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Hmm...come to think of it...I know that VfW is baaad...but I thought that was mainly about drivers. What's so bad about software codec? (types? what is a type? )
VfW is neither "bad" nor "good", it's just a bit less flexible than DirectShow....especially as regards maximum file sizes. Nevertheless there are a lot of capture boards that still use VfW to great effect. My Matrox RT.X100 realtime board is one such device in that it has a VfW capture interface for importing analog footage as either RGB24, YUV, DV/DVCAM or any capture capable softcodecs installed in the system.
A softcodec is a software compressor/decompressor. It's what turns video into digital data for storage and back again. There are many softcodecs ranging from oldies like Indeo and Motion JPeg (MJPeg) to newer entries like DV or HDV (high definition video).
Nevertheless some of the oldies are still highly effective for editing and capture, especially the PicVideo, Morgan and MainConcept MJPeg codecs.
As for the DV type 1 vs. type 2 codecs MSDN (MicroSoft Developers Network) has this short explanation;
Microsoft DirectShow 9.0
Type-1 vs. Type-2 DV AVI Files
DV cameras produce interleaved audio-video; each frame of video also contains the audio information. If you save DV data to an AVI file, you have a choice:
* Store the interleaved data as one stream in the AVI file. This is known as a type-1 file.
* Split the interleaved data into separate audio and video streams. This is known as a type-2 file.
For video capture, where maximum throughput is crucial, it is better to use a type-1 file, because type-2 files carry redundant audio data. (The video stream still has the audio data. The audio is simply hidden by labeling the stream as video.) Also, writing a type-2 file requires some additional processor time to split the interleaved stream.
On the other hand, type-1 files are less efficient for real-time editing. The application must extract the audio from the interleaved stream, make the edits, and interleave the data again. Also, the type-1 format is not compatible with Microsoft® Video for Windows® (VFW). DirectShow can handle both types of files.
In todays extremelly fast systems with high speed HDD's the difference in realtime performance between type 1 and type 2 is not nearly as advantageious to type 2 as M$ indicates in this article, which is why most RT hardware and software have moved beyond type 2, though it remains an option.
And why, exactly, would one use a VfW type2 DV codec in these days of NTFS and software optimized type1 editing?
Ehmm, VirtualDub maybe?
-Off the beaten path I reign-
At Home:
Asus P4P800-E Deluxe / P4-E 3.0Ghz
2 GB PC3200 DDR RAM Matrox Parhelia 128
Terratec Cynergy 600 TV/Radio
Maxtor 80GB OS and Apps
Maxtor 300 GB for video
Plextor PX-755a DVD-R/W DL
Win XP Pro
At work:
Avid Newscutter Adrenaline.
Avid Unity Media Network.
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