metadata.
Codec - choose the audio codec. Unlike the video codec which is set for all video renditions in the preset, the audio codec may be set separately for each rendition. Other fields are disabled when the source audio codec is selected to inform that it would result in an audio stream copy.
Channels - option to keep the source channel layout or to set the downmix from any multi-channel layout to 2.0. (stereo).
By default, ingesting for example multi-channel audio track, Extra Text in file packages sets to "5.1", if set audio encoding profile has a downmix to 2.0, Extra Text field "5.1" or any other manually imputed text will be removed!
Audio BR (kbps) - set the audio bitrate.
Audio SR - set the audio sample rate.
The delete option is available only for renditions that are not included in some file package. Set backup audio tracks for audio file generation under File packages tab (see below for an explanation regarding file packages).
Conditions are settings defining the rules that the source audio must meet for the particular rendition to be generated. Depending on the Conditions you may have self-excluding renditions which are generated for different source audio tracks.
Src. codec - source audio codec has to match the condition for the rendition to be generated.
Src. channels - source channel layout has to meet the condition for the rendition to be generated.
Min. src. bitrate - minimum source audio bitrate for which the rendition is generated.
Max. src. bitrate - maximum source audio bitrate for which the rendition is generated.
Other audio encoding fields:
ISM audio chunk length - audio chunk length for Microsoft Smooth streaming (ISMA). We suggest the value which corresponds to 2 seconds of audio.
No upscale audio - in addition to conditions defined for audio renditions enable this option to ensure that no rendition is generated with higher bitrate as the source video has.
Cut DVB subtitle end time by ms if same as next subtitle show time- cut subtitle endtime by 20; 40 or 80 ms or switch off cutting.
Strip HTML and other formatting tags- remove all HTML formatting for SRT, ISMT and DVB subtitles.
File packages are groups of files and tracks that can be used to generate playback manifests or for uploads.
Click on the package name in the list to edit the package or click Add new button below the list to create a new package.
IMPORTANT!!! Playback manifest is the SMIL file used by the system to package the media asset into streaming formats. Multiple playback manifests with different video, audio and subtitle combinations may be defined for the media asset. To make the playback manifest include the System Manifest file type in the package. Only MP4, M4V, M4A, and TTML tracks are playable. System Manifest files are available only if these file types are chosen in the package.
Files that have to be uploaded to the specific external destination via the Workflow profile settings have to be included in a file package which is later assigned in the Workflow profile settings.
Files of the same type and rendition are generated only once regardless of the number of packages such file is included in.
NOTE! mjpeg source video tracks system defines as data tracks and they are not being transcoded.
The Base package is always generated for a media asset. It contains M4V files for all video tracks, M4A files for all audio tracks, multi-language TTML file for subtitles and System Manifest SMIL file. It is always a playable package. The Base package cannot be deleted or edited. It is updated automatically with all video and audio renditions added to the preset.
All other packages may contain any file types but some file types are incompatible in the same package and disabled for selection if the incompatible type is selected. Only one video type and one audio type can be selected for the package.
Some of the file types have options. For video and audio file types select the video bitrate, for container file types select both and subtitles for some as well. Select the backup audio track for audio file generation. This option to select backup audio tracks works for all formats in case the primary is not generated.
Select accepted and ignored language options for transcoding outputs (ISO 639-2). Note that by default all languages in the base package are being transcoded. Set which languages are muxed into which file packages. Also media manifest allows selecting audio language tracks for each manifest.
For TTML subtitles there is an option to select either multiple language TTML or a set of single language TTMLs. For Elemental SMIL manifest, there are options to set the video, audio and subtitle file naming patterns set inside of the manifest file.
Be aware that these should be equal to the ones used in Workflow profile upload file patterns corresponding to the upload configuration for this file package!
Burn in the logo image into the video tracks.
Position- set the position on the video image for the logo.
Scale percentage - set scaling of the logo image.
Vertical margin - set the vertical distance from the upper or lower border depending on the position setting.
Horizontal margin - set the vertical distance from the left or right border depending on the position setting.
Logo image - the logo image. Use the upload button or click the image to replace it. Other options are for downloading the actual logo to your device or resetting to the default blank logo.
Add fading to the video track.
Fade in duration(sec.) - duration of the fading effect at the beginning of the video.
Fade in start offset(sec.) - starting offset of the fading effect.
Fade out duration(sec.) - duration of the fading effect at the end of the video.
Fade out end offset(sec.) - ending offset of the fading effect.
Perform some basic editing of the video track.
Trim leading seconds - cut the first seconds of video from the resulting video tracks.
Trim trailing seconds - cut the final seconds of video from the resulting video tracks.
Crop left, right, top, bottom offsets - crop the video image in the resulting video tracks.