On Mon Feb 02 2015 at 8:51:23 PM Moritz Barsnick <[email protected]> wrote:
> Hi Wesley, > > On Mon, Feb 02, 2015 at 10:51:12 +0000, Wesley Wen wrote: > > Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, > 426x240 [SAR 149:181 DAR 10579:7240], 80 kb/s, SAR 12800:15549 DAR 320:219, > 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default) > > I have always found those AR numbers a little peculiar, but refused to > look at the code creating them. ;-) > > But this results from your scaling to 426x240, not from the cropping. > > > Input #0, mpeg, from 'sample.mpg': > > Duration: 00:24:28.18, start: 0.262000, bitrate: 8597 kb/s > > Stream #0:0[0x1e0]: Video: mpeg2video (Main), yuv420p(tv), 720x480 > [SAR 8:9 DAR 4:3], 8000 kb/s, 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc > > Stream #0:1[0x1c0]: Audio: mp2, 48000 Hz, stereo, s16p, 384 kb/s > > > > And here is the command I used to do crop. > > ffmpeg -y -i sample.mpg -c:v libx264 -b:v 80k -vf > crop=720:438:0:0,scale=426:240 out.mp4 > > Excuse me? You write you want to remove two lines, but you are removing > 42. Nice number, but different result! (480 - 438 = 42.) Did you > complain about the non-4:3 AR, or that your image is peculiarly > stretched? The latter would be due to your miscalculation. > > > I'd like to keep display aspect ratio as 4:3, and remove those two green > > lines or fill black. > > Well if you snip away something in one dimension, you are going to ruin > the aspect ratio. So you either need to snip accordingly in each > dimension (e.g. 4 columns horizontally, 3 lines vertically), or stretch > to refill the original dimensions, or fill up with something else such > as black. > > Since filling with black is okay for you, let me suggest cutting away > (i.e. "crop"ping) and filling back up (i.e. "pad"ding): > > $ ... -vf "crop=720:478:0:0,pad=720:480:0:0,scale=426:240" > > Thank you Moritz! It resolves the issue. :-) -Wesley > (I think both former filters default to ":0:0", check the docs.) > Let us know if this helps, > Moritz > _______________________________________________ > ffmpeg-user mailing list > [email protected] > http://ffmpeg.org/mailman/listinfo/ffmpeg-user > _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
