Mixing Colorimetries before DVD output

[Anonymous344]

I have three source videos with different colorimetries that I am cropping and resizing to match each other, then combining in Avisynth. My output will be an NTSC DVD, probably encoded with HC Encoder. Two sources are SD; one source is HD. I used DGIndex to determine the colorimetry for the SD sources and DGAVCDec to determine the colorimetry for the HD source.

Source one: BD (Region A) -- BT.709
Source two: NTSC DVD (Region 1) -- SMPTE 170M
Source three: NTSC DVD (Region 3) -- BT.470-2 B,G*

Can these sources be combined? I understand that there is some disagreement about whether DVD should use Rec.601 or Rec.709 because DVDs with Rec.709 in the sequence_display_extension have been observed, and I could not find a definitive answer online. Basically, what I want know is can an encoder, such as Hc Enc, deal with video with parts with different colorimetry or should I combine these sources, then apply a colorimetry conversion before sending my Avisynth script to the encoder?

[manono]

Can these sources be combined?

Yes. With your source 3 the asterisk means no colorimetry was defined. SMPTE-170M is the same as BT.601.

Basically, what I want know is can an encoder, such as Hc Enc, deal with video with parts with different colorimetry

It deals with them by not dealing with them. It's your responsibility to define them in the AviSynth script if necessary, converting from one to the other in the case of Hi-Def to Standard-Def.

should I combine these sources, then apply a colorimetry conversion before sending my Avisynth script to the encoder?

The only one that needs converting is the one from a Hi-Def source.

[Anonymous344]

The only one that needs converting is the one from a Hi-Def source.

Thanks! That makes my job a little easier. I appreciate the reply.

[themaster1]

ntsc DVD is Rec601 (16-235) if you find one that is 709 (0-255) then it's been wrongly encoded, i have a seen a couple like that myself.Most of the pro softwares use rgb hence the levels problems yuv>rgb>yuv i suppose.
If you want to blend these clips i suggest you use the levels filter and also this filter

[Anonymous344]

If you want to blend these clips i suggest you use the levels filter and also this filter

Thanks, but I have managed to match the colors already. I just wanted to know about colorimetry. I appreciate the reply though.