[Libav-user] Big Buck Bunny, Rendering for Encodingtests (UHD, 4K, High Framerate)

Tue Oct 7 17:54:58 CEST 2014

Dear ffmpeg-libav-group,

I am trying to convert the BigBugBunny-EXRs to AVI using this commandline:

"C:\Program Files\ffmpeg\bin\ffmpeg-20140916-git-b76d613-win32-static.exe" -y -start_number 0001 -f image2 -r 50 -i I:\distribution.bbb3d.renderfarming.net\video\exr\right\scene0201_right1174_crop109\%04d.exr -loglevel debug -f avi -filter:v "crop=w=3840:h=2160:x=80:y=90,scale=3840:2160" -pix_fmt bgr24 -aspect 3840:2160 -c:v rawvideo -r 50 -an -sn -threads 0 "I:\distribution.bbb3d.renderfarming.net\video\avi\right\scene0201_right1174_crop109.avi"  

(individual cropping for each scene-directory)

Works quite well, but I get false-colors in dark areas (see PNG and LOG attached).

It doesn’t seem to change no matter if I use “out_color_matrix=bt709” or not. 

It looks like an Bug in the EXR-Reader of ffmpeg or at least an incompatibility compared to the EXR-Decoding of Blender.

When I play the same EXRs in DJV-Player, all colours seem to be correct:

http://djv.sourceforge.net/

If you have any suggestions or a workaround (image magic?), I would be happy for comments.

Thanks Regards,

Martin.

Von: Martin Schmalohr [mailto:schmalohr at irt.de] 
Gesendet: Donnerstag, 17. Juli 2014 09:29
An: 'Janus'
Betreff: AW: AW: AW: AW: AW: Big Buck Bunny, Rendering for Encodingtests (UHD, 4K, High Framerate)

Cool, thanks for the quick reply!

(when we have some encodings online in a few weeks, I will send you the URLs, if you are interested. We should have no problem with traffic-costs, as we can make use of Akamai-CDN…)

Von: Janus [mailto:jbk at visualgroup.dk] 
Gesendet: Mittwoch, 16. Juli 2014 19:03
An:  <mailto:schmalohr at irt.de> schmalohr at irt.de
Cc: 'Julius Tuomisto';  <mailto:siepe at irt.de> siepe at irt.de;  <mailto:vogl at irt.de> vogl at irt.de
Betreff: Re: AW: AW: AW: AW: Big Buck Bunny, Rendering for Encodingtests (UHD, 4K, High Framerate)

1126, 1127, 1228 are not actually part of the movie. They are included in the archive as easter eggs:
 <http://burp.renderfarming.net/session.php?id=1126> http://burp.renderfarming.net/session.php?id=1126

-- J

On 16-07-2014 13:32, Martin Schmalohr wrote:

Hi Janus,

after recognizing, that the BBB 4k 60fps was finished already End of 2013 (we did also contribute a bit to the rendering), I decided to get the EXRs and build an uncompressed AVI as coding-source for my open test-repository:

http://av-standard.irt.de/wiki/index.php/Referenzclips

(there will come another section with the BBB encodings)

When converting the EXRs to ffmpeg (to 50p timebase), I found problems with the following folders: 1126, 1127, 1128

All other folders converted to AVI with no errors.

FFMPEG says:

[exr @ 0282fc60] Wrong magic number 1196314761.

[image2 @ 0283f5a0] Probe buffer size limit of 5000000 bytes reached

[image2 @ 0283f5a0] decoding for stream 0 failed

[image2 @ 0283f5a0] Could not find codec parameters for stream 0 (Video: exr): unspecified size

Please find attached my logs (failed 1126, 1127, 1128) and as example (ok 1129).

Could you give me a hint, if the EXRs are broken, or if I should change my ffmpeg commandline?!

"C:\Program Files\ffmpeg\bin\ffmpeg-20140623-git-ca35037-win32-static.exe" -y -start_number 0001 -f image2 -r 50 -i H:\distribution.bbb3d.renderfarming.net\video\exr\1129\%04d.exr -loglevel debug -f avi -filter:v "crop=iw-0:ih-0:0:0,scale=1280:720" -pix_fmt yuv420p -aspect 1280:720 -c:v rawvideo -r 50 -an -sn -threads 0 "G:\BigBugBunny_1129_ffmpeg.avi"  

Thanks & Regards,

Martin.

Von: Martin Schmalohr [mailto:schmalohr at irt.de] 
Gesendet: Mittwoch, 21. August 2013 10:26
An: Janus
Betreff: Re: AW: AW: AW: Big Buck Bunny, Rendering for Encodingtests (UHD, 4K, High Framerate)

ok, thanks!

I have few people running the boinc-client and helping the burp-rendering now at my institute.i think we are rank 30...but this cpu goes to all burp-projects, not only bbb as far as i understand.

so much for now.best regards.martin.

Martin Schmalohr unterwegs...

Am 20.08.2013 um 20:08 schrieb Janus <jbk at visualgroup.dk>:

The sound is 48KHz if I recall correctly, so depending on your output sample rate there are limits to how much you can resample it without losing quality... but yeah sure, for testing it probably wont matter much unless what you are testing is the sound.

Can you say, when you think, the 4k/60Hz-Version will be available?

Unfortunately no, the computing power is based on people volunteering and for me it is a spare time project. It is done when it is done. We are at more than 95% now. It will take a little while to make the data available on the web too.

-- Janus

Den 20-08-2013 11:24, Martin Schmalohr skrev:

Allright – thanks!

I think, we will try a „50Hz-Slowdown“ (AviSynth: AssumeFPS 50) and make a Pitch-corrected Audio-Resampling from the 4K/60Hz-Footage.

That makes 12mins normal Playtime out of 10mins. This may not be ideal from an artistical Point of View, but it should work perfectly for Device-testing-purposes.

Can you say, when you think, the 4k/60Hz-Version will be available?

Just for our Information: We already connected a some CPU-Power to BURP using BOINC… 

Regards,

Martin.

Von: Janus [ <mailto:jbk at visualgroup.dk> mailto:jbk at visualgroup.dk] 
Gesendet: Montag, 19. August 2013 18:00
An:  <mailto:schmalohr at irt.de> schmalohr at irt.de
Cc: 'Ton Roosendaal'; 'Julius Tuomisto';  <mailto:siepe at irt.de> siepe at irt.de;  <mailto:laabs at irt.de> laabs at irt.de;  <mailto:driesnack at irt.de> driesnack at irt.de;  <mailto:vogl at irt.de> vogl at irt.de; 'Franz Baumann';  <mailto:neudel at irt.de> neudel at irt.de
Betreff: Re: AW: AW: Big Buck Bunny, Rendering for Encodingtests (UHD, 4K, High Framerate)

Den 19-08-2013 11:50, Martin Schmalohr skrev:

Hi Janus,

You said, one of the "downscale" of the intermediary HFR 4K raw files as
final output is 4K 60Hz. Is the intermediary HFR different from 60fps?
I assume, that the stereo Audio-Rendering could be replaced by the 5.1
Channels, with that you have on the BBB-Webpage (e.g. as Dolby-Stream) -
staying in AV-Sync.

Sorry, that would be "stereoscopic". The intermediary format is two half-float EXRs around +4000x2250 pixels each for left and right eyes in 60 fps. The 4K "scaled down" version is simply the left eye scaled down and cropped to quad-full-HD 3840×2160 in 60 fps.

-- Janus

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