Re: WMV9 codec settings

Tech-Archive recommends: Repair Windows Errors & Optimize Windows Performance

Yeah sorry, I often think people may be using WME even when the post
is in this newsgroup ! Sorry for the wrong conclusion.

I really don't know which will be the fastest way to encode video, as
you say, the number of variables on unknown hardware is huge and may
result in unpredictable encoding rates.

I did google on "encoding speed shootout" which drew down a lot of
results from Extremetech such as this one :
http://www.extremetech.com/article2/0,1697,1544897,00.asp

The conclusion seemed to be that disregarding small variations in
quality, Sorenson or Apple MPEG4 encoding gave shorter encode times.
It's wotrh remembering that Apple's H264 implementation is good, but
very slow compared to other variants (and it can only do SP encoding)

Any codec will give variable results depending on the complexity of
the source, so I'm not sure how I'd proceed in your position, only to
say I'd do a lot of research and quantitative testing before coming
down on WMV vs any other particular encoding scheme.

HTH
Cheers - Neil


On Wed, 12 Jul 2006 12:58:51 -0400, Drew Hohmann
<drew@xxxxxxxxxxxxxxxxxx> wrote:

I'm developing a custom application that uses the WMF SDK to read and
write the video files. I tried YUY2 (instead of UYVY) and found no
difference in speed. Currently the images are coming in from the camera
in Mono8 format, and I am converting the Mono8 to UYVY using MMX. At
least by trying the YUY2 I found a few spots to optimize my MMX code.

I also tried WMV8, and noticed no difference in speed. As this
application will be used by a large number of customers on unknown
hardware, I have to make the software as efficient as possible.

Any other suggestions on improving WM9 encode speed, or have I run out
of options and need to switch to a different codec? (I am thinking of
trying MPEG2 next.)

Thanks,
Drew Hohmann
Software Engineer
drew@xxxxxxxxxxxxxxxxxx

Neil Smith [MVP Digital Media] wrote:
Out of curiosity, have you already gone to the encoder Tools ->
Options -> Performance and dragged the slider to the top ?

My tests indicated windows media encoder studio edition is marginally
faster than stock WME, perhaps 4-6%. You may also benefit from slight
overclocking of the PC (for example using NTune, but don't overdo it!)
http://www.microsoft.com/windows/windowsmedia/forpros/encoderse/default.aspx

WMV8 codecs require less compression 'grunt' than WMV9, at the cost of
a slight loss of quality (they're lighter to decompress, too).

This page suggests a range of enhancements, noting YUY2 will avoid
pixel format changes (and therefore require less encoder effort)
http://www.microsoft.com/windows/windowsmedia/howto/articles/AdvancedEncoding.aspx#CapturingtoOptimalPixelFormats

In your case, only the memory-ordering of data bytes differs from the
recommended format, so I can't see any real chance of improvement by
changing to YUY2 (worth a shot, I suppose)

Is hardware acceleration or multiple CPUs something you've considered?

Cheers - Neil


On Tue, 11 Jul 2006 15:30:30 -0400, Drew Hohmann
<drew@xxxxxxxxxxxxxxxxxx> wrote:

Hello,
I am writing 640x480, YUV422 (WMMEDIASUBTYPE_UYVY) at 100fps, and I want
to make sure I have all the WMV9 codec settings set to minimum so
Windows Media compresses the samples as fast as possible. Currently my
settings are

Quality = 0
Complexity = 1
Max Key Frame Spacing = 8 seconds
Bitrate = 4000kbps - 15000kbps (I have tried several different bit rate
settings, doesn't seem to make a whole lot of difference in how fast the
encoder runs)

Is there any settings I'm missing or anything I can do to make WMV9
encode faster?

Thanks,
Drew Hohmann
Software Engineer
drew@xxxxxxxxxxxxxxxxxx
------------------------------------------------
Digital Media MVP : 2004-2006
http://mvp.support.microsoft.com/mvpfaqs
------------------------------------------------
Digital Media MVP : 2004-2006
http://mvp.support.microsoft.com/mvpfaqs
.

Relevant Pages

  • Re: best way to back off from 100% processor use
    ... What are you encoding? ... What settings are you using? ... What is your hardware configuration? ... > As I encode, my processor is running at 100%, which is leading to low fps ...
    (microsoft.public.windowsmedia.encoder)
  • Re: compressing a sequence of numbers
    ... Signal is "noisy", so it isn't pretty, but still DCT does some energy compaction. ... OTOH "trivial" encoding would use same number of bits for each number and that would be 19 bits. ... Now let's try to encode it with 3R. ... Now let's compare this to my baseline encoding scheme -- backward-adaptive Golomb-power-of-two (GPO2) which automatically switches to Exp-Golomb if it encounters particularly large number. ...
    (comp.compression)
  • Re: Slowed playback on audio files converted by Windows Media Encoder
    ... problems or have you made any settings changes Your machine sounds more ... go ahead and rename that encoded files extention to wma. ... Slowed playback on audio files converted by Windows Media ... your not doing a live encode. ...
    (microsoft.public.windowsmedia.encoder)
  • Re: CCertAdmin.SetCertificateExtension
    ... Each extension by convention has its own ASN.1 binary encoding. ... expected encoding as IA5 string. ... You can use CryptEncodeObject to encode IA5 strings. ...
    (microsoft.public.platformsdk.security)
  • Re: POSTing Chinese characters
    ... For the example string I mention, simply encode as ... the client locale could be anywhere... ... > The basic idea of %-encoding is to treat character encoding as a sequence ...
    (microsoft.public.inetserver.iis)