[MEncoder-users] capture: synchronization problems

[Martin Collins]

On Sat, 19 Mar 2005 21:28:15 -0800 (PST)
Kyle Schmitt <azephrahel at yahoo.com> wrote:

> Mjpeg stores each frame separately so it
> might not be computationally as intense, but it chokes
> your disc bandwidth (so you get dropped frames and out
> of sync and all sorts of nastiness).

I think you exaggerate. I record mjpeg at ~10GB/h or ~3MB/s which
is less than a tenth of modern disc bandwidth. I can record for
hours without a dropped frame, albeit with a hardware mjpeg capture
device. I've only suffered desync once and that was because I was
doing three mpeg4 encodes at the same time as capturing.

> but even then I don't know if the
> added visual acuity of mjpeg vs mpeg4 is worth it for
> the pain of setting it up(or if there will even BE a
> visible difference when capturing from broadcast tv)

The two main reasons you would want to use an intermediate format like
mjpeg or DV are editability (do we have frame-accurate mpeg2/4 editors
yet?) and flexibility without huge storage size.
If you want to be able to record several hours of TV and retain the
option of cutting out adverts and archiving in good quality, mjpeg is a
valid solution.

Martin