FrameFormer Filter

The InSync FrameFormer iffc filter may be used for motion-compensated standards conversions. When using FrameFormer, the iffc filter must be used to specify the output properties for standard conversions. The output frame rate is represented by the TimeScale (numerator) and FrameDuration (denominator).

For example:

---
output:
  container:
  - video:
    - filter:
      - type: iffc
        properties:
          Width: 720
          Height: 480
          FieldOrder: 1
          TimeScale: 60
          FrameDuration: 1

{
  "output": {
    "container": [
      {
        "video": [
          {
            "filter": [
              {
                "type": "iffc",
                "properties": {
                  "Width": 720,
                  "Height": 480,
                  "FieldOrder": 1,
                  "TimeScale": 60,
                  "FrameDuration": 1
                }
              }
            ]
          }
        ]
      }
    ]
  }
}

Format

The following properties configure the output video.

Aspect Ratio

By default, FrameFormer maps the contents of input frames to exactly fill output frames. This means that distortion can occur if the output frames have a different display aspect ratio. This is not usually the desired result, and so the API provides an option for specifying the horizontal aspect ratio used for the conversion.

Resolution

These controls permit adjustment of the amount of detail present in output frames. The controls are most relevant to conversions from progressive to interlaced or to a video standard with lower definition e.g. high definition to standard definition. The subjective appearance of output frames is always a trade-off between detail and alias. Detail makes frames appear sharper but too much alias causes unsatisfactory results such as flashing/flickering detail and the appearance of jagged edges.

According to the user preference and source video properties, the resolution overrides may be used to increase or decrease the apparent detail and optimize the degree of alias visibility. The independent horizontal and vertical overrides are specified as scaling factors with a nominal default value of 1. Decreasing the value reduces alias and softens output detail. Increasing the value sharpens output detail. Note a visible increase in sharpness will only been seen where more detail exists in the source, i.e. these controls do not add more detail than is present in the source.

Color

FrameFormer has support for a number of color spaces (BT.709, BT.2020, etc), color formats (RGB vs. YUV) and dynamic range encodings (SDR, HLG, PQ, etc). The color controls listed below focus on how a mapping should be performed rather than which mapping should be used.

Timing

The properties listed below apply to the conversion process.

Temporal

Temporal controls affect the conversion process when the output sample rate is different from the input sample rate. Temporal rate differences can be very small (e.g. 59.94Hz to 60Hz) or much larger (e.g. 24Hz to 60Hz). They correspond to either an increase or a decrease in sample rate.

Cadence

Property values for InputCadenceMode, InputCadencePhase, OutputCadenceMode and OutputCadencePhase are:

Display Mapping

Property values for DisplayMapping are:

Color Method

Property values for DisplayMappingMethod and GammaAdjustmentMethod are:

SDR OETF

Property values for SdrTransferFunction are:

Conversion Mode

Property values for TemporalConversionMode are:

Expand Highlights

Recommended values for varying amounts of highlight expansion are: