[Kdenlive-devel] Does anyone have any AVCHD test clips?

[Dan Dennedy]

On Sat, Dec 13, 2008 at 12:29 PM, Jean-Michel Pouré <jm at poure.com> wrote:
> On Sat, 2008-12-13 at 18:40 +0100, Mads Bondo Dydensborg wrote:
>> My system seems unable to playback mts files in realtime too.
> I tried to play these files using ffplay. No success too, they play in
> slow motion. Not real time. It is probably impossible to drop frames
> because of AVCHD coding. MLT needs to decode all frames.

There are several problems affecting realtime playout of AVCHD:
- AVC High and Main profiles are processor intensive to begin with
- FFmpeg can not yet use multi-threading to decode most (all?) forms of AVCHD
- Those streams are played at half speed by FFmpeg. If you transcode
them to something reasonable like mpeg2 or mpeg4 at lower resolution,
you will see what I mean. You will notice that 'ffmpeg -i X' on each
file will also show double the duration after decoding. I am not yet
sure if FFmpeg is misinterpreting something or repeating frames or
what is going on.

> AVCHD does not seem at hand ...

agreed :)

> The best would be to ask ffmpeg developers.

I think they only want to talk with you if you have started debugging
it and have a patch in the works. Otherwise, they will say they know
about the problems but not willing to just educate you about them.
Basically, you need to do your homework and make a good start into
debugging the problem. Maybe a good place simply to get informed is
the ffmpeg roundup bug tracker. I am certainly not in a position to
start helping ffmpeg.

-- 
+-DRD-+