Good x265 Settings (Mar 2022 update, merged to v11.1)

x265 is just too complex to figure out for past myself, so after watched too much lectures and papers, testing myself and checking forums, here I'm giving out parameters years late. I'll try deleting the old posts regarding x265 as well. In this post I'll give out 6 combinations, and explain key features of each. Since x265 has hundreds of parameters to tackle with, I'll remove all the customizations and just give the fixed amounts.

Note: --strong-intra-smoothing filter is enabled, because it's a parallel feature with 3-tap filter in intra frame search. It only applies in specific conditions according to the formula, and makes overall encoding faster with minor quality loss. Data smoothing is also not blurring which preserves patterned details.

Note: I'm more of an enthusiast instead the expert, the borderline inbetween expert and enthusiast is probably being able to read and explain rate distorsion function where everything becomes university master/doctor level, so please don't exprect these parameters to be prefect

General Purpose for video platforms

Simple and quite effective, less capable at compressing some scenes, qpmax is still configured for perserving output quality, YUV4:2:0 8bit, 10bit

Block Splitting - Transformation: --min-cu-size 16 --limit-tu 1 --tu-intra-depth 2 --tu-inter-depth 2

ME - Compensation: --me umh --subme 5 --merange 48 --rskip 1 --weightb
Referencing - Rate Control: --ref 3 --early-skip --max-merge 2 --no-open-gop --min-keyint 5 --fades --bframes 11 --b-adapt 2 --radl 2 --fast-intra

Various Parameter Sets: --opt-qp-pps --opt-ref-list-length-pps

Intraframe Search: --fast-intra

Quantization: --crf 18 --crqpoffs -3 --cbqpoffs --qpmax 26

Adaptive Quant: --aq-mode 3 --aq-motion --qg-size 16

RDO - Mode Decision: --rd 3 --rdpenalty 1 --splitrd-skip --rdoq-level 1 --limit-modes --rect --tskip-fast
Sample Adaptive Offset: --limit-sao --sao-non-deblock
Output: --hash crc --allow-non-conformance

Multiple CPU nodes: --pools +,-

Standard for video platforms

Takes more compute resources, no advantage against General Purpose in simpler scenes, YUV4:2:0, 4:2:2, 4:4:4 8bit, 10bit

Block Splitting - Transformation: --min-cu-size 16 --tu-intra-depth 3 --tu-inter-depth 4 --limit-tu 1

ME - Compensation: --me star --subme 5 --merange 48 --rskip 1 --weightbReferencing - Rate Control: --ref 3 --max-merge 2 --early-skip --no-open-gop --min-keyint 5 --keyint 390 --fades --bframes 13 --b-adapt 2 --radl 3

Various Parameter Sets: --opt-qp-pps --opt-ref-list-length-pps

Intraframe Search: --fast-intra

Quantization: --crf 20.5 --crqpoffs -4 --cbqpoffs -2 --qpmax 26

RDOQ: --rdoq-level 2

Adaptive Quant: --aq-mode 3 --aq-strength 0.9 --aq-motion --qg-size 16

Mode Decision: --rd 3 --rdpenalty 1 --splitrd-skip --rdoq-level 1 --limit-modes --rect

Rate Distorsion Optimization: --psy-rd 1.6 --rdpenalty 2 --splitrd-skip

Deblocking: --deblock 0:0Sample Adaptive Offset: --limit-sao --sao-non-deblock
Output: --hash crc --allow-non-conformance

Multiple CPU nodes: --pools +,-

NAS/Server playback recovery: --idr-recovery-sei

High Compression - Film

Burst high bitrate scenes will be compressed. Not recommended for video platforms, recommend shifting chroma plane resolution up for this one: YUV4:2:2, 4:4:4 8bit, 10bit

Block Splitting - Transformation: --min-cu-size 16 --tu-intra-depth 4 --tu-inter-depth 4

