Capturing VOD

Downloading an entire presentation

Please note that embedded subtitles, CEA-608/708, will not be transcoded alongside other file information when using frame accurate capture.

MPEG-DASH

The input URL is an MPEG-DASH manifest file. The output is fMP4. We recommend capturing from an MPD that has a $Time$-based SegmentTimeline. (To configure origin for live capture, see: Using a dedicated capture server manifest)

#!/bin/bash

unified_capture -o video.mp4 \
  "https://demo.unified-streaming.com/k8s/features/stable/video/tears-of-steel/tears-of-steel.ism/.mpd"

Note

All the fragments of all the different bitrates are downloaded, therefore the output file contains multiple audio and video tracks.

If the DASH manifest contains a Tiled Thumbnail track, as described in Using CMAF Tiled Thumbnails as a source, the Tiled Thumbnails will also be captured, and saved as a separate track in the fMP4 output.

If timed metadata is present in the MPD or signaled in-band in the media segments, this is saved as a separate track in the fMP4 output.

HTTP Smooth Streaming (HSS)

For Smooth Streaming presentation the input URL is the manifest file to the video. The output is fMP4.

#!/bin/bash

unified_capture -o video.ismv \
  "https://demo.unified-streaming.com/k8s/features/stable/video/tears-of-steel/tears-of-steel.ism/Manifest"

Note

All the fragments of all the different bitrates are downloaded, therefore the output file contains multiple audio and video tracks.

HTTP Live Streaming (HLS)

The input URL for HLS (HTTP Live Streaming) is a media playlist (.m3u8). For convenience the first media playlist is captured when the input is a master/variant playlist. The output is MPEG-TS.

#!/bin/bash

unified_capture -o video.ts \
  "https://demo.unified-streaming.com/k8s/features/stable/video/tears-of-steel/tears-of-steel.ism/tears-of-steel-audio_eng=64008-video_eng=401000.m3u8"

HTTP Dynamic Streaming (HDS)

The input URL is a HTTP Dynamic Streaming manifest file. The output is FLV.

#!/bin/bash

unified_capture -o video.flv \
  "https://demo.unified-streaming.com/k8s/features/stable/video/tears-of-steel/tears-of-steel.ism/.f4m"

Downloading subclips from a stream (previews, chapters)

Unified Capture can create subclips from a larger VOD presentation. One use case is creating preview clips from longer presentations. Another use case is creating multiple chapters from a longer presentation.

Specifying the beginning and end time is in HH:MM:SS.sss format. For example, creating a 15 second preview clip from a presentation:

#!/bin/bash

unified_capture -o video-preview.ismv \
  "http://demo.unified-streaming.com/k8s/features/stable/video/tears-of-steel/tears-of-steel.ism/.mpd?t=00:03:00.000-00:03:15.000"

When only a single value for the t parameter is given, this will be considered the start time of the capture and the end of the presentation will be the end time.

When creating multiple chapters from a longer presentation you should specify both the beginning and end (except for the last chapter, of which you only need to specify the begin time). Let's say we have a 10 minutes and 32 seconds presentation and want to create 3 chapters (4 minutes, 4 minutes, 2:32 minutes):

#!/bin/bash

unified_capture -o chapter1.ismv \
  "https://demo.unified-streaming.com/k8s/features/stable/video/tears-of-steel/tears-of-steel.ism/.mpd?t=00:00:00.000-00:04:00.000"

unified_capture -o chapter2.ismv \
  "https://demo.unified-streaming.com/k8s/features/stable/video/tears-of-steel/tears-of-steel.ism/.mpd?t=00:04:00.000-00:08:00.000"

unified_capture -o chapter3.ismv \
  "https://demo.unified-streaming.com/k8s/features/stable/video/tears-of-steel/tears-of-steel.ism/.mpd?t=00:08:00.000"