Re: [Mjpeg-developer] PROPOSAL for progressive/interlaced/pulldown mixed stream

[Matto M. <ma...@mi...>]

Hi, Hitoshi,

 >PROPOSAL for progressive/interlaced/pulldown mixed stream
 >
 >
 >1. YUV4MPEG2 tags in MJPEG

This part is all about storing YUV4MPEG2 tags in MJPEG frames, ok....

 >2. YUV4MPEG2 tags in edit list

And this part is all about storing tags in edit lists, ok....
(Neat idea.)

 >3. Frame i-tag

And this part is about the actual tags themselves.

Could you compare this to my earlier proposal (the one with S, T, and P
 frame tags)?  What was lacking?  I must admit that your proposal below
 is a bit confusing to me....

 >Variations of frame i-tag:
 >  i? unknown (use stream I-tag)
 >  im progressive, bottom field first
 >  iM progressive, bottom field first, repeat first field
 >  ip progressive, top    field first
 >  iP progressive, top    field first, repeat first field
 >  if film before pulldown (treat as 'ip' or do telecine)
 >  ib interlaced, bottom field first
 >  iB interlaced, bottom field first, repeat first field (maybe never used)
 >  it interlaced, top    field first
 >  iT interlaced, top    field first, repeat first field (maybe never used)
 >  ii interlaced (in 'Ib' stream treat as 'ib', else treat as 'it')
 >  ix progressive with last field (treat as 'ii' or exchange second field)
 >  ia after pulldown (treat as 'ii' or do reverse telecine)


For reference, here is that earlier proposal:

  o Extend the stream header 'I' tag to take the value 'm' (for "mixed")
    in addition to 'p','t' or 'b'.  This value means that interlacing is
    defined on a frame-by-frame basis, not stream-wide.

  o Define three (new) tags for the frame header:

       - Sx to describe subsampling (spatial property):
                'p' = progressive (subsampled as single whole frame)
                'i' = interlaced (subsampled as two independent fields)

       - Tx to describe temporal relation of fields
                'p' = progressive (concurrent fields -- single prog. frame)
                'i' = interlaced (fields sampled at different moments)

       - Px to describe presentation: 
                't' = top-field-first
                'T' = top-field-first, repeat-first-field
                'b' = bottom-field-first
                'B' = bottom-field-first, repeat-first-field
		'1' = one progressive frame
                '2' = two progressive frames
                '3' = three progressive frames

-matt m.