On Fri, Jun 07, 2002 at 10:32:04PM +1200, Paul Eggleton wrote: > > It depends on what type of compresion will you select - > > > > mpeg compression is far less CPU intensive then DivX encoding. > > (Though I think XviD encoding is pretty fast) > > I understand this. However, 320x240 at 25fps is not so taxing that you would > ever expect 70% of the frames to be dropped unless the system is very slow > to begin with or under extreme load. This seems to affect any codec I choose > with avirec (eg. same results with DivX and Huffyuv, which is not CPU > intensive, or shouldn't be anyway). The fact that the frames are dropped in > capture rather than dropped in encoding suggests to me that there is a > problem with the capture end rather than the encoding end. I also still get > a segfault at the end of listing the codecs (avirec -l), but as this doesn't > seem to be affecting actual capture I'm not too worried. However if I can do > anything to help you fix this (gdb trace, etc.) then let me know. > > > Also are you using preview mode or overlay mode ? > > I'm not sure, how can I determine this? I understand the question, just not > sure how this is set with avifile.
I am not really sure, but I think it is not set at all. So I assume that the last set mode is used. You may try calling xawtv and set it there just before you call avirec. If you are a programmer, you may try setting it somewhere in the code, in function main(). Also, if frames are dropped in capture, it is independent of the codec, IMHO it should depend only on the bus speed and speed of the TV card. > > What is your hardware (CPU, capture card) > > My apologies, I should have included this in my first message. The system I > am using is a Celeron 1.1GHz on a Via 686B/694T board, 128MB RAM. The > capture card is a Dynalink TView99 (aka CPH051, a fairly standard > Bt878-based capture card). I am writing to an ATA-100 Seagate Barracuda 4 > drive with DMA set up, so hard drive performance should be pretty good. Should be okay, though a litlle bit more RAM could help. I have a Duron 850, 512MB RAM and a Hauppauge BT878 card. I can capture 480x360, deinterlaced, mp3 stereo with xvid codec, CPU usage is around 90%, hardly any frame drops (though the first 3-5 frames get always dropped). xvid with highest quality. disk is a ATA66 Maxtor, 60GB. > > The problem with all those sample applications is that I'm mostly > > the only one who works on the them - and when there are better or > > more important things to do they are left unmodified and buggy > > and are rather fixed only occasionaly... > > OK. But if I test avirec and find bugs, I presume you are still interested > in hearing about it? I do understand you have limited time to work on > avifile and probably are more interested in spending the time you have > working on avifile's architecture and video playback rather than capture. > However it does seem to me that there are very few decent open source > capture applications for Linux that are being actively maintained these > days. If I find time, a can also fix problems. Problem is though that at weekends I am not at my home, but in another town, and I do not have a capture card there to test it (just a notebook). I can do a few tests next week. I already implemented cutting the first and last lines of the picture (useful if there a black bars), but it is not yes in CVS. Greetings, Oliver
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