audio - FFMPEG：在编码期间更改视频（使用映射）

Question

我目前正在尝试使用复杂的过滤器连接几个视频：

ffmpeg.exe -threads 8 -i "D:\Temporary0.mp4"  -i "D:\Temporary1.mp4"  -i "D:\Temporary2.mp4"  -filter_complex "[0:v] [0:a] [1:v] [1:a] [2:v] [2:a]  concat=n=3:v=1:a=1 [v] [a] " -map "[v]" -map "[a]"  -vcodec libx264 -b 2500000 -s 1920:1080 -y D:\EditedVideo.mp4

该命令工作正常。编辑：这里是命令的输出：

ffmpeg version N-56297-g7ac6c63 Copyright (c) 2000-2013 the FFmpeg developers
  built on Sep 15 2013 18:02:28 with gcc 4.7.3 (GCC)
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libblu
ray --enable-libcaca --enable-libfreetype --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-l
ibopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-li
bvorbis --enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib
  libavutil      52. 43.100 / 52. 43.100
  libavcodec     55. 31.101 / 55. 31.101
  libavformat    55. 16.102 / 55. 16.102
  libavdevice    55.  3.100 / 55.  3.100
  libavfilter     3. 84.100 /  3. 84.100
  libswscale      2.  5.100 /  2.  5.100
  libswresample   0. 17.103 /  0. 17.103
  libpostproc    52.  3.100 / 52.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'D:\Temporary0.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf55.16.102
  Duration: 00:00:02.91, start: 0.033333, bitrate: 8998 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 8965 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'D:\Temporary1.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf55.16.102
  Duration: 00:00:05.00, start: 0.023220, bitrate: 846 kb/s
    Stream #1:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 835 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #1:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 1 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Input #2, mov,mp4,m4a,3gp,3g2,mj2, from 'D:\Temporary2.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf55.16.102
  Duration: 00:00:04.35, start: 0.033333, bitrate: 4684 kb/s
    Stream #2:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 4581 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #2:1(und): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Please use -b:a or -b:v, -b is ambiguous
[libx264 @ 04f617e0] using SAR=1/1
[libx264 @ 04f617e0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
[libx264 @ 04f617e0] profile High, level 4.0
[libx264 @ 04f617e0] 264 - core 135 r2345 f0c1c53 - H.264/MPEG-4 AVC codec - Copyleft 2003-2013 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subm
e=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=12 lookahead_threads=2 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 r
c=abr mbtree=1 bitrate=2500 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to 'D:\EditedVideo.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf55.16.102
    Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=-1--1, 2500 kb/s, 12800 tbn, 25 tbc
    Stream #0:1: Audio: aac (libvo_aacenc) ([64][0][0][0] / 0x0040), 48000 Hz, stereo, s16, 128 kb/s
Stream mapping:
  Stream #0:0 (h264) -> concat:in0:v0
  Stream #0:1 (aac) -> concat:in0:a0
  Stream #1:0 (h264) -> concat:in1:v0
  Stream #1:1 (aac) -> concat:in1:a0
  Stream #2:0 (h264) -> concat:in2:v0
  Stream #2:1 (aac) -> concat:in2:a0
  concat:out:v0 -> Stream #0:0 (libx264)
  concat:out:a0 -> Stream #0:1 (libvo_aacenc)
Press [q] to stop, [?] for help
frame=  306 fps= 43 q=-1.0 Lsize=    3557kB time=00:00:12.29 bitrate=2369.4kbits/s dup=1 drop=0
video:3353kB audio:193kB subtitle:0 global headers:0kB muxing overhead 0.288541%
[libx264 @ 04f617e0] frame I:3     Avg QP:21.78  size:173526
[libx264 @ 04f617e0] frame P:112   Avg QP:25.76  size: 17363
[libx264 @ 04f617e0] frame B:191   Avg QP:31.04  size:  5068
[libx264 @ 04f617e0] consecutive B-frames: 11.8% 14.4%  2.0% 71.9%
[libx264 @ 04f617e0] mb I  I16..4: 14.6% 82.7%  2.6%
[libx264 @ 04f617e0] mb P  I16..4:  3.5%  8.8%  0.2%  P16..4: 30.1%  5.3%  2.6%  0.0%  0.0%    skip:49.4%
[libx264 @ 04f617e0] mb B  I16..4:  0.7%  1.1%  0.0%  B16..8: 21.6%  1.2%  0.1%  direct: 1.2%  skip:74.1%  L0:47.0% L1:50.6% BI: 2.4%
[libx264 @ 04f617e0] final ratefactor: 25.69
[libx264 @ 04f617e0] 8x8 transform intra:70.8% inter:88.5%
[libx264 @ 04f617e0] coded y,uvDC,uvAC intra: 34.3% 50.2% 7.2% inter: 7.3% 13.3% 0.3%
[libx264 @ 04f617e0] i16 v,h,dc,p: 22% 33%  7% 37%
[libx264 @ 04f617e0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 17% 22% 34%  4%  5%  4%  5%  4%  5%
[libx264 @ 04f617e0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 27% 22% 18%  5%  6%  6%  5%  6%  4%
[libx264 @ 04f617e0] i8c dc,h,v,p: 60% 21% 16%  3%
[libx264 @ 04f617e0] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 04f617e0] ref P L0: 62.6%  9.1% 19.8%  8.5%
[libx264 @ 04f617e0] ref B L0: 85.3% 12.6%  2.1%
[libx264 @ 04f617e0] ref B L1: 92.4%  7.6%
[libx264 @ 04f617e0] kb/s:2243.97
[libvo_aacenc @ 0420e900] 1 frames left in the queue on closing

