Why I transcode to 4K and fast bit rate


#1

Here’s a prime example of why I transcode to 4K, using a high bit rate.

The first image is the freeze frame just before action starts.

This is a couple of frames later, as action begins.

Here’s the full video. Jump to 0:48 to see the comparison.
https://youtu.be/-egi3p0hxZo

Transcoding to 4K and high bit rates works around this problem. For Jaufenpass I used the YouTube profile with about 76 Mb/s. By comparison, Timmelsjoch is about 356 Mb/s.

Kinda hard to miss the difference…


YouTube re-encoding degrades the image at "regular" time intervals
Best quality settings for youtube
#2

Umm, sorry I don’t see the difference! What am I missing?

Nice area. It looks very similar to our Mount Rainier area in the State of Washington.

-=Ken=-


#3

Huh?

In the stills, look at the detail in the road in the flash frame. In the motion sample, the road to turns to bleh grey, the detail in the trees is lost, and overall there are blocks of pixelation. The later continues, in varying degrees, for the rest of the video.

Being picky and spot checking freeze frames from the Timmelsjoch video, there are places where the details in the grass on the side of the road are… meh - no harm done. But do a freeze frame with a stone wall at the edge of the frame, and the details are darn close to the original footage.

Overall, the Jaufenpass video is, being extremely charitable, mediocre. The Timmelsjoch video is what I want and what is practical to accomplish. The Jaufenpass video is presently being transcoded “the right way”. [/grin]


#4

‘This video is unavailable’


#5

Yes, the “mediocre” video is missing.

Looking again I missed the fact that I could switch back and forth between freeze frames.There indeed is a difference.

I could swear you must be using an Avid system! Bravo! Now, the only improvement I could suggest is using a camera that supports 10 bit pixel depth. Of course you would need an Avid to process that.

-=Ken=-


#6

The mediocre version went away to make room for the 4K, how it should be, version. NTL the stills tell the story. Jump to 0:50 in the new version (see below) and compare that with the still (see below) from the start of the action in the mediocre upload. .

ADDED: Sorry about the thumbnail choice - it’s YT’s fault. Honest.


#7

Yes, I can see the difference.

BTW, what does NTL mean? Tried looking it up…
National Transportation Library
National Trust Library
Next to Leading
?


#8

#9

? (plus twenty characters)


#10

Maybe NTL is nevertheless.


#11

Yes (plus twenty characters)


#12

Sorry, I wasn’t being serious :smiley:


#13

Ah, ha! (takes me awhile [grin]

I can’t think of the last time I said NTL.

BTW Steve, how did you get the smiley? :smile:

OIC


#14

Or NoneTheLess or Not That Loser or Nola Tangoed Last or Nominally Terrific Laughter or…


#15

Ok, ok. I just never encountered that acronym on the 'net before. 1st time for everything. :grin:

So, Robert, what is your work flow for producing such pristine video? My uneducated “take” on it is to transcode to one of those fancy codecs designed for editing and then Export to the desired playback format. Sorry if this workflow is specific to Youtube. I wouldn’t be too interested in that. -=Ken=-


#16

I built the video (1080p @ 60 fps or, really, 59.94 fps) in Shotcut - the only transition or significant cuts are the clock wipe and the “seams” from the intro and outro clips. (The current project has 18-19?? cuts - mostly to support a smooth - sorta - speed change) I exported the bike soundtrack, used Audacity to normalize it to peak never exceeds -1 db, exported that as a WAV and imported it into Shotcut. The raw bike track was turned off, of course. The music track was brought in through the playlist and dropped into the right place. In this case the music track and bike track got along very nicely, so there’s no gain tweaking. The intro is my stock intro, but the section with the crawl was changed (different background than preceding videos) and the outro was timed to fit the music. (The scroll speed is driven by the duration - 20 seconds for the crawl, 5 seconds for The End). I used DNxHD to port the Shotcut project into Resolve and added the crawls and end title. The final product was rendered using Resolve’s H.264 profile and AAC audio with the image size boosted to 4K. A few hours later, I had a 30.3 Gb .mov with 4K specs and 410 Mb/s bit rate. That goes up to YT and “all” that’s left is wait for it to be published and finally available with up to 4K playback.

The camera is a GoPro clone. It’s rated for up to 4K @ 30 fps. I fiddled with it a bit and it sure seems to work. I shoot 1080p because I can turn the camera on (128 Gb SD, external power) and not stop until I take a break 4-5 hours later. I swap external batteries, check aiming, and hit the road with the same SD. At the moment 1080p is locked into 170° fov, but the latest beta adds a change for that. There’s image stabilization - watch the top of the windscreen relative to the mountains. The St. Gottard pass video, at about 11 minutes in, switches to a cobblestone(!) road. The EIS handles it amazingly well.

