通知
すべてクリア

YUV to RGB conversion issues

固定ページ 2 / 2
   RSS

0
Topic starter

Following the recent Optimize Playback thread, I seem to have opened Pandora's box when it comes to Color Model in Cinelerra.

I work mostly with 8 bit YUV footage from Panasonic and DJI cameras. Up until now, I have always set the color model to RGB-FLOAT for my projects, and this, combined with setting YUV color space to BT709 and YUV color range to MPEG has meant that what I see in the compositor looks the same as my final rendered video.

However, I have noticed that if I set the color model to YUV-8 Bit, then my footage has far more dynamic range (highlights are hard-clipped when set to RGB-FLOAT), and is more saturated. In fact, when set to YUV 8 Bit, the footage looks the same as it does in VLC player.

On the other hand, if I use YUV-8 Bit as the color model, the final rendered video does not look the same in VLC player as it does in the Cinelerra compositor - it is a bit de-saturated compared to the compositor.

What I would like to achieve is to retain the vibrant colour and highlights that I see in the compositor when the color range is set to YUV-8 Bit in my final rendered video. Can anyone point me in the right direction?

17件の回答
0
Topic starter

@igorbeg

Thanks again for your input.

I can confirm that formats using bgra seem to match the compositor when using JPEG as the colour model, I can then convert to m4v using Handbrake, and upload that file to YouTube.

Colours seem reasonably consistent in YouTube.

So the issue appears to be in how JPEG colour model YUV files are written by Cinelerra, as the files converted from RGB to YUV by Handbrake are displayed correctly. Is this a separate issue to the clipping of out-of-range values when in MPEG color model?

0

I made a discovery the other day which may help a little. Having sold my X-T3 I am concentrating my efforts on my HC-X1500, which shoots broadcast restricted (MPEG) video. My action camera shoots full range, so I need Cinelerra set to JPEG for that. I always use RGBA-FLOAT.

I found (understandably) that importing MPEG into JPEG colour space leaves it rather flat even after my best efforts. I also found that yes, if I set Cin to MPEG it hard clips, so the waveform monitor 100% is ususally a straight line. However, if I leave Cin set to JPEG and import MPEG clips, then convert it to JPEG using Colour Space, the flatness disappears and so does the hard clipping.

Edit: I forgot to say the HC-X1500 exposure is normally set using 95% zebras, so the waveform monitor should never hit 100% with a raw clip.

Just thought I would mention it in case it helps.

@dejay 

Thank you, I will put this info on the manual.
To understand accurately:

Source          YUV color Range

MPEG           JPEG                                            ==> Flat Colors

MPEG           MPEG                                          ==> Hard Clipping

MPEG          JPEG + Color Space (to JPEG)   ==> Color OK.

Did you use native color space plugin or F_colorspace?

0

Yes that is correct. I used the native plugin.

固定ページ 2 / 2
共有: