H.264

[afenn]

I’ve read some threads here that talk about how certain codecs are very fast with Syphon Recorder. I’d love to use a codec that yields a higher compression rate than some that I see in the drop down in side Syphon Recorder. I’m recording lots of ~10 minute files at 1280×720, and my resulting recording are huge. I’d like to get them down to a just several megabytes rather than a few gigabytes. Is there a way I can make Syphon Recorder use other codecs that could do this?

Are there any issues I’d run into with this?

Thanks!

[vade]

Why not re-export the resulting file, and delete the original once you are happy with the re-encoded version at h.264?

[afenn]

The reasons are time & CPU. I’m recording files constantly for hours, stopping and starting the record roughly every 10 minutes. Meanwhile, I’m capturing and streaming in HD too.

After the files are done recording, I need to move the files off box, from multiple boxes, to a single box on the network. All that moving files around takes up network bandwidth, and actually get’s me congested to where I can’t keep up if I do that. I could transcode to H.264 before I move the files, but that introduces a delay, and consumes CPU power that I don’t have to spare in my application.

That’s why the ideal situation is to record to hard disk in H.264 in the first place, using the hardware so I don’t take the CPU hit.

By your asking why I’m not doing this, should I infer that recording straight to h.264 using the GPU isn’t possible?

[bangnoise]

H264 takes too long to encode to be well-suited to live recording – the frame-rate is generally terrible, and your CPU usage would rocket. GPU support is for H264 decoding only, when it is present at all.

There is untested support in Syphon Recorder for Matrox hardware encoding to H264 and MPEG 2. As it’s untested I can’t report on its performance, but if you can lay your hands on a Matrox encoder, you could let us know.

We’re always open to adding other codecs to the supported list – if there’s an Apple or third-party codec you’d like us to test then name it and we can see how it performs. Anything with a lower data-rate would be a good addition to the list, for sure.

Sounds like a lot of video!

[Author]

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