Best way to convert from progressive to interlaced in mixed footage project

[Nedo]

Hello everybody,

I got this huge issue, I am supposed to deliver work for TV station and they specifically asked for both the outcome and the footage to be interlaced 1080i. one of the photographers was shooting in progressive and so we got the footage mixed between interlaced and progressive. I worked it all in Vegas Pro and exported all in interlaced format at the end and I thought that should solve it.

The channel rejected it and told us that the parts of the progressive were flickery and unbroadcastable.

my question: what you guys advise to do in this case? shall I try to interlace each footage and then replace the progressive clips in Vegas with their interlaced copies? is there something that is has to be done? or shall I keep the clip and export in something else?

I heard that after effect is the best program to do interlacing of progressive (in terms of final product quality). is it true? and how to do it in it or in any other if there is better option.

I exported my previous one using Mainstream Vegas H1080 50i H264 (into .AVC format). the original progressive footage is 25 FPS so it should be matching in number of frames etc.

here is the info about one of the progressive footage as an example if needed: (the rest should be the same config.)
General
Complete name : G\DCIM\100EOS5D\6A8A2947.MOV
Format : MPEG-4
Format profile : QuickTime
Codec ID : qt 2007.09 (qt /CAEP)
File size : 762 MiB
Duration : 4 min 12 s
Overall bit rate : 25.3 Mb/s
Encoded date : UTC 2016-11-06 13:27:36
Tagged date : UTC 2016-11-07 08:42:21
©TSC : 25000
©TSZ : 1000

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings, CABAC : No
Format settings, ReFrames : 2 frames
Format settings, GOP : M=3, N=12
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 4 min 12 s
Bit rate : 23.8 Mb/s
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 25.000 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.458
Stream size : 715 MiB (94%)
Language : English
Encoded date : UTC 2016-11-06 13:27:36
Tagged date : UTC 2016-11-06 13:27:36
Color range : Full
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709

Audio
ID : 2
Format : PCM
Format settings, Endianness : Little
Format settings, Sign : Signed
Codec ID : sowt
Duration : 4 min 12 s
Bit rate mode : Constant
Bit rate : 1 536 kb/s
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 kHz
Bit depth : 16 bits
Stream size : 46.2 MiB (6%)
Language : English
Encoded date : UTC 2016-11-06 13:27:36
Tagged date : UTC 2016-11-06 13:27:36

Other
ID : 3
Type : Time code
Format : QuickTime TC
Duration : 4 min 12 s
Time code of first frame : 13:53:31:19
Time code, striped : Yes
Language : English
Encoded date : UTC 2016-11-06 13:27:36
Tagged date : UTC 2016-11-06 13:27:36
Bit rate mode : CBR


thanks..

[LigH.de]

Your content has been recorded at 0 ms and 40 ms and 80 ms etc.; but no recording happened at 20 ms and 60 ms ... so how are you supposed to invent the content between two frames if you did not shoot it originally?

Well, there are motion compensating frame interpolation filters (e.g. MFlowInter/MFlowFPS/MBlockFPS in MVTools2, or SVPFlow or InterFrame). But they will not restore the content at a moment in time when you did not take the original picture, only guess what might have happened, and that may be wrong.

[_Al_]

There is usually longer shutter set for 25p, maybe Vegas needs to create that 25i not that destructively, not creating all the fields.

Try first to disable re-sampling for those progressive clips, click on media and disable resampling, watch what Vegas does. It might just double frame rate it and then make it interlaced, not creating those fields all from scratch.

Or pre-process it. Make those clips 50p first in similar fashion. Rendering lossless 50p out of 50p project with disable resampling checked, then loading those into original 25i project, but that first method might just work.

Or apply vertical blur, lowest amount there is, or test it, just vertical blur for those clips, check if it is ok.