ME - Compensation: --me star --subme 5 --merange 48 --rskip 1 --weightb

Referencing - Rate Control: --ref 3 --max-merge 4 --early-skip --no-open-gop --min-keyint 2 --keyint 400 --fades --bframes 15 --b-adapt 2 --radl 3

Various Parameter Sets: --opt-qp-pps --opt-ref-list-length-pps

Intraframe Search: --constrained-intra --b-intra

Quantization: --crf 21 --qpmin 10 --crqpoffs -3 --cbqpoffs -1 --hrd --vbv-bufsize 30000 --vbv-maxrate 50000

RDOQ: --rdoq-level 2

Adaptive Quant: --aq-mode 2 --aq-strength 0.9 --qg-size 8

Mode Decision: --rd 5 --rdpenalty 1 --splitrd-skip --rskip 0 --limit-modes --rect --amp

Rate Distorsion Optimization: --psy-rd 1.9 --rdpenalty 1 --rd-refine

Deblocking: --deblock 0:0

Sample Adaptive Offset: --sao-non-deblock --selective-sao 3Output: --hash crc --allow-non-conformance --nr-inter 5 --nr-intra 5

Multiple CPU nodes: --pools +,-

NAS/Server playback recovery: --idr-recovery-sei

Render to Reuse (video editor --> video editor)

Some filters costs too much computing resources, therefore render a finished video and re-import is cost saving. Not sure when will premiere support hevc, but voukoder is not just for premiere, so this should still be useful: YUV4:2:2 8bit, 10bit

Block Splitting - Transformation: --ctu 32

ME - Compensation - Intrasearch: --me star --subme 6 --merange 48 --analyze-src-pics --weightb --max-merge 4 --early-skip --b-intra

Referencing - Rate Control: --ref 3 --no-open-gop --min-keyint 1 --keyint 350 --fades --bframes 7 --b-adapt 2

Various Parameter Sets: --opt-qp-pps --opt-ref-list-length-pps

Quantization: --crf 17 --qpmax 24

Mode Decision: --rd 5 --limit-modes --limit-refs 1 --rskip 1

Deblocking: --deblock 0:0

Sample Adaptive Offset: --no-sao

Output - Mastering: --hash crc --allow-non-conformance --tune grain

Multiple CPU nodes: --pools +,-

NAS/Server playback recovery: --idr-recovery-sei

High Compression - Anime

For subtitle/translation groups and uploading to video platform. This parameter considers both high and low budget anime, include opening, ending and main content. The secret is to max out all the possible block splittings possible, because high-freq info here are mostly hand drawings and should be perserved: YUV4:2:0 8bit, 10bit

Block Splitting - Transformation: --ctu 64 --min-cu-size 8 --tu-intra-depth 4 --tu-inter-depth 4 --max-tu-size 4 --limit-tu 1

ME - Compensation: --me star --merange 48 --analyze-src-pics --subme 3 --weightb --max-merge 4 --early-skip

Referencing - Rate Control: --ref 3 --no-open-gop --min-keyint 5 --keyint 360 --fades --bframes 15 --b-adapt 2 --radl 2

Various Parameter Sets: --opt-qp-pps --opt-ref-list-length-pps

Intraframe Search: --b-intra

Quantization: --crf 20 --crqpoffs -3 --cbqpoffs -1 --cu-lossless

RDOQ: --psy-rdoq 2.3 --rdoq-level 2

Adaptive Quant: --aq-mode 3 --aq-strength 0.7 --qg-size 8

Mode Decision: --rd 5 --limit-modes --limit-refs 1 --rskip 1 --rect --amp

Rate Distorsion Optimization: --psy-rd 1.5 --rd-refine --splitrd-skip

Deblocking: --deblock 0:0

Sample Adaptive Offset: --limit-sao --sao-non-deblock

Output: --hash crc --allow-non-conformance --single-sei

Multiple CPU nodes: --pools +,-

NAS/Server playback recovery: --idr-recovery-sei

High Quality - Anime BDRip Coldwar Duels

For Blue-ray DVD Ripper social network's common agreement on: high quality encoding means "paused dark scene zoomed-in 4~5 times size" should look just as good as the source footage, and I bet the x265 devs will freakout after reading that line, but that's reality on why some BDRip providers/groups are decent but gets less downloads . Compare to HC-Anime, x265 needs to give up some compression features to realize this requirement: YUV4:2:0 8bit, 10bit

