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When stream playback is requested, transcoding profile name shoould should be added to stream name to transcode this stream, for example
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It is recommended to set hyphenated profile names for convinuenceconvenience.
Server restart is necessary to apply changes in cdn_profiles.yml file.
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| Parameter | Values available | Description |
|---|---|---|
| Audio parameters | ||
| codec | opus mpeg4-generic speex | Audio codec to use |
| bitrate | Depends on quality required and bandwith bandwidth available | Audio bitrate, bps |
| rate | 8000 11025 12000 16000 22050 24000 32000 44100 48000 | Audio sample rate, kHz |
| channels | 1 2 | Channels quantity: mono or stereo |
| Video parameters | ||
| codec | h264 vp8 | Video codec to use |
| bitrate | Depends on quality required and bandwith bandwidth available | Video bitrate, kbps |
| width | Depends on quality required and bandwith bandwidth available | Picture width |
| height | Depends on quality required and bandwith bandwidth available | Picture height |
| codeImpl | FF OPENH264 | Video codec used: based on FFmpeg or OpenH.264 |
| gop | Depends on quality required and bandwith bandwidth available | Key frames frequency (GOP) |
| fps | Depends on quality required and bandwith bandwidth available | Frames frequency per second |
| quality | Depends on quality required and bandwith bandwidth available | Video quality |
| preset | ultrafast superfast veryfast faster fast medium slow slower veryslow placebo | FFmpeg preset, ultrafast by default |
| profile | Depends on required quality required | FFmpeg profile, Baseline by default |
| level | Depends on required quality required | FFmpeg level, 3.1 by default |
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- audio:
- bitrate
- codec
- rate
- channels
- video:
- bitrate
- codec
- width
- height
- quality
If some of those parametes parameters are omitted in profile creation query, they will be added to profile with 0 value for digital parameters and "" for string parameters, in this case default values will be applied.
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- Origin sends published streams data to Transcoder and Edge;
- Transcoder sends pulled streams data to Edge in the same group;
- Edge sends nothing and is always an end poit point of a route.
| Expand | ||
|---|---|---|
| ||
|
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1.2.3. Edge will pull the stteam stream from Transcoder
1.3. In other cases, Edge pulls the streastream, from Origin
2. If transcoding profile is not set on Edge server, Edge pulls the stream Origin
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Node groups and transcoding
By defautldefaut, Edge will choose Transcoder in the same group to transcode the stream by profile. For example, if CDN has two segments grouped by location: in Europe and USA, then stream translation for the stream by one profile from every group looks as follows:
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b) use OpenH264 encoder if it is necessary to keep videbitrate specified video bitrate
| Code Block | ||||
|---|---|---|---|---|
| ||||
profiles:
-240p:
audio:
codec : opus
rate : 48000
video:
height : 240
bitrate : 400
gop : 50
fps : 25
codec : h264
codecImpl : OPENH264 |