MediaInfo CodecID and MaxSlicesCount mismatch on recently captured FFV1 files

[BleakleyMcD]

QC against MediaInfo is failing on freshly captured files. The CodecID is being reported in the Matroska-native form rather than the expected VFW/FOURCC form, and the FFV1 slice count is 4 instead of the expected 24.

MediaInfo output from QC:
Some specified MediaInfo fields or values are missing or don't match:
Metadata field CodecID has a value of: V_FFV1
The expected value is: V_MS/VFW/FOURCC / FFV1
Metadata field MaxSlicesCount has a value of: 4
The expected value is: 24

JPC_AV_03796_capture_options.log

computer_name: Mac-68
computer_model_name: Mac mini
computer_model_id: Mac16,10
computer_processor_name: 
computer_processor_speed: 
computer_processor_count: 
computer_memory: 16 GB
computer_serial: RL4K4FXKGK
computer_cores: 10
user_name: digitizer_a
operating_system_VERSION: Darwin Kernel Version 24.3.0: Thu Jan  2 20:22:58 PST 2025; root:xnu-11215.81.4~3/RELEASE_ARM64_T8132
vrecord version: 2026-03-02
datetime_start: 2026-06-01T13:36:43
capture_device_node: /dev/disk3
capture_device_protocol: Apple Fabric
capture_device_name: APPLE SSD AP0256Z
capture_device_block_size: 4096 Bytes
capture_device_location: Internal
capture_device_partition_type: 41504653-0000-11AA-AA11-00306543ECAC
capture_device_partition_name: APFS
capture_device_volume_uuid: DC2C1AD8-D4FF-4D36-9376-524CB49BE049
capture_device_volume_available: 
capture_device_volume_total: 
FILE_PATH: /Users/digitizer_a/Desktop/Ingestion/JPC_AV_03796/JPC_AV_03796.mkv
video_card_name: UltraStudio 4K Mini
VIDEO_INPUT_CHOICE: Composite
AUDIO_INPUT_CHOICE: Analog
VIDEO_BIT_DEPTH_CHOICE: 10 bit
AUDIO_MAPPING_CHOICE: 2 Stereo Tracks (Channels 1 & 2 -> 1st Track Stereo, Channels 3 & 4 -> 2nd Track Stereo)
STANDARD_CHOICE: NTSC
ASPECT_RATIO_CHOICE: 4/3
NTSC_43_SAR_CHOICE: 10/11
NTSC_169_SAR_CHOICE: 40/33
PAL_43_SAR_CHOICE: 12/11
PAL_169_SAR_CHOICE: 16/11
WAVEFORM_SCALE_CHOICE: digital
SIGNAL_VIEW_CHOICE: Broadcast Range
SIGNAL_INT_CHOICE: auto
MONITOR_AUDIO_CHOICE: Yes
PLAYBACKVIEW_CHOICE: Audio + Video
CONTAINER_CHOICE: Matroska
VIDEO_CODEC_CHOICE: FFV1 version 3
AUDIO_CODEC_CHOICE: 24-bit FLAC
QCTOOLSXML_CHOICE: No
EMBED_LOGS_CHOICE: No


