v2.95 LiveTV mode is hvfhd

[Vangelis forthnet]

On Tue Jul 19 17:44:02 BST 2016, Anthony Kehoe wrote:

> I have tested with v2.94 and the old mode still works,
> however it's not exposed with the new version.

Hi Anthony!

 Are you absolutely certain?
The beeb have killed the old 720p25fps Live TV feeds
(--livetvmode=hlshd) many months ago, for the record
those were 1280x720p/25fps/VideoBR ~ 3500kbps
(AVC profile High at L3.2)/AudioBR ~ 128kbps
(AAC LC), so their specs were different to the
--tvmode=hlshd in use still now for VOD
[1280x720p/25fps/VideoBR ~ 2300kbps
(AVC profile High at L4.1)/AudioBR ~ 96kbps
(AAC LC)].
If in fact they do still exist somewhere, please provide
sound proof of that! GiP surely doesn't know where
to search for/find them!

Last September (2015), issue #202 was created,

https://github.com/get-iplayer/get_iplayer/issues/202

and later closed on 05/10/2015 by commit git-6f81133

https://github.com/get-iplayer/get_iplayer/commit/6f81133

which dealt (among others) with the demise of the former
HD (720p) live TV streams:

> - Removed old method of finding HLS live TV streams
> from HDS data.  Live TV streams now derived
> from Video Factory data

720p25fps live TV AdobeHDS streams were killed-off
by the beeb, so GiP couldn't generate the AppleHLS
equivalents of them...

I have a custom Windows GiP installation so I can check
various different versions of the main get_iplayer perl script;
to test further your claim, with the vanilla "tag 2.94" script
I issued:

perl get_iplayer-294.pl --type=livetv "BBC One" -i -v

which found:

INFO: Found mode hlshigh1: (gip_hls_simulcast_978) hls h264 704x396 978kbps 
stre
am (CDN: ll_hls_live/102)
INFO: Found mode hlshigh2: (gip_hls_simulcast_978) hls h264 704x396 978kbps 
stre
am (CDN: akamai_hls_live/101)
INFO: Found mode hlslow1: (gip_hls_simulcast_348) hls h264 384x216 348kbps 
strea
m (CDN: ll_hls_live/102)
INFO: Found mode hlslow2: (gip_hls_simulcast_348) hls h264 384x216 348kbps 
strea
m (CDN: akamai_hls_live/101)
INFO: Found mode hlsstd1: (gip_hls_simulcast_564) hls h264 512x288 564kbps 
strea
m (CDN: ll_hls_live/102)
INFO: Found mode hlsstd2: (gip_hls_simulcast_564) hls h264 512x288 564kbps 
strea
m (CDN: akamai_hls_live/101)
INFO: Found mode hlsvhigh1: (gip_hls_simulcast_1802) hls h264 960x540 
1802kbps s
tream (CDN: ll_hls_live/102)
INFO: Found mode hlsvhigh2: (gip_hls_simulcast_1802) hls h264 960x540 
1802kbps s
tream (CDN: akamai_hls_live/101)
INFO: Will search for versions: default

As you (or anyone) can see, no trace of a hlshd (1280x720p 3600kbps)
livetvmode! The highest quality GiP 2.94 can currently find is
hlsvhigh (960x540 1802kbps, 25fps) - a test 1min recording confirmed it:

perl get_iplayer-294.pl --type=livetv "BBC 
One" -g --livetvmode=best --hls-livetv-opts="-c copy" --force --stop 60

(my ffmpeg version is > 2.5, so I used
--hls-livetv-opts="-c copy" to avoid an
unnecessary, in my case, audio-video
recoding, the default setting in GiP 2.94)

The "hlsvhigh" livetvmode of GiP 2.94
has been re-labeled to "hvfvhigh" in GiP 2.95,
after the segregation of the "Video Factory" HLS modes...
With the vanilla 2.95 script:

perl get_iplayer-295.pl --type=livetv "BBC One" -i -v

INFO: Found mode hvfhd1: (gip_hvf_simulcast_5380) hls h264 1280x720 5380kbps 
str
eam (CDN: ll_hls_live/102)
INFO: Found mode hvfhd2: (gip_hvf_simulcast_5380) hls h264 1280x720 5380kbps 
str
eam (CDN: akamai_hls_live/101)
(snip)
INFO: Found mode hvfsd1: (gip_hvf_simulcast_3043) hls h264 960x540 3043kbps 
stre
am (CDN: ll_hls_live/102)
INFO: Found mode hvfsd2: (gip_hvf_simulcast_3043) hls h264 960x540 3043kbps 
stre
am (CDN: akamai_hls_live/101)
(snip)
INFO: Found mode hvfvhigh1: (gip_hvf_simulcast_1759) hls h264 960x540 
1759kbps s
tream (CDN: ll_hls_live/102)
INFO: Found mode hvfvhigh2: (gip_hvf_simulcast_1759) hls h264 960x540 
1759kbps s
tream (CDN: akamai_hls_live/101)

> but the default LiveTV mode is now hvfhd for HD streams
> (snip)
> hvfhd downloads at twice the bandwidth (50fps stream)
> compared to the old mode, however there
> is negligible quality improvement in general.

As I've said in the beginning of this reply,
the actual increase in bandwidth for the 720p
live stream is not 100%, but a ~ 50%
one [(5380-3630)*100/3630].
What you describe is true only for on-demand
(file size of hvfhd roughly twice of hlshd=flashhd).

If, as you say, you feel uncomfortable
with the high bitrate of hvfhd livetvmode
for - admittedly - small quality gains, you can stay
away from it by specifically asking in your
commands for --livetvmode=hvfsd
(960x540p/3043kbps/50fps) or
--livetvmode=hvfvhigh
(960x540p/1760kbps/25fps).

Better yet, wait until the TV content you are consuming
via the live TV stream has made it to on-demand,
then record the hlshd tvmode...

> Would it be possible to add
> hls modes back in for LiveTV

Please provide direct instructions as to
how those elusive hlshd (720p25fps)
live TV streams can be located; in the
event your initial claim about their existence
stands true, I wouldn't hold my breath!
In 2.95, the code maintainer has
"deprecated" live stream (TV|radio)
recording functions of GiP - they do still
work at the extent they did at 2.95's release,
however he's not inclined to further continue
support for them; most probably they'll
be ripped out from GiP in the next major release!

(... a search on your website reveals you are
an IT professional, so I guess you'll feel
at ease with the somewhat "techie" nature
of my response...)

Most kind regards,
Vangelis.