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</source>
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=== recording datecode ===
== Tips / How-to ==
* Raw DV files contain recording datecode information (date + time)
=== Recover recording datecode ===
Raw DV files contain recording datecode information (date + time). There are several methods to recover that information and make subtitle files with them ({{file|*.srt}}).

; Capture the DV with <code>dvgrab</code> and <code>-srt</code> option.
* See Capture section.

; Extract the information from a RAW DV file.
* This only works if the DV was extracted in '''raw DV''' format.
* <code>mediainfo</code> must return something like:
<source lang="bash">
mediainfo test001.dv
# General
# Complete name : test001.dv
# Format : DV
# Commercial name : DVCAM
# File size : 1.01 GiB
# Duration : 5 min 0 s
# Overall bit rate mode : Constant
# Overall bit rate : 28.8 Mb/s
# Recorded date : 2003-10-30 19:57:45.000
#
# Video
# Format : DV
# Commercial name : DVCAM
</source>
* In that case, generate again the {{file|*.srt}} files with <code>dvgrab</code>, which accepts directly DV raw files.
<source lang="bash">
dvgrab -input test001.dv -f raw -t -srt -size 0 test001-srt
</source>

; Extract information from an AVI DV file
* If the file is NOT in raw DV format but in AVI, the easiest is to use a Windows application called '''dvdate''' ([https://www.videohelp.com/software/DVdate DVdate on videohelp.com]).
* Open folder containing the AVI file.
* Go to '''Inlay''', and select '''Create a srt file with subtitles'''.


== Benchmarks ==
== Benchmarks ==

Revision as of 13:12, 8 September 2024

Page dedicated to extraction and conversion of DV tape, as used in digital camcorder.

Capture

DV tape capture requires a PC with a firewire (IEEE 1394) port.

  • Check installation:
# Check firewire hardware
lspci | grep -i firewire
# 37:09.0 FireWire (IEEE 1394): LSI Corporation FW322/323 [TrueFire] 1394a Controller (rev 70)

# Check kernel modules are loaded
lsmod | grep firewire
# firewire_ohci          40960  0
# firewire_core          65536  7 firewire_ohci
# crc_itu_t              16384  1 firewire_core

# Install some tools
sudo apt install dvgrab gscanbus
# sudo apt install libraw1394-11   # optional

# See if camera is detected
sudo gscanbus

# Add current users to 'video' (must logout / login) to allow access to /dev/fw
sudo usermod -aG video $USER
  • Grab the DV tape
dvgrab -format=dv2 -rewind -autosplit=14400 -srt -size 0 myvideo-
# -format=dv2: recommended format. Alternative: raw (extension .dv)
# -rewing: rewing before capture
# -size 0: Do not split files based on size
# -autosplit=14400: Split file if there is a gap bigger than 4h.
# -srt: generate subtitles with recording date and time.

Tips / How-to

Recover recording datecode

Raw DV files contain recording datecode information (date + time). There are several methods to recover that information and make subtitle files with them (*.srt).

Capture the DV with dvgrab and -srt option.
  • See Capture section.
Extract the information from a RAW DV file.
  • This only works if the DV was extracted in raw DV format.
  • mediainfo must return something like:
mediainfo test001.dv
# General
# Complete name                            : test001.dv
# Format                                   : DV
# Commercial name                          : DVCAM
# File size                                : 1.01 GiB
# Duration                                 : 5 min 0 s
# Overall bit rate mode                    : Constant
# Overall bit rate                         : 28.8 Mb/s
# Recorded date                            : 2003-10-30 19:57:45.000
# 
# Video
# Format                                   : DV
# Commercial name                          : DVCAM
  • In that case, generate again the *.srt files with dvgrab, which accepts directly DV raw files.
dvgrab -input test001.dv -f raw -t -srt -size 0 test001-srt
Extract information from an AVI DV file
  • If the file is NOT in raw DV format but in AVI, the easiest is to use a Windows application called dvdate (DVdate on videohelp.com).
  • Open folder containing the AVI file.
  • Go to Inlay, and select Create a srt file with subtitles.

Benchmarks

# Source: dv1_tlg_to_jan_2005
 size  | enc fps  | format
-------|----------|----------------------------------------------------------------------
14543M |          | DV
 1489M | 64.1 fps | x264 slow-20-high-3.1
 2082M |  9.4 fps | x265 slow-18-auto-auto
 1815M | 21.0 fps | x265 medium-18-auto-auto
 1215M | 24.1 fps | x265 medium-20-auto-auto
  917M | 27.35 fps| x265 medium-20-auto-auto + strong-intra-smoothing=0:rect=0:aq-mode=1
  • We choose x265-medium-20-auto-auto.
  • Better than the x265-medium-20 with extra options (extra noise).
  • No significant differences compared to best quality file (x265 slow).