Re: [rtcweb] H.261

Maik Merten <maikmerten@googlemail.com> Sun, 24 November 2013 09:12 UTC

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Date: Sun, 24 Nov 2013 10:12:37 +0100
From: Maik Merten <maikmerten@googlemail.com>
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Subject: Re: [rtcweb] H.261
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Am 24.11.2013 05:29, schrieb Stefan Slivinski:
> What few seem to acknowledge is that companies like intel, TI, qualcomm, broadcom (just to name a few) have spent hundreds of millions (if not billions) of dollars adding hardware accelerate for H.264 to their chips.  Purpose designed hardware will always be faster and require less power than software implementations and no one is spending anything supporting H.261 hardware acceleration.

It appears that these hardware accelerators are usually not accessible 
to 3rd-party applications on mobile platforms (as has been discussed 
before). Even if they are they may not be consistent regarding available 
settings and performance. Can hardware accelerators, e.g., decode 
several incoming streams in parallel (honest question, I really don't 
know)? How does bitrate control of the embedded encoders behave? Do they 
offer options for error resilience etc. etc.?

IIRC it has been confirmed on this list that Skype deploys H.264 in 
software across all platforms for such reasons. So clearly, the 
theoretical advantages of H.264 hardware support (which works nicely in 
media playback, no doubt) do clearly not transfer quite easily to 
real-time communication on consumer devices. Given that older codecs 
currently in discussion are much more frugal in terms of overall 
computation, deployments in software don't look especially intimidating.


Maik