Re: Apple's Fat Margins

On 2007-08-26 01:01:59 -0700, Sandman <mr@xxxxxxxxxxx> said:

In article <200708252342308930-jcrnospam@nospammaccom>,
John C. Randolph <jcr.nospam@xxxxxxxxxxxxxx> wrote:

And even as a co-processor it's interesting. What kind of encoding speeds does the card itself provide for, say, a DVD mpeg2 stream? (no, not looking to pirate movies, just using a known example).

The encoding speed will depend on several factors, like the framerate, whether you reduce the raster size during encoding, etc. Assuming that you encode a 640x480x30fps source, we have four codecs on the card, so you'll be able to hit at least 4x real-time.

When transcoding a file on disk though, we're limited by I/O bandwidth into the codecs, and we're not sure where that will top out. We might be able to get each codec up to 2x, so the whole card can get you to 8x. By way of comparison, an 8-core Mac Pro will reach about 1.6x real-time using the software h2.46 encoder, with all the cores running flat-out. We will also be building a version of this board without video inputs, but we haven't determined what our pricing will be for that model.

That sounds interesting as well. I have one of those 8 core Mac Pros and if I could increase encoding time from 2x to 8x that would be great.

Elgato has a USB stick that does this as well.

Elgato's product (which is the same one that ADS is selling, too) uses the same codec chip that we do, but it wasn't suited for our applications. USB bandwidth doesn't really cut it when you need to send multiple uncompressed streams out and take compressed streams back in.

What we're working towards are devices to handle video acquisition for properties that have thousands of cameras.

-jcr

.

Relevant Pages

  • Re: Apples Fat Margins
    ... speeds does the card itself provide for, say, a DVD mpeg2 stream? ... The encoding speed will depend on several factors, like the framerate, ... into the codecs, and we're not sure where that will top out. ... I have one of those 8 core Mac Pros ...
    (comp.sys.mac.advocacy)
  • Re: Which TV card?
    ... I could not find a link that duscussed the time required by any of the brands of encoding chips used by PVR TV Tuner cards to perform the work required, however, I did find a link that discuses the amoung of work required which should help you to understand that the encoding can not occur instantanly wheter done in hardware or software. ... I agree with you that most of the decoding is also done in hardware by your graphics card and possibly also by your tuner card when using the TV2000 Hauppauge program. ... In any case it also can not occure instantly but does take less clock time then the encoding process. ... When MCE receives the encoided buffer from the tuner card it schedules it to be recorded and as long as disk caching is enabled on the drive the disk handler immediatly returnes to MCE and MCE can read the buffer dirctly from the cach buffer and pass it to the Decoder without waiting for any acutal disk read operation to be performed as long as the OS has not determinded that the buffer is no longer still in memory and this will not occure until all previous memory buffers have had to be reused.which could be minutes. ...
    (microsoft.public.windows.mediacenter)
  • Re: Workable encryption in Tcl??
    ... abstract characters using the concrete UTF-8 encoding, ... character streams and octet streams when doing input and output. ... How does this relate to encryption? ...
    (comp.lang.tcl)
  • Re: Id like to get rid of pulseaudio but ...
    ... Also most of the hi-end boards ... today support multiple streams. ... would be something like a skype call on a headphone without ... I am using the same card right now and I did not know ...
    (Fedora)
  • Re: Id like to get rid of pulseaudio but ...
    ... today support multiple streams. ... would be something like a skype call on a headphone without ... I am using the same card right now and I did not know ...
    (Fedora)