We use Jmeter with the BZM - Streaming Sampler to load test a streaming service. With this we are requesting a dash main.mpd file. That url would look like: https://url.com/5bf9c52c17e072d89e6527d45587d03826512bfa3b53a30bb90ecd7ed1bb7a77/dash/Main.mpd

Within the schema we have defined ContentProtection with value="cenc" as such:

<ContentProtection schemeIdUri="urn:mpeg:dash:mp4protection:2011" cenc:default_KID="string" value="cenc"></ContentProtection>

This schema is being auto-generated via a third party code source... So, we do not have much flexibility to change the order... I mention this because with the below schema (from a previous version of the xml generator) Jmeter works perfectly fine:

<ContentProtection value="cenc" schemeIdUri="urn:mpeg:dash:mp4protection:2011" cenc:default_KID="string"/>

The issue we are now facing is that jmeter is throwing this error:

2022-03-14 07:15:40,574 WARN c.b.j.v.c.VideoStreamingSampler: Problem downloading playlist
com.blazemeter.jmeter.videostreaming.core.exception.PlaylistParsingException: Error parsing contents from https://url/5bf9c52c17e072d89e6527d45587d03826512bfa3b53a30bb90ecd7ed1bb7a77/dash/Main.mpd
at com.blazemeter.jmeter.videostreaming.dash.Manifest.fromUriAndBody(Manifest.java:56) ~[jmeter-bzm-hls-3.0.3.jar:?]
at com.blazemeter.jmeter.videostreaming.core.VideoStreamingSampler.downloadPlaylist(VideoStreamingSampler.java:20) ~[jmeter-bzm-hls-3.0.3.jar:?]
at com.blazemeter.jmeter.videostreaming.dash.DashSampler.sample(DashSampler.java:34) ~[jmeter-bzm-hls-3.0.3.jar:?]
at com.blazemeter.jmeter.videostreaming.core.VideoStreamingSampler.sample(VideoStreamingSampler.java:79) [jmeter-bzm-hls-3.0.3.jar:?]
at com.blazemeter.jmeter.hls.logic.HlsSampler.sample(HlsSampler.java:198) [jmeter-bzm-hls-3.0.3.jar:?]
at org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.sample(HTTPSamplerBase.java:1285) [ApacheJMeter_http.jar:5.4.1]
at org.apache.jmeter.threads.JMeterThread.doSampling(JMeterThread.java:638) [ApacheJMeter_core.jar:5.4.1]
at org.apache.jmeter.threads.JMeterThread.executeSamplePackage(JMeterThread.java:558) [ApacheJMeter_core.jar:5.4.1]
at org.apache.jmeter.threads.JMeterThread.processSampler(JMeterThread.java:489) [ApacheJMeter_core.jar:5.4.1]
at org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:256) [ApacheJMeter_core.jar:5.4.1]
at java.lang.Thread.run(Thread.java:832) [?:?]
Caused by: com.fasterxml.jackson.databind.JsonMappingException: Undeclared namespace prefix "cenc" (for attribute "default_KID")
 at [row,col {unknown-source}]: [5,141]

My question is, can I alter this payload before it is ingested by Streaming Sampler to change the ContentProtection string? Or, can I automatically set the ContentProtection value as "cenc"?

EDIT

After digging through my main.mpd XML I found that the "cenc" namespace was left out. After adding:

xmlns:cenc="urn:mpeg:cenc:2013"

To the file, the main.mpd worked correctly.

CodePudding user response：

It is possible to:

1. Download the playlist using HTTP Request sampler and Save Responses to a file listener so it would be saved to your local drive. See Performance Testing: Upload and Download Scenarios with Apache JMeter article for more comprehensive instructions if needed

2. Amend the playlist as needed using JSR223 Sampler or OS Process Sampler

3. In the bzm - Streaming Sampler use local URL via file URI scheme i.e.

   file:///folder/anotherFolder/playlist.mpd 
   

You can also raise an issue in the plugin repo or if you're a BlazeMeter Customer open a BlazeMeter support ticket