ffmpeg -r 1 -i x_%d.jpg  test3.mp4

Input #0, image2, from 'x_%d.jpg':
  Duration: 00:00:05.96, start: 0.000000, bitrate: N/A
    Stream #0.0: Video: mjpeg, yuvj422p, 480x640 [PAR 144:144 DAR 3:4], 25 fps, 25 tbr, 25 tbn
[libvpx @ 0xdecce0] v1.3.0
Output #0, webm, to 'test3.webm':
  Metadata:
    encoder         : Lavf54.20.4
    Stream #0.0: Video: libvpx, yuv420p, 480x640 [PAR 1:1 DAR 3:4], q=-1--1, 200 kb/s, 1k tbn, 1 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (mjpeg -> libvpx)
Press ctrl-c to stop encoding
frame=    8 fps=  0 q=0.0 size=     179kB time=8.00 bitrate= 183.3kbits/s
frame=   14 fps= 12 q=0.0 size=     351kB time=14.00 bitrate= 205.2kbits/s
Input stream #0:0 frame changed from size:480x640 fmt:yuvj422p to size:640x480 fmt:yuvj422p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj422p to size:480x640 fmt:yuvj422p
Input stream #0:0 frame changed from size:480x640 fmt:yuvj422p to size:640x480 fmt:yuvj422p
frame=   15 fps=  9 q=0.0 size=     383kB time=15.00 bitrate= 209.0kbits/s dup=0 drop=22
Input stream #0:0 frame changed from size:640x480 fmt:yuvj422p to size:480x640 fmt:yuvj422p
Input stream #0:0 frame changed from size:480x640 fmt:yuvj422p to size:640x480 fmt:yuvj422p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj422p to size:480x640 fmt:yuvj422p
Input stream #0:0 frame changed from size:480x640 fmt:yuvj422p to size:640x480 fmt:yuvj422p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj422p to size:480x640 fmt:yuvj422p
Input stream #0:0 frame changed from size:480x640 fmt:yuvj422p to size:640x480 fmt:yuvj422p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj422p to size:480x640 fmt:yuvj422p
frame=   15 fps=  7 q=0.0 size=     383kB time=15.00 bitrate= 209.0kbits/s dup=0 drop=47
Input stream #0:0 frame changed from size:480x640 fmt:yuvj422p to size:640x480 fmt:yuvj422p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj422p to size:640x480 fmt:yuvj420p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj420p to size:480x640 fmt:yuvj422p
Input stream #0:0 frame changed from size:480x640 fmt:yuvj422p to size:640x480 fmt:yuvj444p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj444p to size:414x468 fmt:yuvj444p
Input stream #0:0 frame changed from size:414x468 fmt:yuvj444p to size:640x480 fmt:yuvj444p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj444p to size:448x474 fmt:yuvj444p
frame=   15 fps=  6 q=0.0 size=     383kB time=15.00 bitrate= 209.0kbits/s dup=0 drop=73
Input stream #0:0 frame changed from size:448x474 fmt:yuvj444p to size:640x480 fmt:yuvj444p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj444p to size:437x477 fmt:yuvj444p
Input stream #0:0 frame changed from size:437x477 fmt:yuvj444p to size:640x480 fmt:yuvj444p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj444p to size:466x462 fmt:yuvj444p
Input stream #0:0 frame changed from size:466x462 fmt:yuvj444p to size:507x469 fmt:yuvj444p
Input stream #0:0 frame changed from size:507x469 fmt:yuvj444p to size:330x454 fmt:yuvj444p
Input stream #0:0 frame changed from size:330x454 fmt:yuvj444p to size:353x422 fmt:yuvj444p
Input stream #0:0 frame changed from size:353x422 fmt:yuvj444p to size:393x459 fmt:yuvj444p
Input stream #0:0 frame changed from size:393x459 fmt:yuvj444p to size:310x424 fmt:yuvj444p
Input stream #0:0 frame changed from size:310x424 fmt:yuvj444p to size:377x359 fmt:yuvj444p
Input stream #0:0 frame changed from size:377x359 fmt:yuvj444p to size:640x480 fmt:yuvj444p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj444p to size:195x466 fmt:yuvj444p
Input stream #0:0 frame changed from size:195x466 fmt:yuvj444p to size:503x410 fmt:yuvj444p
Input stream #0:0 frame changed from size:503x410 fmt:yuvj444p to size:492x469 fmt:yuvj444p
Input stream #0:0 frame changed from size:492x469 fmt:yuvj444p to size:591x475 fmt:yuvj444p
