Firecore says ATV 4th gen can direct play HEVC up to 20mb/s bitrate. I'm having playback issues at around 8000kb/s video bitrate

Hardware - Apple TV 4th Generation
tvOS - Infuse Pro 5.6.3
Connection - 5ghz WIFI at 179mbps (tvOS speedtest app)
Problem - HEVC playback issues at 8197 kb/s video bitrate (highest HEVC I have tested - prior HEVC media was 3000 kb/s maximum with smooth playback. I was told by staff that HEVC on ATV 4th gen can direct play up to 20mb/s bitrate video. I want to know why I am having issues.

MediaInfo
General
Unique ID : 200288164977247418182362362970998163772 (0x96AE18F21069623584DB3B8B0771C93C)
Complete name : H:\Downloads\1Filebot\Zero Days (2016)\Zero Days (2016).mkv
Format : Matroska
Format version : Version 4 / Version 2
File size : 7.05 GiB
Duration : 1 h 54 min
Overall bit rate : 8 849 kb/s
Movie name : Zero Days
Encoded date : UTC 2017-01-07 13:55:01
Writing application : mkvmerge v9.7.1 (‘Pandemonium’) 64bit
Writing library : libebml v1.3.4 + libmatroska v1.4.5
Cover : Yes
Attachments : cover.jpeg

Video
ID : 1
Format : HEVC
Format/Info : High Efficiency Video Coding
Format profile : Main 10@L4@Main
Codec ID : V_MPEGH/ISO/HEVC
Duration : 1 h 54 min
Bit rate : 8 197 kb/s
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 23.976 (24000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 10 bits
Bits/(Pixel*Frame) : 0.165
Stream size : 6.53 GiB (93%)
Title : Hevc
Writing library : x265 2.2+17-a2fe29ca5c6c:[Windows][MSVC 1910][64 bit] 10bit
Encoding settings : cpuid=1173503 / frame-threads=3 / numa-pools=8 / wpp / no-pmode / no-pme / no-psnr / no-ssim / log-level=2 / input-csp=1 / input-res=1920x1080 / interlace=0 / total-frames=164069 / level-idc=0 / high-tier=1 / uhd-bd=0 / ref=4 / no-allow-non-conformance / no-repeat-headers / annexb / no-aud / no-hrd / info / hash=0 / no-temporal-layers / open-gop / min-keyint=23 / keyint=250 / bframes=8 / b-adapt=2 / b-pyramid / bframe-bias=0 / rc-lookahead=120 / lookahead-slices=4 / scenecut=40 / no-intra-refresh / ctu=32 / min-cu-size=8 / no-rect / no-amp / max-tu-size=16 / tu-inter-depth=4 / tu-intra-depth=4 / limit-tu=3 / rdoq-level=2 / signhide / no-tskip / nr-intra=0 / nr-inter=0 / no-constrained-intra / no-strong-intra-smoothing / max-merge=3 / limit-refs=3 / limit-modes / me=3 / subme=5 / merange=44 / temporal-mvp / weightp / weightb / no-analyze-src-pics / deblock=-3:-3 / no-sao / no-sao-non-deblock / rd=4 / no-early-skip / no-rskip / no-fast-intra / no-tskip-fast / no-cu-lossless / b-intra / rdpenalty=0 / psy-rd=2.50 / psy-rdoq=10.00 / no-rd-refine / analysis-mode=0 / no-lossless / cbqpoffs=-3 / crqpoffs=-3 / rc=crf / crf=20.5 / qcomp=0.65 / qpstep=4 / stats-write=0 / stats-read=0 / ipratio=1.40 / pbratio=1.20 / aq-mode=2 / aq-strength=1.00 / cutree / zone-count=0 / no-strict-cbr / qg-size=16 / no-rc-grain / qpmax=69 / qpmin=0 / sar=0 / overscan=0 / videoformat=5 / range=0 / colorprim=2 / transfer=2 / colormatrix=2 / chromaloc=0 / display-window=0 / max-cll=0,0 / min-luma=0 / max-luma=1023 / log2-max-poc-lsb=8 / vui-timing-info / vui-hrd-info / slices=1 / opt-qp-pps / opt-ref-list-length-pps / no-multi-pass-opt-rps / scenecut-bias=0.05 / no-opt-cu-delta-qp / no-aq-motion
Default : Yes
Forced : No

Audio
ID : 2
Format : AAC

Issue - Video stops and starts, while audio continues playing. Video catches back up after ~5-15 seconds, and process repeats intermittently throughout the remainder of the film.

I have had no issues direct playing x264 files up to bitrate of 15mb/s (I haven’t tested higher bitrates). I read on a forum post from a staff member that the 4th Gen Apple TV.

Any guess why this is happening?

Just out of curiosity, have you tried an Ethernet connection? I know your tests showed that you should have the wireless speed but wifi can be a real bag of voodoo and it may be just on the edge of working.

Unfortunately, HEVC has very limited support on the Apple TV 4 as the A8 chip does not include hardware decoding support for HEVC.

In our tests, we’ve been able to play some 1080p with bitrates right around 20 Mbps. However, these videos were 8bit, and I see that this particular video is 10bit. Playing 10bit videos will lower the threshold quite a bit, and unfortunately it’s likely this particular sample is simply beyond what the Apple TV 4 hardware is capable of.

If you have a lot of these videos you wish to play, I’d recommend looking at upgrading to an Apple TV 4K as this will play just about any HEVC video you can find.

Thank you for the clarification about the 10bit vs 8bit differences and chip performance. I’m glad that info is now on my radar. I tested the same file on an ATV 4k in another room which handles this HEVC encode and others just fine. Keep up the great work with Infuse! I love it.

1 Like

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.