Adaptive Streaming

This topic describes how to implement media playback using adaptive bitrate streaming, including live streaming.

Related Info

Adaptive streaming is media streaming which adjusts its bit rate during playback. It offers reduced network usage and buffering time, and increased picture quality compared to traditional media streaming. For more information, see Adaptive bitrate streaming on Wikipedia.

The AVPlay API supports 3 common adaptive streaming engines. The following table lists the file extensions for which adaptive streaming is enabled.

Streaming Engine	File Extensions
MPEG-DASH	.xml .mpd
Smooth Streaming	.ism/Manifest
HTTP Live Streaming (HLS)	.m3u8

Table 1. Supported file extensions for adaptive streaming

NoteFor more information on the versions of HLS supported on Samsung TVs, see the General Features.

The HTML5 video element does not support adaptive streaming. You must use the AVPlay API.

Playing Adaptive Streaming Media

Adaptive streaming media playback is implemented using the AVPlay API in the same way as other media. The AVPlay instance handles the adaptive streaming media type based on the basic specifications for the stream.

When the AVPlay instance is in the IDLE state, you can adjust some adaptive streaming parameters by calling the setStreamingProperty() method with the ADAPTIVE_INFO property:

...
var bitRateString = 'BITRATES=5000~10000|STARTBITRATE=HIGHEST|SKIPBITRATE=LOWEST';

webapis.avplay.setStreamingProperty('ADAPTIVE_INFO', bitRateString);
...
webapis.avplay.prepare();

The following table specifies the allowed parameters and values for the ADAPTIVE_INFO property. You can set multiple parameters by separating them with a "|" character.

Parameter	Description	Values
`BITRATES`	Bit rate of the stream	Range indicated by a "~" character, or a fixed bit rate. For example: BITRATES= 5000~50000 BITRATES=6000
`FIXED_MAX_RESOLUTION`	Maximum streaming resolution (for 4K and 8K streaming only, if resolutions not defined in meta data)	"widthXheight" in pixels, for example "3000x2000"
`STARTBITRATE`	Bit rate for the start of adaptive streaming	`LOWEST`, `HIGHEST`, `AVERAGE`, or a fixed number as a string
`SKIPBITRATE`	Bit rate to ignore during streaming	`LOWEST`, `HIGHEST`, `AVERAGE`, or a fixed number as a string
`START_TIME`	Resume time for live streaming	Time in milliseconds

Table 2. ADAPTIVE_INFO parameters

The following bit rates are recommended for each stream resolution:

Resolution	Bit Rates
8K (7680x4320)	60Mbps / 45Mbps / 25Mbps
4K (3840x2160)	15Mbps / 10Mbps
2560x1440	6.5Mbps
FHD (1920x1080)	5Mbps, 3Mbps
HD (1280x720)	1.5Mbps

Table 3. Recommended streaming bit rates

Implementing 4K and 8K Adaptive Streaming

To implement adaptive streaming for 4K and 8K resolution TVs:

Check whether the device supports 4K or 8K video streaming.

Define the supported screen resolutions for your content.

You can do this in 2 ways:

Define each stream resolution in the content meta data:

MPEG-DASH stream meta data ("MPD" file)

...  
<AdaptationSet ...>
  ... 
  <Representation id="2" mimeType="video/mp4" codecs="hev1.2.4.L150.90" width="3840" height="2130" ...>
    <BaseURL>input_video_3840x2130_7000k_dashinit.mp4 </BaseURL>
    <SegmentBase indexRangeExact="true" indexRange="2923-3194"> 
      <Initialization range="0-2922"/>
    </SegmentBase>
  </Representation> 
  …
  <Representation id="6" mimeType="video/mp4" codecs="hev1.2.4.L180.90" width="7680" height="4320" ...>
    <BaseURL>input_video_7680x4320_30000k_dashinit.mp4</BaseURL> 
      <SegmentBase indexRangeExact="true" indexRange="2889-3172">
        <Initialization range="0-2888"/>
      </SegmentBase>
    </Representation>
    ...
  </AdaptationSet>

HLS stream meta data ("M3U8" file)

