Adaptive Bitrate Streaming
Last update：2025-03-21 14:58:38
Adaptive Bitrate (ABR) streaming solves the challenges of diverse user devices and varying network conditions. This technology automatically delivers video content at the most appropriate bitrate for each user’s current connection, ensuring optimal viewing experiences across all devices and network conditions.
CDNetworks provides comprehensive ABR support for both HLS and DASH packaging formats.
How to Use
Structure your fops parameter in the request body as follows:
<op>/<Format>
/envBandWidth/<value>
/multiAb/<value>
/multiVb/<value>
/multiResolution/<value>
|saveas/<Urlsafe_Base64_Encode(bucket:filekey)>
Parameters
| Parameter | Required | Description |
|---|---|---|
op |
Yes | Operation type. For Adaptive Bitrate Streaming, use avthumb. |
format |
Yes | Target format for output. Supports m3u8 (HLS), mpd (DASH), etc. |
envBandWidth |
No | The bandwidth thresholds for HLS streaming that trigger stream switching. • Configure up to five thresholds (minimum of two required) • Valid range: 50,000 to 30,000,000 b/s • Example: 60000:150000:500000Important Notes: 1. Required when output is in HLS format 2. Must match the count of multiVb, multiAb, and multiResolution values3. Threshold values should be close to transcoding bitrate values 4. Values must be arranged in ascending order |
multiAb |
No | Audio bitrates for each quality level, in bits per second. • Configure up to five audio bitrates (minimum of two required) • Example: 64k:128k:256kImportant Notes: 1. Must match the count of multiVb and multiResolution values2. Cannot be used with the standard audio transcoding parameter ab |
multiVb |
No | Video bitrates for each quality level, in bits per second. • Configure up to five video bitrates (minimum of two required) • Example: 128k:600k:1.25mImportant Notes: 1. Must match the count of multiAb and multiResolution values2. Cannot be used with the standard video transcoding parameter vb |
multiResolution |
No | Resolutions for each quality level, formatted as wxh.• Configure up to five resolutions (minimum of two required) • Resolution can be specified in two ways: 1. Width and Height: Define both dimensions explicitly (e.g., 320x240:640x480:1080x720)Note: This may stretch videos if output aspect ratios differ from the original 2. Width or Height: Set only one dimension and use -1 for the other (e.g., 320x-1:-1x480:1080x-1)The unspecified dimension will automatically scale to maintain the original aspect ratio |
saveas |
No | Output location as URL-safe Base64-encoded string: Urlsafe_Base64_Encode(bucket:savedfilename) |
Examples
Example 1: HLS Adaptive Bitrate
This example creates an adaptive bitrate HLS stream with two quality levels from a source file named test_hls.m3u8:
Quality Levels:
- Level 1:
- Bandwidth threshold: 60 kb/s
- Video bitrate: 128 kbit/s
- Audio bitrate: 64 kbit/s
- Resolution: 320x240
- Level 2:
- Bandwidth threshold: 100 kb/s
- Video bitrate: 600 kbit/s
- Audio bitrate: 128 kbit/s
- Resolution: 640x480
Pseudocode request:
curl -v -X POST
–d "bucket=Urlsafe_Base64_Encode(vod-wcs-test001)&key=Urlsafe_Base64_Encode(test_hls.m3u8)&fops=Urlsafe_Base64_Encode(avthumb/m3u8/envBandWidth/60000:100000/multiAb/64k:128k/multiVb/128k:600k/multiResolution/320x240:640x480|saveas/Urlsafe_Base64_Encode(vod-wcs-test001:test_file.m3u8))&force=1&separate=1"
–H "Authorization:AccessKey:EncodeSign"
--url "http://mgrDomain/fops"
Actual request:
curl -v -X POST
-d "bucket=dm9kLXdjcy10ZXN0MDAx&key=dGVzdF9obHMubTN1OA==&fops=YXZ0aHVtYi9tM3U4L2VudkJhbmRXaWR0aC81MDAwMDoxMDAwMDAvbXVsdGlBYi82NGs6MTI4ay9tdWx0aVZiLzEyOGs6NjAway9tdWx0aVJlc29sdXRpb24vMzIweDI0MDo2NDB4NDgwfHNhdmVhcy9kbTlrTFhkamN5MTBaWE4wTURBeE9uUmxjM1JmWm1sc1pTNXRNM1U0&force=1&separate=1"
-H "Authorization:AccessKey:EncodeSign"
--url "http://mgrDomain/fops"
Example 2: DASH Adaptive Bitrate
This example creates an adaptive bitrate DASH stream with two video quality levels and one audio stream from a source file named test.mp4:
Streams:
- Video Stream 1:
- Bitrate: 128 kbit/s
- Resolution: 320x240
- Video Stream 2:
- Bitrate: 600 kbit/s
- Resolution: 640x480
- Audio Stream:
- Bitrate: 64 kbit/s
Pseudocode request:
curl -v -X POST
–d "bucket=Urlsafe_Base64_Encode(vod-wcs-test001)&key=Urlsafe_Base64_Encode(test_hls.m3u8)&fops=Urlsafe_Base64_Encode(avthumb/mpd/multiVb/128k:600k/multiAb/64k/multiResolution/320x240:640x480|saveas/Urlsafe_Base64_Encode(vod-wcs-test001:test.mpd))&force=1&separate=1"
–H "Authorization:AccessKey:EncodeSign"
--url "http://mgrDomain/fops"
For the actual request format, please refer to Example 1.
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