Reduced resolution and sync problems

[RS]

From: Alan Milewczyk
Sent: Tuesday, January 9, 2018 3:52 AM

>Hi Dave

>On 09/01/2018 07:04, Dave Widgery wrote:
>> My internet connection is very poor at the moment and I am guessing
> >that if either the sound and vision files get an error they do not
> >match up correctly when the final file is created. but I still don't
> >understand why the quality and file size has dropped when I am still
> >using the same --tvmode=vgood

>Without looking at the release notes, my guess would be that the definition 
>of what --tvmode=vgood actually means has varied periodically. Dinky has a 
>habit of tinkering around with things, as we saw recently with the merging 
>of higher quality audio into the video files, then going back on that once 
>it became evident that there were sync problems.

Alan is right that the --tvmode aliases change their meaning from time to
time.  For that reason I prefer to select the mode I want from
https://github.com/get-iplayer/get_iplayer/wiki/modesref#recording-mode-details
despite what it says after STOP.

I don't think your problem is being caused by such a change.  That page only
shows the current aliases and it is not easy to retrieve the historical
information.  Even so
--tvmode=vgood
translates to
--tvmode=hlsvhigh,hvfxhigh,dvfxhigh,hlsstd,hlsxstd,hvflow,hvflow

600 Mbyte/h is about right for HLSvhigh.  I suspect what is happening is
that your poor connection is causing errors and/or timeouts.  If there is an
error which can't be recovered from get_iplayer will step through all the
HLSvhigh modes and then on to the HVFxhigh modes and then on through the
list.  If you are seeing separate video and audio downloads it may have got
to DVFxhigh.

That is only speculation.  To find out what is happening you will have to
look at the get_iplayer stdout output.

Best wishes
Richard