Input stream #0:0 frame changed from size:591x475 fmt:yuvj444p to size:492x467 fmt:yuvj444p
Input stream #0:0 frame changed from size:492x467 fmt:yuvj444p to size:521x476 fmt:yuvj444p
Input stream #0:0 frame changed from size:521x476 fmt:yuvj444p to size:558x468 fmt:yuvj444p
Input stream #0:0 frame changed from size:558x468 fmt:yuvj444p to size:518x477 fmt:yuvj444p
Input stream #0:0 frame changed from size:518x477 fmt:yuvj444p to size:496x478 fmt:yuvj444p
Input stream #0:0 frame changed from size:496x478 fmt:yuvj444p to size:572x474 fmt:yuvj444p
frame=   15 fps=  5 q=0.0 size=     383kB time=15.00 bitrate= 209.0kbits/s dup=0 drop=96
Input stream #0:0 frame changed from size:572x474 fmt:yuvj444p to size:640x480 fmt:yuvj444p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj444p to size:247x348 fmt:yuvj444p
Input stream #0:0 frame changed from size:247x348 fmt:yuvj444p to size:640x480 fmt:yuvj444p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj444p to size:351x479 fmt:yuvj444p
Input stream #0:0 frame changed from size:351x479 fmt:yuvj444p to size:261x479 fmt:yuvj444p
Input stream #0:0 frame changed from size:261x479 fmt:yuvj444p to size:234x469 fmt:yuvj444p
Input stream #0:0 frame changed from size:234x469 fmt:yuvj444p to size:577x476 fmt:yuvj444p
Input stream #0:0 frame changed from size:577x476 fmt:yuvj444p to size:172x378 fmt:yuvj444p
Input stream #0:0 frame changed from size:172x378 fmt:yuvj444p to size:309x425 fmt:yuvj444p
Input stream #0:0 frame changed from size:309x425 fmt:yuvj444p to size:220x475 fmt:yuvj444p
Input stream #0:0 frame changed from size:220x475 fmt:yuvj444p to size:183x443 fmt:yuvj444p
Input stream #0:0 frame changed from size:183x443 fmt:yuvj444p to size:640x480 fmt:yuvj444p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj444p to size:322x479 fmt:yuvj444p
Input stream #0:0 frame changed from size:322x479 fmt:yuvj444p to size:200x421 fmt:yuvj444p
Input stream #0:0 frame changed from size:200x421 fmt:yuvj444p to size:483x385 fmt:yuvj444p
Input stream #0:0 frame changed from size:483x385 fmt:yuvj444p to size:433x382 fmt:yuvj444p
Input stream #0:0 frame changed from size:433x382 fmt:yuvj444p to size:640x480 fmt:yuvj444p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj444p to size:497x436 fmt:yuvj444p
Input stream #0:0 frame changed from size:497x436 fmt:yuvj444p to size:523x479 fmt:yuvj444p
Input stream #0:0 frame changed from size:523x479 fmt:yuvj444p to size:433x478 fmt:yuvj444p
Input stream #0:0 frame changed from size:433x478 fmt:yuvj444p to size:480x367 fmt:yuvj444p
Input stream #0:0 frame changed from size:480x367 fmt:yuvj444p to size:589x371 fmt:yuvj444p
Input stream #0:0 frame changed from size:589x371 fmt:yuvj444p to size:640x480 fmt:yuvj444p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj444p to size:330x477 fmt:yuvj444p
Input stream #0:0 frame changed from size:330x477 fmt:yuvj444p to size:640x480 fmt:yuvj444p
frame=   15 fps=  4 q=0.0 size=     383kB time=15.00 bitrate= 209.0kbits/s dup=0 drop=123
Input stream #0:0 frame changed from size:640x480 fmt:yuvj444p to size:273x454 fmt:yuvj444p
Input stream #0:0 frame changed from size:273x454 fmt:yuvj444p to size:640x480 fmt:yuvj444p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj444p to size:283x437 fmt:yuvj444p
Input stream #0:0 frame changed from size:283x437 fmt:yuvj444p to size:640x480 fmt:yuvj444p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj444p to size:259x450 fmt:yuvj444p
Input stream #0:0 frame changed from size:259x450 fmt:yuvj444p to size:640x480 fmt:yuvj444p
Input stream #0:0 frame changed from size:640x480 fmt:yuvj444p to size:237x435 fmt:yuvj444p
Input stream #0:0 frame changed from size:237x435 fmt:yuvj444p to size:640x480 fmt:yuvj444p
frame=   15 fps=  4 q=0.0 Lsize=     407kB time=15.00 bitrate= 222.1kbits/s dup=0 drop=134
video:406kB audio:0kB global headers:0kB muxing overhead 0.152459%