Package: ffmpeg Version: 0.cvs20060823-8 Severity: wishlist I am trying to encode a video stream using ffmpeg (or indeed ffmpeg2theora). The input data to be encoded comes from a series of netpbm runes, one small shell scriptlet per frame.
Ideally I would like to use the `image2pipe' format but this has a critical bug which AFAICT renders it unuseable. See my other report. Instead I provide ffmpeg with a directory full of named pipes, for use by -f image2. However, there are two problems: 1. ffmpeg opens and then closes many prospective files right at the start, apparently trying to figure out which files exist so it knows how many frames there are. There is no need to open the files at this stage - stat() or access() would be the right calls to use. 2. When it actually starts encoding, ffmpeg lseeks each file right after opening it, apparently trying to find out its length. This is not necessary: in particular, we know that it's not supposed to be necessary at all (or at least it's unnecessary for many frame image formats) because the image2pipe format is supposed to be able to achieve the same thing. I observed these behaviours in strace. I solved my problem with a subterfugue trick, which makes it seem to ffmpeg that these things are all plain seekable files even though in fact they're pipes which are opened and written to by the data provider in order. This is obviously less than ideal. Ian. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
