> My computer is an SMP dual 460 MHz system, 256 meg of ram, bt848 tv card. I had a similar system once (dual Celeron 355's OCed to 550) > I am experimenting with recording at a higher resolution then scaling > down to obtain a higher quality image. I have tried recording at a resolution > of 352x288, and the results on a vcd > appear to be worse than straight video recording. However my computer only > appears capable of saving data at a higher resolution without misses > by directly saving raw data to a raw file. > I am having the following problems with the available tools. > > My problems with lavrec from mjpegtools are > - I cant see how to output raw data to a raw file device. > (also, is this a sensible thing to do?) lavrec prolly can write to a raw device. But the AVI formats are limited to 1.7GB per file becoz it doesn't support OpenDML. Therefore, since you are writing to a raw device (ie. 1 file only) you may well run out of filesize very quickly I am told the quicktime format has no such file restrictions, but I have never tried it. I have no idea what the movtar format is. > - It mutes the sound on my TV card, while streamer doesnt. Should only do that if you use the -m/--mute flag, otherwise, it won't touch the mixer (unless you use the -l/--audio-volume flags as well) > My problems with streamer are: > - How do I find out how big the file size is if I > output to a raw output device. That's the problem with writing to a raw device. It doesn't have filesystem concepts like filesize, permissions etc... You can tar the device to /dev/null and using the verbose flags, it will give you some stats. dd will do the same...but you can't just ls the device. > - The format, using 4mpeg output format, is not accepted > by lavtools/mjpegtools utilities. But the first few bytes of the > file does indicate an attempt at this format. the mjpegtools specfically say they only support files created by other mjpegtools. Though I have found them to support streamer's MJPEG AVI's. But since streamer will use the OpenDML standard once a file goes beyond 2GB, then it won't support it any more. I haven't used streamer in quite a while to remember whether it will record to multiple files, and a quick, cursory look at streamer -h suggests not. I use lavrec for my recordings. in NTSC, 352x240 @ 29.97 with an 85% MJPEG quality, and get about 3.5GB/hr (more for animations). I gave a presentation to our LUG last month on using a Linux box to record and transcode TV input. If you're interested, some of the files are on http://www.kernel-panic.org/index.pl/200209gen where I give some pointers to improving your HD speed via the use of hdparm (IDE of course). -- Michael O'Keefe | mokeefe@xxxxxxxxxxxxx Live on and Ride a '96 Honda CBR1000F| roxus@xxxxxxx / | I like less more or less less than |Work:+1 858 845 3514 / | more. UNIX-live it,love it,fork() it |Fax :+1 858 651 1984 /_p_| My views are MINE ALONE, blah, blah, |Home:+1 858 748 5432 \`O'| blah, yackety yack - don't come back |Fax :+1 858 _/_\|_,
