On Tue, Dec 18, 2012 at 1:07 PM, Taha Ansari <[email protected]> wrote: > After first run, if we change > > #define ENCODER_WIDTH 640 > #define ENCODER_HEIGHT 480 > > to > > #define ENCODER_WIDTH 160 > #define ENCODER_HEIGHT 120 > > and run again, file size is almost the same. Question now is why? shouldn't > smaller sized video be taking up much lesser space than the original sized > video?
Note that you have the encoder bit rate hard coded: > c->bit_rate = 400000; ... so, one would expect a well-tempered encoder to produce same encoded frame sizes. You could try to compare the resulting video quality in two cases. E.g., decode the two streams and display them at 160x120. You are expected to see very similar images. If you increase the requested bit rate, the VGA stream will still be improving, but the 160x120 stream is probably saturated. You can consult the "video bitrate calculator" at http://www.dr-lex.be/info-stuff/videocalc.html to find the optimal bit rate - it would be more than 1Mbps for VGA at 25 FPS. BR, Alex _______________________________________________ Libav-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/libav-user
