Fastly's On-the-Fly Packager service

Fastly offers an "on-the-fly," dynamic, video-on-demand content packager service. Rather than requiring you to pre-package all protocols of a viewer-requested video, Fastly allows you to dynamically package video content in different HTTP streaming formats in real time, using source files. That video content then becomes immediately available to viewers.

Supported on-the-fly packager features

Fastly's OTFP service supports the following specific features.

Supported HTTP streaming formats and codecs

• HDS, HLS, and MPEG-DASH packaging. Fastly provides support for version 1 of the Adobe HTTP Dynamic Streaming (HDS) specification and support for the ISO/IEC 23009-1:2014 specification defining Dynamic Adaptive Streaming over HTTP (MPEG-DASH). We support all features included in up to version 3 (draft 6) of the HTTP Live Streaming (HLS) specification and popular features from later versions such as subtitle, trick play and media segmentation in fragmented MPEG-4 (fMP4) format (per ISO/IEC 14996-12:2015 specification).
• Standard codecs. Fastly supports Advanced Video Coding (H.264/AVC/MPEG-4 Part 10) and High Efficiency Video Coding (H.265/HEVC) video codecs. Fastly also supports Advanced Audio Coding (AAC, AAC-LC, HE-AAC), Dolby Digital (AC-3) and MPEG-1 Audio Layer III (MP3) audio codecs.
• Source video container format. Fastly supports the Progressive MP4 specification (specifically the .mp4, unencrypted .mov, and audio-only .m4a extensions) as source container format for packaging into all supported HTTP streaming formats.

Accessibility and user experience

• HLS multi-language subtitles and closed captions. Fastly provides support for both in-band (EIA-608 and CEA-708) and out-of-band (Web Video Text Tracks or WebVTT) subtitle and closed caption delivery.
• HLS trick play. Fastly supports trick play (also called trick mode), a feature that displays video scenes during fast-forwarding and rewinding. The HLS Authoring Specification requires this feature for distributing video on the Apple TV.

Content protection

• Media encryption. Fastly can encrypt videos packaged into HLS (supports both Envelope/AES-128 and SAMPLE-AES methods) and MPEG-DASH (ISO/IEC 23001-7, a common encryption in ISO base media file format file) streaming formats by generating a unique content encryption key for each video, enabling secure video delivery to viewers.
• Multi-DRM. Fastly can support multiple Digital Rights Management (DRM) technologies including Apple FairPlay for HLS and Microsoft PlayReady, Google Widevine and Marlin DRM for MPEG-DASH streaming formats. OTFP is integrated with Multi-DRM service providers that are responsible for content rights management and DRM license delivery.

Dynamic Ad Insertion (DAI) readiness

• HLS timed metadata injection. Fastly supports HLS time-based metadata, which allows you embed custom metadata or ad markers about a stream into video segments at specified time instances in ID3v2 format.
• Content preconditioning. Fastly can segment video at the intended break points, such as for ad markers via HLS and MPEG-DASH protocols. Fastly can also add any third-party service-specific cues or metadata into video manifests at those break points to implement server or client-side ad stitching.

Clip creation

• Clip creation (also known as "timeline trimming"). Fastly supports clip creation features for all supported packaging formats, allowing you to deliver sections of video without segmenting a longer, archived video. Time query parameters ("start" and "end") allow you to break up videos into discrete sections so users don't have to find the relevant section using the timeline.

Standard content delivery network features

Fastly also provides the following features as part of standard content delivery network services:

• Token-based validation for decreasing response time by placing validation at the edge
• Geolocation and device detection for content targeting
• Dictionaries for real-time business rules and decision making at the edge
• Remote log streaming for data aggregation and viewer diagnostics
• Transport Layer Security (TLS) for secure communications delivery

How the on-the-fly packager service works

Fastly's OTFP service gets configured between our caching network and your origin storage (e.g., Amazon S3, Google Cloud Storage, or Rackspace Cloud Files).

When users request manifests or video segments, those requests initially come to Fastly caches instead of going to your origin storage. Fastly's edge caches deliver those objects if they are available and valid. If the objects don't already exist in the edge caches, the requests will be passed on to a designated shield cache to be delivered instead as long as the objects are available and valid. If neither the edge caches nor the shield cache can deliver the objects, the requests for those objects will go directly to and be fulfilled by the OTFP service which acts as an origin for Fastly's cache nodes.

The OTFP service will make the necessary request to your origin storage to fulfill the original request from the user. The OTFP service also maintains a small, local, in-memory cache for video metadata indexes. These indexes are created using mp4 moov atom (or movie atom) that provide information about the video file such as its timescale, duration, audio and video codec information, and video resolution (among other characteristics).

For adaptive bitrate playback, the OTFP service will cache indexes of each quality level requested. If a user requests a manifest, OTFP will look for the corresponding indexes and, if it is available and valid, OTFP will generate the manifest and deliver it to the user. Otherwise, OTFP will fetch the moov atom from origin storage to generate the corresponding index. If a user requests video segments, OTFP will look for the corresponding audio and video sample entries in the cached index, download those samples from origin storage, and package them in the format requested.