I need to be able to take a single, high quality ,audio only, mp3 stream . . . convert it to ACC and create several different rates for an HLS audio stream Is this possible using Wowza Transcoder?
We have an article on how to deliver an audio only stream using Transcoder. You can add different bitrates as appropriate to your audio only Transcoder template.
https://www.wowza.com/docs/how-to-transcode-only-the-audio-channel-of-an-incoming-stream
Please make sure that you follow the instructions in the article below to have audio only HLS content to be played back.
I have followed that article (and am able to transcode the file) but how do I take that newly transcoded audio and make three lower bit rate streams that can then be bound up in a SMIL file for HLS?
Below is an audio only Transcoder template I just created that disables all video conversion and converts the audio to AAC at 48Kbps, 64Kbps, 128Kbps, and 192Kbps.
It was created via Wowza Streaming Engine Manager / live / Transcoder / Add Template after copying the audio stream name from the “Audio Only (Default)” template.
As I created each audio rendition I made sure to disable video and change audio from passthrough to AAC.
<?xml version="1.0" encoding="UTF-8"?>
<Root>
<Transcode>
<Description></Description>
<Decode>
<Video>
<Implementation>default</Implementation>
<Deinterlace>false</Deinterlace>
</Video>
</Decode>
<Encodes>
<Encode>
<Name>48K</Name>
<Enable>true</Enable>
<Description></Description>
<StreamName>mp4:${SourceStreamName}_48k_aac</StreamName>
<Video>
<Codec>Disable</Codec>
<Implementation></Implementation>
<GPUID>-1</GPUID>
<Profile></Profile>
<Bitrate>0</Bitrate>
<KeyFrameInterval>
<FollowSource>false</FollowSource>
<Interval>0</Interval>
</KeyFrameInterval>
<FrameSize>
<FitMode></FitMode>
<Width>0</Width>
<Height>0</Height>
<Crop></Crop>
<SourceRectangle></SourceRectangle>
</FrameSize>
</Video>
<Audio>
<Codec>AAC</Codec>
<Bitrate>48000</Bitrate>
</Audio>
</Encode>
<Encode>
<Name>64k</Name>
<Enable>true</Enable>
<Description></Description>
<StreamName>mp4:${SourceStreamName}_64k_aac</StreamName>
<Video>
<Codec>Disable</Codec>
<Implementation></Implementation>
<GPUID>-1</GPUID>
<Profile></Profile>
<Bitrate>0</Bitrate>
<KeyFrameInterval>
<FollowSource>false</FollowSource>
<Interval>0</Interval>
</KeyFrameInterval>
<FrameSize>
<FitMode></FitMode>
<Width>0</Width>
<Height>0</Height>
<Crop></Crop>
<SourceRectangle></SourceRectangle>
</FrameSize>
</Video>
<Audio>
<Codec>AAC</Codec>
<Bitrate>64000</Bitrate>
</Audio>
</Encode>
<Encode>
<Name>128k</Name>
<Enable>true</Enable>
<Description></Description>
<StreamName>mp4:${SourceStreamName}_128k_aac</StreamName>
<Video>
<Codec>Disable</Codec>
<Implementation></Implementation>
<GPUID>-1</GPUID>
<Profile></Profile>
<Bitrate>0</Bitrate>
<KeyFrameInterval>
<FollowSource>false</FollowSource>
<Interval>0</Interval>
</KeyFrameInterval>
<FrameSize>
<FitMode></FitMode>
<Width>0</Width>
<Height>0</Height>
<Crop></Crop>
<SourceRectangle></SourceRectangle>
</FrameSize>
</Video>
<Audio>
<Codec>AAC</Codec>
<Bitrate>128000</Bitrate>
</Audio>
</Encode>
<Encode>
<Name>192K</Name>
<Enable>true</Enable>
<Description></Description>
<StreamName>mp4:${SourceStreamName}_192k_aac</StreamName>
<Video>
<Codec>Disable</Codec>
<Implementation></Implementation>
<GPUID>-1</GPUID>
<Profile></Profile>
<Bitrate>0</Bitrate>
<KeyFrameInterval>
<FollowSource>false</FollowSource>
<Interval>0</Interval>
</KeyFrameInterval>
<FrameSize>
<FitMode></FitMode>
<Width>0</Width>
<Height>0</Height>
<Crop></Crop>
<SourceRectangle></SourceRectangle>
</FrameSize>
</Video>
<Audio>
<Codec>AAC</Codec>
<Bitrate>192000</Bitrate>
</Audio>
</Encode>
</Encodes>
</Transcode>
</Root>
Brilliant, Thanks Kevin. Works like a charm.
You will need to install the MultiTrackVOD module to switch between audio tracks when video is included.
https://www.wowza.com/docs/how-to-select-multiple-tracks-from-a-vod-file-modulemultitrackvod
Apple HLS:
MPEG-DASH:
