"...with no b-frames, do CABAC and 8x8 DCT really make a difference in compression?"

The short and honest answer is, "I don't know." The longer answer is that I noticed that none of my cameras waste processor power encoding B-frames and I was curious about why. AMD VCE doesn't either in some/most versions. Mulling...

The Custom Command Line in Happy Otter Scripts gives one a window through which to look at such esoteric questions and try, try, try.

Our minds seem to run in parallel, at times.

I was able to get this using a modified XDCAM -EX template, but it's only good up to 1080 p30. It of course renders faster not using the frameserver.

General

Complete name :C:\Users\Mark\Desktop\Zebras3.mxf

Format :MXF

Commercial name :XDCAM HD 35

Format version :1.3

Format profile :OP-1a

Format settings :Closed / Complete

File size :152 MiB

Duration :45 s 600 ms

Overall bit rate mode :Variable

Overall bit rate :27.9 Mb/s

Encoded date :2019-07-19 10:00:26.000

Writing application :SONY Vegas 14.0.0.270

Writing library :Sony MXF Development Kit (Win32) 4.0.0.5000.1

 

Video

ID :2

Format :MPEG Video

Commercial name :XDCAM HD 35

Format version :Version 2

Format profile :Main@High

Format settings :CustomMatrix / BVOP

Format settings, BVOP :Yes

Format settings, Matrix :Custom

Format settings, GOP :M=3, N=12

Format settings, wrapping mode :Frame

Codec ID :0D01030102046001-0401020201030300

Duration :45 s 600 ms

Bit rate mode :Variable

Bit rate :35.0 Mb/s

Width :1 920 pixels

Height :1 080 pixels

Display aspect ratio :16:9

Frame rate :25.000 FPS

Standard :Component

Color space :YUV

Chroma subsampling :4:2:0

Bit depth :8 bits

Scan type :Progressive

Compression mode :Lossy

Bits/(Pixel*Frame) :0.675

Time code of first frame :00:00:00:00

Time code source :Group of pictures header

GOP, Open/Closed :Open

GOP, Open/Closed of first frame :Closed

Stream size :190 MiB

Color primaries :BT.709

Transfer characteristics :BT.709

Matrix coefficients :BT.709

The new DebugMode FrameServer (DMFS) Build (3.0), which supports V13-V16, has brought about a significant change to HOS renders. The previous version was 32bit and required the use of avs2pipemod to pipe the output from Vegas and Avisynth into the 64 bit rendering apps such as FFmpeg. The new version of DMFS includes a 64bit decoder so that avs2pipemod can be eliminated altogether, thus speeding up renders a bit. Here is the command line John uploaded.

avs2pipemod -y4mp <inAVS>  | ffmpeg -y -f yuv4mpegpipe -i -  -itsoffset 0.0444 -i <inTempWav> -map 0:0 -map 1:0  -c:v libx264  -force_key_frames "expr:eq(mod(n,15),0)" -x264opts rc-lookahead=30:keyint=30:min-keyint=15 -pix_fmt yuv420p -crf 20 -preset slow -tune zerolatency -profile:v high -level:v 5.1 -movflags +faststart  -c:a aac -b:a 320k  <outFile>.mp4|||

For the new DMFS, the correct CommandLine is

ffmpeg -y -i <inAVS> -itsoffset 0.0444 -i <inTempWav> -map 0:0 -map 1:0  -c:v libx264  -force_key_frames "expr:eq(mod(n,15),0)" -x264opts rc-lookahead=30:keyint=30:min-keyint=15 -pix_fmt yuv420p -crf 20 -preset slow -tune zerolatency -profile:v high -level:v 5.1 -movflags +faststart  -c:a aac -b:a 320k  <outFile>.mp4|||

In other words, simply replace

avs2pipemod -y4mp <inAVS>  | ffmpeg -y -f yuv4mpegpipe -i -

with

ffmpeg -y -i <inAVS>

Note that this change only affects Vegas versions 13-16. For V12 users and instances where only a 32bit filter is available such as the Defish filter for fisheye removal, the avs2pipemod syntax is still used.

BluRay Compatability. For anyone interested in BluRay compatability encoding using x264, here is a useful link. http://www.x264bluray.com/

Within HOS, I have used the following command line:

ffmpeg -y -i <inAVS> -c:v libx264  -pix_fmt yuv420p -b:v 35000k  -preset medium -tune film -level:v 4.1 --x264-params  bluray-compat --vbv-maxrate 40000 --vbv-bufsize 30000 --keyint 60 --open-gop --slices 4 --colorprim "bt709" --transfer "bt709" --colormatrix "bt709" --sar 1:1 -an  <outFile>.mp4

The commandline is only for a single pass and uses the "medium" preset rather than the recommended two-pass, "very slow" preset.

In testing I did awhile back, I found that the files produced could be successfully used without re-encoding in TMPGEnc Authoring Works 6 http://tmpgenc.pegasys-inc.com/en/product/taw6.html, but not DVD Architect.

Thanks Wayne.

...and I thought this thread was going to be superfluous.

Oh no, it's just getting warmed up. Leave your fluous at home.