What are the codecs, bitrates and protocols used for BBC Radio online?

Since 2015, all of BBC Radio's online content has been produced by the Audio Factory platform that provides the same quality and device support for all of our stations.

Audio Factory is the BBC’s internal name for its audio streaming infrastructure. It is not related to the radio production company of the same name or with the website www.audiofactory.co.uk.
 

Audio Factory encodes BBC Radio content using the following codecs and bitrates:

Profile Codec Bitrate Channels
1 AAC-LC 320kbs Stereo
2 AAC-LC 128kbs Stereo
3 HE-AACv1 96kbs Stereo
4 HE-AACv1 48kbs Stereo
2a MP3 128kbs Stereo


Not all of these bitrates are necessarily supported by all devices at all times. For example, a mobile phone may only be offered the lower bit rate streams when on 3G/4G to ensure the connection is more reliable and a better listening experience is achieved. Also, some devices may only be able to cope with a single bitrate and so may not offer the other options, e.g. some internet radios.

Audio Factory does not support the WMA (Windows Media Audio) encoding or delivery protocol.
 

Audio Factory packages and delivers BBC Radio using the following protocols:

Protocol Profiles Target devices
HDS 1, 2, 3 & 4 Desktop computers (PC, MAC). Requires browser Flash plugin.
HLS 1, 2, 3 & 4 Smartphones, tablets and IP radios and streamers.
MPEG-DASH 1, 2, 3 & 4 New format to replace HDS and some HLS uses.
ICY (SHOUTcast) 2a Low end Internet Radio devices and 3rd party Apps.


With the exception of Radio 3 HD, we no longer provide ICY (SHOUTcast) streams using the AAC+ codec. MP3 at 128kbs was chosen following advice from a number of internet radio device manufacturers regarding the codec and streaming protocols supported by the largest possible number of their legacy devices. Newer internet radio devices should be able to make use of the HLS and/or MPEG-DASH protocols using the higher quality AAC+ codec.