1080i AVC-I 100 frame rate conversion

Previous Topic Next Topic
 
classic Classic list List threaded Threaded
32 messages Options
12
Reply | Threaded
Open this post in threaded view
|

Re: 1080i AVC-I 100 frame rate conversion

FFmpeg-users mailing list
 Are you contending that there is no such thing as video at 24000/1001 fps?

    On Monday, 29 March 2021, 22:08:03 BST, Nicolas George <[hidden email]> wrote:  
 
 Phil Rhodes via ffmpeg-user (12021-03-29):
> What?

I have nothing to add to what I have written. Get a clue.

--
  Nicolas George
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".  
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: 1080i AVC-I 100 frame rate conversion

Nicolas George
Phil Rhodes via ffmpeg-user (12021-03-29):
>  Are you contending that there is no such thing as video at 24000/1001 fps?

Are you capable of understanding a simple phrase made of less ten words?

--
  Nicolas George
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: 1080i AVC-I 100 frame rate conversion

FFmpeg-users mailing list
 I see we've entered Open Source World here, where everyone starts speaking in tongues and obfuscating everything because...
...because...
...Um. I guess it's something to do with open source software, because nobody seems to behave like this in professional-world.
P
    On Monday, 29 March 2021, 23:19:28 BST, Nicolas George <[hidden email]> wrote:  
 
 Phil Rhodes via ffmpeg-user (12021-03-29):
>  Are you contending that there is no such thing as video at 24000/1001 fps?

Are you capable of understanding a simple phrase made of less ten words?

--
  Nicolas George
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".  
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: 1080i AVC-I 100 frame rate conversion

Mark Filipak (ffmpeg)
In reply to this post by Bruce Roberts
On 2021-03-29 07:11, Bruce Roberts wrote:
> Yes, my apologies - I don't get the luminance bands either when I don't try
> to deinterlace the progressive source or if I do deinterlace and
> reinterlace interlaced inputs so it seems there was no problem with the
> framerate filter after all.
>
> I would still be very interested to hear any optimisation tips and I look
> forward to seeing the results of Mark's work.

Hey Bruce,

The 1-pass, fractional picture interpolation I'm trying to develop depends on the 'shuffleframes' &
'mix' filters in order to do a weighted 119.880fps rendition of 23.976fps. For example,

given the input (processed 2 frames at a time):
[a_____________________________________][b_____________________________________]

and 'fps' boosting to 119.880fps and 'split'ting that into 2 substreams:
[1a5___][1b2___][1b4___][1b6___][1b8___][1b5___][1a2___][1a4___][1a6___][1a8___]
[2a5___][2a8___][2a6___][2a4___][2a2___][2b5___][2b8___][2b6___][2b4___][2b2___]

and creating multiplex shuffleframes (at 11.988fps):
[1A5___________________________________________________________________________]
_______][1B2____________________________________________________________________
_______________][1B4____________________________________________________________
_______________________][1B6____________________________________________________
_______________________________][1B8____________________________________________
_______________________________________][1B5____________________________________
_______________________________________________][1A2____________________________
_______________________________________________________][1A4____________________
_______________________________________________________________][1A6____________
_______________________________________________________________________][1A8____
[2A5___________________________________________________________________________]
_______][2A8____________________________________________________________________
_______________][2A6____________________________________________________________
_______________________][2A4____________________________________________________
_______________________________][2A2____________________________________________
_______________________________________][2B5____________________________________
_______________________________________________][2B8____________________________
_______________________________________________________][2B6____________________
_______________________________________________________________][2B4____________
_______________________________________________________________________][2B2____
(note: to here, the 'a's & 'A's are identical, all the 'b's & 'B's are identical.)

then summing them with the weights (a5+a5)/10, (a8+b2)/10, (a6+b4)/10, etc.
[A5A5__________________________________________________________________________]
_______][B2A8___________________________________________________________________
_______________][B4A6___________________________________________________________
_______________________][B6A4___________________________________________________
_______________________________][B8A2___________________________________________
_______________________________________][B5B5___________________________________
_______________________________________________][A2B8___________________________
_______________________________________________________][A4B6___________________
_______________________________________________________________][A6B4___________
_______________________________________________________________________][A8B2___
(note: now, they are different, they are weighted sums.)

and interleaving to produce the 119.880fps output:
[A5A5__][B2A8__][B4A6__][B6A4__][B8A2__][B5B5__][A2B8__][A4B6__][A6B4__][A8B2__]

