Broadcasting 4k TV over ATSC 1.0 -- How??

We didn’t say it’d be easy

IEEE Madison, Feb 25th, 2025

Anton Kapela, Channel 3, Eugene - K03IM-D

CONTEXT

This talk is not about a translator, it’s a LP-D

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This talk is about how someone used mostly open source tools to get UltraHD programs working over ATSC 1.0

BUT REALLY…

This talk is about codecs

-

Our relationship with them

-

Human sense & perception

Glossary - Warning: buzzwords ahead!

• AVC: Advanced Video Coding, H.264 or MPEG-4 Part 10
• HEVC: High Efficiency Video Coding, H.265 and MPEG-H Part 2
• SSIM/SSIMPLUS: Structural similarity index measure, plus extensions matched to human subjective ratings
• CODEC: portmanteau of coder/decoder
• SPTS: single program transport stream
• MPTS: multi program transport stream
• PCR: Program Clock Reference
• PTS/DTS: Presentation/Decode Time Stamp
• GOP: group of pictures, usually all pictures between I/IDR frames
• MiniGOP: series of B frames between P frames (display order)
• CPB: Coded Picture Buffer
• DBP: Decoded Picture Buffer
• I/IDR: Intra-coded frame, depends on no other frames; “instantaneous decoder refresh” = intra coded frame + flush all prior frames in DBP
• UHD: Ultra HD resolution, ie. four panels of 1920x1080 = 3840x2160
• RTT: Round-trip time, usually referring to measured latency on a packet switched network
• HRD: A receiver buffering state anticipation model defined by a “hypothetical reference decoder”
• FGS: Film Grain Synthesis, encoder-directed, noise-like data inserted by decoder - similar to spectral band replication in HE-AAC, but for pictures

Past

Present

Future

Live

Demo

Past: How’d we get here?

Journey Into Wireless

1996

Garage Sale

1999/00

Aironet 900Mhz

2001

Ooh!

WiFi

2002

Mesh

Madison

2006+

Wireless

for real

Past: But Who is this Anton guy?

But Who is this Anton guy?

In The Beginning

Worked in/near A/V/IPTV for much of my career; data centers, ISPs, microwave, mobility networks, you name it: if it moves bits, I touch(ed) it

…But Mostly Ignored Broadcast!

Everything was great, until one day:

Happened to buy a UHD TV in 2020; nothing on the air besides MPEG2…

No ATSC 3 in Madison, and this dumb TV didn’t even support it!

…couldn’t let this stand; had to get something working with UHD resolutions

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But …

Can 19.3 megabits do anything visually interesting?

… with HEVC?

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And: Can anything DECODE HEVC over a normal Transport Stream (TS) … over the air (or cable)?

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Let’s get something working

• Small step: Buy cheap Dektec DVB-C modulator; test with SPTS, no frills goal: one audio + video PID + ffmpeg playout working

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• Takeaway: It works, but poorly, out of the box:
• Timing dynamics matter, rate shaping matters, GOP params really matter

A Starting Point for UHD - Rate Targets Circa 2020

Credit: https://codecalamity.com/encoding-settings-for-hdr-4k-videos-using-10-bit-x265/

Typical UHD rates

Bitrates we want

SSIM we want

19.39 mbit - ATSC 1.0 Phy Rate

Orienting the discussion - Human perception system

Let’s get something working

Oops

Oops

Real Lab: Figure It Out @ the datacenter

Setup a “personal cloud” to explore transcoding options in HEVC with x.265

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~750 GHz lets you figure it out with brute-force

Write programs to run through variations of 1000’s of these, compare results:

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Average Case: “Offline” transcode example - 10 bit, ~4.5mbit ABR/VBR:

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$ ffmpeg -fflags +discardcorrupt -ec guess_mvs+deblock+favor_inter -i input.mkv -vf'scale=3840:2160:force_original_aspect_ratio=decrease,�pad=3840:2160:-1:-1:color=black'-c:a ac3 -ac 2 -ar 48000 -c:v libx265 -preset medium -x265-params 'hdr-opt=1:repeat-headers=1:colorprim=bt2020:transfer=smpte2084:colormatrix=bt2020nc:master-display=G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(10000000,50):max-cll=3201,386:keyint=72:ref=5:bframes=3:b-adapt=2:bitrate=4000:vbv-maxrate=4500:vbv-bufsize=8000:merange=256:me=hex:no-open-gop=1:hrd=1:aq-mode=3:pmode=1:rect=1:rc-lookahead=36' -map_metadata -1 -map_chapters -1 output.mkv

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What does that look like?