[vipren369]

Hey - so i have a similar problem relating to that issue recorded a video from a HDMI source unfortunately the only way to record is with a progressive stream and its got sort of ghosting around the edges every few frames also done it in 50 fps because the tv was outputting same rate noticed that weather 50 or 25fps its the same result

[Bernix]

you can encode it f.e. with x264 flag interlaced top field first. The result is same framerate, but when playing in player that has deinterlace on or on auto, it plays 2x framerate. And mediainfo shows interlaced top field first. So this is way how to go around this.

Edit: and using something like DGBOB, you can get twice framerate 25->50 for real.

[hello_hello]

I''m obviously way too late to help the OP, but there's such a thing as interlaced progressive video, kind of.....
Progressive segmented frame

Not that I've ever had a need for it, but I think x264's fake interlaced option turn progressive video into Progressive Segmented Frame.

For the sample in post #4, it appears to have been butchered long before you recorded it.
At 50fps every frame is repeated, so if you're an Avisynth user, SelectEven() in a script will remove every second frame.
The remaining frames have been subjected to some sort of frame/field blending, and that's the problem you're seeing. You didn't cause it because you simply doubled the number of frames and each is a copy of the previous frame, including it's blending problem.

I haven't played much more than that, but if there's a blending pattern to be found to allow it to be de-blending, I've not found it yet. Maybe someone else will come along and look at that, or I can try again tomorrow. There's no guarantee it won't be broadcast in a butchered fashion each time its aired, but maybe try recording it again if you can. You might get lucky.

[LigH.de]

The "fake interlace" mode of x264 uses MBAFF (Macroblock-adaptive frame-field), means, a subset of the macroblocks in a frame can be encoded as interlaced, another as progressive ... but all of them are decided to be progressive, so it should only be enabled if you are really sure that all the content is progressive. Just the chance that some of them might be interlaced qualifies the result to be compatible with e.g. Blu-ray 1080i.

If there is indeed a non-zero chance that a few areas of a few frames might in fact contain interlaced content (remember, "interlaced" means specifically that fields represent video content of different timestamps, the temporal difference is the key attribute), then there is only one recommendation: Encode it in "interlaced encoding mode" and trust in the encoder to detect where field-wise processing turns out to be actually more efficient. For AVC encoding, x264 with MBAFF is certainly smart enough to do that with a satisfying result. Some tools even use ultrafast interlaced encoding with x264 in both field dominances to auto-detect the presence of interlacing, analyzing the MBAFF statistics it prints out as summary.

And before AVC (H.264) was invented, e.g. encoding MPEG-2 for DVD Video which only supports PAFF interlacing, many video studios simply left their MPEG-2 encoders fixed in interlaced mode, simply not to risk encoding interlaced scenes in progressive mode accidently, which would be a disaster regarding quality. Instead, encoding progressive video in interlaced encoding mode (field-wise) is rather harmless, just not optimal.

[hello_hello]

Thanks for the info.

[Bernix]

Hi,
so I have interlaced content that I want to be encoded as interlaced. So I always do this.

[Attachment 43775 - Click to enlarge]
Is this the fake x264 interlace, or real interlace? Because this works for both interlaced and progressive -> become interlaced. I am using this to append it to other interlaced content. Do I this wrong? When I playing resulting file whole file behave as interlaced, when encoding first part without this and append to interlaced content, the first part is played as progressive and rest as interlaced.
So my question is is this fake or real? I though it is real and worked with progressive content as well.
Thank you for your reply.

Bernix

[Guy UK]

I have found the bast way to do this is by using a vector algorithm to create the intermediate fields.
Unfortunately using vectors sometimes produces unexpected results during the conversion process, requiring manual intervention to get a perfect result.
Consequently I cannot market this as a product. However, if anyone has an urgent problem in converting progressive to interlace, please contact me directly and I will help if I can.

[KarMa]

@Bernix

With x264 interlacing, it just interlaces the frames that are interlaced and leaves the other progressive frames alone for more efficient compression. So x264 works fine with mixed content in interlaced mode.

[Bernix]

Thank you KarMa,
so I do it proper way. Thank you again
Bernix