Key fields for converting scan type

Description

Configuring for scan type conversion involves setting fields in specific ways. The three key fields to convert the scan type of the input are Configuration - Deinterlace Mode, Configuration - Interlace Mode, and Configuration - Telecine. The following table describes how to set these three key fields to convert a given input to a given output.

Input	Output	Configuration - Deinterlace mode	Configuration - Interlace mode	Configuration - Telecine
Progressive	Progressive	Off	Progressive	None
Interlaced	Progressive	Deinterlace	Progressive	None
Interlaced	Progressive	Adaptive	Progressive	None
Hard telecine	Progressive	Inverse telecine	Progressive	None
Hard telecine	Progressive	Adaptive	Progressive	None
Soft telecine	Progressive	Off	Progressive	None
Mixed	Progressive	Adaptive	Progressive	None
Progressive	Hard telecine	Off	One of the other options	Hard telecine
Hard telecine	Hard telecine	Off	One of the other options	None
Soft telecine	Hard telecine	Off	One of the other options	Hard telecine
Mixed	Hard telecine	Off	One of the other options	Hard telecine
Interlaced	Interlaced	Off	One of the other options	None
Mixed	Interlaced	Off	One of the other options	None
Progressive	Soft telecine	Off	One of the other options	Soft telecine
Hard telecine	Soft telecine	Inverse telecine	One of the other options	Soft telecine
Hard telecine	Soft telecine	Adaptive	One of the other options	Soft telecine
Soft telecine	Soft telecine	Off	One of the other options	Soft telecine
Mixed	Soft telecine	Adaptive	One of the other options	Soft telecine

* Deinterlace Mode is an image processing control. Interlace Mode and Telecine are encoding controls.

Note: Converting the scan type to progressive

If content is not being converted to a higher framerate, the deinterlacer outputs one frame for every two fields in the source content (i.e., 1080i30 content is converted to 1080p30). If the framerate is being doubled (e.g. 29.97 fps to 59.94 fps, 29.97 to 60, or 25 to 50), the deinterlacer converts each field into a frame.

Deinterlace mode

This field applies an initial conversion for certain from/to conversions (as shown in the table above).

• Deinterlace: Applies a deinterlace algorithm to content. If Elemental Live detects that the source content is already progressive, no deinterlacing is applied.

• Inverse Telecine: Converts hard telecine 29.97i to progressive 23.976p.

• Adaptive: Analyzes source content to determine whether to apply the deinterlace or inverse telecine algorithm on source content.

Interlace mode

This field controls video field order and how the scan type is represented in the output bitstream.

• Progressive: Encodes output as "progressive."

• Top Field First or Bottom Field First: Forces field polarity (top or bottom first) to the specified value, reordering fields if the source has a different order and encodes the result as interlaced.

• Follow (Default Top) and Follow (Default Bottom): Produces interlaced output, with the output having the same field polarity as the source. Therefore:

  • If the source is "interlaced", the output is interlaced with the same polarity as the source (it follows the source). The output could therefore be a mix of “top field first” and “bottom field first.”

  • If the source is "progressive", the output is interlaced with “top field first” or “bottom field first” polarity (depending on which Follow option you chose).

Telecine

This field appears for MPEG-4 AVC and MPEG-2 only if the Streams > Advanced > framerate field is set to 29.970.

• Hard: Produce 29.97i output from 23.976 input.

• Soft: Produce 23.976; the player converts this output to 29.97i.

Recommendations

• Converting to progressive output always improves output quality and should be enabled in any use case where progressive output is required or acceptable.

• Interlace coding is inherently less efficient than progressive coding so use interlace coding only for content that has already been interlaced.

• The choice of deinterlacing algorithm is very subjective. Motion Adaptive Interpolation is generally recommended as the sharper image quality tends to provide the best perceived quality across a broad set of users. Use the Force Mode option for deinterlacing only when the input is known to be interlaced content incorrectly flagged as "progressive."

• Use the Force Mode option for Inverse Hard Telecine when the input is known to consist entirely of Hard Telecine content.

Location of fields

Location of field on web interface	Location of tag in XML
Streams > Advanced > Telecine	stream_assembly/video_description/codec/telecine where codec is one of the following: h264_settings mpeg2_settings h265_settings prores_settings
Streams > Advanced > Interlace Mode	stream_assembly/video_description/codec/interlace_mode where codec is one of the following: vc1_settings h264_settings mpeg2_settings h265_settings prores_settings
Streams > Advanced >Preprocessors > Deinterlacer > Deinterlace Mode	stream_assembly/video_description/video_preprocessors/deinterlacer/deinterlace_mode
Streams > Advanced >Preprocessors > Deinterlacer > Deinterlace Algorithm	stream_assembly/video_description/video_preprocessors/deinterlacer/algorithm
Streams > Advanced >Preprocessors > Deinterlacer > Force Mode	stream_assembly/video_description/video_preprocessors/deinterlacer/force