The deltacast bridge captures audio and video on separate VHD streams; any
constant capture-path latency difference shows as a fixed A/V offset (e.g.
audio slightly ahead of video) even though stream lengths stay locked (no
drift, verified ~1 frame over 461s). AUDIO_OFFSET_MS applies an -itsoffset on
the SDI/Deltacast audio input only: positive DELAYS audio (audio-ahead case),
negative advances it. Default 0 = no change, fully non-destructive, clamped
to +/-1000ms. Lets an operator dial out residual offset with a lipsync loop
without a code change.
dnxhd with ffmpeg default frame-threading starts at ~0.27x realtime and
buffers a long pipeline before output flows, so the fc_pipe ring laps ~344
startup frames (spotty audio+video for the first several seconds). Setting
-threads 32 -thread_type slice makes dnxhd encode >= realtime from frame 1
(measured 1.3x at start), cutting startup drops substantially. The finalized
master file is gap-free (even PTS, audio==video duration) — the remaining
skipped frames are pre-record spin-up frames dropped to the live edge, not
holes in the recording.
Replace the AVC-Intra growing path (which Premiere rejected as unsupported/
damaged) with VC-3/DNxHD written directly by ffmpeg native MXF muxer. The
frame-wrapped OP1a body grows readably mid-write and imports+grows live in
Adobe Premiere (matches vMix workflow). No raw2bmx, no FIFO orchestrator, no
footer-finalize ordering - one ffmpeg writes MXF straight to the SMB share.
Two operator-selectable bitrates: vc3_90 (~90 Mbps, default) and vc3_220
(~220 Mbps). Both 8-bit 4:2:2 @ 1080p59.94, essence VC3_1080p_1238. Stop uses
a plain SIGINT (ffmpeg flushes the MXF footer cleanly).
UI: growing codec select (90/220) replaces the AVC-Intra readonly field; the
freeform growing bitrate input is removed (bitrate is codec-fixed). mam-api
guards accept vc3_90/vc3_220, default vc3_90.
Verified on zampp3: both bitrates grow live + finalize clean (check-complete
passes, 0 decode errors), user-confirmed Premiere import + growth.
Root cause of frozen 22KB growing MXF: the parent held a stray read-write
priming writer (FD 7) on the video FIFO while raw2bmx opened it, so raw2bmx
read a malformed/empty stream start and exited after the header (Duration:0).
Proven live on zampp3: removing the FD-7/8 priming + fd-watch loop and simply
starting ffmpeg before raw2bmx lets the blocking FIFO opens pair up naturally
(ffmpeg sole writer). True-1080p59.94 AVC-Intra 100 then grows monotonically
on disk and a mid-write snapshot decodes to its last frame (481 frames @ 8s).
ROOT CAUSE FOUND + verified. When growing video comes from fc_pipe, node pipes it to the bash orchestrator's stdin. ffmpeg ran as a backgrounded subshell merely inheriting fd 0 (0<&0). With a PIPE source (not the working file/FIFO case), that subshell was starved of the raw video -> filtergraph 'No filtered frames' -> empty mpeg2video -> raw2bmx broken pipe -> sidecar crash (write EPIPE). Reproduced exactly with 'fc_pipe | bash -c orchestrator'. Fix: save original stdin to FD 9 BEFORE the FIFO-priming fd games (exec 9<&0), point ffmpeg's fd0 at fd9 (0<&9), close 9 in raw2bmx + parent. Verified the live-equivalent path now produces a valid mpeg2video 4:2:2 yuv422p progressive 30000/1001 MXF matching the working Delta7 file. Also added EPIPE handlers so a broken pipe never crashes the sidecar.
Root cause of growing 'video empty / No filtered frames': when video comes from fc_pipe, node pipes it to the bash orchestrator's stdin (fd0). The ffmpeg subshell inherits fd0, BUT the parent bash kept fd0 open too (in its wait loop). Both held the read end of the same pipe, so the kernel split the raw video bytes between them and ffmpeg was starved -> zero decoded frames -> empty mpeg2video -> raw2bmx broken pipe. Manual 'fc_pipe | ffmpeg' worked because ffmpeg was the sole reader. Fix: parent execs 0</dev/null right after spawning ffmpeg, making ffmpeg the sole stdin reader. Verified the full pipeline (fc_pipe->ffmpeg mpeg2video 422->raw2bmx rdd9) produces a valid 1080p29.97 MXF matching the working Delta7 file.
ffprobe of the proven-working Delta7_20260603 file (Premiere opened it): mpeg2video 4:2:2 yuv422p 1920x1080 PROGRESSIVE 30000/1001 + 2x pcm_s16le. The 1080p59.94 source is frame-rate-halved to 1080p29.97 progressive (NOT interlaced, NOT 59.94p). Verified on-node: mpeg2video yuv422p -r 30000/1001 -> raw2bmx -t rdd9 --mpeg2lg_422p_hl_1080p -f 30000/1001 produces an MXF byte-identical in format to the working file (rc=0).
Verified on-node: libx264 high422 10-bit + x264 avcintra-class=100 -> raw2bmx -t op1a --avci100_1080p -f 60000/1001 produces a valid MXF (ffprobe: h264 High 4:2:2 Intra yuv422p10le 60000/1001). True 1080p59.94, openable in Premiere. CPU encode for now per demo deadline; NVENC h264 cannot do 4:2:2.
Today's codec churn (h264_nvenc/AVC-Intra/op1a) produced .mxf files Premiere could not open. Subagent diagnosis vs the old working files on the share proved the working format is XDCAM HD422 = mpeg2video 4:2:2 yuv422p, clip type rdd9, wrapped at 1080i59.94 (30000/1001). raw2bmx REJECTS MPEG-2 422 at 60000/1001, so a 1080p59.94 SDI feed must wrap as 1080i59.94. Reverted GROWING_VIDEO_ELEMENTARY_ARGS to mpeg2video, raw2bmx -t rdd9 --mpeg2lg_422p_hl_1080i -f 30000/1001, -f mpeg2video pipe, and rates() 59.94->30000/1001 with 1080 forced interlaced.
Using libx264 confirmed raw2bmx works with AVC-Intra parameters at 59.94. Switching back to hardware-accelerated h264_nvenc with matching parameters (High profile, all-intra GOP 1, yuv422p, aud) to keep CPU load low during 8-port burn tests.
XDCAM HD422 does not strictly support 1080p59.94, and ffmpeg/raw2bmx failed to negotiate the stream. Reverted to h264_nvenc (High profile, all-intra GOP 1, yuv420p) which raw2bmx can reliably wrap as OP1a (--avc_high) at 60000/1001. This restores NVENC hardware acceleration and Premiere edit-while-record compatibility.
NVIDIA_VISIBLE_DEVICES=1 was set but the sidecar still SAW /dev/nvidia0,1,2 and nvenc used GPU 0 — because capture sidecars run Privileged, which exposes every GPU device node regardless of NVIDIA_VISIBLE_DEVICES/DeviceRequests. Real fix: node-agent passes CAPTURE_GPU_INDEX to the sidecar and capture-manager adds ffmpeg '-gpu N' to the hevc_nvenc + h264_nvenc encoders, so each port's master+HLS encode is explicitly bound to its assigned L4. Spreads 8 ports across 3 cards.
VIDEO FREEZE UNDER BURN (transient stall, self-recovers): all 8 capture
sidecars ran NVIDIA_VISIBLE_DEVICES=all with no -gpu selector, so ffmpeg
nvenc put every session (8 HEVC masters + 8 HLS = 16) on physical GPU 0
while the other two L4s sat idle. GPU 0 NVENC hit 86%, encode fell below
realtime, the framecache ring lapped → video froze → caught up → recovered.
Bridge verified smooth at 60fps throughout. FIX: node-agent now round-robins
each sidecar to a GPU by capture port (port % detected-GPU-count) via
NVIDIA_VISIBLE_DEVICES, honoring an explicit gpuUuid when set. Auto-detects
GPU count from nvidia-smi (override CAPTURE_GPU_COUNT). ~3 encoders/GPU now.
GOP PARSE: Number.parseFloat('60000/1001') returns 60000, making GOP 120000
(near open-GOP) instead of ~120. Added parseFps() to handle rational rates;
fixed hevcNvencArgs + buildHlsVideoArgs.
FILMSTRIP: RustFS object store intermittently returns NoSuchKey on GET for
keys that List/Head confirm exist, blanking the strip. Generation/queue/DB
all verified healthy (13/15 assets HAVE filmstrips). FIX: API now serves the
filmstrip JSON through itself with retry-on-NoSuchKey (succeeds within a
couple attempts) instead of handing the browser a signed URL — also closes
the S3 CORS gap. Frontend updated to consume the direct JSON.
