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@KaairaGupta
Created June 22, 2020 19:09
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tpg_gen_text explained
  • 'step' is used to emulate interlaced video: if the TPG generates single fields (top or bottom) instead of full frames, then when you generate text in a field you only generate every other line of the text: one field shows the odd lines, the other the even lines of a text character. Hence step == 2 when you generate the text into a field, and 'first' determines whether you start with the first or second line of a text character.
  • If the video source (the TPG in this case) generates interlaced video, then each frame actually consists of a top and bottom field that for high-def formats are typically transmitted as two separate fields.
  • vimc doesn't do interlaced, but vivid does.
  • https://hverkuil.home.xs4all.nl/spec/userspace-api/v4l/field-order.html
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