Fine-Grained Control Over MediaConvert HLS Output?

Question

In order to be backwards-compatible with our Elastic Transcoder lambda function I'm hoping I can figure out a way to achieve finer-grained control over how the output M3U8 and TS files are created.  
  
In Elastic Transcoder we can create a JobPlaylist containing a list of OutputKeys that are tailored to other public-facing services.  These services expect to see "sgmt\[N].m3u8" for each of the streams we're creating (low, medium, and high resolution), with the name of each TS segment formatted as "sgmt\[N]NNNNN.ts" (for example, "sgmt100001.ts").  
  
I've been able to get fairly close to satisfying this requirement with the existing MediaConvert jobs and presets... except I still haven't been able to figure out how to eliminate the underscore that MediaConvert insists on including in the filenames ("sgmt1_00001.ts").  
  
Is there any way to eliminate this underscore?  Barring that, is there any way (aside from having to write another lambda to wait for the first lambda to complete the transcoding) to either iterate / rename the TS files or use another MediaConvert API to achieve the same playlist effect we're currently getting with Elastic Transcoder?  
  
EDIT 26NOV19: I've also tried using the "$Number$" formatter described in the MediaConvert documentation ("Using Settings Variables with Streaming Outputs"), and it's treated as a string literal instead of a formatter in the output filename.

AWS-User-8506763 · Accepted Answer

Hi there,  
  
Thanks for reaching out.  
  
Unfortunately, at this time the '_' between the segment number and segment modifier and name modifier is hardcoded. I have passed along your request to make this parameter a custom field where you can choose to not include it to our product team.  
  
There is nothing that can be activated in the service to achieve this today. The workaround would be as you mentioned would be to wait for the job to complete triggering the file name change.  
  
Another thing to note would be that you would need to make sure to change the segment references in the variant manifest to also account for this file name change.   
  
$Number$ is a special format variable only to be used in the DASH ISO output group, name modifier.   
  
Thanks,  
Jeremy

JerryH · Answer

Thanks for looking into this for me, and hope to see a flag in the JSON configuration parameters to configure the presence / absence of the underscore soon!  I know it's probably a pretty low priority for the AWS MediaConvert development team, but I'm hoping it's a low-hanging fruit that can be released without much effort!

Fine-Grained Control Over MediaConvert HLS Output?

Relevant content