Station FAQ

Live and Stored Programs (Updated 03/07/07)

Q: What is the difference between live streams and stored programs?

A: The ContentDepot delivers to stations both live programs (streams) and stored programs (files). Programs that are recorded ahead of time (stored) are uploaded into the ContentDepot and subsequently downloaded into the station's satellite receiver.

Separating live and stored content reduces the need for concurrent live audio outputs. Four stereo analog and digital (AES/EBU) outputs will be the complement for station installations. The architecture supports more should a station need to expand beyond the base complement.

Q: How does the ContentDepot handle a show that some record for later and others play live?

A: We have considered two mechanisms to support these types of programs. The first includes automatic ingest of the live feed into the ContentDepot for subsequent distribution as a stored program. The stored programs would be sent to subscribed (authorized) stations and stored on their receivers after the live feed is complete.

The second alternative requires a station to capture the stream when it airs live, store it, and then play it out when it is time for air using local automation. For those stations that air the show at a later time, it's also possible that the producer might arrange to send out additional live streams of the same program for later playback.

We believe the first option is best because it is easiest for stations. Either way, the ContentDepot accommodates these types of programs and their associated cues (if any).

Q: If a program is being produced close to deadline, how long is the whole turnaround process?

A: One of the benefits of direct producer upload of pre-recorded episodes into the ContentDepot is that it gives producers the ability to submit programs "closer to deadline." The file submission deadline would be the producer-specified available airdate less a minimum threshold for delivery. That threshold is less than the delivery time it would take to submit programs on physical media via mail or Fedex.

Q: How soon before my local air time can I expect to receive files for program XXX?

A: We are asking producers of pre-recorded programs to submit files to the ContentDepot early enough so programs will be in receivers no later than 2 hours before the earliest air time. In some cases where a program is both live on a satellite stream and available for repeats at stations, files will be sent after the live feed is complete. Whether or not files are generated from a particular live program is strictly up to the producer of that program; in some cases local repeats can only be accomplished by local recording of the live feed.

Q: With the new system, are we still able to get a time sync from NPR Distribution to keep our automation computers on the correct time?

A: We are keenly aware of station reliance on clean time data to synchronize station clocks, automation systems and other devices.

The new time-of-day system will not deliver the SOSS-era proprietary time data to station devices. The new system delivers Network Time Protocol (NTP) to the storage receiver at each station. LAN-connected workstations and systems can retrieve time messages from the storage receiver. Using a standards-based protocol also gives station staffs the option of using an alternate trusted time standard like a locally provided GPS clock as their primary time reference.

Q: What file format standard does the ContentDepot use for stored programs?

A: ISO/MPEG I, Layer II (MP2), 256 kilobits per second for stereo audio, 128 kilobits per second for mono audio, 44.1 kHz sampling rate.

ISO/MPEG I, Layer II is a well-known and well-understood data reduction scheme that has been in use for more than ten years. It's considered comparatively benign in environments where there are multiple transcoding stages. It's also a comparatively 'fast' algorithm to encode and decode audio—a characteristic confirmed during NPR's testing at the BBC in January 2003.

Q: Where is the digital encoding of pre-recorded programs accomplished? Are producers still be able to send PRSS a DAT or CD?

A: For pre-recorded programs, the ContentDepot enables producers to upload encoded audio files directly via a web interface. This gives producers the ability to maintain audio control over their files and upload at their convenience.

ContentDepot staff will encode CDs and DATs for producers who do not have the capability of encoding files or uploading them via the web. We anticipate that there will be a surcharge for this additional service.

Q: Will there be any additional cost to download missed programs?

A: Much like refeeds today, it takes additional bandwidth to transfer the file again, so a charge for on-demand download of missed programs is certainly a possibility. That being said, we are using techniques that make the reliability of successful delivery high.