~3 FPS

As good as it got in 2022/23: ~20-threads per node, latest-greatest x.265 library and Intel Xeon E5 v4 cpus, 3840x2160 main10

~70 watt/seconds per frame, per node

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Result:

squeezing non-noisy things beyond the visual rate floor: ~4.5 Mbits coded rate @2160

Ok, what about live HEVC UHD transcoding?

• Nothing commercially optimal for me: wanted good VBR at low bitrates, cheap, off the shelf
• First person to mention “but SVT or Mainconcept …” owes me a beer!
• Own integration: FOSS code, standard x86 parts, Nvidia GPU, CUDA/NVENC API

Micro ITX 1RU half depth case

Tiny 300W PS

Nvidia GPUs (nvenc, CUDA, npp offload)

i9 10k Extreme CPU

10c/20t

Legit OOB

and IPMI!

Standard copper gige for IP video I/O

Quad channel, lowest-latency supported DDR4

Hot-swap SATA bays

Rude blue LED power light

Custom kapton PCI-e ribbon adapter

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Magic: Live transcode NASA UHD to 10-bit SDR at ~4 Mbits VBR on GPU:

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while :; do ffmpeg -fflags +discardcorrupt -i udp://238.1.1.1:2000?fifo_size=400000\?overrun_nonfatal=1\&buffer_size=10000000 -map 0:i:4161 -map 0:i:4164 -vf fps=fps=30000/1001 -pix_fmt p010le -c:v hevc_nvenc -g 90 -preset p7 -b:v 3.2M -maxrate 4.5M -bufsize 8M -bf 2 -refs 5 -rc-lookahead 27 -weighted_pred 0 -b_ref_mode each -nonref_p 0 -spatial_aq 1 -temporal_aq 1 -aq-strength 8 -forced-idr 1 -strict_gop 1 -c:a copy -program title="NASA-4K":st=0:st=1 -color_primaries bt709 -color_trc bt709 -colorspace bt709 -f mpegts -mpegts_start_pid 160 -max_interleave_delta 200000 -muxpreload 2 -flush_packets 0 udp://224.2.2.254:1466?pkt_size=1316\&bitrate=8121600 ; sleep 1 ; done

*take a breath

All of the books in the world contain no more information than is broadcast as video in a single large American city in a single year. Not all bits have equal value.

• Carl Sagan

What’s in a CODEC, besides few bits?

Lies, approximations, exploits, and shortcuts.

Exploits

Exploits

Exploits

Q: What’s in a CODEC? A: Silencing (c. 2010)

Applied Silencing:

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Motion Vectors

Exhaustive motion estimation, coded pict: <20 Kbytes

Exhaustive motion estimation, coded pict: <10 Kbytes

Summary of Findings

Enablers for ultra-low rate HD/UHD

Absolutely Essential: to reach the visual-silencing-floor in HEVC, we need:

• Large coded picture buffer, with VBV HRD signaling
• Long & fully dynamic GoP construction
• Fully dynamic mode (I/B/P) decisions
• Exhaustive, full-frame motion search area + masking + silencing
• Mixed (B and P) reference frames for B and P frames
• Well, maybe not all B-frames (decoder trouble!) should be kept for references
• “Smart” bit allocation/rate distortion across the whole GoP and mini-GoPs
• Spatial + temporal + reference-aware Adaptive Quantizer (ie. “MB tree” and friends)

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Enablers for ultra-low rate HD/UHD

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These algorithmic mechanisms (in previous slide) have substantial compute/power cost, generally not fully exploited by OTT/streamers, and impractical at YouTube/etc scale. YouTube ingests >30,000 hours per hour of video in 2022: no time & power for bespoke encoding of everything.