Here is the filter_complex:

settb=720000,setpts=N*30030,fps=fps=24000/1001,
fps=fps=120000/1001,split=2[1][2],
   [1]shuffleframes=0 5 6 7 8 9 1 2 3 4,split=10[1a5][1b2][1b4][1b6][1b8][1b5][1a2][1a4][1a6][1a8],
     [1a5]shuffleframes=0 -1 -1 -1 -1 -1 -1 -1 -1 -1[1A5],
     [1b2]shuffleframes=-1 1 -1 -1 -1 -1 -1 -1 -1 -1[1B2],
     [1b4]shuffleframes=-1 -1 2 -1 -1 -1 -1 -1 -1 -1[1B4],
     [1b6]shuffleframes=-1 -1 -1 3 -1 -1 -1 -1 -1 -1[1B6],
     [1b8]shuffleframes=-1 -1 -1 -1 4 -1 -1 -1 -1 -1[1B8],
     [1b5]shuffleframes=-1 -1 -1 -1 -1 5 -1 -1 -1 -1[1B5],
     [1a2]shuffleframes=-1 -1 -1 -1 -1 -1 6 -1 -1 -1[1A2],
     [1a4]shuffleframes=-1 -1 -1 -1 -1 -1 -1 7 -1 -1[1A4],
     [1a6]shuffleframes=-1 -1 -1 -1 -1 -1 -1 -1 8 -1[1A6],
     [1a8]shuffleframes=-1 -1 -1 -1 -1 -1 -1 -1 -1 9[1A8],
   [2]split=10[2a5][2a8][2a6][2a4][2a2][2b5][2b8][2b6][2b4][2b2],
     [2a5]shuffleframes=0 -1 -1 -1 -1 -1 -1 -1 -1 -1[2A5],
     [2a8]shuffleframes=-1 1 -1 -1 -1 -1 -1 -1 -1 -1[2A8],
     [2a6]shuffleframes=-1 -1 2 -1 -1 -1 -1 -1 -1 -1[2A6],
     [2a4]shuffleframes=-1 -1 -1 3 -1 -1 -1 -1 -1 -1[2A4],
     [2a2]shuffleframes=-1 -1 -1 -1 4 -1 -1 -1 -1 -1[2A2],
     [2b5]shuffleframes=-1 -1 -1 -1 -1 5 -1 -1 -1 -1[2B5],
     [2b8]shuffleframes=-1 -1 -1 -1 -1 -1 6 -1 -1 -1[2B8],
     [2b6]shuffleframes=-1 -1 -1 -1 -1 -1 -1 7 -1 -1[2B6],
     [2b4]shuffleframes=-1 -1 -1 -1 -1 -1 -1 -1 8 -1[2B4],
     [2b2]shuffleframes=-1 -1 -1 -1 -1 -1 -1 -1 -1 9[2B2],
   [1A5][2A5]mix=inputs=2:weights=5 5[A5A5],
   [1B2][2A8]mix=inputs=2:weights=2 8[B2A8],
   [1B4][2A6]mix=inputs=2:weights=4 6[B4A6],
   [1B6][2A4]mix=inputs=2:weights=6 4[B6A4],
   [1B8][2A2]mix=inputs=2:weights=8 2[B8A2],
   [1B5][2B5]mix=inputs=2:weights=5 5[B5B5],
   [1A2][2B8]mix=inputs=2:weights=2 8[A2B8],
   [1A4][2B6]mix=inputs=2:weights=4 6[A4B6],
   [1A6][2B4]mix=inputs=2:weights=6 4[A6B4],
   [1A8][2B2]mix=inputs=2:weights=8 2[A8B2],
[A5A5][B2A8][B4A6][B6A4][B8A2][B5B5][A2B8][A4B6][A6B4][A8B2]interleave=nb_inputs=10

This simple scheme depends on shuffleframes behaving (or at least behaving predictably). That's
where the problem lies. I'm still trying to figure out why shuffleframes acts unexpectedly. It seems
to have 3 interacting modes of unexpected behavior that are factors of whether the input #frames is
odd or even, whether the input #frames can be spanned by a whole number of map elements (for
example, the shuffleframes above have 10 map elements), and how it handles cases where the ending of
the input results in fractional map-spans. That doesn't completely account for the behavior, so I
reckon there's another unexpected mode that needs to be discovered.

