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 \ http://demo.unified-streaming.com/video/tears-of-steel/tears-of-steel.ism/Manifest
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 \ http://demo.unified-streaming.com/video/tears-of-steel/tears-of-steel.ism/tears-of-steel-audio_eng=64013-video_eng=407000.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 \ http://demo.unified-streaming.com/video/tears-of-steel/tears-of-steel.ism/.f4m
The URL is an MPEG-DASH manifest file. The output is fMP4.
#!/bin/bash unified_capture -o video.mp4 \ http://demo.unified-streaming.com/video/tears-of-steel/tears-of-steel.ism/.mpd
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.
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/video/tears-of-steel/tears-of-steel.ism/Manifest?t=00:00:15.000"
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 \ "http://demo.unified-streaming.com/video/tears-of-steel/tears-of-steel.ism/Manifest?t=00:00:00.000-00:04:00.000" unified_capture -o chapter2.ismv \ "http://demo.unified-streaming.com/video/tears-of-steel/tears-of-steel.ism/Manifest?t=00:04:00.000-00:08:00.000" unified_capture -o chapter3.ismv \ "http://demo.unified-streaming.com/video/tears-of-steel/tears-of-steel.ism/Manifest?t=00:08:00.000"
Once the output is fully captured, it can be processed further.
You can use the Unified Origin for playback in all formats, use specially
purposed tools to verify the audio/video streams, or use Unified Packager
to convert from fragmented MP4 to progressive MP4. Do note that progressive MP4's
created from content that was captured using the
--frame-accurate option will only
play on advanced players.