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Hi Paul,
Most people will output to mpeg if they plan on showing their clips on systems that don't have the hardware to decode the clip for playback. If you want to show your clip on a vcr, then don't worry about it. Capture with the hardware codec and dump out your clip to a tape.
Hard drive space may be cheap but a lossless video system isn't
Ideally, you want to capture with as minimal compression as you can without sacrificing quality. The only way to do this is:
- Capture in RGB (uncompressed) but this means you need a system that can handle ~ 20Mbytes/sec sustained and gigs a gigs of hard drive space, depending on how long you want to capture for.
- Capture with some kind of hardware codec that will not sacrifice your quality while at the sametime, using minimum compression to save on HD space and bring down the sustained thru put problem.
You can use any hardware mjpeg or mpeg2 card for this.
- Get a firewire card and dump your video via firewire to firewire onto your system. Firewire keeps your data in the digital domain and the datarate is a joke even with DV50 rated capture cards.
However you are correct about the effects. For each effect, overlay, video filter, etc, the editor has to create a new frame which means something is getting recompressed. Only way around this is to get a real time card that actually works.
Depending on people's budgets, they will get a mjpeg card and then convert it to mpeg format. I'm personally not crazy about this because this means that a software is recompressing and re-scaling my original capture which will result in some kind of quality loss if I capture at full res and then convert it to mpeg 1.
However, you can bypass the re-scaling if you convert to mpeg2 but this brings in another problem.
If you capture in 704x480 or 352x480, you are capturing both fields. By standard, mpeg2 displays both fields. Since most software converters are cheap, they will not convert both fields. So in reality, all you have is an mpeg1 clip with a faster data rate.
To solve this, you can either get an expensive converter package that actually converts both fields or use a dvd authoring tool like dvd it.
I use dvd it with my RT and the final quality is really is extremely close to a lossless clip.
Haig
Most people will output to mpeg if they plan on showing their clips on systems that don't have the hardware to decode the clip for playback. If you want to show your clip on a vcr, then don't worry about it. Capture with the hardware codec and dump out your clip to a tape.
Hard drive space may be cheap but a lossless video system isn't
Ideally, you want to capture with as minimal compression as you can without sacrificing quality. The only way to do this is:
- Capture in RGB (uncompressed) but this means you need a system that can handle ~ 20Mbytes/sec sustained and gigs a gigs of hard drive space, depending on how long you want to capture for.
- Capture with some kind of hardware codec that will not sacrifice your quality while at the sametime, using minimum compression to save on HD space and bring down the sustained thru put problem.
You can use any hardware mjpeg or mpeg2 card for this.
- Get a firewire card and dump your video via firewire to firewire onto your system. Firewire keeps your data in the digital domain and the datarate is a joke even with DV50 rated capture cards.
However you are correct about the effects. For each effect, overlay, video filter, etc, the editor has to create a new frame which means something is getting recompressed. Only way around this is to get a real time card that actually works.
Depending on people's budgets, they will get a mjpeg card and then convert it to mpeg format. I'm personally not crazy about this because this means that a software is recompressing and re-scaling my original capture which will result in some kind of quality loss if I capture at full res and then convert it to mpeg 1.
However, you can bypass the re-scaling if you convert to mpeg2 but this brings in another problem.
If you capture in 704x480 or 352x480, you are capturing both fields. By standard, mpeg2 displays both fields. Since most software converters are cheap, they will not convert both fields. So in reality, all you have is an mpeg1 clip with a faster data rate.
To solve this, you can either get an expensive converter package that actually converts both fields or use a dvd authoring tool like dvd it.
I use dvd it with my RT and the final quality is really is extremely close to a lossless clip.
Haig
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