The scheme is working except that some of the output frames in the 10-frame sequence above move
backward for a few frames before leaping back to the forward cadence it should have. That of course
indicates that the presentation time stamps (PTS) of the backward frames are wrong, but I haven't
been able to figure out why. That's why I'm testing shuffleframes. The task is rather mind wracking.
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: 1080i AVC-I 100 frame rate conversion

Mark Filipak (ffmpeg)
In reply to this post by Nicolas George
On 2021-03-29 18:19, Nicolas George wrote:
> Phil Rhodes via ffmpeg-user (12021-03-29):
>>   Are you contending that there is no such thing as video at 24000/1001 fps?
>
> Are you capable of understanding a simple phrase made of less ten words?

I believe that Nicolas is correct, Phil. I know that 24pps cinema is encoded at 24000/1001fps and
therefore running time is extended by about 0.4%.

BTW, I'm not getting all the posts in this thread. Everything from Carl Eugen is missing (and
perhaps others).

-Mark.
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: 1080i AVC-I 100 frame rate conversion

Mark Filipak (ffmpeg)
In reply to this post by Nicolas George
Addition: I'm also not receiving Phil's posts (and perhaps others).

On 2021-03-29 18:19, Nicolas George wrote:
> Phil Rhodes via ffmpeg-user (12021-03-29):
>>   Are you contending that there is no such thing as video at 24000/1001 fps?
>
> Are you capable of understanding a simple phrase made of less ten words?

I believe that Nicolas is correct, Phil. I know that 24pps cinema is encoded at 24000/1001fps and
therefore running time is extended by about 0.4%.

BTW, I'm not getting all the posts in this thread. Everything from Carl Eugen is missing (and
perhaps others).

-Mark.
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: 1080i AVC-I 100 frame rate conversion

Bruce Roberts
In reply to this post by Mark Filipak (ffmpeg)
Hi Mark,

Thank you once again for that detailed explanation of your ingenious
solution! I think I finally understand it now (having spent a few hours
working through it) and I might also understand the leaping back behaviour:
It looks to me like your interleave filter will output the following
sequence of weighted frame index mixes: [0+0], [0+1], [0+1], [0+1], [0+1],
[1+1], [2+3], [2+3],  [2+3], [2+3], *[2+2]*, [2+3], [2+3], [2+3], [2+3],
[3+3], [4+5],  [4+5],  [4+5],  [4+5], *[4+4]*...

Is that right?

I've attached a spreadsheet that shows how I see the command behaving for
the first 35 frames.

Also, am I correct in thinking that there is a decimate stage that isn't
shown in the command you shared?

I think the fact that you're missing some of this email thread might be
because I didn't "reply all" at some point. Sorry about that. I'll happily
forward the entire thread to you personally if you like.

Best wishes,
Bruce.

_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".

mix_interleave.xlsx (18K) Download Attachment
Reply | Threaded
Open this post in threaded view
|

Re: 1080i AVC-I 100 frame rate conversion

Bruce Roberts
In reply to this post by Mark Filipak (ffmpeg)
Sorry - ignore what I said about the jumping back - I've had another look
and I was wrong about that.
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: 1080i AVC-I 100 frame rate conversion

FFmpeg-users mailing list
In reply to this post by Mark Filipak (ffmpeg)
 > I believe that Nicolas is correct, Phil. I know that 24pps cinema is encoded at 24000/1001fps and> therefore running time is extended by about 0.4%.
Lots of cinema stuff is or at least was shot at 23.976, or at least that's the way the frame rate is often labelled in the cameras.
The reason people originally started doing this is that editing was often done on 29.97 video, so there might be audio sync problems if the original material was shot at 24.00.
It's still often done today, at least partly out of force of habit. Sometimes audio timecode is still 29.97 even though the production might never actually see a 29.97 environment unless and until it goes out on TV or on DVD.
I get the impression most of the people behind ffmpeg do not have very much experience in actual film and TV production.
P  
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: 1080i AVC-I 100 frame rate conversion

Bruce Roberts
Sorry to keep contradicting myself Mark Filipak, but I'm still wondering if
perhaps there is something wrong in your shuffle/mix/interleave command
because to me, having looked once again, the output sequence doesn't appear
to included any weighted mixes of source frames 1 and 2 or 3 and 4, for
example. Have I misunderstood something? I'm not sure if this table will
help illustrate my question.

Best regards,
Bruce.

