[FFmpeg-devel] Decoding AVCHD using multi-threaded code

Jean-Michel Pouré jm
Thu Dec 18 22:32:18 CET 2008

On Thu, 2008-12-18 at 16:09 -0500, Alexander Strange wrote:
> In the meantime, what are you doing the decoding for?

http://www.kdenlive.org free video editor

Modern camcorder output 20Mb/s to 35Mb/s h264/AVCHD streams. 

Camcorders users expect to edit the streams natively, out of the camcorders, without prior encoding to mpeg2. 
During editing, we need to display the streams in the editing monitor (top right of Kdenlive screenshot).

While testing FFplay, we found good results with the following command:
ffplay -skiploop 48 -skipframe 16 -threads 4 avchd-test-4.mts 

Skiping B frames speeds the viewer. 
Quality is enough for display in Kdenlive window during editing.
I don't understand the meaning of skiploop 48.

Of course, we don't expect to skip B-frames during final rendering.

On the short run, very high h264 bitrates are coming along and FFmpeg 
and we expect that FFmpeg will be able to decode them on the fly.

Kind regards,

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