[FFmpeg-user] ffprobe bug in 'interlaced_frame'?

[Mark Filipak]

On 01/26/2020 08:26 PM, Carl Eugen Hoyos wrote:
> Am Mo., 27. Jan. 2020 um 02:21 Uhr schrieb Mark Filipak
> <markfilipak.windows+ffmpeg at gmail.com>:
>>
>> On 01/26/2020 08:08 PM, Carl Eugen Hoyos wrote:
>>> Am So., 26. Jan. 2020 um 22:21 Uhr schrieb Mark Filipak
>>> <markfilipak.windows+ffmpeg at gmail.com>:
>>>
>>>>> (hard-telecine encoding and decoding is - of course - supported
>>>>> by FFmpeg)
>>>>
>>>> No, it's not. ffmpeg makes only frame pictures, not field pictures. Hard
>>>> telecine is an interlaced format and ffmpeg doesn't make interlaced output.
>>>
>>> Note that at least the reasoning is wrong here:
>>> MEncoder is able to produce both hard- and soft-telecined vob
>>> files (and progressive and interlaced) with FFmpeg's mpeg2video encoder.
>>
>> Well, that's interesting, Carl. In the past I've longed for a method to
>> encode TV segments as 30i and the embedded movie clips as 24i in the
>> same transcode (as an alternative to transcoding both to 60p via line
>> doubling and thereby suffering 70% larger output files). Such is needed
>> for "Making of" documentaries in DVD Extra Features. HandBrake doesn't
>> support any output (target) except progressive, but you say MEncoder
>> does, eh?
> 
> It may only support cfr but you can probably concatenate.
> Otoh, you can also concatenate the vob files produced with any other
> software...
> 
>> Can X264 or X265 encode to 30i (or to 24p with 30i soft telecine metadata)?
> 
> Soft-telecine is not related to video encoders but why would you
> want h264-encoded soft-telecined vob files?
> And even more important: What would you do with them?
> 
> Carl Eugen

Good questions. I'm not sure. May I explain the need?

Right now, if I want the absolute best MKV transcode of a "Making of" 
Special Feature (or Extra Feature or whatever you want to call it) that 
includes real NTSC TV and embedded movie clips, my only alternative is 
to transcode to 60 FPS CFR and suffer an MKV that's about 70% larger 
than it would need to be. What I'd prefer is to encode the NTSC TV 
sections as 30i and encode the movie clips as 24p. I think it's possible 
to mix those two as separate GOPs, but I must confess that I'm not sure.

Right now, if I detelecine both sections, of course I get extreme 
combing in the NTSC TV sections, and if I hard telecine both sections, I 
get judder in the movie clips. Transcoding to 60p works, but the 
resulting MKV is 70% or more larger than the source.