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They are eminently practical for broadcast:

one screen target, one rate target, one program stream

​

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Some Just Can’t Even (do one stream)

Everyone gets their own thing!

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What does that look like, in 2025?

“LOL wut”

“LOL wut”

“LOL wut”

“LOL wut”

“LOL wut”

“LOL wut”

“LOL wut”

“LOL wut”

“LOL wut”

“LOL wut”

“LOL wut”

“LOL wut”

“LOL wut”

“LOL wut”

“LOL wut”

Thus, in OTA Broadcast:

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No side-by-side ABX → “is it wrong?”

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Don’t let perfect block good

Nitpicks

Nitpicks

Nitpicks

Nitpicks - or total breakdown? (NO FGS!)

Nitpicks - or total breakdown? (NO FGS!)

Nerdy Transport Stream Stuff

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Statistics & Mux Handling

Coded UHD pictures on the wire:

I-frame: ~50 to 150 Kilobytes

B-frame: <1 up to ~17 kbytes

P-frame: ~30 to 70 Kilobytes

Viewed another way… Presentation order & Reference weights

Props to Elecard StreamEye! →

So what’s the problem challenge of VBR streams?

• It’s just not nice to mix packetized elementary stream (PES) objects (ie. encoded video frames) that are >2 orders of mag different in size, into the same transport stream (TS), while holding a constant output rate, with competing programs, unless we do some special things in the multiplexer:�
• Hold just enough TS packets in input buffers
• “Smear” TS packets over time at defined output rate (~19,392,658 bits/sec for ATSC 1.0/8VSB)
• Dequeue packets using something like fair queue scheduling, with deficit-weighted round robin (FQ-DWRR) tracking
• Interpose TS packets from all streams in a mostly-PCR-position preserving manner
1. Absolute PCR timestamp values must be updated anyway - but we want to ensure “good spacing” and expected PCR density, as was originally inserted in the source program stream
• Try to ensure output DTS value is always greater than PCR value
• carefully manage rate sum from encoders, discard TS packets if we’re “under water”

TS packet timestamps on the wire:

Present: What’s Channel 3 up to?

K03IM-D Rundown

If it works on DVB-C, maybe it’ll also work over ATSC 1.0

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Just add: PSIP, TVCT, EAS switching

Channel 3 Broadcast System

Power Amp

Ant.

ADV-8300

Ethernet Switch

D2D 5220

Control systems & OAM terminals

ASI Monitoring

(Ineoquest IQ / ASI Cricket-A6x,

Nucomm ASI-IP)

Mask Filter

Ref In

GPS ant.

MPEG TS Mux

8VSB modulator

Enter: D2D Tech

After semi-exhaustive research, determined D2D Technologies has best price/perf/hackability ratio* (Linux inside!) for muxing & “finishing” (ie. PSIP, EIT, ETT, other ATSC 1 adornments): https://d2dtechnologies.com/d2flex5220/

Got to know Steve Doll and Jessica Colyer, agreed to “try supporting” more codecs in VBR modes

With mux hardware in hand, I:

1. Setup 8VSB/ATSC modulator & lab parts
2. Tested everything
3. Sent bug reports
4. Got new code
5. Goto #2

Caveats

• NOTE: The D2D 5220 mux is doing what FFmpeg, today in March 2024 cannot: generate PSIP stuff, robustly combine programs into a multi-program output TS composite, without “losing its mind” and halting all outputs when any single input is lost, etc.

​

• FFmpeg alone cannot generate a complete, ready-to-go, ATSC 1.0 MPTS appropriate for OTA broadcast

​

Where we started - Broken VBR

Initially, mux logic would simply drop TS packets that weren’t “within CBR rate estimate window” - oops!

