[Ffmpeg-devel] Re: MPEG-2 Acceleration Under Mac OS X - Can We Move This Forward?
galenz at zinkconsulting.com
galenz
Tue Aug 29 13:49:47 CEST 2006
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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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
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