[Ffmpeg-devel] Re: MPEG-2 Acceleration Under Mac OS X - Can We Move This Forward?

[galenz at zinkconsulting.com]

On Aug 29, 2006, at 4:31 AM, Baptiste Coudurier wrote:

> Hi
>
> galenz at zinkconsulting.com wrote:
>> [...]
>>
>> I know the allure of such a function - but I question the reality  
>> of it,
>> at least at the moment. Keep in mind, MPEG-2 is quality king at  
>> higher
>> bitrates, and CPU usage climbs with bitrate, so it can be pretty
>> intensive under the right circumstances. Try watching a 60 fps,  
>> 1920 x
>> 1080 19 megabit stream - that's what they broadcast over the air  
>> in many
>> countries - and let me know how your system fares. Now toss in the  
>> fact
>> you may need to de-interlace this. MPEG-2 acceleration is a very  
>> real need.
>
> Does anyone actually broadcast at 1080p ? I only know broadcasters at
> 720 60p(ESPN, ABC ?) and 1080 60i.
>
> -- 
> Baptiste COUDURIER                              GnuPG Key Id:  
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> SMARTJOG S.A.                                    http:// 
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Sorry, I wasn't completely clear there - I only made an offhand  
reference to the fact the content is interlaced. ("Now toss in the  
fact you may need to de-interlace this.") 1080p is outside the  
specification for terrestrial broadcasts in the US. Everything is  
720p (up to 60 fps) or 1080i (up to 60 fps). I've seen 1080i used in  
such a way that 30 fps progressive content is broadcast as interlaced  
60 fps content, effectively meaning that you can de-interlace without  
quality loss.

That said, 1080p is not outside the specifications for MPEG-2 on HD/ 
BR discs.

-Galen