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M1 builds struggling playback with 4K HEVC content
Posted: 07 Mar 2021 12:23
by eXhumer
I tried to playback the same video (4K HEVC) on both the Intel build and the native ARM build on Mac mini. Funnily enough, Intel build was able to playback the video without issue. The native ARM build however was experiencing stutters/grey screens/audio cutouts during playback. Both downloaded straight from VLC website. Is this software bug that needs to be fixed, or is this user error?
Intel Build Video Output
M1 Build Video Output
Re: M1 builds struggling playback with 4K HEVC content
Posted: 08 Mar 2021 11:42
by fkuehne
This is unexpected. Please provide media-info output for the sample file.
Re: M1 builds struggling playback with 4K HEVC content
Posted: 09 Mar 2021 09:01
by eXhumer
I excluded the subtitle stream information from the output as I was reaching the post character limit.
Code: Select all
General
Unique ID : 56894977862465882574635961795040070247 (0x2ACD92FBD3697A576A3E7A8D4A8D4A67)
Complete name : REDACTED.mkv
Format : Matroska
Format version : Version 4
File size : 4.13 GiB
Duration : 36 min 14 s
Overall bit rate : 16.3 Mb/s
Encoded date : UTC 2020-08-21 06:38:26
Writing application : mkvmerge v48.0.0 ('Fortress Around Your Heart') 64-bit
Writing library : libebml v1.4.0 + libmatroska v1.6.0
Video
ID : 1
Format : HEVC
Format/Info : High Efficiency Video Coding
Format profile : Main 10@L5.1@Main
Codec ID : V_MPEGH/ISO/HEVC
Duration : 36 min 14 s
Bit rate : 15.5 Mb/s
Width : 3 840 pixels
Height : 2 160 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 50.000 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 10 bits
Bits/(Pixel*Frame) : 0.037
Stream size : 3.93 GiB (95%)
Default : Yes
Forced : No
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Audio
ID : 2
Format : E-AC-3 JOC
Format/Info : Enhanced AC-3 with Joint Object Coding
Commercial name : Dolby Digital Plus with Dolby Atmos
Codec ID : A_EAC3
Duration : 36 min 14 s
Bit rate mode : Constant
Bit rate : 768 kb/s
Channel(s) : 6 channels
Channel layout : L R C LFE Ls Rs
Sampling rate : 48.0 kHz
Frame rate : 31.250 FPS (1536 SPF)
Compression mode : Lossy
Stream size : 199 MiB (5%)
Title : English [Original]
Language : English
Service kind : Complete Main
Default : Yes
Forced : No
Complexity index : 16
Number of dynamic objects : 15
Bed channel count : 1 channel
Bed channel configuration : LFE
Re: M1 builds struggling playback with 4K HEVC content
Posted: 09 Mar 2021 11:40
by fkuehne
Excellent, thanks for the details! I had to return the DTK last week so I'm without a M1 Mac for now to test myself.
Could you add a VLC debug log? To create, open the Messages panel from the Window menu before starting playback and then just save the output after playing a few frames with the distortion.
Thanks again!
Re: M1 builds struggling playback with 4K HEVC content
Posted: 09 Mar 2021 12:36
by eXhumer
Full log as requested with the filename of the playback file being replaced by REDACTED.
https://gist.github.com/eXhumer/e85a3bc ... e3ef41a901
Re: M1 builds struggling playback with 4K HEVC content
Posted: 09 Mar 2021 12:48
by fkuehne
OK, as I feared we fail to enable hardware decoding on the M1:
videotoolbox warning: unknown vt session error (-6)
This needs to be debugged with an actual M1 device.
Thank you for your help!