[Ffmpeg-devel] h264 playback performance

Andreas Öman andreas
Thu Sep 14 20:44:15 CEST 2006


First of all, let me make you understand that the intention of
this mail is not to whine about the performance of ffmpeg.

Now, during the summer my tv-provider did some trials with HDTV.
The video format used was CABAC-encoded h.264 in 720p @ 50Hz running
at approx 20Mbps.

Sadly, i discovered that my current machine (Pentium-M w/ 2Mb cache @
1.8Ghz) decodes a frame in ~33ms in average (which obviously is too
slow). I know that the CABAC encoding is quite CPU hungry so it's
not very surprising.

I'm about to buy a new machine and I'm interested if anyone with
a "hot" CPU can try playing the clip I've uploaded and report back.

The file is called 'SVT HD Teaser-ac3-chopped.ts' and uploaded to

Secondly... (and the reason i sent the mail to ffmpeg-devel)

Has there been any thoughts about making the h264-decoder
multithreaded? With the arrival of multi-core CPUs it would
seem like a wise thing to ponder.

I'd be happy to contribute to such a thing, though, it be
nice to get a few pointers or directions.

Can h264-slices be decoded independently ?

Should one move the entropy-decoding to an individual thread
and push decoded macro-blocks between the threads?

Any other ideas?

.. or is this all an too unfeasible thing to do?

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