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SIGNAL INGEST IN UNCOMPROMISING, LINEAR VIDEO ARCHIVING: PITFALLS, LOOPHOLES AND SOLUTIONS. Franz Pavuza Phonogrammarchiv Vienna. STATUS: Considerable analog video footage, sometimes questionable storage conditions. SOLUTION: Digitisation, adequate storage, migration.
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SIGNAL INGEST IN UNCOMPROMISING, LINEAR VIDEO ARCHIVING: PITFALLS, LOOPHOLES AND SOLUTIONS Franz Pavuza Phonogrammarchiv Vienna
STATUS: Considerable analog video footage, sometimes questionable storage conditions SOLUTION: Digitisation, adequate storage, migration PROBLEMS: (Cost, compression, standards, storage media, metadata…..), Signal ingest
SIGNAL INGEST Playback devices (+service manuals, maintenance equipment) Supporting devices (synchroniser/converter) “Upgrades”? (replacement; enhancement) PC/Mac-compatible workstation? Interface (A/D-converter)
DIGITISATION Plug-in A/D card or external A/D module? (consumer- or professional devices) Input signal flexibility? Digital signal representation (compressed, uncompressed) “Fast” PC (hard disk array) “Archiving” software (for processing and backup)
CONVERTER ISSUES • Speed • Resolution • Errors • Technology (monolithic, multi-chip) • Support circuits • (sample&hold circuits, filters, references) • costs: € 50.- to > € 10000.- for complete A/D module
CONVERTER ISSUES SPEED: Video sampling (ITU-601 4:2:2) 13,5 MHz (b/w) 6,75 MHz (colour) Modern ADCs: 12 bit/210 MSPS (monolithic) 12 bit/400 MSPS (multi-chip) 14 bit/105 MSPS (monolithic) 16 bit/105 MSPS (multi-chip)
CONVERTER ISSUES RESOLUTION: 8 bit – 16 bit < 8 bit…. contouring 3 x 8 bit (“component” signal): 16 Mill. colour shades; OK with excellent ADC and no editing 3 x 12 bit: perfect for archives (expensive)
CONVERTER ISSUES ERRORS: DC: offset, gain, linearity (differential, integral) AC: distortion (harmonic, intermodulation) bandwidth (Full Power, Small Signal) signal/noise ratio (quantisation: SNR 6.02xN+1.76dB, noise from active and passive components) aperture jitter (sample&hold)
SYNCHRONISER Analog playback devices (in most cases used equipment) supported by stabilizing circuits (frame synchronisation, time base correction) Benefit: correct colour hue and saturation Additional signal conditioner (Format conversion, noise reduction, enhanced colour decoding) Superior ADC-performance
ENHANCED SIGNAL EXTRACTION Replacement of critical electronic circuits Improved signal pickup Example: U-Matic Recorder Replacement of “composite” signal processing by Y-C pre-amplifiers and AD-conversion; pure digital solution?) Expensive infrastructure required!
THANK YOU! Franz PAVUZA Phonogrammarchiv (Austrian Academy of Sciences) Liebiggasse 5 A-1010 Vienna/AUSTRIA franz.pavuza@oeaw.ac.at