Re: [Libquicktime-devel] [PATCH] chunk_to_offset and PCM 'sowt' fixes

[Erik J. <eri...@gm...>]

Hello,

On Tue, May 7, 2013 at 11:33 AM, Burkhard Plaum
<bur...@ig...> wrote:
> How sure you about that? Do you have any sample files?
>
> I can remember double-checking the sample formats a while ago, and it turned
> out that 8 bit PCM seems *always* unsigned, even if the name sowt (twos backwards)
> suggests something else.

I came across this on movie files created by a Panasonic FX35 compact
camera. There's a sample file at http://goo.gl/2RtVy (link to google
drive document, use File->Download to get a non-streamed version). I
used google to try and find out what the right thing to do here was
and ended up at http://wiki.multimedia.cx/index.php?title=ADPCM, so I
may well be wrong. I wouldn't be surprised if some encoders do the
wrong thing here.

Regards
// Erik