Where we started - Broken VBR handling

Tried to ‘better constrain’ HEVC code rate to be “almost CBR” – still insufficient: I-frame bursts created gaps in TS output cadence. PCR packets spaced too far apart for most receivers to tolerate.

How to support VBR in MPTS?

• New (Thanks Steve!) rate estimation for input -> mux -> output routines
• We now only count TS bytes between PCRs
• Count TS packet bytes between TS with PCR, ignore input null padding, save system tick deltas between PCRs as a 64 bit integer: do math
• robust min/max/mean/sum of squares vs mean
• handily tolerates missing PCRs
• Output round-robin is 1/n portionally fair among buffered TS inputs
• Current algorithm now scales down to ~18 kbits/sec TS rates
• Can now reliably mux ultra-low rate video, audio-only, and ancillary low-speed data programming
• AAC ADTS 8 kb/s mode --> 23.1 kbits/s over TS, now works
• AC3 32 kb/s mode --> 45.1 kbits/s over TS, also now works

Where we are now - Robust VBR

Input Loss

Input Return

With new rate estimation logic, D2D mux properly transmits packets in a weighted-fair round robin scheme; PCR continuity within tolerances; perfect adaptation to input loss/restoration.

TS/PES pacing is preserved through mux: greater PES/NAL byte counts for I/IDR than B/P-frames reveals corresponding “gaps” of PTS in time, while retaining consistent PCR intervals: receiver remains phase locked + Rx slack buffer managed (ie. PCR < PTS/DTS)

Where we are now - Robust VBR

Input Loss

Input Return

Where we are now - Robust When Maxed Out

Oversubscribed mux rate is fine, within limits

If PTS/DTS greater than PCR timestamp value, we’re fine. Note PCR cleanly “linear” (despite interval variance) while DTS/PTS delta “wanders” due to momentary mux queue depth. Long term VBR encoder control ensures DTS/DTS > PCR (ie. pictures can’t “happen” before current time in PCR).

Where we are now - Maxed Out 4x UHD progs

Hurdle: Cleared, next:

Take this on the road:

• Landed on K03IM-D, Eugene, OR

https://www.rabbitears.info/market.php?request=print_station&facility_id=185855

https://enterpriseefiling.fcc.gov/dataentry/public/tv/publicFacilityDetails.html?facilityId=185855

• Find content networks (TCN, Funroads, etc.), negotiate

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Channel 3 Eugene Photo Gallery: https://imgur.com/a/IyNAxlz

Program Flow: ~2100 miles, ~53 Msec RTT

Madison Datacenter

K03IM-D Xmitter

Internets

Cool site pics

Cool site pics

Cool site pics

What about measurements/performance?

L/R & Contours

Mux Feb 2024, 14 programs

More Mux Pics

PCR Off Air Stats: Not bad!

PCR Off Air Stats: Not bad!

PCR From FFMPEG: Actually Perfect

Feedback from the field

Other subtle adjustments for “good display compatibility” with VBR-style AVC and HEVC:

• MPTS “transport buffering” burst-spreading is constrained by PCR to DTS/PTS delay - usually too small in most encoders & multiplexers
• Is the “DVB default” of ~750 msec really the limit? No: up to ~2000 msec actually works on every HEVC display/decoder tested!
• ~1700 msec seems more compatible with some AVC and MPEG2 video decoders
• Limiting HEVC reference frames - seems like 5 is workable everywhere, 7+ for a few
• AVC decoders seem “stuck” at 4 refs, even on latest-gen UHD/HEVC-supporting TVs

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Back To

The

Future!

What’s next?

• Supporting Intermittent .2’s, direct program bcast from cell phone -> air
• Larix Broadcaster, OBS, others
• Ultra-dense music programming (HE-AACv2, EAC3), “slow TV”
• Fast-flux programming: subchannels may appear, disappear, change, at various timescales: minutes, hours, days
• “Configuration as code”
• Ad or Program Insertion On Steroids
• Datacasting integration: add support for Automatic Multicast Tunneling (AMT)
• Engage “flash crowd” video offloading from Internet CDNs to broadcasters
• We can get paid to haul IP packets over Multiprotocol Encapsulation (MPE) over TS packets!
• AI/ML methods to enhance AVC, HEVC, and other codecs
• “Mostly real” - fully exhaustive comparison of all regions of all frames within a program, movie, etc.