The camera wasn’t in a housing in July (no housing supporting external power), but I use one now. The internal mic is …well… an internal mic in a GoPro clone. Although it did surprisingly well when I said something (check out the phone call near the end of the Leutasch video, or negotiating the toll for the Ötztal glacier road). Cow bells are heard in the St. Gotthard, Kauntal “Rest of the road”, and Ötztal). Not great, but not bad for what it is. I plan to add an external mic to minimize air noise and improve motor noise. The camera uses a Panasonic sensor (forgot the specs) and an Ambarella programmable DSP. The YT videos, viewed in 4K, are not very far off from the original footage. Works for me… [/grin]

PS RBE = Richard Booth Emerson (AKA Rick and never, ever Rich - no joke - only people who don’t know me do that). I spent two months in an Army training company with a Robert M Emerson (AFAIK no relation) - great fun to confuse people about which “Emerson, R” is which. No connection with ELP or Emerson Electric. Ralph Waldo is a cousin. [/big grin]


#17

I called you Robert :scream: Mea culpa, to my embarrassment. The email notices give your name.

Thank you Richard for giving such a detailed review of how you made your videos. I thought the first step would be converting the source video to an intermediate codec for editing since that is what they are for. And yet you say you do most of the editing on the 1080p source.

Source video comes from GoPro clone. GoPros have a good but pricey reputation, clones not so much. Would you share the brand/model of the clone since it seems to do a wonderful job? You say it is capable of 4k. Why not use that and carry extra SD cards? Is it because you value the higher frame rate more than the resolution?

Those who call me “Kenny” get “THE LOOK.” :rage:

-=KEN=-


#18

The work flow I described is the collection of “works for me” things. There’s no deep reasoning or anything left over from a couple of film classes in college.

Working in 1080p works - if it ain’t broke… I very specifically want 60 fps to minimize motion blurring. Overall, for me, The Image Matters. “If a job isn’t worth doing right, why do it?”

To avoid a possible confusion about what I’m carving up, of course I work with copies of the original footage. I use TerraCopy to duplicate the files and, importantly, verify the copy. For the Alps trip, I’m working with about 475 Gb of video. The good news is I have real-time GPS tracks laid on a map. What time was I where? The file names (about 3.8 Gb each) are tt:tt:ttyyyymmdd and I’ve put a day’s files in a folder with the date on it (stunning clever, eh?). Refer to the GPS track, get the TOD for some spot, and… there’s the ride over Penserjoch.

I started with Resolve. As I’ve said elsewhere, life with BMD isn’t a lot of fun. Shotcut does about 80-90% of what I need, and I much prefer the help available here. Lack of key frames, inability to vary volume or speed across a clip (Shotcut varies sound pitch with speed, AFAIK Resolve doesn’t allow stretching sound - score one for Shotcut), and the far too inadequate titling ability are what send me back to Resolve, as required. And the final rendering, with Shotcut, just isn’t what I need. I’m moderately confident I can duplicate the Resolve rendering in Shotcut, but I’ll stick with what works.

(The amount of time I’ve burned on editors and dealing with their quirks is… I don’t want to think about how many man-days, and possibly into man-weeks I’ve burned on sorting out or trying different editors. At this point, if it’s not working, it’s in the bit bucket.)


OK, stepping, I’m sure, OT…
IMHO much of the cost of a GoPro is paying for the name. Yes, there are all manner of sexy features. With tools, 90% of the time, 10% of the tools, in the tool box, are used. Ditto for cameras.

Name one action cam not built by China, Inc. They build some good ones, some mediocre ones, and some trash. The difference IMHO is the company. The good companies turn out good products… the scale’s obvious.

My first camera (see any of my videos prior to the Alps trip), a Sena Prism, integrates nicely with my intercom/phone unit (Sena 20S). It talks to me (low battery, video on, etc.). The form factor is slim and not as obvious as the GP-style cams. I can use external power. With a little computer magic I can use 64 Gb SD’s instead of the stated 32 Gb limit. Kewl! But!

The images are …um… lacking. 1080p @ 30 fps is the limit. I talked myself into thinking “close enough”. The really bad news is the signal processor between the sensor (somewhat lacking) and SD turns out inadequate, poorly processed images - blobs of color where there should be detail with 1080p. The good company/product thing - Sena’s relationship with the users is not good - they just don’t interact. Wanting to avoid “cheap Chinese junk”, not willing to pay GoPro prices, and having some Sena gear, I bought the Prism. Maybe a passable idea at the time, but maybe not.

The Prism literally fell apart (the right side of the camera started to leave the rest of the camera). I did some clever gluing to the point of creating “Franken-camera”. But the monster died anyway. By that point, I was just over a month from leaving for the Alps trip. Having no camera was simply not acceptable. Jumping ahead…

Sena did accept a warranty claim but the camera came back after I came back. The thing is still in the box.