我想更新此命令以在 concat 和编码时间更改音量：

ffmpeg.exe -threads 8 -i "D:\Temporary0.mp4"  -i "D:\Temporary1.mp4"  -i "D:\Temporary2.mp4"  -filter_complex "[0:v] [0:a] [1:v] [1:a] [2:v] [2:a]  concat=n=3:v=1:a=1 [v] [a] " -map "[v]" -map "[a]"  -vcodec libx264 -b 2500000 -s 1920:1080 -af volume="volume=20dB:precision=double" -y D:\EditedVideo.mp4

此命令已执行，但音频流未随 +20db 更改

PS：如果我做一个简单的编码命令，比如

ffmpeg.exe -i source -vcodec libx264 -af volume="volume=20dB:precision=double" -y output

命令工作正常，音频流被修改。

那么我该怎么做才能同时连接我的视频和更改音量呢？

谢谢

score 1 · Accepted Answer

例子

所有过滤都应该在一个filtergraph中完成：

$ ffmpeg -y -i input0.mp4 -i input1.mp4 -i input2.mp4 -filter_complex \
  "[1:a]pan=stereo:c0=c0:c0=c1,aresample=48000[a1]; \
   [0:v][0:a][1:v][a1][2:v][2:a]concat=n=3:v=1:a=1[v1][a2]; \
   [v1]scale=1920:-1[v2]; \
   [a2]volume=volume=20dB:precision=double[a3]" \
   -map "[v2]" -map "[a3]" -codec:v libx264 -crf 23 -preset medium output.mp4

_{注意：这是一个未经测试的示例。}

过滤

您的其中一个输入是单声道，而不是立体声，因此第一步是使用将其更改为立体声pan，然后使用对其重新采样aresample以匹配其他输入。
然后concat用于连接所有内容。
尽管您的输入都是 1920x1080，但-s 1920x1080由于某种原因您仍然包含在内。我将缩放移动到过滤器图中，因此scale您可以使用过滤器精确控制缩放发生在哪些特定流上。我只声明了宽度并被-1告知scale在保留方面的同时自动提供高度。
然后volume用过滤器调节音量。

其他

-b是模棱两可的。您应该明确说明它适用于哪个流：视频 ( -b:v) 或音频 ( -b:a)。
除非您针对特定的输出文件大小，否则通常建议使用libx264: 。有关详细信息，请参阅FFmpeg 和 x264 编码指南。-crf-b:v

audio - FFMPEG：在编码期间更改视频（使用映射）

1 回答 1

例子

过滤

其他

Related

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