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-STREAM-INF:BANDWIDTH=24576000,RESOLUTION=7680x4320 
  7680x4320_1/output.m3u8 
#EXT-X-STREAM-INF:BANDWIDTH=10240000,RESOLUTION=3840x2160
  3840x2160_1/output.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=6502400,RESOLUTION=2560x1440
  2560x1440_1/output.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=4403200,RESOLUTION=1920x1080
  1920x1080_1/output.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=3072000,RESOLUTION=1280x720
  1280x720_1/output.m3u8

If the stream resolutions are not fully defined in the meta data, or if you want simply to define a maximum stream resolution, set the desired maximum resolution using the setStreamingProperty() method of the AVPlay API:
```
...
webapis.avplay.setStreamingProperty("ADAPTIVE_INFO", "FIXED_MAX_RESOLUTION=7680x4320");
...
webapis.avplay.prepare();
```

Recommended 8K Adaptive Streaming Content Specifications

The following table describes the recommended specifications for MPEG-DASH streaming at 8K resolution.

Item	Recommendation	Notes
Video Codec	HEVC (H.265)	Profile: Main10 6.1 Maximum reference frames (decoded buffers): 6 Recommeded number of I-frames: 1 frame/GOP GOP structure: SAP1 or SAP2 If any GOP has continuous I-frames, data feeding delay can cause jittering. Maximum I-frame size: 60p: 3.5Mbyte 30p: 7Mbyte
Audio Codec	AAC (2 channel) DD/DD+ (5.1, 7.1)	-
Media Format	fMP4	fMP4 recommended for compatibility with 2018-19 models Supported: CMAF (since 2020 models)
Resolution	Maximum 7680x4320	Multiple resolutions and bit rates recommended to support changes in network conditions.
Frame Rate	30fps, 25fps, or 24fps	Supported: Maximum 60fps (50, 25, 24, 23.97)
Bit Rate	Maximum 80Mps	Supported: Average 100Mbps
Streaming Protocol	MPEG-DASH	Recommeded segment duration: VOD: max 6 seconds LIVE: max 2 seconds
HDR	HDR10+	Supported: HLG, HDR10, HDR10+
DRM	PlayReady CENC (CTR) encryption	Supported: CBCS encryption (since 2019 models)
Subtitles	SMPTE-TT (internal) WebVTT (external)	-

Table 4. Recommended content specifications for 8K MPEG-DASH streaming

The following table describes the recommended specifications for HLS streaming at 8K resolution.

Item	Recommendation	Remarks
Video Codec	HEVC (H.265)	Profile: Main10 6.1 Maximum reference frames (decoded buffers): 6 Recommeded number of I-frames: 1 frame/GOP GOP structure: SAP1 or SAP2 If any GOP has continuous I-frames, data feeding delay can cause jittering. Maximum I-frame size: 60p: 3.5Mbyte 30p: 7Mbyte
Audio Codec	AAC (2 channel) DD/DD+ (5.1, 7.1)
Media Format	MPEG-TS	MPEG-TS recommended for compatibility with 2018-19 models Supported: fMP4, CMAF (since 2020 models)
Resolution	maximum 7680x4320	Multiple resolutions and bit rates recommended to support changes in network conditions.
Frame rate	30fps, 25fps or 24fps	Supported: Maximum 60fps (50, 25, 24, 23.97)
Bitrate	Maximum 80Mps	Supported: Average 100Mbps
Streaming Protocol	HLS	Recommeded segment duration: VOD: max 6 seconds LIVE: max 4 seconds
HDR	HDR10+	Supported: HLG, HDR10, HDR10+
DRM	AES-128 encryption	Supported: PlayReady with CMAF format (since 2020 models) CENC (CTR) encryption , CBCS (since 2019 models)
Subtitles	SMPTE-TT (text) (external) WebVTT (external)	-

Table 5. Recommended content specifications for 8K HLS streaming

Live Streaming Limitations

The jumpForward(), jumpBackward(), and seekTo() methods of the AVPlay API, which are related to live seeking, have limited functionality in live streaming. If you want to use live seek, the streaming server must maintain past and future segments. The seekable range is limited to the segments maintained on the server. The following table lists the streaming engines that support live seek.

Streaming Engine	Live Seek Support
MPEG-DASH	Yes
Smooth Streaming
HTTP Live Streaming (HLS)

Table 6. Streaming engines supporting live seek