4

I have a .MTS 1080i of 25fps (mediainfo) that I deinterlaced with avconv -i input.MTS -vf yadif -c:a copy output.mp4. As the wiki says, the default value for yadif is 0 which "outputs one frame for each frame".

My question is, why does output.mp4 have 50fps? Also, is it normal that it is much smaller than the input?

As requested:

wantoast@crunchbang:~/videos/video/videocamera$ avconv -i 00000.MTS
avconv version 0.8.16-6:0.8.16-1, Copyright (c) 2000-2014 the Libav developers
  built on Sep 16 2014 23:10:48 with gcc 4.7.2
Input #0, mpegts, from '00000.MTS':
  Duration: 00:00:37.44, start: 1.000033, bitrate: 16506 kb/s
  Program 1 
    Stream #0.0[0x1011]: Video: h264 (High), yuv420p, 1920x1080 [PAR 1:1 DAR 16:9], 50 fps, 50 tbr, 90k tbn, 50 tbc
    Stream #0.1[0x1100]: Audio: ac3, 48000 Hz, stereo, s16, 256 kb/s
    Stream #0.2[0x1200]: Subtitle: pgssub
At least one output file must be specified

wantoast@crunchbang:~/videos/video/videocamera$ avconv -i 00000.MTS -vf yadif -c:a copy output.mp4
avconv version 0.8.16-6:0.8.16-1, Copyright (c) 2000-2014 the Libav developers
  built on Sep 16 2014 23:10:48 with gcc 4.7.2
Input #0, mpegts, from '00000.MTS':
  Duration: 00:00:37.44, start: 1.000033, bitrate: 16506 kb/s
  Program 1 
    Stream #0.0[0x1011]: Video: h264 (High), yuv420p, 1920x1080 [PAR 1:1 DAR 16:9], 50 fps, 50 tbr, 90k tbn, 50 tbc
    Stream #0.1[0x1100]: Audio: ac3, 48000 Hz, stereo, s16, 256 kb/s
    Stream #0.2[0x1200]: Subtitle: pgssub
[buffer @ 0xa5eb40] w:1920 h:1080 pixfmt:yuv420p
[yadif @ 0xa5cba0] mode:0 parity:-1 auto_enable:0
[libx264 @ 0xa59b00] using SAR=1/1
[libx264 @ 0xa59b00] using cpu capabilities: MMX2 SSE2Fast SSSE3 FastShuffle SSE4.2 AVX
[libx264 @ 0xa59b00] profile Main, level 4.2
[libx264 @ 0xa59b00] 264 - core 123 r2189 35cf912 - H.264/MPEG-4 AVC codec - Copyleft 2003-2012 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x1:0x111 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=0 me_range=16 chroma_me=1 trellis=1 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=0 b_adapt=1 b_bias=0 direct=1 weightb=0 open_gop=1 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.25 aq=1:1.00
Output #0, mp4, to 'output.mp4':
  Metadata:
    encoder         : Lavf53.21.1
    Stream #0.0: Video: libx264, yuv420p, 1920x1080 [PAR 1:1 DAR 16:9], q=-1--1, 50 tbn, 50 tbc
    Stream #0.1: Audio: ac3, 48000 Hz, stereo, 256 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (h264 -> libx264)
  Stream #0:1 -> #0:1 (copy)
Press ctrl-c to stop encoding
frame= 1870 fps= 16 q=-1.0 Lsize=   29093kB time=37.38 bitrate=6375.8kbits/s dup=935 drop=0    
video:27902kB audio:1170kB global headers:0kB muxing overhead 0.070776%
[libx264 @ 0xa59b00] frame I:122   Avg QP:22.47  size: 49023
[libx264 @ 0xa59b00] frame P:1748  Avg QP:25.43  size: 12923
[libx264 @ 0xa59b00] mb I  I16..4: 61.9%  0.0% 38.1%
[libx264 @ 0xa59b00] mb P  I16..4:  2.8%  0.0%  0.5%  P16..4: 36.5%  2.8%  1.7%  0.0%  0.0%    skip:55.7%
[libx264 @ 0xa59b00] coded y,uvDC,uvAC intra: 38.5% 80.0% 19.8% inter: 7.1% 27.2% 0.2%
[libx264 @ 0xa59b00] i16 v,h,dc,p: 35% 18% 15% 31%
[libx264 @ 0xa59b00] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 28% 18% 35%  4%  3%  3%  4%  3%  2%
[libx264 @ 0xa59b00] i8c dc,h,v,p: 50% 18% 26%  6%
[libx264 @ 0xa59b00] Weighted P-Frames: Y:1.1% UV:0.7%
[libx264 @ 0xa59b00] ref P L0: 63.3%  9.7% 13.0% 13.9%  0.1%
[libx264 @ 0xa59b00] kb/s:6111.45

wantoast@crunchbang:~/videos/video/videocamera$ avconv -i output.mp4 
avconv version 0.8.16-6:0.8.16-1, Copyright (c) 2000-2014 the Libav developers
  built on Sep 16 2014 23:10:48 with gcc 4.7.2
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x216e460] multiple edit list entries, a/v desync might occur, patch welcome
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'output.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf53.21.1
  Duration: 00:00:37.47, start: 0.000000, bitrate: 6358 kb/s
    Stream #0.0(und): Video: h264 (Main), yuv420p, 1920x1080 [PAR 1:1 DAR 16:9], 6111 kb/s, 50 fps, 50 tbr, 50 tbn, 100 tbc
    Stream #0.1(und): Audio: ac3, 48000 Hz, stereo, s16, 256 kb/s
At least one output file must be specified
Wantoast
  • 41

1 Answers1

0

The original file is 25 fields per second and 50 frames per second are required to preserve correct motion. The fact of the matter even youtube uses 25 frames per second and loses half of motion. That is just wrong.

Other than that -crf 18 is needed to get good enough quality.

Валерий Заподовников
  • 395