Progressive for TV?
I wonder if I can get some views here - I'm a video producer mainly working in broadcast TV and used to interlaced shooting, recently in HD formats such as XDCAM and HDV.
I'm interested in using my 60D for an upcoming shoot, but there's one thing I don't quite get. Most people extol the virtues of using progressive frames when filming, but my experience is that as soon as you get movement, either camera movement or objects moving within the frame, the progressive frame format gives a powerful strobe or flicker effect on TV, when compared to interlaced footage. Now I understand the advantages of progressive, but for me this one single 'disadvantage' outweighs all the plusses. What am I missing here? Should I train myself to like strobing video and call it a film effect?
My solution to get the best out of DSLR shooting while maintaining smooth movement is to shoot 720 50p and interlace the 50p to 25i after ingest (which to me looks fantastic, and is super smooth). But it's a shame to miss out on full HD 1920. Which also leads me to wonder what is the best way to do the progressive to interlaced conversion on a Mac - I used compressor in my test, with frames turned on.
Thanks for any thoughts on this topic, a great forum,
Mac OSX 10.6.5
I would guess that most things that are on TV have been shoot as Progressive. Most TV shows, most commercials. What is not is mostly sports and news.
Although here in Europe most shooting and post production is done HD, there are comparatively few HD channels, most of the audience watches SD and on CRT monitors, and in post production suites CRT monitors are still considered the reference by which others are judged - and this is my stumbling point, progressive video may look great on a progressive LCD screen, but it doesn't on an interlaced CRT, which I understand is what most people still watch, and most facilities still use for reference. I certainly do - but maybe I need to change?
I was working with SD and HDV interlaced footage for similar reasons, until I was "forced" to produce progressive footage for some web-clips, switching back to interlaced for the next projects whenever possible.
For about two years now, I have to produce material that will be shown on both: on TV and on the web. So I use a CRT monitor for the TV/DVD version for post work (color correction etc).
Unless it's not sports (where my footage must be interlace for a couple of reasons), I shoot progressive, because over time I got so used to the progressive look (even on my CRT and an TV), that I really started to like it so much that I don't want to switch back to interlaced.
Just my thoughts. HTH
What it is watched on it not my point. We have been watching Material shoot as progressive on interlaced TVs for years. This is not a new thing at all. Almost every VHS was originally a Progressive movie that had pulldown add to make the interlaced tapes. Most hollywood DVDs are 24p with players adding the pulldown and interlacing.
My point is that Progressive to interlace looks fine, we watch it all the time, it is not a new thing, new problem. The difference is that it doesn't look like interlaced footage on an interlaced TV, which for most people is a good thing.
30p to 30i or 25p to 25i is a none issue IMO unless you are shooting sports or you want the video look.
This is something I have been wondering about as well.
For me, and my mostly-self-taught experience with the 7D and progressive footage this past year, I have had mixed emotions about it. I have not used 24p or any flavor of progressive footage (I am from the US, BTW, and have been using HDV 1080i60 for the past 6 years). I am still learning, and that's why I'm posting now.
My opinion of the footage from the 7D is that it looks awesome on the computer/internet, it looks awesome on a Blu-ray, it looks pretty good on a SD DVD on a LCD TV, and it doesn't look very good on a SD-DVD on a tube TV.
I now understand that "Most hollywood DVDs are 24p with players adding the pulldown and interlacing", which is good to know!
However, in my experience, my 7D with 24p on a DVD does not look nearly as good as a typical hollywood DVD. My footage on a tube TV looks like a cheap film effect...it has the strobe/flicker look to it, which the hollywood DVDs don't have.
I like when Ken said "Should I train myself to like strobing video and call it a film effect?", because that's how I feel too. I don't think it looks as good and I have to pretend that it does.
I don't think I'm doing anything wrong in the conversion process from h.264 to ProRes...I am using the same method and settings (even Final Cut Pro settings) that many respectable people recommend. However, I have only seen samples of their work online, where my stuff looks just as good.
