Serverless Video Transcoding with AWS Elemental MediaConvert - HLS Delivery and Thumbnail Generation

Transcode file-based video at broadcast quality and generate multiple formats including HLS, DASH, and MP4 in a single job. Learn how to build large-scale video processing pipelines with job templates and queue priority control.

About 9 min readLast updated: 2026-10-26

Overview of MediaConvert

AWS Elemental MediaConvert is a service that transcodes file-based video content at broadcast quality. It converts input files (MP4, MOV, MXF, etc.) into multiple formats such as HLS, DASH, MP4, and CMAF in a single job and outputs them to S3. A single job can simultaneously generate multiple outputs (combinations of resolution, bitrate, and codec), and manifest files for adaptive bitrate streaming are automatically generated. While MediaLive specializes in real-time encoding for live streaming, MediaConvert is optimized for file-based transcoding of VOD (Video on Demand) content.

Job Configuration and Codecs

MediaConvert jobs are structured in three layers: input settings, output groups, and output settings. Input settings specify the source file's S3 path, clipping (start and end times), deinterlacing, and noise reduction. Output groups define delivery formats such as HLS groups, DASH groups, and file groups, with multiple outputs (720p/1080p/4K) configured within each group. Supported codecs include H.264 (AVC), H.265 (HEVC), AV1, and VP9. H.265 achieves equivalent quality to H.264 at approximately 50% lower bitrate. AV1 offers even higher compression efficiency but requires longer encoding times. Note that output with codecs such as H.265, AV1, and XAVC falls under Professional Tier, and the unit price is higher than when everything is done with H.264 alone (as of August 2026). Codec choice is a design decision that affects not only image quality and encoding time but also billing. Job templates let you save frequently used settings and reuse them from the API or console.

Pipeline and Automation

You can build a video processing pipeline that detects file uploads to S3 via EventBridge and automatically triggers MediaConvert jobs from a Lambda function. Job completion and error events are also delivered as EventBridge events, so you can automate downstream processing (metadata updates, CDN cache invalidation, notification delivery). Queue priority control makes it possible to process urgent jobs with priority while running batch processing on low-priority queues. Reserved queues (RTS = Reserved Transcode Slots) secure dedicated transcoding capacity at a fixed rate and process large volumes of jobs at stable throughput. However, purchasing RTS involves a 12-month commitment, and after purchase you cannot cancel it, nor can you reduce the number of slots. Charges for the reserved capacity accrue even if you do not use up the queue, so choose this when you can expect a steady processing volume. DRM (Digital Rights Management) integration lets you apply Widevine, FairPlay, and PlayReady content protection to outputs.

MediaConvert Pricing

MediaConvert pricing is pay-per-use based on the output's resolution, codec, frame rate, and quality setting (Single pass / Single pass HQ) (as of August 2026, N. Virginia Region and Tokyo Region). All of the following are unit prices per minute of output for H.264 (AVC), 30 fps or lower, and Single pass HQ. In the N. Virginia Region, Basic Tier is $0.0075 for SD (480p and below), $0.015 for HD (720p/1080p), and $0.030 for 4K UHD, while Professional Tier is $0.012 for SD, $0.024 for HD, and $0.048 for 4K UHD. The Tokyo Region is higher than this: Basic Tier is SD $0.0085, HD $0.017, and 4K UHD $0.034, and Professional Tier is SD $0.0136, HD $0.0272, and 4K UHD $0.0544. As the frame rate rises, so does the unit price: for Basic Tier HD in the N. Virginia Region, more than 30 fps and up to 60 fps is $0.0188, and more than 60 fps and up to 120 fps is $0.0225. Professional Tier applies when using output codecs such as H.265 (HEVC), AV1, and XAVC, in addition to advanced features such as HDR10+ and Dolby audio. For example, HD H.265 output (under the same conditions) is $0.048 per minute in the N. Virginia Region, a wide gap from the Basic Tier unit price ($0.015) for outputting the same HD with H.264. Reserved queues (RTS) are a format in which you pay a fixed rate for the number of slots reserved, and for workloads with consistently high processing volumes they can keep the unit price lower than on-demand. However, purchase involves a 12-month commitment, you cannot cancel after purchase, and you cannot reduce the number of slots (to increase them, you switch to a new 12-month commitment with a larger number of slots). When the commitment period ends, the queue remains but jobs are no longer run, so decide on your operating policy together with the auto-renewal setting. For estimates, keep in mind that the unit price changes for each combination of resolution, codec, and frame rate, not just with the number of outputs, and calculate using the total duration of all outputs generated for adaptive bitrate delivery.

Designing Adaptive Bitrate Delivery

In adaptive bitrate delivery, which switches image quality according to the viewer's network conditions, the key is a design that prepares outputs at multiple resolutions and bitrates. Build stepwise variations from low to high quality (a so-called ladder) so that the player can choose the optimal one for the available bandwidth. A single job can generate all rungs at once, and HLS and DASH manifests are also created automatically. Adopting CMAF, which allows common assets to be reused across multiple delivery formats, can keep storage capacity and operational duplication down. This is the core part of delivery design, balancing viewing experience and delivery efficiency.

Delivery Integration with CloudFront

The standard practice is to deliver transcoded video from CloudFront with S3 as the origin. By caching at the edge, you can deliver to viewers around the world with low latency and also keep the load on the origin down. For paid content, restrict access with signed URLs or signed cookies so that only authorized viewers can play it. Integration such as detecting transcoding completion with EventBridge and updating the CDN cache as needed can also be automated. By assembling everything from conversion to delivery as a pipeline, you can minimize operational effort.

Captions, Audio, and Accessibility

MediaConvert also supports processing of captions and multiple audio tracks. Captions can be added in formats such as WebVTT, which helps ensure accessibility for people with hearing needs and supports multiple languages. For audio, you can bundle tracks in multiple languages and make it possible for viewers to switch between them. If you apply loudness adjustment to align volume levels with the standards of the delivery destination, you can prevent the discomfort of volume varying between pieces of content. By refining not only the video but also captions and audio, you can achieve delivery that is easy to use for a wide range of viewers.

Optimizing Image Quality and Processing Efficiency

To maintain image quality at a limited bitrate, an encoding method that automatically adjusts the required bitrate based on quality works well. Because it optimizes the amount of data according to the scene while maintaining a consistent level of quality, you can deliver high image quality without waste. Newer codecs have higher compression efficiency but take longer to encode, so choose based on the balance between delivery scale and processing time. When handling large volumes of video, use features that speed up processing and mechanisms that separate queues by purpose to control priority, so that urgent jobs and batch processing are both handled. Design the trade-offs among cost, quality, and speed.

Summary

AWS Elemental MediaConvert is a service that transcodes file-based video at broadcast quality and generates multiple formats including HLS, DASH, and MP4 in a single job. It lets you build large-scale VOD content processing workflows with EventBridge and Lambda automation pipelines, queue priority control, and DRM integration.

References (Official AWS Resources)

The primary sources for this page are the official AWS website and documentation. Check the official pages below for the latest specifications and pricing.

If this page and the official documentation disagree, treat the official documentation as authoritative.

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