Enablers for ultra-low rate HD/UHD Cont.

Channel 3 Refinement wishlist:

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• Efficient hierarchical motion estimation in HEVC

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• Flexible direct and synthetic prediction modes (ie. “grain simulation” and vector graphics)
• Open x.265 added FGS SEI signalling in v3.6, 4th April, 2024!
• GET WITH IT NVIDIA, Geez!

Does the world really need *another* mux/transcoder/router?

• Yes
• Ground-up rethinking
• Written in Go
• Doing real-time stuff on non-real-time systems
• Channel 3 supports development
• Spinoff to launch as Envelope Inc.

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Questions?

tkapela@gmail.com

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Appendix A

FFMPEG notes & etc

RX stream from an SRT source, relay back out to mcast, output connection stats every 4000 msec, using fairly robust options - 2000 msec ARQ time to live, 2100 msec fixed sender/receiver latency, sender buffer allocation 10 megabytes, and overhead bandwidth of 100%

while :; do srt-live-transmit -s 4000 "srt://source.host.net:1234?mode=caller&latency=2100&lossmaxttl=2000&&sndbuf=10000000&oheadbw=100" udp://233.65.202.50:1234 ; sleep 1 ; done

Pulling from YT live source, conforming to 720p at lowest-possible bcastable frame rate of 23.976, low-bitate target

while :; do yt-dlp --socket-timeout 6 https://www.youtube.com/watch?v=xxxx -f best -o - | mbuffer -q -W 32 -m 64k | ffmpeg -xerror -async 1 -re -i - -map 0:0 -map 0:1 -c:a ac3 -ab 96k -cutoff 18000 -ac 2 -ar 48000 -vf "minterpolate=fps=24000/1001:mi_mode=blend" -fps_mode cfr -c:v libx264 -g 72 -rc-lookahead 48 -preset veryslow -tune animation -b:v 400K -nal-hrd vbr -maxrate:v 1.5M -bufsize 1.5M -me_method umh -me_range 64 -refs 4 -bf 4 -aq-mode 3 -aq-strength 0.9 -qcomp .1 -flags +loop+qpel+cgop -map_metadata -1 -map_chapters -1 -f mpegts -flush_packets 0 udp://233.65.202.201:1234?pkt_size=1316 ; sleep 1 ; done

Listening to a mcast source, connecting to remote host via TCP, relaying A/V stream to target host

while :; do ffmpeg -i udp://233.65.202.201:1234 -c copy -f mpegts -flush_packets 0 tcp://10.0.3.2:1423?pkt_size=3008 ; sleep 1 ; done

Relaying a unicast TSoTCP stream in a CBR TS, to another TS mux, via unicast UDP

while :; do ffmpeg -fflags +genpts+discardcorrupt -i tcp://:1490?listen=1\&listen_timeout=10000\&timeout=20000000 -map 0:v -map 0:a -c:v copy -c:a copy -program title=Some Program Name:st=0:st=1 -f mpegts -mpegts_start_pid 300 -flush_packets 0 -muxdelay 1.7 -max_interleave_delta 200000 -muxrate 2000320 -pcr_period 70 udp://10.0.3.19:1402?pkt_size=1316\&bitrate=2000320\&fifo_size=40000\&overrun_nonfatal=1 ; sleep 1 ; done