Frame indexes (shuffleframes output indexes correspond to the input frame
indexes)
Input (24000/1001) 120000/1001 stream [1A5] [2A5] Interleavedoutput [1B2]
[2A8] Interleavedoutput [1B4] [2A6] Interleavedoutput [1B6] [2A4]
Interleavedoutput [1B8] [2A2] Interleavedoutput [1B5] [2B5]
Interleavedoutput [1A2] [2B8] Interleavedoutput [1A4] [2B6]
Interleavedoutput [1A6] [2B4] Interleavedoutput [1A8] [2B2]
Interleavedoutput
0 0 0 0 0
0 1                                     0 1 6
0 2                                           0 1 7
0 3                                                 0 1 8
0 4                                                       0 1 9
1 5       1 0 1
1 6             1 0 2
1 7                   1 0 3
1 8                         1 0 4
1 9                               1 1 5
2 10 2 2 10
2 11                                     2 3 16
2 12                                           2 3 17
2 13                                                 2 3 18
2 14                                                       2 3 19
3 15       3 2 11
3 16             3 2 12
3 17                   3 2 13
3 18                         3 2 14
3 19                               3 3 15
4 20 4 4 20
4 21                                     4 5 26
4 22                                           4 5 27
4 23                                                 4 5 28
4 24                                                       4 5 29
5 25       5 4 21
5 26             5 4 22
5 27                   5 4 23
5 28                         5 4 24
5 29                               5 5 25
6 30 6 6 30
6 31                                     6 7 36
6 32                                           6 7 37
6 33                                                 6 7 38
6 34                                                       6 7 39
7 35       7 6 31
7 36             7 6 32
7 37                   7 6 33
7 38                         7 6 34
7 39                               7 7 35
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: 1080i AVC-I 100 frame rate conversion

Mark Filipak (ffmpeg)
On 2021-03-30 08:40, Bruce Roberts wrote:
> Sorry to keep contradicting myself Mark Filipak, but I'm still wondering if
> perhaps there is something wrong in your shuffle/mix/interleave command
> because to me, having looked once again, ...

"Looked"? Have you run that filter_complex_script? I don't know what a 50Hz TV would do with it, but
a computer running MPV should be able to play it.

>... the output sequence doesn't appear
> to included any weighted mixes of source frames 1 and 2 or 3 and 4, for
> example. ...

I don't know what frames 1 and 2 or 3 and 4 are. Let me explain my diagrams.

The source frames are
[a_____________________________________][b_____________________________________]
The diagram shows 2, 24000/1001fps frames: [a] followed by [b]. The diagram has 80 characters
representing 83.4ms (i.e. 2*41.7ms). Thus, the diagram has ~1ms per character.

The 20 frames below (at the same ~1ms per character) are copies of the [a] & [b] frames above that
have been rearranged by 20 shuffleframes filters. They have differing pad labels because 'a' & 'b'
have already been used.
[1A5___________________________________________________________________________]
_______][1B2____________________________________________________________________
_______________][1B4____________________________________________________________
_______________________][1B6____________________________________________________
_______________________________][1B8____________________________________________
_______________________________________][1B5____________________________________
_______________________________________________][1A2____________________________
_______________________________________________________][1A4____________________
_______________________________________________________________][1A6____________
_______________________________________________________________________][1A8____
[2A5___________________________________________________________________________]
_______][2A8____________________________________________________________________
_______________][2A6____________________________________________________________
_______________________][2A4____________________________________________________
_______________________________][2A2____________________________________________
_______________________________________][2B5____________________________________
_______________________________________________][2B8____________________________
_______________________________________________________][2B6____________________
_______________________________________________________________][2B4____________
_______________________________________________________________________][2B2____


Each mix filter has 2 inputs and 1 output. There are 10 mix filters.
[1A5][2A5]mix=inputs=2:weights=5 5[A5A5]   ...output is (1A5*5 + 2A5*5)/10
[1B2][2A8]mix=inputs=2:weights=2 8[B2A8]   ...output is (1B2*2 + 2A8*8)/10
[1B4][2A6]mix=inputs=2:weights=4 6[B4A6]   ...output is (1B4*4 + 2A6*6)/10
[1B6][2A4]mix=inputs=2:weights=6 4[B6A4]   ...output is (1B6*6 + 2A4*4)/10
[1B8][2A2]mix=inputs=2:weights=8 2[B8A2]   ...output is (1B8*8 + 2A2*2)/10
[1B5][2B5]mix=inputs=2:weights=5 5[B5B5]   ...output is (1B5*5 + 2B5*5)/10
[1A2][2B8]mix=inputs=2:weights=2 8[A2B8]   ...output is (1A2*2 + 2B8*8)/10
[1A4][2B6]mix=inputs=2:weights=4 6[A4B6]   ...output is (1A4*4 + 2B6*6)/10
[1A6][2B4]mix=inputs=2:weights=6 4[A6B4]   ...output is (1A6*6 + 2B4*4)/10
[1A8][2B2]mix=inputs=2:weights=8 2[A8B2]   ...output is (1A8*8 + 2B2*2)/10
The pixel weights are 2, 4, 5, 6, and 8. Since the scale is not specified, the filter uses 1/(sum of
weights) which, in every case, is 1/10. There's 2 special cases: (1A5*5 + 2A5*5)/10 & (1B5*5 +
2B5*5)/10. What they are doing is taking (pixel_value*5 + pixel_value*5)/10 -- in other words,
pixel_value. Seems like a busy do nothing, eh? I'm doing what seems a silly thing because it makes
the operation on all the pixels uniform -- and, in fact, if you attempt to interleave [a] & [b]
directly into the output you'll find it makes everything a lot more complicated.

