[Ffmpeg-devel] h264 playback performance

[Corey Hickey]

Loren Merritt wrote:
> On Thu, 14 Sep 2006, Corey Hickey wrote:
>> Andreas ?man wrote:
>>>
>>> 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.
>>
>> I can't say for sure with such a short clip, but my system can almost 
>> handle what you uploaded.
>>
>> $ mplayer SVT\ HD\ Teaser-ac3-chopped.ts
>> Triggers the "your system is too slow" message.
>>
>> $ mplayer SVT\ HD\ Teaser-ac3-chopped.ts -lavdopts skiploopfilter=nonref
>> A-V desync fluctuates but remains below 0.3 seconds at all times.
> 
> 20mbit/s, and it's still not low enough qp to elminate deblocking?

I don't know; I haven't looked at it, but merely played it remotely. :) 
I'll have a look at the quality when I get home tonight.

>>> 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.
>>
>> There's '-lavdopts threads=n'. I don't know how well it works, but it 
>> does run multithreaded.
> 
> The only lavc codecs that implement it are mpeg1/2.

Ah. I stand corrected.

-Corey