Why mp4 or mp4.ts from identical installation?

[Charles Bradshaw]

Hi RS,

I did, sort of, say which version of get_iplayer I'm using. If you
looked at dumps.txt.zip in my original post the last lines both say:
"get_iplayer Web PVR Manager v2.97, ©2009-2010 Phil Lewis - Licensed
under GPLv3".

I have been completely deceived by the fact that both installs are the
same, but the results are radically different! Further posts telling me
that ffmpeg versions might be the cause are, as it turns out, a complete
red herring.

I think you might eventualy understand the problem if I tell you that
with get_iplayer v2.98 the problem goes away completely. Then both
installs, but still using original package manager installed with
different versions of ffmpeg, produce identical .mpg files. Albeit ~1.4
times the size than when the intermediate is flash.

I'm very happy that the problem has gone away, but suggest that
somebody, hopefully with a better understanding of the internals than
me, will find themselves revisiting what must be a subtle bug. :-(

Thanks very much for your help and patients. Charles Bradshaw

On 10/02/17 10:32, RS wrote:
>> From: RS Sent: Thursday, February 9, 2017 2:00 PM
>
>> You won't get any support for Flash or rtmpdump.  They have been
>> deprecated for some months, and have been withdrawn in v2.98 of
>> get_iplayer.
>
>> You don't say which version of get_iplayer you are using or which
>> Flash mode you are trying to receive.  If you have v2.95 or above you
>> can use the HLS modes.  If you have been receiving Flashhd, try
>> tvmode=HLShd
>
>> You can find a table of modes available in v2.98 at
>> https://github.com/get-iplayer/get_iplayer/wiki/modesref
>
> Sorry, I am being obtuse.  If the downloaded file before multiplexing
> by ffmpeg has a suffix .mp4.ts, it is not a Flash file generated by
> rtmpdump. Flash files have a suffix .flv
> .mp4.ts files are generated by the newer modes, HLS, HVF, and now in
> v2.98 DVF.
> The file size with HLShd is the same as the file size with FlashHD.
> The file size with HLSvhigh is the same as the file size with Flashvhigh.
>
> If the files sizes are different it is because you have specified
> different resolutions in your --tvmode options for the two
> installations.  That is not necessarily because of something you have
> done.  Confusingly the defaults have changed between versions of
> get_iplayer, and the definitions of composite modes such as best and
> better have also changed.
>
> You can see which mode has been used from a line beginning
> INFO: Trying hlshd1 mode to record
> where hlshd1 will be replaced with the mode you are using.
>
> You are more likely to get similar results between installations if
> you use the same versions of get_iplayer.  It will also help if you
> specify the --tvmode explicitly.  I suggest to begin with you stick to
> hlshd, hlsvhigh, and hlsstd.  Unless your connection is very slow you
> will find HLS is much faster than Flash, up to 80Mbit/s.
>
> You are right that the lack of AtomicParsley will not make your files
> unplayable.  It may make seeking slower.
>
>
>
>
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