Video streaming API
A video streaming API is a programming interface that delivers video to viewers as adaptive streams instead of single files. It takes a video, encodes it into several qualities, packages them into short segments with a manifest in formats such as HLS or DASH, and serves them through a CDN. The app gets back a playback URL, and the player uses it to start fast and switch quality as each viewer's network changes. Most streaming APIs cover on-demand video, and many add live.
How does a video streaming API work?
The API's job is to turn one file into something a player can adapt. After upload, the source is transcoded into a bitrate ladder, such as 1080p, 720p, 480p and 360p at matched bitrates. Each rendition is cut into segments of a few seconds and described in a manifest: an HLS playlist or a DASH MPD that lists every rendition and where its segments live. CMAF, a shared segment format, lets one set of files serve both.
The API returns a playback URL that points at the top-level manifest. A player loads it, picks a starting rendition from a quick throughput estimate, and requests segments from the nearest CDN edge. While it plays, the player measures download speed and buffer level and moves up or down the ladder between segments. That loop, adaptive bitrate streaming, is the whole point. A viewer on a fast home line gets the top rung, and a phone on a crowded train gets a lower one instead of a spinner.
Video streaming API for on-demand vs. live video
On-demand and live use the same formats, but the API does different work for each. For on-demand video the whole file exists before anyone watches. The API can encode every rendition in advance, or just in time, and publish a complete manifest that never changes. Segments are the same for every viewer, so CDN edges can cache them for a long time, and seeking anywhere in the file is an ordinary request.
Live video arrives as a continuous feed from an encoder, usually over RTMP, RTMPS or SRT. The API has to transcode it as it comes in, add each new segment to a manifest that keeps changing, and publish that manifest often enough for players to find new segments. Edges can cache the manifest only for a moment. Latency becomes a design choice: shorter segments, or LL-HLS partial segments, bring viewers closer to real time at the cost of more requests. Live also needs features on-demand does not, such as stream keys, health monitoring, DVR and a recording when the broadcast ends.
Video streaming API vs. video API
The terms overlap, and providers use them loosely. A video streaming API focuses on the delivery path: encoding for streaming, packaging, CDN distribution and playback URLs. A video API is usually broader. It adds upload handling, asset management, live ingest, access control, analytics, media utilities such as thumbnails and clips, and AI features such as transcripts.
The difference shows up once you go past playback. A delivery-only streaming API can leave you wiring a separate uploader, a separate analytics tool and a separate DRM provider, each with its own IDs and its own webhooks. A full video API keeps those on the same asset. When evaluating, list every step from a user pressing upload to a support engineer debugging a stalled view, and check which of them the API covers with one identifier.
How do you choose a video streaming API?
Start with what reaches the viewer. Check that the API outputs HLS for Apple devices, DASH or CMAF where your other players need it, and LL-HLS if you run live events. Check the codecs: H.264 for reach, plus HEVC or AV1 renditions for devices that decode them. Ask how the ladder is built, fixed or per title, and whether you can cap the top resolution.
Then test delivery from where your viewers are. Server counts matter less than measured startup time and rebuffering on the networks your audience uses, so run a trial from those regions and mobile carriers, and ask what happens when one CDN slows down.
Finally, look at the parts around playback: how soon a new upload can play, whether webhooks report each stage, how access is controlled with signed URLs or DRM, which players are supported, and whether per-view data comes back. The billing unit, gigabytes or minutes watched, belongs on the same list.
How does the FastPix video streaming API work?
FastPix runs the streaming path from source file to player behind one API. A video arrives by resumable upload or a pull from cloud storage. FastPix profiles each source and builds a ladder in H.264 and HEVC (H.265) as standard, with AV1 available on request, up to 4K with HDR10, Dolby Vision and HLG, and measures quality with VMAF. Packaging is just-in-time CMAF for HLS and DASH, so playback can start before the full encode finishes. You can cap the top resolution at 720p, 1080p, 2K or 4K.
Delivery runs on a multi-CDN network of 300+ points of presence with per-viewer routing and per-region failover for on-demand, and you can serve video and images from your own custom domain. Playback IDs can be public, signed with expiring JWTs, or protected with Widevine, FairPlay and PlayReady DRM. The free, open-source FastPix Player plays them on web, Android (built on Media3), iOS, tvOS and visionOS (built on AVPlayer) and Flutter, and any HLS player works too. On Android, fast start begins playback after 500 ms of buffered media, where Media3's stock default is 1000 ms, and preloading and disk caching prepare the next items in a feed. Live streams use the same delivery as LL-HLS at 4 to 7 seconds.
Every view reports to Video Data across 56 dimensions, broken down by country, region, CDN and ASN, with threshold alerts routed to Slack, PagerDuty or Opsgenie.
Delivery is metered in minutes, not gigabytes: streaming bills per minute watched, with ingress, egress and request charges included in that rate. Storage bills per rendition-minute, and Standard encoding is free per source minute up to 4K. The free plan includes 100,000 streaming minutes a month, with no card.
