PJ,
This is a fairly comprehensive reply and has not been fact checked and so,
at my age, memory is always an issue. Hope all is correct and something
here will help...
Keep in mind that MPEG-1 Layer2 encoded audio is fairly straightforward and
also the exact same audio compression standard used for MPEG-1 VCDs; same
audio format for mpeg-1 & 2. Since WMP natively supports the playing of
VCDs, it stands to reason that Direct Show must inherently support MPEG-1
Layer2 playback within the directx runtime environment. Thus, if you are
looking at a standard MPEG-1 Layer2 encoded audio stream, you do, in fact,
already have an alternative MPEG audio decoder available (quartz.dll).
If I uncheck the iviaudioncss.ax codec to take it out of the picture, and
there's another appropriate codec on my system, wouldn't Movie Maker then
use it automatically?
Only if the audio codec (DS Filter) was properly registered as a Direct Show
compliant system resource, otherwise, it may be available only to the
specific software which installed it. One can usually identify properly
registered DS compliant filters (splitters, decoders, etc) directly from
within Graphedit...
Open Graphedit.exe... Graph | Insert Filters | Direct Show Filters
By double clicking any existing filter, the filename & installed location is
readily visible and filters will usually display vendor name and purpose;
i.e. "Cyberlink Audio Decoder (ATI)"
Note: GSpot, DXMan/ ACMProperties (AnalogX), and a host of other freely
available Dx utilities can also provide useful information with
respect to registered filters.
Examples of additional 3rd party DS compliant decoders include A/V products
by vendors such as CyberLink, ULead, Pinnicale, Sonic, Creative Labs, etc.
Note: There are serious driver compatibility issues for existing
Pinnicale users with Turtle Beach Sound cards (Santa Cruz). Pinnicale
has been really slow to address this, or even admit that a problem
exists...it does indeed exist and serious enough that many former
TB/ Pinnicale users, including myself, have moved to other products.
I have often found that, for some reason or another, existing codec
registration may inadvertently become corrupted or may even be removed
during the installation of competing products, Directx upgrades, and/ or
service pack updates. In such cases, the simple solution is to use "Add or
Remove Programs" to force a repair install of the affected program. The
alternative is to manually re-register the affected codec --> regsvr32.exe
*.ax.
Direct Show based audio issues can become far more complex when the source
audio stream is encoded as LPCM, DD, or AC3, which may or may not be
directly supported by 3rd party software...
LPCM (Linear Pulse Code Modulation) decoding is inherently supported within
Dx runtime libraries by default (quartz.dll). Since support is inclusive
(native to MS supplied runtimes), audio rendering for most 3rd party vendors
only requires providing a hook into the existing runtime. Thus, failure to
render LPCM encoded streams is generally the result of a misregistered
Directx component, or, as may occur after an update, the rendering software
may no longer recognize the Dx filter as valid. I have seen some really
weird problems while attempting to render LPCM encoded streams...one such
issue was finally resolved by forcing a repair install of an older VideoWave
product.
DD/ AC3 playback is still very much an after-market option, but competition
is rapidly forcing the issue and newer product versions now include Direct
Show compliant Dolby Digital/ AC3 support by default. What this means is
that decoding, via Direct Show, is currently iffy and may, or may not, be
readily available. A quick check of individual product specifications
should indicate native support. If support is indicated and yet not visible
from within Graphedit, one may still be able to manually locate the
appropriate filter and attempt to register system wide availability.
Working with Graphs is definitely not for the faint of heart. But, after
almost 2 years of constant experimentation, I have found that I now spend
far less money on special purpose 3rd party solutions to address unique
problems or perform type conversions, join multiple clips, or batch process
on the fly. Directx, and Direct Show in particular, offers an incredibly
amazing flexibility in developing alternative approaches and possible
solutions to everyday problems.
Example:
I was recently faced with the task of converting RealMedia archives, circa
1997, and I dreaded the thought of installing any version of Realplayer
anything. Without getting into specific details, I found a way to convert
the *.rm & *.ram files through persistent testing of a variety of
experimental graphs. The ultimate solution was eventually realized through
the combined use of AviSynth, a custom filter graph, and VirtualDub. Since
I don't normally mess with RM or MOV encoded clips, I may never need to do
those conversions again, but I can quickly do so if necessary.
--
Digger
PapaJohn said:
Hi Digger,
My last venture into Graphedit was with the private build 011008 version,
which brought along one of the problem codecs. I have it installed on my
desktop but never got into figuring out how to use it. I'm interested in
learning more about it....
If I uncheck the iviaudioncss.ax codec to take it out of the picture, and
there's another appropriate codec on my system, wouldn't Movie Maker then
use it automatically?
--
PapaJohn
Movie Maker 2:
www.papajohn.org
PhotoStory 2:
www.photostory.papajohn.org
.
.
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