FFMpeg Concat 过滤器 - 设置文件的起始位置

Question

我想使用 concat 连接两个视频文件筛选。第一个文件必须完整包含，而第二个视频必须从第 10 秒开始包含。我需要先从第 10 秒开始创建中间文件，还是可以一步完成？

我正在使用的命令是

/usr/local/bin/ffmpeg -i intro.mp4 -i input.mp4 -filter_complex '[0:v] scale=720:576 [in1]; [1:v] scale=720:576 [in2]; [in1][in2] concat [v]; [0:a][1:a] concat=v=0:a=1 [a]' -map '[v]' -map '[a]' output.mp4

我尝试指定 -ss在 -i input.mp4 之后，但它应用于最终输出文件。

iMac:files joyce$ /usr/local/bin/ffmpeg -i intro.mp4 -i input.mp4 -filter_complex '[0:v] scale=720:576 [in1]; [1:v] scale=720:576 [in2]; [in1][in2] concat [v]; [0:a][1:a] concat=v=0:a=1 [a]' -map '[v]' -map '[a]' output.mp4
ffmpeg version 2.1.4 Copyright (c) 2000-2014 the FFmpeg developers
  built on Mar 22 2014 16:19:43 with Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/2.1.4 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-nonfree --enable-hardcoded-tables --enable-avresample --enable-vda --cc=clang --host-cflags= --host-ldflags= --enable-libx264 --enable-libfaac --enable-libmp3lame --enable-libxvid --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libfdk-aac
  libavutil      52. 48.101 / 52. 48.101
  libavcodec     55. 39.101 / 55. 39.101
  libavformat    55. 19.104 / 55. 19.104
  libavdevice    55.  5.100 / 55.  5.100
  libavfilter     3. 90.100 /  3. 90.100
  libavresample   1.  1.  0 /  1.  1.  0
  libswscale      2.  5.101 /  2.  5.101
  libswresample   0. 17.104 /  0. 17.104
  libpostproc    52.  3.100 / 52.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'intro.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf55.19.104
  Duration: 00:00:03.05, start: 0.046440, bitrate: 1304 kb/s
    Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 1920x1080, 1167 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 132 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf55.19.104
    episode_sort    : 1
    season_number   : 1
    media_type      : 9
    hd_video        : 0
  Duration: 00:00:45.43, start: 0.042667, bitrate: 906 kb/s
    Stream #1:0(eng): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 720x576 [SAR 1:1 DAR 5:4], 774 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #1:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 127 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
File 'output.mp4' already exists. Overwrite ? [y/N] y
[libx264 @ 0x7fa9a8828e00] using SAR=1/1
[libx264 @ 0x7fa9a8828e00] using cpu capabilities: MMX2 SSE2Fast SSSE3 FastShuffle SSE4.2 AVX
[libx264 @ 0x7fa9a8828e00] profile High, level 3.1
[libx264 @ 0x7fa9a8828e00] 264 - core 125 - 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=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 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=1.40 aq=1:1.00
Output #0, mp4, to 'output.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf55.19.104
    Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 720x576 [SAR 1:1 DAR 5:4], q=-1--1, 30k tbn, 29.97 tbc (default)
    Stream #0:1: Audio: aac (libfaac) ([64][0][0][0] / 0x0040), 44100 Hz, stereo, s16, 128 kb/s (default)
Stream mapping:
  Stream #0:0 (h264) -> scale
  Stream #0:1 (aac) -> concat:in0:a0
  Stream #1:0 (h264) -> scale
  Stream #1:1 (aac) -> concat:in1:a0
  concat -> Stream #0:0 (libx264)
  concat -> Stream #0:1 (libfaac)
Press [q] to stop, [?] for help
frame= 1453 fps= 42 q=-1.0 Lsize=    4536kB time=00:00:48.50 bitrate= 766.1kbits/s dup=227 drop=0    
video:3796kB audio:691kB subtitle:0 global headers:0kB muxing overhead 1.102067%
[libx264 @ 0x7fa9a8828e00] frame I:31    Avg QP:17.02  size: 14953
[libx264 @ 0x7fa9a8828e00] frame P:764   Avg QP:24.14  size:  3677
[libx264 @ 0x7fa9a8828e00] frame B:658   Avg QP:28.17  size:   933
[libx264 @ 0x7fa9a8828e00] consecutive B-frames: 36.4%  6.2% 10.3% 47.1%
[libx264 @ 0x7fa9a8828e00] mb I  I16..4: 40.4% 32.3% 27.3%
[libx264 @ 0x7fa9a8828e00] mb P  I16..4:  6.6%  4.0%  1.1%  P16..4: 25.2%  5.7%  2.3%  0.0%  0.0%    skip:55.0%
[libx264 @ 0x7fa9a8828e00] mb B  I16..4:  0.8%  0.4%  0.2%  B16..8: 24.5%  1.7%  0.2%  direct: 0.5%  skip:71.6%  L0:50.7% L1:45.5% BI: 3.9%
[libx264 @ 0x7fa9a8828e00] 8x8 transform intra:33.3% inter:59.0%
[libx264 @ 0x7fa9a8828e00] coded y,uvDC,uvAC intra: 26.4% 41.2% 8.0% inter: 5.6% 7.9% 0.2%
[libx264 @ 0x7fa9a8828e00] i16 v,h,dc,p: 46% 29%  8% 17%
[libx264 @ 0x7fa9a8828e00] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 31% 19% 28%  3%  3%  4%  3%  4%  3%
[libx264 @ 0x7fa9a8828e00] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 34% 22% 13%  4%  6%  7%  5%  5%  3%
[libx264 @ 0x7fa9a8828e00] i8c dc,h,v,p: 57% 19% 20%  4%
[libx264 @ 0x7fa9a8828e00] Weighted P-Frames: Y:1.8% UV:1.2%
[libx264 @ 0x7fa9a8828e00] ref P L0: 73.2%  9.1% 11.7%  5.3%  0.7%
[libx264 @ 0x7fa9a8828e00] ref B L0: 89.3%  8.9%  1.8%
[libx264 @ 0x7fa9a8828e00] ref B L1: 95.3%  4.7%
[libx264 @ 0x7fa9a8828e00] kb/s:641.26

Answer 1

我放置了-ss -i 之后的参数选项，这就是它没有正确应用的原因。

/usr/local/bin/ffmpeg -i intro.mp4 -i input.mp4 -ss 1.5 -filter_complex '[0:v] scale=720:576 [in1]; [1:v] scale=720:576 [in2]; [in1][in2] concat [v]; [0:a][1:a] concat=v=0:a=1 [a]' -map '[v]' -map '[a]' output.mp4

我试着把它放在 -i 之前选项，现在它按预期工作。

/usr/local/bin/ffmpeg -i intro.mp4 -ss 1.5 -i input.mp4 -filter_complex '[0:v] scale=720:576 [in1]; [1:v] scale=720:576 [in2]; [in1][in2] concat [v]; [0:a][1:a] concat=v=0:a=1 [a]' -map '[v]' -map '[a]' output.mp4