Playing BBC R3 FLAC files recorded by nightly VLC

Jim web web at audiomisc.co.uk
Mon Aug 7 01:29:18 PDT 2017


In article <DF099DCAC84F459DA06BA26B62590C0C at vasonote>, Vangelis
forthnet
<northmedia1 at the.forthnet.gr> wrote:
> @jim web The longest recording of the R3 live flac stream I ever did
> with my patched FFmpeg was 4 hour long; I did not witness any gaps;
> judging from past GiP experience, loss of segments of an HLS/DASH stream
> may happen when latency is introduced or some technical fault at the
> server side (e.g. overload); so many factors come into play that it's
> impossible to control everything on the client side; when your ffmpeg
> errors out, what is the exact nature of the error and does it resume
> recording afterwards?

The first half dozen or so Proms I've recorded work fine. Occasional 'TLS'
errors about packets of unexpected length which seem to have no effect on
the recorded audio.

Some later recordings (but not the 'Ella and Dizzy' Prom) have begun giving
me 'HTTPS' errors which represent a missed chunk of audio data. I suspect
this *is* an 'overloading' issue but can't tell. In general these ruin the
recording for me in terms of listening, but are useful for analysis
purposes. [1]

I run an ffmpeg command in a terminal window so I can watch for errors,
etc, as things get saved to files. The 'freeze' shows as the last printed
line ceases to change. Normally it updates every 4sec or so, refrehsting
the value of the amount recorded. That ceases, but no error is issued. It
just 'waits'....

Normally pressing 'q' tells ffmpeg to quit. But that doesn't work when the
above freezes occur. Either a ctrl-C or forcing the terminal window to
close is needed. The resulting file (mkv) then needs a 'cleaning' pass
though ffmpeg to play correctly.

I guess that the connection just gets 'lost' and ffpeg sits and waits for
something that never arrives.

I'm using the specific built and patched version of ffmpeg as described in
the past for the original tests which were run some time before the proms.

Jim

[1] Although in practice I'm currently more occupied with writing more on
the 1980s for http://jcgl.orpheusweb.co.uk/history/ups_and_downs.html than
analysing the recordings! Anyone of a nervous disposition should be warned
in advance that photos of events like me in a grass skirt lurk within...
8-]  I'll get back to serious analysis after the proms.

-- 
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Armstrong Audio  http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc  http://www.audiomisc.co.uk/index.html




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