Hi Peter, *, On Sun, Oct 24, 2010 at 10:39 AM, Peter Junge <[email protected]> wrote: > Christian Lohmaier wrote: >> On Sat, Oct 23, 2010 at 11:44 AM, Peter Junge <[email protected]> wrote: >>> >>> as well the files are quite large (average 500MB) as the resolution is >>> DVD >>> quality (720x400), which might be an issue for people who live in >>> countries >>> with low-bandwidth Internet connection. If anyone intends to work on >>> format >>> and resolution, >> >> What would be an acceptable filesize? And what are the seeking >> requirements? if it is not required to be able to seek, h264 can be >> very efficient for more or less static scenes.. > > Well I wouldn't target a specific file size, but the smallest file size, > that still delivers an acceptable quality and it's quite certain, that > people who own a low-bandwidth connection have also lower requirements > regarding the term "acceptable". ;-)
:-) - I created a file of http://users2.ooodev.org/~ooocon2010/02_september/FT_409/18.15_michael_stehmann.flv (201MB) with ffmpeg's x264 preset "placebo" to get an idea what is doable without fiddling around with parameters, just burning CPU cycles (5fps encoding speed :-)). The presets defaults to ~200kbps average bitrate (for comparison: included audio is mp3 with 128kbps) - that results in a file of around 40MB (for 16:46) > The Beijing Videos are around 250MB > per 45 minutes. So with that preset it would be around half of that - of course depends on the source quality whether all results can deal with a low bitrate, but for just a little over the audio bitrate, the result is quite OK :-) http://users2.ooodev.org/~cloph/videos/placebo_200kbits.mkv > Reducing the resolution of the Budapest videos to 540x300 > should still give good quality. the 720x400 is kind of misleading anyway, at least for the one I picked, as there are big black borders that I did crop. > I would guess even 360x200 should work. I also created a version encoded/sampled at 320x240 with xvid encoding, no bframes (as required by my Samsung T10 (portable music/video/fm,.. device). It requires them in an avi container, but those must be named svi (shame on them for "inventing" a new "video format") So in case your player doesn't want to play, rename to avi and it should work. I also uses 200kbps average bitrate. The quality is much worse compared to the h264 version, but the portable unfortunately only supports wmv and xvid... http://users2.ooodev.org/~cloph/videos/xvid_200kbits.svi > When > making experiments for the Beijing videos two years ago, I also ended up > with the perception that h264 delivers the best quality/file size ratio for > the job I was trying to achieve. Yes - it really deserves the term "Advanced" Video Codec. I created another version with the placebo setting, this time with 100kbps average rate, i.e. less for video than for audio, and it is still acceptable. http://users2.ooodev.org/~cloph/videos/placebo_100kbits.mkv So tell me what you think. ciao Christian --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