Rx a slice-encoded (note: single decoder thread to avoid race conditions) 1080i program from mcast source, convert to 10 bit non-subsampled chroma, deinterlace/etc, convert back to yuv420 subsampled, force constant frame rate at 29.97, normalize audio level to ~-6 dBfs peak, various x.264 adjustments tuning encoder for “talking head” news programming; note custom quantizer matrix, output encoded stream towards mcast destination

while :; do ./ffmpeg-6.1-amd64-static/ffmpeg -xerror -async 1 -threads:v 1 -i udp://233.65.202.50:1234?fifo_size=200000\&overrun_nonfatal=1\&reuse=1\&timeout=900000000\&buffer_size=10000000 \

-vf format=yuv444p10le,yadif=mode=0:deint=all,format=yuv420p,fps=fps=30000/1001 \

-fps_mode cfr \

-map 0:v:0 -map 0:a:0 \

-af "dynaudnorm=p=.25" \

-c:a ac3 -ac 2 -ab 96k -ar 48000 -cutoff 18000 \

-c:v libx264 -g 90 -preset veryslow -b:v 1M -maxrate:v 2M -bufsize 2M -refs 4 -bf 4 \

-aq-mode 3 -aq-strength 0.90 -b_qfactor 1.0 -b_qoffset 0.0 -qcomp 0.3 \

-dc 9 -subq 10 -weightp 2 -weightb 1 -bidir_refine 4 -mixed-refs 1 \

-8x8dct 1 -partitions all -direct-pred auto -nal-hrd vbr \

-rc-lookahead 30 -me_range 64 -me_method umh -trellis 2 -b_strategy 2 -b-pyramid 2 \

-fast-pskip 0 -flags +qpel+loop+cgop \

-intra_matrix "8,8,9,9,10,10,11,11,8,9,9,10,10,11,11,12,9,9,10,10,11,11,12,12,9,10,10,11,11,12,13,13,10,10,11,11,12,13,13,14,10,11,11,12,13,13,14,15,11,11,12,13,13,14,15,15,11,12,12,13,14,15,15,16" \

-inter_matrix "8,8,9,9,10,10,11,11,8,9,9,10,10,11,11,12,9,9,10,10,11,11,12,12,9,10,10,11,11,12,13,13,10,10,11,11,12,13,13,14,10,11,11,12,13,13,14,15,11,11,12,13,13,14,15,15,11,12,12,13,14,15,15,16" \

-f mpegts -max_interleave_delta 0 -flush_packets 0 udp://233.65.202.15:1234?pkt_size=1316 ; sleep 1 ; done

Pick a random file from a list of files matching a pattern, transcode this file at native playback rate, keeping multichannel audio intact (or conform to 6 chan/5.1 layout); conform all output to 1440x1080 at 4:3 aspect ratio, stop muxing when audio or video inputs have no more data (-shortest), to ensure output a/v pids of matching lengths; restart a/v PTS’s from zero, and signal an explicit TS discontinuity to inform receivers that a new TS is starting

IFS=$'\n' ; while :; do for i in `find "/mnt/space3/blah/" -name "*.mkv" -type f |shuf` ; do \

./ffmpeg-6.1-amd64-static/ffmpeg -fflags +discardcorrupt \

-ec guess_mvs+deblock+favor_inter -err_detect ignore_err \

-readrate_initial_burst 4 -async 1 -re -i "$i" \

-fps_mode cfr -map 0:v -map 0:a \

-ar 48000 -c:a eac3 -b:a 192k -cutoff 18000 -ac 6 -channel_layout "5.1" \

-color_primaries 1 -color_trc 1 -colorspace 1 \

-c:v libx264 -g 72 -preset veryslow -b:v 0.9M -maxrate:v 2M -bufsize 2M -refs 4 -bf 4 \

-psy-rd 1.1:0.5 -deblock -5:-3 -tune grain -b_qfactor 1.0 -b_qoffset 0.0 \

-dc 9 -subq 7 -weightp 2 -weightb 1 -aq-mode 3 -aq-strength 0.80 -qcomp 0.4 \

-mixed-refs 1 -8x8dct 1 -partitions all -direct-pred auto -nal-hrd vbr \

-rc-lookahead 36 -me_range 64 -me_method umh -trellis 2 -b_strategy 2 \

-b-pyramid 2 -bidir_refine 2 -fast-pskip 0 \

-flags +qpel+loop \

-intra_matrix "8,8,8,9,8,9,11,11,11,11,11,11,13,12,13,13,13,13,13,13,13,13,13,13,13,14,14,14,17,17,17,13,13,13,14,13,15,15,16,16,17,17,18,16,18,17,17,17,17,19,19,20,20,20,24,24,23,23,28,28,29,34,34,41" \

