Converting unusual image file resolutions into videos

[Martin Pfeifer]

I made an HAP Alpha file out of image sequences with 3452x3070 px. I did it with ffmpeg by setting the output resolution to 
3452x3072 px so that the pixel sizes are divisible by 4 and ffmpeg could do its job.

However with pixel sizes from 268x3070 to 268x3072 or from 2929x3070 to 2928x3072 ffmpeg promts the error message
Invalid frame size.

Does anyone know a solution or do I have to leave the image sequences as they are?

 

Martin

 

[Martin Pfeifer]

I found a solution:

 

ffmpeg -video_size 2928x2416 -start_number 00287 -i C:\MEDIA\SHOWROOM\GRAFITTY\1COLOR\IN\5G\05-2929x4217_%05d.png C:\MEDIA\SHOWROOM\GRAFITTY\1COLOR\OUT\5Gdemux\05-2928x4216_%05d.png

 

ffmpeg -start_number 00287 -i C:\MEDIA\SHOWROOM\GRAFITTY\1COLOR\OUT\5Gdemux\05-2928x4216_%05d.png -vcodec hap -format hap_alpha -chunks 8 -b:v 50000k -minrate 50000k -maxrate 50000k -s 2928x4216 C:\MEDIA\SHOWROOM\GRAFITTY\1COLOR\OUT\5G-2\5G-2.mov

 

however ffmpeg ignores the specified bitrate and encodes with aproximately max. 120000Kbit/s

 

Martin

 

[Erik Rönnqvist]

There is no way to set the bitrate i Hap, that's why ffmpeg ignores your bitrate setting. It is inherent to the compression algorithms used in Hap that there is no way to control the bitrate, except for the fact that HapQ uses a higher bitrate than regular Hap. This means that the only way to lower the bitrate if using HapQ is to switch to standard Hap (or lower the resolution). I you want a lower bitrate when using standard Hap, the only way is to lower the resolution and scale the movie in Watchout. 

 

/Erik 

[Vollmers]

I use HAP for all video material. The great advantage with HAP is that it streams more or less directly to the GPU. When it comes to odd aspects, which I use a lot, I use good old Quicktime. Yes, you get bigger files, but with HAP its not a problem. I used to do conversions to mpg, but also experienced a lot of problems doing that, when I used odd aspect video. True you can make a regular aspect video, a resize it in Watchout, but then you might get a quality degrade.I tried to run 5 enormous QT HAP 1 minute video loops in 6400x1080, and it played out perfectly. I normally don't use HAP Q, since I don't experience any quality improvement in the shows I normally design. With QT HAP you can do all your work in Adobe After Effects, and render it out directly and it'll be ready to use. BTW - I've discovered there's a difference rendering out from PC and MAC. Loops from MAC with HAP doesn't loop correctly. The same loop rendered on PC works like they should.

[jfk]

One other thing to try is to make the largest dimension the first dimension (as in 1920x1080, etc.)

If necessary, rotate the file in WATCHOUT.

Not sure why, but have seen this cure issues with odd sized video dimensions before.

[Martin Pfeifer]

With ffmpeg, I made these special resolution HAP alpha and HAP Q videos from png images. All play smooth and without problems:

268x3072, 268x3452, 764x3072, 1000x4216, 2928x3072 and 3452x3072