Is there something in the DVD compression/authoring process that needs to be done differently than I have been doing for years with my interlaced footage. I use Compressor's presets for DVD encoding (DVD Best Settings 90 minutes or 120 minutes), and I just drop those files into DVD Studio Pro without changing any settings or doing anything different. Is there somewhere where I need to tell Compressor or DVDSP that it is 24p and it would handle it correctly?
I watched the House finale that was shot on 5DMKII cameras, and watched it both on an HDTV and a tube TV, and they both looked fantastic...so what am I doing wrong? I assume that if this were a problem, everybody would be complaining about it, and since that's not happening, I think it's an issue of people like me who are not experienced with using progressive footage correctly.
Any thoughts/help would be greatly appreciated!
I uploaded a short sample of a DVD that I made that shows my attempt at 24p. It looks like it's in slow motion, but it isn't.
It's 45mb and you can download a ZIP file of my VIDEO_TS folder here
I would appreciate it if someone would burn it to DVD, look at it on a tube TV and tell me what I'm doing wrong.
I took a look at it and to me it looked pretty good to me. I played it on my Sony Broadcast monitor via component and a consumer Sony via S-VHS. The one thing that is noticeable is the aliasing around the sharp edges of the canvas, which is to be excepted with the interlacing. But I didn't think there was any bad jittering/strobing on the movement. I have also been shooting only progressive for years, even with DV we where shooting 95% as 24P with the DVX100s.
The encoding could be a bit better, do you have to use 120 minute preset? You do need to make sure the Compressor's Frame Rate is set to 24P and not 29.97.
Compressor's frame rate was set for 24p (The inspector's A/V attributes reads 1920x1080, pixel aspect ratio-square, native field dominance-progressive, frame rate 23.976). I was using the Best Quality 90 minutes setting (frame rate-100% of source, selected 23.976). I didn't change anything on the Compressor settings...just the default.
One thing I have noticed with Compressor is that it is not very good at going from HDV to standard def. mpeg2 video. I get better results taking my edit back to HDV tape and recapturing as NTSC, then doing the encode. Maybe I'm having the same type of issue here? I suppose hollywood isn't using Compressor or going to DVD before broadcasting.
[Casey Petersen] " I suppose hollywood isn't using Compressor or going to DVD before broadcasting." I would say that COmpressor is not in there workflow, unless they are using additional plug-ins inside of compressor.
Turning on Frame Controls and setting the Resize filter to best will help with the scaling to SD. I think COmpressor does a very good job with the m2v encoding but not with the VBR method (which are what the defaults all). If you change it to CBR and can have the bitrate at or above 6 Mbps I feel you get better results. 90 minutes of video can use a bitrate of 6.5Mbps with ac3 audio.
CinemaCraft MP for the Mac is getting up into a professional level encoder at a modest price. A lot of people swear by BitVice but I have had mixed results and feel I can get as good and in some case better encodes with just Compressor.
Episode is another encoder plugin that is well thought of, especially for H.264 for web and BluRay.
I recommend at least trying CBR method with Frame Controls set to best and see if you like that better.
I gave that a shot and it looks slightly better, but it still doesn't have the same look as a hollywood DVD. The motion still looks a little too stuttery on my monitor. The shutter speed on this footage was at 1/50, so that shouldn't be the issue, right?
I will run some more tests tomorrow.
Someone on another forum suggested adding a motion blur...what do you think about that?
[Casey Petersen] "The shutter speed on this footage was at 1/50"
[Casey Petersen] "Someone on another forum suggested adding a motion blur...what do you think about that?"
If you did, I would recommend a very light blur.
Check your Chroma levels, maybe reducing the saturation and lowering the highlights might help also.
I do think you are fighting a little bit because this is a different look from what you have been watching. Like I said I love the look of what you have, personally I like things a bit darker but your footage looks good.
Thanks for looking at it and for your feedback...that's good to know.
It appears that I'm doing things right...maybe I like the video look too much!