The output is the 10 mix outputs interleaved.
[A5A5__][B2A8__][B4A6__][B6A4__][B8A2__][B5B5__][A2B8__][A4B6__][A6B4__][A8B2__]

So, as you can see, 2 input frames @24000/1001fps become 10 output frames @120000/1001fps -- that's
a 2:10 frame rate conversion with 10 pixel value levels.

Your 100fps target would be achieved by the same method but with much bigger numbers. Here's the
picture:
24fps
[_______________________][_______________________][_______________________][_______________________][_______________________][_______________________]
100fps
[____][____][____][____][____][____][____][____][____][____][____][____][____][____][____][____][____][____][____][____][____][____][____][____][____]

So, 6 input frames become 25 output frames. The question for you is what do the 25 pairs of
weightings need to be for the 25 mixers?

The rest of your reply is too cryptic. I don't know what the numbers are.

Regards,
Mark.

>... Have I misunderstood something? I'm not sure if this table will
> help illustrate my question.
>
> Best regards,
> Bruce.
>
> Frame indexes (shuffleframes output indexes correspond to the input frame
> indexes)
> Input (24000/1001) 120000/1001 stream [1A5] [2A5] Interleavedoutput [1B2]
> [2A8] Interleavedoutput [1B4] [2A6] Interleavedoutput [1B6] [2A4]
> Interleavedoutput [1B8] [2A2] Interleavedoutput [1B5] [2B5]
> Interleavedoutput [1A2] [2B8] Interleavedoutput [1A4] [2B6]
> Interleavedoutput [1A6] [2B4] Interleavedoutput [1A8] [2B2]
> Interleavedoutput
> 0 0 0 0 0
> 0 1                                     0 1 6
> 0 2                                           0 1 7
> 0 3                                                 0 1 8
> 0 4                                                       0 1 9
> 1 5       1 0 1
> 1 6             1 0 2
> 1 7                   1 0 3
> 1 8                         1 0 4
> 1 9                               1 1 5
> 2 10 2 2 10
> 2 11                                     2 3 16
> 2 12                                           2 3 17
> 2 13                                                 2 3 18
> 2 14                                                       2 3 19
> 3 15       3 2 11
> 3 16             3 2 12
> 3 17                   3 2 13
> 3 18                         3 2 14
> 3 19                               3 3 15
> 4 20 4 4 20
> 4 21                                     4 5 26
> 4 22                                           4 5 27
> 4 23                                                 4 5 28
> 4 24                                                       4 5 29
> 5 25       5 4 21
> 5 26             5 4 22
> 5 27                   5 4 23
> 5 28                         5 4 24
> 5 29                               5 5 25
> 6 30 6 6 30
> 6 31                                     6 7 36
> 6 32                                           6 7 37
> 6 33                                                 6 7 38
> 6 34                                                       6 7 39
> 7 35       7 6 31
> 7 36             7 6 32
> 7 37                   7 6 33
> 7 38                         7 6 34
> 7 39                               7 7 35

_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: 1080i AVC-I 100 frame rate conversion

Mark Filipak (ffmpeg)
In reply to this post by Bruce Roberts
Oh! Returning to my editor from replying to your last message, I suddenly saw what I'm doing wrong.

The fix: I need to create a 2-frame sliding window that ping-pongs between this:

PTS=0                                   30030
:                                       :
[a_____________________________________][b_____________________________________]
0       6006    12012   18018   24024
:       :       :       :       :
[A5A5__][B2A8__][B4A6__][B6A4__][B8A2__]

and this:

30030                                   60060
:                                       :
[b_____________________________________][a_____________________________________]
30030   36036   42042   48048   54054
:       :       :       :       :
[B5B5__][A2B8__][A4B6__][A6B4__][A8B2__]

Hmmm... How to create a sliding window? I'll have to think about it some more.
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
12