| Author |
Message |
Amit
Guest
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 Posted:
Mon Oct 04, 2004 2:33 am Post subject:
Windows Media Format SDK or Windows Media Audio/Video Interf |
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Developing an application that would encode into WMV format. The application
is Dshow compliant driver that takes in an MPEG2(transport program or regular
video) file and through the filter graph decodes until the mpeg 2 stream is
decoded via a MPEG2 decoder.
After this point, if one intends to encode it to a WMV format, what would be
tha appropriate API ? since both APi's will alow you to encode the
content...one would directly use the Audio/video codecs through the DMO
objects( Audio/Video interface) and the other through the ASF read/writer
objects( WM Format SDK)
The preferable output is WMV9, using say 2 pass VBR operation.
Thanks.
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Alessandro Angeli [MVP::D
Guest
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| Posted:
Mon Oct 04, 2004 3:57 am Post subject:
Re: Windows Media Format SDK or Windows Media Audio/Video In |
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Amit wrote:
| Quote: | Developing an application that would encode into WMV
format. The application is Dshow compliant driver that
takes in an MPEG2(transport program or regular video)
file and through the filter graph decodes until the mpeg
2 stream is decoded via a MPEG2 decoder.
After this point, if one intends to encode it to a WMV
format, what would be tha appropriate API ? since both
APi's will alow you to encode the content...one would
directly use the Audio/video codecs through the DMO
objects( Audio/Video interface) and the other through
the ASF read/writer objects( WM Format SDK)
The preferable output is WMV9, using say 2 pass VBR
operation.
|
The WMASFWriter filter will compress the streams and write
out an ASF file for you.
Using the WMWriter object from the WMFSDK you can do the
same, but you need to wrap it in a custom filter to use it
in a DirectShow graph (while the WMASFWriter is a
ready-to-use wrapper).
Using the DMOs directly you can compress the streams but
then you would have to mux them in some container format and
write it out somehow and, if the container you want if ASF,
this can be difficult, especially in a DirectShow graph
(while the WMASFWriter does it for you).
--
// Alessandro Angeli
// MVP :: Digital Media
// a dot angeli at psynet dot net |
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Amit
Guest
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| Posted:
Mon Oct 04, 2004 4:27 am Post subject:
Re: Windows Media Format SDK or Windows Media Audio/Video In |
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"Alessandro Angeli [MVP::DigitalMedia]" wrote:
| Quote: | Amit wrote:
Developing an application that would encode into WMV
format. The application is Dshow compliant driver that
takes in an MPEG2(transport program or regular video)
file and through the filter graph decodes until the mpeg
2 stream is decoded via a MPEG2 decoder.
After this point, if one intends to encode it to a WMV
format, what would be tha appropriate API ? since both
APi's will alow you to encode the content...one would
directly use the Audio/video codecs through the DMO
objects( Audio/Video interface) and the other through
the ASF read/writer objects( WM Format SDK)
The preferable output is WMV9, using say 2 pass VBR
operation.
|
| Quote: | The WMASFWriter filter will compress the streams and write
out an ASF file for you.
Using the WMWriter object from the WMFSDK you can do the
same, but you need to wrap it in a custom filter to use it
in a DirectShow graph (while the WMASFWriter is a
ready-to-use wrapper).
Can you please elaborate a little on this ? I have seen the UncompAVIToWMV sample in the SDK and that uses WMWriter, but I didnt see any wrapper there.
|
so can I still use WMASFWriter for what I intend or wmwriter is till the way
? I just want to handle it programmatically.
| Quote: |
Using the DMOs directly you can compress the streams but
then you would have to mux them in some container format and
write it out somehow and, if the container you want if ASF,
this can be difficult, especially in a DirectShow graph
(while the WMASFWriter does it for you).
|
so, then I cant insert into graphedit, but programmatically it would still
work ?
| Quote: |
--
// Alessandro Angeli
// MVP :: Digital Media
// a dot angeli at psynet dot net
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Alessandro Angeli [MVP::D
Guest
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| Posted:
Mon Oct 04, 2004 2:09 pm Post subject:
Re: Windows Media Format SDK or Windows Media Audio/Video In |
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"Amit" <Amit@discussions.microsoft.com> wrote:
| Quote: | Can you please elaborate a little on this ? I have seen the
UncompAVIToWMV sample in the SDK and that uses WMWriter, but I
didnt see any wrapper there.
so can I still use WMASFWriter for what I intend or wmwriter is till
the way ? I just want to handle it programmatically.
|
Correct me if I didn't underastand your requirements, but I thought you were
using DirectShow, so you need something you can use in a DirectShow graph.
For that, you need the compressors, a muxer and a writer, all implemented as
filters or DMOs that can work in a DirectShow graph.
The WMASFWriter filter provides all 3 in a single filter, which works in a
DirectShow graph, and outputs an ASF file.
The WM DMOs provide only the compressors, which work in a DirectShow graph.
This means you need to provide the muxer/writer that outputs an ASF file or
whatever you like.
The WMWriter object provide all 3 and it also outputs an ASF file, but it
doesn't work in a DirectShow graph. This means you need to either extract
the data from the graph and pass it to the WMWriter or to wrap the WMWriter
in a filter.
--
Alessandro Angeli
MVP::DigitalMedia
a dot angeli at biosys dot net |
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Amit
Guest
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| Posted:
Mon Oct 04, 2004 8:45 pm Post subject:
Re: Windows Media Format SDK or Windows Media Audio/Video In |
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Ok thanks for the clarification.
The reason I wanted to clarify is because I got the impression that you can
even use the native WMWriter directly under DShow.
But this should help.
Thanks.
"Alessandro Angeli [MVP::DigitalMedia]" wrote:
| Quote: | "Amit" <Amit@discussions.microsoft.com> wrote:
Can you please elaborate a little on this ? I have seen the
UncompAVIToWMV sample in the SDK and that uses WMWriter, but I
didnt see any wrapper there.
so can I still use WMASFWriter for what I intend or wmwriter is till
the way ? I just want to handle it programmatically.
Correct me if I didn't underastand your requirements, but I thought you were
using DirectShow, so you need something you can use in a DirectShow graph.
For that, you need the compressors, a muxer and a writer, all implemented as
filters or DMOs that can work in a DirectShow graph.
The WMASFWriter filter provides all 3 in a single filter, which works in a
DirectShow graph, and outputs an ASF file.
The WM DMOs provide only the compressors, which work in a DirectShow graph.
This means you need to provide the muxer/writer that outputs an ASF file or
whatever you like.
The WMWriter object provide all 3 and it also outputs an ASF file, but it
doesn't work in a DirectShow graph. This means you need to either extract
the data from the graph and pass it to the WMWriter or to wrap the WMWriter
in a filter.
--
Alessandro Angeli
MVP::DigitalMedia
a dot angeli at biosys dot net
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