Hallo > I've decided to investigate a bit a dependence of mpeg2enc encoding speed from > the value of its -M (--multithread) encoding option & the type of the kernel > (UP/SMP) the system runs on the Pentium 4 with hyperthreading support. > For the tests with UP kernel hyperthreading was disabled in BIOS, for SMP - > enabled. > > Testing platform: > System: Pentium-4 2,4Gz with hyperthreading support, i865PE, 256M RAM > (single-channel mode) > OS: Linux, Fedora Core 1, kernel-2.4.22-1.2194.nptl (and its SMP version) > Software version: mjpegtools-1.6.2 The values should be even better with a new 2.6.x Kernel
> Source file: stream.yuv, > $ LANG=C ls -lh stream.yuv > -rw-rw-rw- 1 root root 1.5G Jan 21 16:23 stream.yuv > This is a actually a small uncompressed fragment of "Finding the Nemo" NTSC > DVD (3000 frames). > > Testing command: > time cat stream.yuv | yuvscaler -n n -O SVCD 2> /dev/null | mpeg2enc -f 4 -F 1 > -p -M <thread number> -o stream.m2v 2> /dev/null > 1. Hyperthreading disabled, UP kernel: > -M 0 1m42.133s > -M 1 1m41.043s * > -M 2 1m44.355s > -M 3 1m46.544s > -M 4 1m43.633s ??? > -M 5 1m51.273s Were you able you use your system like normal ? Or was moving the mouse a bit tricky ? > BTW, also the results showed that on a such system it is possible to encode to > SVCD resolution in real time, even faster - the video fragment is ~ 2min. :-) Realtime encoding is not the main goal of the project. > Encoding without hyperthreading is ~7% faster in this case - "-R 2" perfomance > hit is terrible for the system with hyperthreading (or to any SMP system?) - > nearly half ot the perfomance is lost :-( BTW, the resulting file is also a > bit bigger :-( -R 2 is slower also on a SMP system. The curreny problem for mpeg2enc on SMP system is that even with threads is cannot generate mor load that one CPU can handle. So when I encode the video with -M2 mpeg2enc does not need more than 100% of one cpu. Even if you have 4 threads. So the machine. With your command the other cpu has nearly no load. And could do something else, which "slows down" encoding. But you can compensate that with filtering the video. Than yuvdenoise needs about 85% of one cpu and the other CPU is decoding the images (i was lazy and used a mjpeg encoded avi the cpu had to decode) and doing some encoding. auf hoffentlich bald, Berni the Chaos of Woodquarter Email: [EMAIL PROTECTED] www: http://www.lysator.liu.se/~gz/bernhard ------------------------------------------------------- This SF.Net email sponsored by Black Hat Briefings & Training. Attend Black Hat Briefings & Training, Las Vegas July 24-29 - digital self defense, top technical experts, no vendor pitches, unmatched networking opportunities. Visit www.blackhat.com _______________________________________________ Mjpeg-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/mjpeg-users
