This avoids automatic conversions to rgb if scene change score is used in the expression.

Below is the tested results for the new added pixel format without autoscale to rgb24:
1. AV_PIX_FMT_YUVJ420P
time ./ffprobe -of compact=p=0 -show_entries frame=pkt_pts:frame_tags -bitexact -f lavfi \
"sws_flags=+accurate_rnd+bitexact;movie=../fate-suite/svq3/Vertical400kbit.sorenson3.mov,select=gt(scene\,.25)"

master:
pkt_pts=1620|tag:lavfi.scene_score=1.000000
pkt_pts=4140|tag:lavfi.scene_score=0.875036
pkt_pts=5800|tag:lavfi.scene_score=1.000000
pkt_pts=6720|tag:lavfi.scene_score=0.461625
pkt_pts=8160|tag:lavfi.scene_score=1.000000
pkt_pts=9760|tag:lavfi.scene_score=1.000000
pkt_pts=14080|tag:lavfi.scene_score=0.838916
pkt_pts=15700|tag:lavfi.scene_score=1.000000
pkt_pts=18500|tag:lavfi.scene_score=0.474948
pkt_pts=20040|tag:lavfi.scene_score=0.379700
pkt_pts=21760|tag:lavfi.scene_score=1.000000
./ffprobe -of compact=p=0 -show_entries frame=pkt_pts:frame_tags -bitexact -f  0.71s user 0.01s system 99% cpu 0.721 total

patch applied:
pkt_pts=1620|tag:lavfi.scene_score=1.000000
pkt_pts=4140|tag:lavfi.scene_score=0.668643
pkt_pts=5800|tag:lavfi.scene_score=0.996721
pkt_pts=6720|tag:lavfi.scene_score=0.357390
pkt_pts=8160|tag:lavfi.scene_score=0.886268
pkt_pts=9760|tag:lavfi.scene_score=0.926219
pkt_pts=14080|tag:lavfi.scene_score=0.650033
pkt_pts=15700|tag:lavfi.scene_score=1.000000
pkt_pts=18500|tag:lavfi.scene_score=0.316402
pkt_pts=20040|tag:lavfi.scene_score=0.269509
pkt_pts=21760|tag:lavfi.scene_score=1.000000
./ffprobe -of compact=p=0 -show_entries frame=pkt_pts:frame_tags -bitexact -f  0.19s user 0.01s system 81% cpu 0.240 total

2. AV_PIX_FMT_YUV420P
time ./ffprobe -of compact=p=0 -show_entries frame=pkt_pts:frame_tags -bitexact -f lavfi \
"sws_flags=+accurate_rnd+bitexact;movie=../Passengers_Breakfast_1080-sdr.mkv,select=gt(scene\,.2)"
master:
pkt_pts=3587|tag:lavfi.scene_score=0.462364
pkt_pts=4838|tag:lavfi.scene_score=0.419519
pkt_pts=6548|tag:lavfi.scene_score=0.397027
pkt_pts=9968|tag:lavfi.scene_score=0.419245
pkt_pts=12471|tag:lavfi.scene_score=0.413084
pkt_pts=16225|tag:lavfi.scene_score=0.506370
pkt_pts=19645|tag:lavfi.scene_score=0.507538
pkt_pts=22314|tag:lavfi.scene_score=0.504319
pkt_pts=24817|tag:lavfi.scene_score=0.417544
pkt_pts=25651|tag:lavfi.scene_score=0.413916
pkt_pts=26652|tag:lavfi.scene_score=0.487707
18.58s user 0.07s system 99% cpu 18.663 total

patch applied:
pkt_pts=3587|tag:lavfi.scene_score=0.272173
pkt_pts=4838|tag:lavfi.scene_score=0.247841
pkt_pts=6548|tag:lavfi.scene_score=0.233134
pkt_pts=9968|tag:lavfi.scene_score=0.247253
pkt_pts=12471|tag:lavfi.scene_score=0.244129
pkt_pts=16225|tag:lavfi.scene_score=0.302531
pkt_pts=19645|tag:lavfi.scene_score=0.303560
pkt_pts=22314|tag:lavfi.scene_score=0.301861
pkt_pts=24817|tag:lavfi.scene_score=0.249331
pkt_pts=25651|tag:lavfi.scene_score=0.247096
pkt_pts=26652|tag:lavfi.scene_score=0.287728
10.90s user 0.06s system 99% cpu 10.967 total

3. AV_PIX_FMT_YUV422P

time ./ffprobe -of compact=p=0 -show_entries frame=pkt_pts:frame_tags -bitexact -f lavfi \
"sws_flags=+accurate_rnd+bitexact;movie=../Passengers_Breakfast_1080-sdr.mkv,format=yuv422p,select=gt(scene\,.2)"
master:

patched applied:
pkt_pts=3587|tag:lavfi.scene_score=0.224017
pkt_pts=4838|tag:lavfi.scene_score=0.204225
pkt_pts=9968|tag:lavfi.scene_score=0.204636
pkt_pts=12471|tag:lavfi.scene_score=0.202772
pkt_pts=16225|tag:lavfi.scene_score=0.248765
pkt_pts=19645|tag:lavfi.scene_score=0.250144
pkt_pts=22314|tag:lavfi.scene_score=0.248802
pkt_pts=24817|tag:lavfi.scene_score=0.208362
pkt_pts=25651|tag:lavfi.scene_score=0.205777
pkt_pts=26652|tag:lavfi.scene_score=0.230742

