Ray_Gates
12th June 2004, 11:04
i've read this in windows media format sdk:
Inserting Native Stream Formats Into ASF Files (QASF)
By default, the WM ASF Writer expects uncompressed audio and video streams on its input pins, and uses the Windows Media Format SDK to access the Windows Media Audio and Windows Media Video codecs, which compress the streams. But the ASF file container can be used for any type of data. By placing digital media data into an ASF file container, you can add features provided by ASF, such as metadata and digital rights management (DRM), without having to transcode your content.
To create an ASF file that contains content that is not Windows Media–based, the application must compress the stream in the filter graph upstream of the WM ASF Writer and bypass the WM ASF Writer's compression mechanism by calling IConfigAsfWriter2::SetParam as follows:
pConfigAsfWriter2->SetParam(AM_CONFIGASFWRITER_PARAM_DONTCOMPRESS,TRUE,0)
Then configure the filter with the desired profile. It is essential that the media type of the input stream exactly matches the format in the profile. In some cases, it may be necessary to examine the input stream's format, and create a custom profile to match it. For more information, see To Create ASF Files Using Third-Party Codecs.
When you connect the WM ASF Writer to the upstream filter, use the IGraphBuilder::ConnectDirect method. Do not use any "intelligent connect" methods such as IGraphBuilder::Connect or IGraphBuilder::RenderFile to connect the filter because this will disable the filter's "bypass compression" mode.
but is there any tool can implement it?
Inserting Native Stream Formats Into ASF Files (QASF)
By default, the WM ASF Writer expects uncompressed audio and video streams on its input pins, and uses the Windows Media Format SDK to access the Windows Media Audio and Windows Media Video codecs, which compress the streams. But the ASF file container can be used for any type of data. By placing digital media data into an ASF file container, you can add features provided by ASF, such as metadata and digital rights management (DRM), without having to transcode your content.
To create an ASF file that contains content that is not Windows Media–based, the application must compress the stream in the filter graph upstream of the WM ASF Writer and bypass the WM ASF Writer's compression mechanism by calling IConfigAsfWriter2::SetParam as follows:
pConfigAsfWriter2->SetParam(AM_CONFIGASFWRITER_PARAM_DONTCOMPRESS,TRUE,0)
Then configure the filter with the desired profile. It is essential that the media type of the input stream exactly matches the format in the profile. In some cases, it may be necessary to examine the input stream's format, and create a custom profile to match it. For more information, see To Create ASF Files Using Third-Party Codecs.
When you connect the WM ASF Writer to the upstream filter, use the IGraphBuilder::ConnectDirect method. Do not use any "intelligent connect" methods such as IGraphBuilder::Connect or IGraphBuilder::RenderFile to connect the filter because this will disable the filter's "bypass compression" mode.
but is there any tool can implement it?