Encoder Audio Bitrates and Custom Bitrate

Encoder Audio Bitrates
(HD Encoder, 3D Encoder, 4K Encoder)

Based on versions E3.159.14/D3.152.04 1080i5994, tested 05/07/2014.
CodecMono (1ch)2ch*4ch*6ch*8ch**
AAC***128 kbps256 kbps512 kbps768 kbps1024 kbps
GSM (mono only)77 kbps
CELP (mono only)24 kbps
AAC LOW***64 kbps
128 kbps
256 kbps
384 kbps512 kbps
GSM LOW (mono only)20 kbps
CELP LOW (mono only)12 kbps
* Set the Decoder "Audio Channels" setting to 6-channel mode when sending 1-6 channels from the Encoder.
** Set the Decoder "Audio Channels setting to 8-channel mode when sending 7-8 channels from the Encoder.
***AAC Audio bitrates are half of these above values in the SD encoder

NOTE: Mono-only codecs such as CELP and GSM will blend all channels into a single mixed channel.

Custom AAC Bitrate

As of Encoder version 3.159.17, a custom AAC bitrate is possible in HD Encoder. Only on HD streams is the bitrate customizable; SD streams will remain with pre-programmed audio bitrates, above.

For Rackmount Encoders:
  1. Access the Windows Desktop on the Encoder using Remote Desktop or by connecting a VGA monitor, as well as a keyboard and mouse.
  2. Check the software version by accessing the Help menu, and selecting "About."
  3. Open the file c:\Windows\win.ini on the Encoder
  4. Locate the section heading [SB_HD_ENCODER]
  5. Under that heading, add the line AAC_custom=N where N is the desired audio bitrate in Kbps per channel.
  6. Save and close the file.
For Windows Software Encoder:
  1. See above instructions for the Rackmount HD Encoder.
For OSX Software Encoder:
  1. Check the software version by accessing the Streambox HD Encoder Menu, and selecting "About Streambox Encoder."
  2. If an update is required to get above version 3.159.17, you can connect to the internet and download updates using the same menu.
  3. Locate the file /Users/<username>/Library/Preferences/com.streambox.TransportEncoderHD.plist
  4. Open the file in a plist editor such as PlistEditPro or Pref Setter.
  5. Add a new key (of the type "string") with the name "AAC_custom"
  6. Set the value of that key to the desired audio bitrate in Kbps per channel.
  7. Save and close the plist file.
For Avenir:
  1. Contact Streambox Support for assistance. Currently an internal settings xml file must be edited by an expert user to make this change.
NOTE: After making and saving changes, the Encoder software must be restarted to take effect. Close the Encoder software. On Rackmount units, the software will re-open automatically. On Laptops/desktops, it must be opened manually.
To confirm thatbitrate setting is working correctly, check the encoder logfile for the following line. (Using 256 as the example setting):
AAC_custombitrateper channel=256 Kbps