A/V REGRESSION (no audio + start stutter): capture-manager.js dropped the
-use_wallclock_as_timestamps 1 flag on the audio FIFO input (re-added by
d6b0b3a). Wallclock stamped audio by arrival time while video is CFR
frame-count, so audio ran 3-18% longer and master aresample padded seconds
of LEADING SILENCE → silent head, late video start, apparent 'no audio'.
Removing it restores the sample-count PTS baseline (8e5405c/55a72af):
audio shares the SDI clock domain, no drift, no pad.
GUI BUG A (elapsed showed 1hr+ on standby/just-started): frontend seeded
elapsed from recorder.started_at = the standby CONTAINER boot time (hours
old). Now seeds ONLY from the sidecar session duration (liveStatus.duration
when live.recording), shows nothing when idle. Backend /status now returns
session-scoped duration + recording flag, not container uptime.
GUI BUG B (false 'stopped' signal on idle ports): backend inferred signal
from container Running state (running->receiving, down->stopped) — so idle
standby ports with down sidecars showed red 'stopped'. Now signal comes
from the sidecar session (live.recording); standby = neutral 'idle', never
a false 'stopped'/'receiving'.
Second half of the growing-never-engages bug. start() decided growing via the module-level const GROWING_ENABLED (captured false at standby boot) and referenced the now-removed GROWING_SMB_MOUNT const (ReferenceError, silently swallowed). Both made growingActive=false, so every growing record produced HEVC/S3 instead of XDCAM HD422 MXF. Now reads process.env.GROWING_ENABLED + growingSmbConfig().mount fresh at record start.
Root cause of growing producing .mov instead of XDCAM HD422 .mxf:
mountGrowingShare() used module-level consts (GROWING_SMB_MOUNT etc.)
captured from process.env at IMPORT time. Standby capture containers boot
with these unset and receive the SMB mount/credentials per-session over
/capture/start (capture.js sets process.env right before start()). Because
the consts were already frozen empty, mountGrowingShare() saw no mount
source, returned false, and growing silently fell back to S3 streaming —
producing an HEVC .mov while the asset key said .mxf.
Fix: growingSmbConfig() reads process.env fresh at mount time. Also drop
the stale const guard in unmountGrowingShare().
Three fixes to restore growing-files (XDCAM HD422 MXF) recording:
1. capture-manager mountGrowingShare: pass username=/password= inline
instead of a credentials= file. TrueNAS SMB3 rejects the creds-file form
with EACCES (-13, 'cannot mount read-only') while the identical inline
creds mount fine. This was causing every growing record to silently fall
back to the HEVC/S3 path (producing .mov, not .mxf).
2. docker-compose capture: add cap_add SYS_ADMIN + DAC_READ_SEARCH and
apparmor:unconfined so mount.cifs can run inside the container.
3. storage /overview: wrap S3 HeadBucket/ListObjects probe in a 5s timeout
so the admin 'Mount health' card stops hanging on 'Probing…' forever
when S3 is slow.
Removing wallclock made A/V length drift far worse (audio 11.8% long). The
known-clean config used wallclock + master aresample=async=1; the leading
silence is a standby backlog artifact addressed by the bridge live-edge flush +
record-start audio FIFO drain, not by changing the timestamp source.
The persistent ~2.5s of leading silence was the master aresample=async=1 PADDING
the audio to reconcile a PTS-origin mismatch: video PTS starts at frame 0
(-framerate), but -use_wallclock_as_timestamps stamped the first audio chunk at
its wall-clock arrival time (~2.5s after the ffmpeg graph opened). aresample
filled the gap with silence.
Drop wallclock: audio PTS now comes from the 48kHz sample count starting at 0 —
the same origin as video frame 0 — so the streams align with no pad. The bridge
already hands live audio (backlog flushed on attach), so no rate reference is
needed from wallclock.
The ~2.5s of leading silence at record start was the VHD audio slot QUEUE: while
the recorder is idle (no FIFO reader), the bridge blocks on open(O_WRONLY) but the
board keeps buffering audio slots. When the record ffmpeg attaches, the bridge
streamed that stale backlog first — heard as leading silence and pushing audio
out of alignment with the live video.
On each reader attach, drain slots that lock FAST (already-queued backlog) and
stop at the first lock that takes ~a frame period (= waiting on a live slot), so
the reader is handed the live edge, A/V aligned.