-inter_matrix "8,8,9,9,10,10,11,11,8,9,9,10,10,11,11,12,9,9,10,10,11,11,12,12,9,10,10,11,11,12,13,13,10,10,11,11,12,13,13,14,10,11,11,12,13,13,14,15,11,11,12,13,13,14,15,15,11,12,12,13,14,15,15,16" \

-vf "fps=24000/1001,format=yuv444p10le,atadenoise,setpts=PTS-STARTPTS,\

scale=iw*sar:ih:flags=lanczos,setsar=1,\

scale=1440:1080:force_original_aspect_ratio=decrease:flags=lanczos,\

pad=1440:1080:-1:-1:color=black,setsar=1,setdar=4/3,format=yuv420p" \

-af "asetpts=PTS-STARTPTS,volume=+3dB" \

-map_metadata -1 -map_chapters -1 \

-f mpegts -flush_packets 0 -shortest -mpegts_flags initial_discontinuity udp://233.6.2.9:1090?pkt_size=1316 \

; done ; done

Ultra-low-rate mpeg2 video encoding, targeting 1.1 mbits/sec for 16:9 720x480p - note for super-low rates, variable length coding table 0 (vlc) is recommended. We convert to non-subsampled 10 bit 4:4:4 chroma for deinterlacing, noise reduction, and scaling - ie. example assumes input is 1080i, lowrez progressive out. Max motion vector search area at 511 pixels. Set spatial and temporal masking to bias quantizer upwards for higher motion and higher complexity areas, leaving more bits for gradients/smooth areas. Less banding, more reduction on details that won’t be visible to most viewers.

while :; do ./ffmpeg-6.1-amd64-static/ffmpeg -threads 16 -fflags +discardcorrupt -ec guess_mvs+deblock+favor_inter -async 1 \

-i http://208.66.132.245:5004/auto/v15.1?overrun_nonfatal=1 \

-map 0:v:0 -map 0:a:0 \

-c:a ac3 -ac 2 -ab 96k -ar 48000 -cutoff 18000 \

-vf "format=yuv444p10le,yadif=mode=0:deint=all,fps=fps=30000/1001,\

hqdn3d=3:3:3:3,scale=720x480:flags=lanczos+accurate_rnd,\

hqdn3d=2:2:2:2,format=yuv420p" \

-fps_mode cfr \

-c:v mpeg2video -threads 16 -me_range 511 -intra_vlc 0 \

-tcplx_mask 0.3 -scplx_mask 0.2 -qcomp 0.06 \

-cmp satd -subcmp satd -mbcmp satd -dct int -idct int \

-qmin 2 -qmax 200 \

-trellis 0 -keyint_min 8 -g 60 -bf 3 -b_strategy 2 -brd_scale 2 -bidir_refine 2 -border_mask 2.0 \

-b:v 1.1M -maxrate 4M -bufsize 4M -dc 9 \

-intra_matrix "8,8,8,9,8,9,11,11,11,11,11,11,13,12,13,13,13,13,13,13,13,13,13,13,13,14,14,14,\

17,17,17,13,13,13,14,13,15,15,16,16,17,17,18,16,18,17,17,17,17,19,19,20,20,20,24,24,23,23,28,28,29,34,34,41" \

-inter_matrix "8,8,8,8,8,8,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,10,10,10,10,10,10,10,\

10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,11,11,11,11,11,11,11,11,11,12" \

-f mpegts -flush_packets 0 udp://233.65.202.151:1234?overrun_nonfatal=1\&pkt_size=1316 ; sleep 1 ; done