[LAU] Syncing MP4 video files with LTC on CH1, and a BWF WAV containing timecode metadata

robertlazarski . robertlazarski at gmail.com
Sat Mar 31 18:38:01 CEST 2018

Hello! I am a long time Linux user and I used to participate in the LAU
group many years ago. A while ago, I decided to do my music "out of the
box" with mostly analog gear.

I am returning once again to LAU. My goal here is to edit several cameras
videos together using different angles, into one video. And use the WAV
generated from the F8 as the audio. Actually I plan on having some
professional mastering done on the tracks from the F8. But I am doing the
video editing part.

I need to sync videos from multiple Android phone cameras that are
recording some "live" music instrument performances in my home studio. The
videos contain CH1 as LTC audio (sounds nasty!) , and a scratch track on
CH2 - both coming from a Zoom F8 outputs. The phone camera inputs are from
an Irig DUO over USB. The F8 is recording the performances via its 8
inputs, to a BWF WAV file on a removable SD that contains all 8 tracks.

I can see the timecode metadata of the WAV using bwftool. I can see all the
tracks in Ardour when importing the WAV (compiled latest release from
source on OpenSuse LEAP 42.2) and also Audacity.

About the LTC and timecode: Lots of people use "Plural Eyes" and closed
source software to sync audio and video. I believe LAU will understand why
that is not an option for me. Really though I have a personal interest in
timecode, and some equipment that uses it. I want to try it.

Nice cameras like REDD can accept timecode on a BNC input, or generate it.
Phone cameras and even many Cannon cameras AFAIK do not have that
capability. While not ideal, it is common I believe to record the timecode
as LTC audio on one of the stereo tracks on the camera. These performances
are mostly under 5 minutes and I don't expect drift to be an issue - if so
I will need a better camera later on.

My idea was to startup XJadeo with the "-l" (LTC) option, and receive
events via "mplayer -ao jack F8.WAV"  .

I have it backwards though: The MP4 loaded into Xjadeo has the LTC audio
track. The WAV has the timecode metadata. And I have several MP4 files with
LTC. Ardour doesn't read MP4 files. I am stuck on the next step here. I am
a little weak in my video skills, I am trying to use this project to learn

Any advice? Well, besides skipping timecode ... I got that a lot already on
the "gearslutz" forum :-) .
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