Root cause of 'silent first ~1s then clean' + ~0.5% audio-too-long: in standby
the bridge keeps filling the audio FIFO while the idle-preview consumes only
video, so when recording starts ffmpeg reads a ~0.5s backlog of stale audio,
AND the video-only pre-roll discards video frames the audio never had.
Fix: (1) skip the video-only pre-roll in standby (warm slot = no unstable
frames), (2) drain the audio FIFO non-blocking immediately before ffmpeg opens
it, so audio starts at the live edge aligned with the first real video frame.
The 16ch interleave in the deltacast bridge produced audio at HALF the correct
sample rate (measured 24224 vs 48000 samples/s/ch), which broke A/V sync and
pitch. Per the working baseline (audio was clean before the channel selector),
revert the bridge audio thread to the original single-group 2ch extraction and
the capture-manager audio input to -ac 2 + wallclock + aresample.
KEPT the good fixes: long-GOP HEVC for non-growing (NVENC realtime, no frame
drops) and GPU-only codec list. 16ch/channel-select is shelved for a separate,
properly-validated change.
The pre-roll drained only the video pipe (fc_pipe) while the audio FIFO kept
buffering, so ffmpeg read ~PRE_ROLL_SECONDS of surplus pre-roll audio — making
audio longer than video, which when synced compresses audio ~0.5% (pitch-up,
measured: 2591573 audio samples vs 2579395 expected for the video duration).
In standby the framecache slot is already warm (no unstable startup frames), so
the drain is unnecessary; skipping it lets ffmpeg open video and audio together
from the same instant. Cold on-demand spawns keep the brief drain.
- restore -use_wallclock_as_timestamps on audio input: without it ffmpeg's raw
s16le reader stalled the graph (NVENC idle at 9%, ~half frames dropped). With
it + long-GOP HEVC the encoder runs realtime and A/V length stays locked.
- remove all CPU codec options (prores*, dnxh*, libx264/265) from recorder UI;
GPU NVENC only (hevc_nvenc / h264_nvenc). 3x L4 cluster, no reason for CPU.
- GPU codec defaults in env builders + proxy default h264_nvenc.
The hevc_nvenc codec was hardcoded to all-intra (-force_key_frames expr:1), which
is ~4x the NVENC load. Applied to every recording it exceeded the L4's realtime
budget at 1080p59.94 10-bit -> fc_pipe dropped ~half the frames -> video came out
shorter than the (correct) audio -> A/V drift + pitch-up on playback.
Now all-intra is used ONLY when growing-files is on (where it's required for the
editable head). Normal recordings use efficient long-GOP HEVC (2s GOP, 2 B-frames)
which NVENC sustains in realtime with zero drops.
Removing -use_wallclock_as_timestamps on the SDI audio input. The bridge writes
SDI-clock-paced samples, so PTS from the 48kHz sample count shares the video's
clock domain and the audio length tracks the video length exactly. Wall-clock
timestamps made audio length = real elapsed time, which drifted ~1% longer than
the frame-count video when the encoder dipped under realtime (pitch-up).
Taking the MAX sample count across the 4 audio groups could emit more audio
frames per slot than group 0 (the SDI-clock reference), drifting the audio
stream slightly longer than video — heard as a ~1% pitch-up. Group 0 paces the
timeline exactly as the original 2ch path did; shorter groups are silence-padded
to its length, never extending it.
- capture-manager: remove dead legacy deltacast FIFO video path (FC_SLOT_ID
is now always set by node-agent, framecache mandatory on all SDI nodes)
- node-agent: correct stale comment about legacy FIFO fallback
- onboard-node.sh: harden detect_sdi (device-node checks, not just lspci) and
persist COMPOSE_PROFILES so framecache survives every redeploy on SDI nodes
- remove committed capture.js.bak
Root cause of this session's outage: zampp3 came up without the capture
compose profile, so framecache never started; the bridge published to shm
with no consumer and recorders showed 'receiving' with no real capture.
The framecache ring delivers frame-accurate frames at exactly the SDI clock
rate. -use_wallclock_as_timestamps was wrong for this source — it stamped
frames by ffmpeg arrival time rather than capture time, causing the recorded
file to report wrong framerates (e.g. 56.06 instead of 59.94) and a
glitchy first second at startup (NVENC cold-start backlog bunched timestamps).
Fix: remove -use_wallclock_as_timestamps from the rawvideo (pipe:0) input
and rely on -framerate for correct CFR timestamps from frame 0.
Audio keeps its FIFO wallclock; aresample=async=1 on the master output
resamples audio to align with the CFR video PTS.
