Hi,
Am 19.10.2010 00:33, schrieb Rob:
--- On Sun, 10/17/10, Ichthyostega<p...@ichthyostega.de> wrote:
I agree that using the quicktime wrapper as an
intermediate format is a good
thing, ... However, the sound support seems pretty
dismal.
Indeed
However, the defacto standard for pc pcm sound
(pcm_s16le)
In containers invented by Microsoft (like wav or avi), yes.
On all Apple formats it's pcm_s16be. I would be careful
calling something "defacto standard".
The best supported uncompressed audio format in quicktime
is "twos" (big endian, 16 bit). But there is also a "sowt"
codec, (little endian, 16 bit), which is identical to
M$-style formats.
...
processed as follows: ffmpeg -i 01.MTS -vcodec mjpeg
-deinterlace -s 848x480
-r 29.97 \ -sameq -acodec pcm_s16le -ac 2 -ab 48000
out.mov
This should make a "sowt" audio track
We all know Cinelerra is queer :-D But maybe ffmpeg is
"crossed over" too...
I don't know is cinelerra supports "sowt". But it could easily be
added though. "twos" always works.
I had only success when using big endian sound samples,
i.e. "-acodec pcm_s16be" when transcoding with ffmpeg
This makes "twos"
OK. so I downloaded the quicktime file format specification document from apple
and it came to me like a vision, like a flash written across the sky...or at
least on one of the pages in the PDF document:
quicktime is a network order wrapper format. It likes things in big endian
format.
and that's always the question with wrappers: do they expect the data in them
to follow their byte ordering? has lead to much pulling of out of my hair on
other projects as well, dealing with obscure networking protocols.
In theory the container and codec should be independent. In practice,
the company which defines the container also defines the codecs. And
therefore the byte ordering is usually the same.
Quicktime is actually the more flexible format since it has a "sowt"
codec. Storing big endian audio in wav or avi isn't possible AFAIK.
Burkhard
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