I did some serious searching for a camera I was willing to pay for, and which did what I demanded: 1080p@60 fps with good images. More jumping…

I bought, on Amazon, an SJCam SJ7 Star for $200, or roughly half of a GoPro. The original firmware was buggy - that scared me. A lot. SJCam, however, chats regularly with the customer base. A couple of weeks later I had updated firmware. And have shot 500+ Gb with V1.15 and, now, V1.19. Good companies/products. Probably the best camera demo video is the St. Gottard Pass/Tremola video. For an “under $500” class camera, the color’s good, the resolution is very good, the camera is (now) reliable, and I can use big SD’s and external power. The form factor isn’t great, but very few companies vary from the GP “standard”. OTOH, all of the “session gear” (GP’s silly term for brackets and mounts) is interchangeable among GP clones.

Coming back to the camera specs, name the common resolutions, it’s in there. Above 1080p, it’s 30 fps, period, but 120 fps is available for at least 1080 and maybe 720 - I forget. 16:9 or 4:3 framing, of course. Time lapse, single and burst stills… the usual. The menu is long enough to be a short book, and a short book is needed to find them all. But the 90%/10% rule holds here, too. The SJ7 uses an excellent Sony sensor behind a very good lens and an Amberalla processor. The processor is programmable and Amberalla releases, to OEM’s, occasional updates. SJCam includes them in their own firmware updates. Coming features include RAW for stills, and enhanced electronic image stabilization.

Gripes. I got 'em. The camera would probably drown in a heavy dew. The SD slot is open to the interior. Internal battery life is about 3-40 minutes depending on speed and res. All the computing horsepower means a lot of radiated heat. With the camera inside its dive case (dew thing, 'member?) or external power case, I’m not sure how well the camera will do with cooking, thanks to bright and hot summer weather… Pull the external power cable and the camera shuts off instead of picking up with the internal battery (lost more than a couple of hours that way).

Would I buy the SJ7 again - dunno… The SJ8 just came out… LOL

Riding work flow. I did a trip similar to this year’s trip last year. Watching people tracking batteries, SD’s, fumbling with stuff, pulling over because the battery is about to fade, etc., etc. made it clear that’s not the way to go. With an external 50,000 mAh battery (vs typically 1500-3000 mAh), the camera can easily run, non-stop, for about 5 hours. A 128 Gb SD will, with a bit of off and on (I didn’t shoot a couple of hours on an autobahn, for example), last two days. That means changing the SD in the hotel room, and swapping the power cable, to the second pack, at lunch. Easy-peasy.

Another SJ7 feature is real-time video to a smart phone. That takes care of aiming and it also allows stopping and staring on the fly (My riding gloves have conductive thread so I can use the screen without stopping to fiddle with gloves.)

I’ve lost video (the first day’s ride from Munich, three mountain passes, and some village footage). NTL I’m satisfied with what I brought back.

My YT channel address

All of this is effectively dashcam video with music and titles. But it fills a niche - for some folks. [/smile]

And that’s the name of that tune.


#19

So, that is the result of a collage education, huh? (Kidding, just kidding :grin:)

The video is marvelous and your strategy for collecting it seems to work well. Seems there is always “something” wrong with all tech. Witness, all the iPhone quirks and patches since Stev Jobs passed on. Thanks for the pointers on action cams. Perhaps it will be useful for the forum users. Thanks again for going into such detail about your hardware/software and methods.

I see that Resolve is available for Linux. Didn’t want to sign up. Maybe I should.

I think I will read up on intermediate codecs for editing. Best,

Edit: Shotcut supports "intermediate/ProRes - codec has GOP=1 and 0 B-frames in mov container.
Trying it - converting. Looks like it will take 4x length of .m2t video. Four cores running about ~65 percent this time.

-=Ken=-


#20

The classes (at Temple U.) were done in… ooohhh wait for it… 8mm. High tech stuff.

Re : “something wrong” - if it were perfect, it wouldn’t need tinkering, and that’s bad, so it’s not perfect. LOL

There are zillions of the cams around - the elves in Guangzhou are busy, busy, busy. IMHO the best anyone can do is look for reviews that converge on some point, good or bad, and buy, or not, accordingly. If the reviews (if they even exist) are all over the map, not a camera I’d care to buy.

My experience with Resolve under Linux is simple: don’t waste your time. 14.0 has very spotty record (if the forum postings count), and 12.5.6 won’t work on newer Linux versions. There’s a particular library (libpng) that recently updated. 12.5.6 demands the old version. There’s no hope of having the old and new versions concurrently. When I said “uh, the libpng maintainers have called the old version obsolete and out of support” on the BMD forum, the BMD reply amounted to “so what’s your point”. As I said, save your time. I wish I had.

In general, once I’m done cutting and pasting, I don’t worry about transcoding that, on occasion, took eight hours. I know it’s coming and plan on doing something else. What does annoy me is slowness while I’m editing. If I can’t see what a transition or cut really looks like, I get irritable. And, on occasion, downright cranky, too.

Thanks for the DNxHD ProRes link. I hope folks find it useful.