iplayer audio to lpcm

[Jim Lesurf]

On 08 Nov, batguano999 <batguano999 at zoho.com> wrote:
>  > 
> >What I'm hoping to do using get_iplayer is to be able to compare such
> >results with an analysis or decoding to LPCM of the flv by other means.
> > i.e. use ffmpeg or similar. I'm wondering if anyone else here has
> >already done this, or has comments that would help. 
> > 
> Hi Are you asking for instructions how to use FFmpeg to convert an m4a
> file downloaded with get_iplayer to a different format?

No. I already know how to do something like

ffmpeg -i <infilename> -f wav outfilename.wav 

to get the required coconut. :-)

What I am asking about is if anyone has done this *and compared the results
with using the 'official' BBC flash player*. Specifically by comparing the
LPCM results.

FWIW my 'traditional' method is to get as close as possible to a system
with no needless mixings, gain changes, etc. Just to have the flash output
to LPCM delivered to an external audio DAC and digital recorder. That uses
the conversion method expected by the BBC. For all I know, get_iplayer'ing
an flv and using ffmpeg produces bit-identical results. But I suspect not,
so want to investigate.

I'm wondering what - if any - measurable difference using ffmpeg (or other
'decoders' like avcodec) may introduce. And I'd do that by comparing the
output LPCM as sets of data samples.

What I don't know is who may have already done this, by what methods, and
what their detailed results were.

Jim

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