How to download 96kbps HE-AAC radio 3 stream?

Tue Apr 19 11:19:28 PDT 2016

On Tue Apr 19 16:35:18 BST 2016, ChenZhe wrote:

> I am out of UK, so normally I could only download
> in 'hlsaaclow' and 'flashaaclow' mode
> which are of 48kbps HE-AAC quality @ 48kHz.

Hello ChenZhe, welcome to the list :-)
... Yes, that is true, for non-UK IPs flash (over RTMP)
and hls (i.e. AppleHLS, over HTTP) radiomodes will get
you the "*aaclow" quality variants (only for those streams
that impose geo-filtering), which are
HE-AACv1 @ 48kbpsABR; v1 stands for SBR
(read more at:
https://en.wikipedia.org/wiki/High-Efficiency_Advanced_Audio_Coding
https://en.wikipedia.org/wiki/Spectral_band_replication ),
if your software/hardware audio player is SBR compatible,
then it can play back the full SR of 48kHz, else it'll
fall back to just half the value @24kHz.

Since October 2015, most AOD on BBCiPlayerRadio
received the "Audio Factory" treament (BBC World Service
was the last to get it), so the default BR on desktop browsers
was uplifted to AAC LC @320kbpsABR[48kHz] in the UK
and HE-AACv1 @ 96kbpsABR[48kHz] elsewhere.

(NB: I can't see how you found out the SR to be 44.1kHz,
I am also overseas and all AOD (even the 48kbps encodes)
are at a SR of  48kHz; 44.1kHz (downsampled) may have been
the case in the past, but well over a year ago it was restored
by Audio Factory to original value of 48kHz; currently, only
MP3 podcasts and Shoutcast live MP3 streams are downsampled
to 44.1kHz, for compatibility with legacy devices...)

World Service does not geo-locate,  96kbps is the maximum
BR you get globally.
 But sadly, the method of delivery has also changed:
For desktop browsers with the Adobe Flash Player Plugin
(ActiveX, NPAPI, PPAPI) it is now AdobeHDS
https://en.wikipedia.org/wiki/Adaptive_bitrate_streaming#Adobe_HTTP_Dynamic_Streaming
while if you have
1) a compatible OS
2) a compatible browser
3) opted-in to HTML5 BBC iPlayer beta
http://www.bbc.co.uk/html5

then you get those audio streams via MPEG-DASH
https://en.wikipedia.org/wiki/Dynamic_Adaptive_Streaming_over_HTTP

The current stable (2.94) release of GiP does not support
either AdobeHDS nor MPEG-DASH :-(

There exist other tools that can download unencrypted
AdobeHDS streams (the beeb do not use DRM - yet?),
have a look at
https://github.com/K-S-V/Scripts/wiki
then google for the rest, I can't be more verbose on
this subject as being off-topic...

HOWEVER, the develop branch of GiP (2.95dev)

https://github.com/get-iplayer/get_iplayer/tree/develop

did introduce support for MPEG-DASH streams
(both video and audio in the beginning, currently only
for audio, due to inherent problems with video streams).
MPEG-DASH support is realised via a native pure
perl downloader, as FFmpeg does not still have
an MPEG-DASH demuxer...

You fail to provide any info on your OS used,
GiP-2.95dev is undocumented and unsupported by its developer.
Have a read at
https://github.com/get-iplayer/get_iplayer/wiki/gipdev
If on Windows, I have posted in the past
about trialing the dev version, it's in the list
archives, most recent post at:
http://lists.infradead.org/pipermail/get_iplayer/2016-April/008848.html

MPEG-DASH streaming method is reflected in
the "dash" modes - in latest 2.95dev snapshot, tv
and radio modes have been consolidated, dash for AOD
is the default (radio)mode, --type=radio, though recommended,
is now not strictly needed, so with latest 2.95dev you'd type:

perl get_iplayer-295dev.pl --pid=b0770h0q

==================================
C:\Program Files\get_iplayer>perl get_iplayer-295dev.pl --pid=b0770h0q
(harmless WARNINGS snipped)
get_iplayer 2.95-dev, Copyright (C) 2008-2010 Phil Lewis
  This program comes with ABSOLUTELY NO WARRANTY; for details 
use --warranty.
  This is free software, and you are welcome to redistribute it under 
certain
  conditions; use --conditions for details.

INFO: Episode-only pid detected
INFO: Trying pid: b0770h0q using type: tv
INFO: Trying to stream pid using type tv
INFO: pid not found in tv cache
Matches:

INFO: 1 Matching Programmes
INFO: Checking existence of original version
INFO: dashmed1,dashmed2,dashlow1,dashlow2 modes will be tried for version 
origin
al
INFO: Trying dashmed1 mode to record radio: Sunday Feature - Menuhin at 100
INFO: File name prefix = Sunday_Feature_-_Menuhin_at_100_b0770h0q_original

INFO: Begin recording file: D:\Vangelis\iPlayer 
Recordings\Sunday_Feature_-_Menu
hin_at_100_b0770h0q_original.partial.m4a.m4a
INFO: Recorded: 29.99MB in 00:02:23 at  1718kbps to D:\Vangelis\iPlayer 
Recordin
gs\Sunday_Feature_-_Menuhin_at_100_b0770h0q_original.partial.m4a.m4a
INFO: Begin converting file: D:\Vangelis\iPlayer 
Recordings\Sunday_Feature_-_Men
uhin_at_100_b0770h0q_original.partial.m4a.m4a
size=   30669kB time=00:43:16.69 bitrate=  96.8kbits/s speed=1.37e+003x
INFO: Converted file: D:\Vangelis\iPlayer 
Recordings\Sunday_Feature_-_Menuhin_at
_100_b0770h0q_original.partial.m4a
INFO: Recorded file: D:\Vangelis\iPlayer 
Recordings\Sunday_Feature_-_Menuhin_at_
100_b0770h0q_original.m4a

INFO: MP4 tagging M4A file

 Started writing to temp file.
 Progress: =============================================>100%|
 Finished writing to temp file.
==================================

dashmed => HE-AACv1 96kbpsABR
dashlow => HE-AACv1 48kbpsABR

As for downloading speeds, experiment with either dashmed1 or dashmed2
and stick in the future with the one that works best for your 
location/connection
particulars (this has been a list topic in the past, many random factors
control DL speeds, so it's not safe to generalise..).

Best Regards,
Vangelis. 