4.  AV_PIX_FMT_YUV420P10
time ./ffprobe -of compact=p=0 -show_entries frame=pkt_pts:frame_tags -bitexact -f lavfi \
"sws_flags=+accurate_rnd+bitexact;movie=../Passengers_Breakfast_4k.mkv,select=gt(scene\,.2)"

master:
pkt_pts=3587|tag:lavfi.scene_score=0.269890
pkt_pts=4838|tag:lavfi.scene_score=0.248957
pkt_pts=6548|tag:lavfi.scene_score=0.234619
pkt_pts=9969|tag:lavfi.scene_score=0.224912
pkt_pts=12471|tag:lavfi.scene_score=0.225158
pkt_pts=16225|tag:lavfi.scene_score=0.289809
pkt_pts=19645|tag:lavfi.scene_score=0.285013
pkt_pts=22314|tag:lavfi.scene_score=0.280295
pkt_pts=24817|tag:lavfi.scene_score=0.206486
pkt_pts=25651|tag:lavfi.scene_score=0.208556
pkt_pts=26652|tag:lavfi.scene_score=0.249577
./ffprobe -of compact=p=0 -show_entries frame=pkt_pts:frame_tags -bitexact -f  76.03s user 0.22s system 99% cpu 1:16.27 total

patch applied
pkt_pts=3587|tag:lavfi.scene_score=0.269890
pkt_pts=4838|tag:lavfi.scene_score=0.248957
pkt_pts=6548|tag:lavfi.scene_score=0.234619
pkt_pts=9969|tag:lavfi.scene_score=0.224912
pkt_pts=12471|tag:lavfi.scene_score=0.225158
pkt_pts=16225|tag:lavfi.scene_score=0.289809
pkt_pts=19645|tag:lavfi.scene_score=0.285013
pkt_pts=22314|tag:lavfi.scene_score=0.280295
pkt_pts=24817|tag:lavfi.scene_score=0.206486
pkt_pts=25651|tag:lavfi.scene_score=0.208556
pkt_pts=26652|tag:lavfi.scene_score=0.249577
./ffprobe -of compact=p=0 -show_entries frame=pkt_pts:frame_tags -bitexact -f  50.27s user 0.20s system 99% cpu 50.476 total

5. AV_PIX_FMT_RGBA, AV_PIX_FMT_ABGR, AV_PIX_FMT_BGRA, AV_PIX_FMT_GRAY8
are tested by format= with the fate sample: Vertical400kbit.sorenson3.mov like below:
time ./ffprobe -of compact=p=0 -show_entries frame=pkt_pts:frame_tags -bitexact -f lavfi \
"sws_flags=+accurate_rnd+bitexact;movie=../fate-suite/svq3/Vertical400kbit.sorenson3.mov,format=rgba,select=gt(scene\,.25)"

patch applied:
pkt_pts=1620|tag:lavfi.scene_score=1.000000
pkt_pts=4140|tag:lavfi.scene_score=0.656277
pkt_pts=5800|tag:lavfi.scene_score=1.000000
pkt_pts=6720|tag:lavfi.scene_score=0.346218
pkt_pts=8160|tag:lavfi.scene_score=0.987686
pkt_pts=9760|tag:lavfi.scene_score=1.000000
pkt_pts=14080|tag:lavfi.scene_score=0.629187
pkt_pts=15700|tag:lavfi.scene_score=1.000000
pkt_pts=18500|tag:lavfi.scene_score=0.356211
pkt_pts=20040|tag:lavfi.scene_score=0.284775
pkt_pts=21760|tag:lavfi.scene_score=1.000000

6. AV_PIX_FMT_YUVJ422P
time ./ffprobe -of compact=p=0 -show_entries frame=pkt_pts:frame_tags -bitexact -f lavfi \
"sws_flags=+accurate_rnd+bitexact;movie=../fate-suite/svq3/Vertical400kbit.sorenson3.mov,format=yuvj422p,select=gt(scene\,.25)"

patch applied:
pkt_pts=1620|tag:lavfi.scene_score=0.838281
pkt_pts=4140|tag:lavfi.scene_score=0.541382
pkt_pts=5800|tag:lavfi.scene_score=0.780588
pkt_pts=6720|tag:lavfi.scene_score=0.298274
pkt_pts=8160|tag:lavfi.scene_score=0.699106
pkt_pts=9760|tag:lavfi.scene_score=0.730136
pkt_pts=14080|tag:lavfi.scene_score=0.537742
pkt_pts=15700|tag:lavfi.scene_score=0.811946
pkt_pts=18500|tag:lavfi.scene_score=0.263382
pkt_pts=21760|tag:lavfi.scene_score=0.880773
Reviewed-by: Marton Balint <cus@passwd.hu>
Signed-off-by: Limin Wang <lance.lmwang@gmail.com>