Re: transcoding flv to mp4

[Celejar <celejar@gmail.com>]

On Tue, 5 Oct 2010 17:31:59 -0400
Rob Owens <rowens@ptd.net> wrote:

> On Tue, Oct 05, 2010 at 01:15:16PM -0400, Celejar wrote:
> > And why on earth is the default behavior to multiply the size by a
> > factor of four just to retain the same quality?  Is mp4 really such an
> > inferior format to flv that this is required to retain the level of
> > quality?
> > 
> mp4 is a container, but my understanding is that it can use many
> different codecs for both audio and video.  I don't know if there is a
> "standard" codec that is normally used with mp4 containers, and I don't
> know what ffmpeg uses by default.  But I do know that with most
> containers, ffmpeg lets you specify the -vcodec and -acodec separately.
> Perhaps there is a better video codec to use.  And more importantly, you
> should find out what codec the recipient is expecting to see in your mp4
> container.

And flv is also a container, so I suppose that what I really want to do
is "transcontainerify" rather than transcode, i.e., to repack the video
into a different container, without reencoding it.  Is this even
possible?

In the YouTube video that I was working with, the video codec of the
initial video was h264, and ffmpeg was (by defaulting) producing video
output in mpeg4.  I suppose that I could try playing with the output
codec and see how that affects quality and size.  But as stated above,
it would really be great to do this without transcoding, just repacking
into a different container.

Celejar
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