New submission from tripp <[EMAIL PROTECTED]>: Hi,
i think -bt should be clearer documented or it's fuctionality revised. in fact i consider this a bug. as i'm pretty sure no-one knows how it works and worse, misinterpret. my understanding is that -bt has a minimum value of timebase*bitrate and a default of default_bitarte*20=4000,000 but how do you estimate a good setting? i'd say from limited trials 1/2-2/3 of bitrate also, i've seen somewhere a description which said: that if say 90% of the video was encoded at 1/2 the bitrate set, -bt would see that there'd be a compensation push in the remaining 10% which i've not seen. i checked 1000 frames in 100s for framesize with and without -bt, and the change is throughout the file, not just the final bit. also on a functionality note, I've seen it work only as a limiter, ffmpeg -i input.avi -b 1300k out.avi which undershoots, only undershoots worse with the addition of -bt, so -bt doesn't seem to be able to force bit padding when touching the lower quants and acts only as a limiter. on the request part, aside from documentation, i'd rather see -bt implementes so that -bt value would be set as a percentage of variation from set bitrate, or as actual variance tolerance in a bitrate value ty tripp ---------- messages: 2506 nosy: tripp priority: normal status: new substatus: new title: -bt tolerance type: feature_request ______________________________________________________ FFmpeg issue tracker <[EMAIL PROTECTED]> <https://roundup.mplayerhq.hu/roundup/ffmpeg/issue543> ______________________________________________________
