Aegisub - YUV4MPEG: video is not in a supported format

[riffraff11235]

I'm trying my hand at editing/typesetting with Aegisub, and so far I've had no issues. But when trying to open a particular .mkv file, I get this error message:

Could not open [Filename]
YUV4MPEG: video is not in a supported format
FFmpegSource: Unknown video color space

I've tried some solutions I've found on this website and elsewhere, from installing LAV filters to running the file through MkvToolNix, but nothing seems to work. Is there something I can change within Aegisub to make this work? I should also mention that FFmpegSource is the only video provider that appears within Aegisub's advanced video settings. Any help is greatly appreciated.

[davexnet]

Use Mediainfo to see what it says about the files color sub-sampling

[riffraff11235]

Use Mediainfo to see what it says about the files color sub-sampling

Mediainfo says it's 4:4:4.

That's another thing I noticed: in MkvToolNix the header editor said that a bunch of the data fields regarding color were blank, but in Mediainfo they're all populated.

[riffraff11235]

I tried remuxing the file with Avidemux into a version with 4:2:0 color sub-sampling, and Aegisub is able to open that one. I'd still like to find a way to have Aegisub open the original, though. I don't want to have to go through this rigamaroll every time a similar file comes up.

[davexnet]

May I ask, what is the source of these 4:4:4 files ? Your camera? If it's possible please post
A small sample here in the thread

[riffraff11235]

May I ask, what is the source of these 4:4:4 files ? Your camera? If it's possible please post
A small sample here in the thread

I believe it was ripped from a Blu-Ray. I'm not sure how much more I can say without breaking forum rules. I managed to snip off a small sample that reproduces the same error when I try to open it in Aegisub. Would it be ok for me to upload it?

[davexnet]

Yes, small samples are fair use -
it's my understanding even UHD blu-ray sticks to the 4:2:0 chroma

[riffraff11235]

Yes, small samples are fair use -
it's my understanding even UHD blu-ray sticks to the 4:2:0 chroma

Yeah, all of the similar .mkv files I've dealt with seem to have 4:2:0 chroma, except for this one. The source says it was taken from a UHD Blu-Ray and downscaled to 1080p 4:4:4. I've included a ~2 min sample. Also, here's the MediaInfo dump for the video track in case it helps:

Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High 4:4:4 Predictive@L5
Format settings                          : CABAC / 16 Ref Frames
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 16 frames
Codec ID                                 : V_MPEG4/ISO/AVC
Duration                                 : 1 h 35 min
Bit rate                                 : 4 914 kb/s
Width                                    : 1 920 pixels
Height                                   : 816 pixels
Display aspect ratio                     : 2.35:1
Frame rate mode                          : Constant
Frame rate                               : 23.976 (24000/1001) FPS
Color space                              : YUV
Chroma subsampling                       : 4:4:4
Bit depth                                : 10 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.131
Stream size                              : 3.29 GiB (59%)
Title                                    : UHD to 1080p 4:4:4
Writing library                          : x264 core 163 r3078M 72c3504 (DJATOM's mod)
Encoding settings                        : cabac=1 / ref=16 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=10 / psy=1 / fade_compensate=0.72 / psy_rd=0.80:0.20 / mixed_ref=1 / me_range=24 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-1 / threads=16 / lookahead_threads=3 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=16 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=24 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=crf / mbtree=1 / crf=14.0000 / qcomp=0.72 / qpmin=0 / qpmax=81 / qpstep=4 / ip_ratio=1.40 / aq=3:0.80
Language                                 : Japanese
Default                                  : Yes
Forced                                   : No
Color range                              : Limited
Color primaries                          : BT.2020
Transfer characteristics                 : BT.2020 (10-bit)
Matrix coefficients                      : BT.2020 non-constant

[davexnet]

Thanks for the sample. I wonder what the idea was to encode it that way? Wouldn't play properly on my Chromecast nor natively in the LG
TV via DLNA. I don't think you're going to have any choice except convert it for your subtitle program

[riffraff11235]

Thanks for the sample. I wonder what what idea was to encode it that way? Wouldn't play properly on my Chromecast nor natively in the LG
TV via DLNA. I don't think you're going to have any choice except convert it for your subtitle program

Huh, more strangeness. It's played fine on every player I've tried on my computer, including MPC-HC, VLC, mpv and avidemux. Downgrading the chroma subsampling when I remuxed did have the added bonus of reducing the video stream size a little, so there's that I guess. Would still be nice if this gets resolved in some future release of Aegisub.

[davexnet]

Thanks for the sample. I wonder what what idea was to encode it that way? Wouldn't play properly on my Chromecast nor natively in the LG
TV via DLNA. I don't think you're going to have any choice except convert it for your subtitle program

Would still be nice if this gets resolved in some future release of Aegisub.

I wouldn't hold my breath, it hasn't been updated in almost 4 years. 4:4:4 is just not used in consumer video
(if I'm wrong about this I'm sure somebody will correct me)

[riffraff11235]

I wouldn't hold my breath, it hasn't been updated in almost 4 years. 4:4:4 is just not used in consumer video
(if I'm wrong about this I'm sure somebody will correct me)

It seems like someone forked it here. Last build was released this past October. Just noticed that they have a Discord. I'll try asking about the issue there.

[davexnet]

Thanks for the update. Let us know how it turns out

[Norberto!]

Hi all, I think I have the same problem.
Aegisub gives me this message when I try to upload a video:
"yuv4mpeg: video is not in a supported format. FFmpegSource: unknown video color space"
Does anyone know what to do to fix the problem?
T.I.A.