[Cin] Analog DV Capture

[Andrea paz]

@Andrew-R
@Terje
Found this discussion on an Italian NewsGroup; no idea if it can be useful...

> 1) How to capture on Hard Disk video-films recorded on magnetic cassette tapes  "Mini Dv" without losing the date and time of the original video recording on
 the magnetic tape?
> 2) And without losing the best quality obtainable by downloading with cable and  DV sockets (with digital signals; e.g. with i.Link, IEEE.1394 standard)


The two things coincide: date/time data and other information
(timecode, aspect-ratio, color/BN, DV type [DV25, DV50, DVCPROHD_1080i,
DVCPROHD_720p], PAL/NTSC, interlaced/progressive, audio locked/
unlocked, aperture, frame rate, etc.
unlocked, aperture, gain, shutter) are contained in VAUX blocks of each frame.
VAUX blocks of in each DV frame (to be exact, they could be contained in each
contained in each DIF block, 12000 bytes, and each frame in PAL is composed of
composed of 12 DIF blocks, 144000 bytes, but usually they are put only
on the first DIF block of the frame), then downloading on PC the
digital data of the
digital data of the MiniDV cassette you also make a backup of the
information about
date/time information.

Similarly for HDV (MPEG-2 Transport Stream) data stored on the MiniDV
cassette: all this information is contained in packets.
MiniDV cassette: all this information is contained in Private Stream
A1 packages (commonly called Sony A1).

> 3) And perhaps by having such data captured in the "detail-properties" of the   video files that are created, as is normally the case with today's cameras, instead of seeing them
cameras of today, instead of seeing them appear inside the image of the video
when of the image of the video when you watch it on the monitor?

This one is a tad more complicated.... While cameras
enter this information once into the EXIF/XMP/
IPTC sections of the JPG/RAW[TIFF] file, for DV video this information is
relative to each frame (or inserted on each frame of type I
or P for HDV videos, i.e. every 3 frames), and so it is a little bit
difficult to show you all the information.
You could show the information of the first frame, but if, for example, a
for example, a file was composed by more recordings, that information
would be wrong for the recordings
would be wrong for the recordings following the first one, not to mention that
diaphragm/gain/shutter could change frame by frame.
frame by frame.

Back in the day (2010, so a bit after 2004...) I had made available a
small program to extract data in text format:

https://video.liberdomus.org/software/extract_dvaux.zip

Just run the program from DOS prompt (or shell unix, they are also
compiled for Linux/64bit):

extract_dvaux.exe filedv > info.txt

The "filedv" can be any file format (AVI, MOV, RAW DV) that contains
DV packets (also compatible with the Canopus-DV codec):
a line is written every time some parameter changes.
At the end a short report is also written about how many frames/blocks
have been analyzed and if the audio is "locked" or not.