Certainty about integrity and quality of ingest and transcoding is of highest priority to any digitization facility which is why NOA is investing special attention on QC and QA. When transferring SD-video carriers in a large-scale digitization project running within a jobDB or a mediARC environment, NOA is able to implement 4 subsequent layers of quality control:
1) Transfer Quality Control
The first level of QC happens directly during running ingest. By logging ISR events (a Sony protocol provided by some VTRs) and by grabbing the RF signal directly from the main board of the VTR, ingest technicians and QC employees are able to clearly distinguish between “errors on tape” and “errors during transfer”. The visual characteristics of an error which is already in the picture (e.g. due to a faulty previous migration or a playout error during original recording the tape) and those of an error during transfer (e.g. by faulty tape or a smeared VTR reading head) remain virtually indistinguisable without this kind of analysis. ISR events are logged via RS232 port on the VTRs (depending on availability), RF levels are grabbed by a chip which will be soldered onto the main board of the VTR. NOA FrameLector is the only SD-video transfer application on the market offering readout of RF signals.
2) Wrapper Quality Control
When producing .mxf files, IRT’s MXF Analyser is making sure every file was encoded according to predefined parameters. Following a traffic light system, only validated files will be allowed toproceed through the workflow.
3) File/Content Quality Control
After transcoding (and eventual confirmation of .mxf integrity in step 2) 3rd party video analysis tools are implemented into the workflow to analyze produced files. While some tools (like e.g. Vidchecker) work with a traffic light system to automatically forward (resp. stop) the workflow and produce a .pdf file which can be saved with the encoded file, other tools (e.g. Vidicert) come with a built-in player, which is able to display detected errors in a timeline based view. Vidicert’s player is also able to include ISR/RF events and traces forwarded by NOA systems to allow for a direct comparison between “errors on tape” (e.g. from previous migration) versus “error during transfer”. This layer of QC is in any case detached from actual ingest of tapes, allowing for task- and labour-separated projects, where employees with higher qualifications are able to work separated from more simple tasks (like carrier handling and ingest).
4) Process Quality Control
Within a jobDB or mediARC workflow, the history of a carrier will be logged during its entire lifecycle. From the first step to the last, a comprehensive logfile is produced automatically allowing the user to observe progress of every carrier through the workflow. Timestamps, user and machine information, and logfiles produced by individual steps of the workflow can be accessed from a single, aggregated logfile to facilitate every kind of investigation (e.g. identification of bottlenecks, investigation in case of errors, productivity analysis, etc.).