TECHNICIAN: Colley, Tom
Record command: /opt/homebrew/bin/ffmpeg-ma -nostdin -nostats -timecode_format all -guess_layout_max 0 -loglevel warning -f decklink -signal_loss_action none -audio_input analog -video_input composite -format_code ntsc -channels 8 -audio_depth 32 -raw_format yuv422p10 -i UltraStudio 4K Mini -c:v ffv1 -level 3 -g 1 -slicecrc 1 -c:a flac -sample_fmt s32 -bits_per_raw_sample:a 24 -map_metadata 0:s:v:0 -metadata:s:v:0 encoder=FFV1 version 3 -metadata creation_time=now -filter_complex [0:v:0]setparams=range=limited:color_primaries=smpte170m:color_trc=bt709:colorspace=smpte170m:field_mode=auto,setsar=10/11,readeia608=lp=1:spw=0.27,metadata=mode=print:key=lavfi.readeia608.0.cc:file=/tmp/vrecord.34bJki.eia608.txt[vout];[0:a:0]asplit[orig],pan=stereo| c0=c0 | c1=c1[stereo1];[0:a:0]pan=stereo| c0=c2 | c1=c3[stereo2] -map [vout] -map [orig] -map [stereo1] -map [stereo2] -f tee [f=matroska:select=v,a\\:1,a\\:2]/Users/digitizer_a/Desktop/Ingestion/JPC_AV_03796/JPC_AV_03796.mkv|[f=nut:onfail=abort:select=v,a\\:1,a\\:2,a\\:0]pipe:1 -an -f framemd5 /Users/digitizer_a/Desktop/Ingestion/JPC_AV_03796/JPC_AV_03796.framemd5
Playback command: /opt/homebrew/bin/ffplay-ma -v info -hide_banner -stats -autoexit -window_title mode:record - video:'composite' audio:'analog' - to end recording press q, esc, or close video window -f lavfi amovie='pipe\:0':streams=dv+da[vid][aud],    [aud]asplit=2[original_audio][audio_to_map];[audio_to_map]pan=4c|c0=c0|c1=c1|c2=c2|c3=c3[out1];    [original_audio]showvolume=t=0:dm=5400:rate=30000/1001,drawtext=fontfile=/System/Library/Fonts/Supplemental/Andale Mono.ttf:text='L(1)':fontcolor=white:fontsize=18:x=0:y=0,drawtext=fontfile=/System/Library/Fonts/Supplemental/Andale Mono.ttf:text='R(1)':fontcolor=white:fontsize=18:x=0:y=20,drawtext=fontfile=/System/Library/Fonts/Supplemental/Andale Mono.ttf:text='L(2)':fontcolor=white:fontsize=18:x=0:y=40,drawtext=fontfile=/System/Library/Fonts/Supplemental/Andale Mono.ttf:text='R(2)':fontcolor=white:fontsize=18:x=0:y=60[aud2];    [vid]split=5[a][b][c][d][e];    [a]copy[a1];    [b]field=top,    format=yuv422p,    waveform=scale=digital:intensity=0.1:mode=column:mirror=1:c=1:f=lowpass:e=instant:graticule=green:flags=numbers+dots[b1];    [c]field=bottom,    format=yuv422p,    waveform=scale=digital:intensity=0.1:mode=column:mirror=1:c=1:f=lowpass:e=instant:graticule=green:flags=numbers+dots[c1];    [d]    format=yuv422p,    vectorscope=i=0.04:mode=color2:c=1:envelope=instant:graticule=green:flags=name,    scale=512:512,    drawbox=w=9:h=9:t=1:x=128-3:y=512-452-5:c=sienna@0.8,    drawbox=w=9:h=9:t=1:x=160-3:y=512-404-5:c=sienna@0.8,    drawbox=w=9:h=9:t=1:x=192-3:y=512-354-5:c=sienna@0.8,    drawbox=w=9:h=9:t=1:x=224-3:y=512-304-5:c=sienna@0.8,    drawgrid=w=32:h=32:t=1:c=white@0.1,    drawgrid=w=256:h=256:t=1:c=white@0.2[d1];    [e]scale=512:ih,signalstats=out=brng[e1];    [a1][b1][c1][e1][d1]xstack=inputs=5:layout=0_0|0_h0|0_h0+h1|w0_0|w0_h0[vidstack];    [vidstack][aud2]overlay=10:10:format=yuv444[out0]
Record exit code: 224
Playback exit code: 0
datetime_end: 2026-06-01T13:42:03
PTS_DISCONTINUITY: none
mediaconch_outcome: passed

no -slices in the ffmpeg command... so does it default to 4?? vrecord nixed setting the slices....

[dericed]

There was a brief discussion about this here. Ping @retokromer @bturkus @privatezero. I think there's a few options:

• keep as is where ffmpeg recommends what slice count (4 for SD, 20 for HD, generally)
• put the option back for the user to pick slice count, maybe one for SD and one for HD
• change vrecord's own slice count recs, and set 24 for SD and, dunno, maybe 120 for HD

[BleakleyMcD]

i'd vote for change vrecord's own slice count recs, and set 24 for SD and, dunno, maybe 120 for HD first followed by keep as is where ffmpeg recommends what slice count (4 for SD, 20 for HD, generally) second

[retokromer]

(We take a different approach. We determine the number of slides based on the computing power of the machine on which the files are generated. However, that’s not the topic of this discussion.)

[privatezero]

Hmm, after digging a bit, I think I'd agree with @BleakleyMcD's preferences (in the same order)

[dericed]

I like the idea of changing the use vrecord recommendations for slice count over ffmpeg's. I think ffmpeg opts a bit too low.

How about this:

• SD gets 24 slices
• 720 gets 64 slices
• 1080 gets 128 slices

That keeps the pixel to slice ratios in the range of (14,400 to 17,280), favors powers of 2, and focuses on values that divide well in the frame dimensions. The slice grids would be 8x3 for SD, 8x8 for 720, and 16x8 for 1080.

[retokromer]

That keeps the pixel to slice ratios in the range of (14,400 to 17,280), favors powers of 2, and focuses on values that divide well in the frame dimensions. The slice grids would be 8x3 for SD, 8x8 for 720, and 16x8 for 1080.

For ordinary computers, I would personally have chosen smaller numbers, but I like this approach.

[dericed]

I merged #996. @BleakleyMcD is this closable?

[BleakleyMcD]

sure!

[BleakleyMcD]

@dericed when will the next release be that has this slice reset?