Block Splitting - Transformation: --ctu 64 --min-cu-size 8 --tu-intra-depth 4 --tu-inter-depth 4 --max-tu-size 4 --limit-tu 1

ME - Compensation: --me star --merange 52 --analyze-src-pics --subme 3 --weightb --max-merge 4 --early-skip

Referencing - Rate Control: --ref 3 --no-open-gop --min-keyint 1 --keyint 360 --fades --bframes 11 --b-adapt 2 --radl 2 --pbratio 1.2

Various Parameter Sets: --opt-qp-pps --opt-ref-list-length-pps

Intraframe Search: --b-intra

Quantization: --crf 18.5 --crqpoffs -5 --cbqpoffs -3 --cu-lossless

RDOQ: --psy-rdoq 2.3 --rdoq-level 2

Adaptive Quant: --aq-mode 3 --aq-strength 0.7 --qg-size 8 --aq-motion

Mode Decision:  --rd 5 --limit-modes --limit-refs 1 --rskip 2 --rskip-edge-threshold 2 --rect --amp --no-cutree

Rate Distorsion Optimization: --psy-rd 1.5 --rd-refine --splitrd-skip

Deblocking: --deblock 0:0

Sample Adaptive Offset: --no-sao

Output: --hash md5 --allow-non-conformance --single-sei

Multiple CPU nodes: --pools +,-

NAS/Server playback recovery: --idr-recovery-sei

Thats it.

HDR Support (x264 & x265):

Tagging DCI-P3: --master-display G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(?,1)

Tagging BT.709: --master-display G(15000,30000)B(7500,3000)R(32000,16500)WP(15635,16450)L(?,1)

TaggingBT2020: --master-display G(8500,39850)B(6550,2300)R(35400,14600)WP(15635,16450)L(?,1)

The L(?,1) indicates lux ratio (e.g., 1000:1). This value has no standard and needs to be checked and written manually on each HDR video.

If tagging for the source vid is unknown, find 1 of the following format in source video metadata:

DCI-P3: G(x0.265, y0.690), B(x0.150, y0.060), R(x0.680, y0.320), WP(x0.3127, y0.329)

bt.709: G(x0.30, y0.60), B(x0.150, y0.060), R(x0.640, y0.330), WP(x0.3127,y0.329)

bt.2020: G(x0.170, y0.797), B(x0.131, y0.046), R(x0.708, y0.292), WP(x0.3127,y0.329)

Content lumiance x265: --max-cll <max content light level cd/m², max frame-avg light level cd/m²> e.g., 1000,640

Content lumiance x264: --cll <max content light level cd/m², max frame-avg light level cd/m²> e.g., 1000,640

CLL has no standard and needs to be checked and written manually on each HDR video

Indicate HDR10 content in supplemential enhance info (SEI),  x264 : --hdr10

Optimize HDR10 content (increase video size) per block (optional, x264 ): --hdr10-opt

Indicate color range and transfer properties: --colormatrix <as source> --transfer <as source>

Color range can vary thanks for both compatibility and multple HDR implementations, (e.g., gbr bt709 fcc bt470bg smpte170m YCgCo bt2020nc bt2020c smpte2085 ictcp). Check the source video metadata for them

It seems that voukoder is still using x265 v3.4. These parameters are build around v3.5 and since x265 devs sometimes change the parameter name and enabling-disabling some feature, it's better wait for a new Voukoder release before impementing them