I'll look into those other encoders...I'm sure that hollywood is not using Compressor. And again...the problem is in the standard def DVDs, not online or Blu-ray.
Interesting stuff - If Casey feels his footage looks strobey on his CRT tube monitor - but it looks fine on Michaels monitor, then assuming there is not a totally different aesthetic at work here - then it must come down to the monitor, no? CRT screens cannot playback progressive frames, instead they repeat them to get 50i, hence the strobe effect because the image is jumping backwards and forwards. However a good flat screen broadcast monitor, which I suspect Michael has, will play both, switching as necessary. This is my conclusion. However it follows that DSLR footage and progressive video will only look good on a screen capable of playing progressive, which most of the world don't have.
Personally I think the only thing to do is to correctly interlace the progressive footage prior to delivering for broadcast, or screening on a CRT monitor, as indeed Hollywood movies were prior to recording to VHS (which was also a interlace only format).
There is a great way to do this outlined on this forum in the link copied below - but you wouldn't want to do this to the rushes. So for me I think the solution is buying a progressive capable monitor for editing, and keep the broadcast standard interlace only CRT for viewing the final interlaced master - so one can check the CRT viewers get a correctly interlaced final product.
Having said all that I do accept Michael's point - I've discovered that some digital broadcasters do transmit progressive video - so in this case the domestic receiver must correctly handle the interlacing process - just like the process Michael was describing with some DVD players. So I don't think I've quite got to the bottom of this yet! Otherwise all those Paul Greengrass films would be totally unwatchable on my domestic CRT...
Thanks for all the feedback,
Thanks Ken, I'll give that a try.
I also should clarify that I am not testing this on a high quality CRT monitor, but rather an inexpensive tube tv set (I'm trying to play to the lowest common denominator, or at least low).
I tried the re-interlace method using After Effects - works really well! Super smooth pans with no judder. However I did get quite a bit of jelly vision, where the vertical lines 'bend' in proportion to the speed of the pan.... but that's another story - along with chroma crawl, moire, no fluid exposure changes, pulling focus changing the frame size, overheating after an hour of filming.... but never mind, just think of the lovely soft focus background and the low light capability and be happy!
All the best,
I tried it...not quite the way it was described...I don't have After Effects and couldn't figure out how to do it in Motion, so I tried changing the speed in Final Cut to 50% with frame blending off, then rendering that out to a new QuickTime and changing it to 200% with frame blending on. The end result didn't look very good.
Is it really going to be that different using Motion? How do I do it in Motion?
Mark didn't make the first stage crystal clear (for me at least) - and it took me a little experimenting before I cracked it. The crucial thing is that the software has to make intermediate frames when you slow the footage down. Does FCP do this? I'm not sure it does. After Effects does it really well - and I assume Motion will do as well (but I'm not up to speed with this as I use AE for all my compositing requirements).
So, slow the footage to 50%. Then render and re-import the footage. Make sure interlace is turned off, you must keep it progressive. Then after re-import check as you step through the frames that each one is now different. You don't want 'frame doubling' where the software just repeats each frame in the same position to slow it down, and you don't want frame blending, where it does a mix to create the new frame, using the frame before and the frame after as a source. Instead you want a new progressive frame in a different position relative to the frame before and after. So if you are looking at a pan each frame must be slightly to the left (if you're panning left) of the one before.
So now you have a 50% clip - then you need to tell the software that this is not a (in PAL land) a 50% speed clip running at 25 frames - but a 100% speed clip running at 50 frames. Then when you render this (with interlace now turned on), the software takes each frame and makes it part of the interlace - so 50p becomes 50i.
This last stage is the same as shooting 50p in the Canon, then after import rendering as 50i with interlace turned on.
I was amazed how good this technique was, but the crucial part is using software that can create the intermediate progressive frames - ask in the FCP forum I'm sure they'll know of a few plugins that could do this. Or get some tips how to do this in Motion - if you do let me know as I'd like to try this too.