[Kdenlive-devel] AVCHD/h264 decoding benchmarking

[Dan Dennedy]

On Wed, Dec 17, 2008 at 12:50 AM, Jean-Michel Pouré <jm at poure.com> wrote:
>
> * Does h264 and AVCHD use sliced decoding which I saw in SVN? Is h264

There are various flavors of AVCHD, and I expect to see differing
number of slices per frame, but this is not yet something I have
investigated even though I have samples from a few different cameras.

> decoding really multi-threaded?

Maybe. For me, by default, it always complains "Cannot parallelize
deblocking type 1," meaning no. However, if I supply the ffplay option
"-skiploop 48" then the complaint goes away. I am still doing testing
and investigation.

> When using ffplay, I see only one core
> working at 100%. How to activate multi-threading decoding.

configure with --enable-pthreads and run ffplay with the -threads
option followed by the number of worker threads to use. It will still
keep a decoder control thread and separate reader/output threads, all
of which are fairly light, so it is a good idea to use (#cores - 1)
for the worker threads.

-- 
+-DRD-+