Я пытаюсь наложить несколько видео на базовое видео, видео накладывается, но звук основного базового видео теряется. Кроме того, если я хочу добавить больше видео, какие шаги нужно предпринять?

Следующее - моя команда:

ffmpeg -i master_video.mp4 -i comment_1_offset.mp4 -i comment_2_offset.mp4 -filter_complex "[0:v][1:v]overlay=900:450:enable='between(t\,06,12)'[bg];[bg][2:v]overlay=0:0:enable='between(t\,8,15)'[v]; [1:a][2:a]amerge=inputs=2[a]"  -map "[v]" -map "[a]" -ac 2 final_comments.mp4

OUTPUT:
ffmpeg version 3.1 Copyright (c) 2000-2016 the FFmpeg developers
  built with Apple LLVM version 7.3.0 (clang-703.0.31)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/3.1 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-opencl --enable-libx264 --enable-libmp3lame --enable-libxvid --disable-lzma --enable-vda
  libavutil      55. 27.100 / 55. 27.100
  libavcodec     57. 48.101 / 57. 48.101
  libavformat    57. 40.101 / 57. 40.101
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 46.102 /  6. 46.102
  libavresample   3.  0.  0 /  3.  0.  0
  libswscale      4.  1.100 /  4.  1.100
  libswresample   2.  1.100 /  2.  1.100
  libpostproc    54.  0.100 / 54.  0.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'master_video.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    creation_time   : 1970-01-01 00:00:00
    encoder         : Lavf53.24.2
  Duration: 00:00:29.57, start: 0.000000, bitrate: 1421 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 1032 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      creation_time   : 1970-01-01 00:00:00
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, 5.1, fltp, 383 kb/s (default)
    Metadata:
      creation_time   : 1970-01-01 00:00:00
      handler_name    : SoundHandler
Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'comment_1_offset.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.40.101
  Duration: 00:00:11.28, start: 0.000000, bitrate: 292 kb/s
    Stream #1:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 320x240 [SAR 4:3 DAR 16:9], 127 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #1:1(und): Audio: aac (mp4a / 0x6134706D), 48000 Hz, 5.1, fltp, 338 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Input #2, mov,mp4,m4a,3gp,3g2,mj2, from 'comment_2_offset.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.40.101
  Duration: 00:00:15.03, start: 0.000000, bitrate: 409 kb/s
    Stream #2:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 320x568, 359 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #2:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 70 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
File 'final_comments.mp4' already exists. Overwrite ? [y/N] y
[Parsed_amerge_2 @ 0x7fc833703300] No channel layout for input 1
[Parsed_amerge_2 @ 0x7fc833703300] Input channel layouts overlap: output layout will be determined by the number of distinct input channels
[libx264 @ 0x7fc833831e00] using SAR=1/1
[libx264 @ 0x7fc833831e00] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 AVX2 LZCNT BMI2
[libx264 @ 0x7fc833831e00] profile High, level 3.1
[libx264 @ 0x7fc833831e00] 264 - core 148 r2668 fd2c324 - H.264/MPEG-4 AVC codec - Copyleft 2003-2016 - 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
[mp4 @ 0x7fc833830c00] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.
    Last message repeated 1 times
Output #0, mp4, to 'final_comments.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.40.101
    Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], q=-1--1, 25 fps, 12800 tbn, 25 tbc (default)
    Metadata:
      encoder         : Lavc57.48.101 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
    Stream #0:1: Audio: aac (LC) ([64][0][0][0] / 0x0040), 48000 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      encoder         : Lavc57.48.101 aac
Stream mapping:
  Stream #0:0 (h264) -> overlay:main
  Stream #1:0 (h264) -> overlay:overlay
  Stream #1:1 (aac) -> amerge:in0
  Stream #2:0 (h264) -> overlay:overlay
  Stream #2:1 (aac) -> amerge:in1
  overlay -> Stream #0:0 (libx264)
  amerge -> Stream #0:1 (aac)
Press [q] to stop, [?] for help
[Parsed_overlay_0 @ 0x7fc833702200] [framesync @ 0x7fc8337024e8] Buffer queue overflow, dropping.
    Last message repeated 80 times
[Parsed_overlay_1 @ 0x7fc833702be0] [framesync @ 0x7fc833702cc8] Buffer queue overflow, dropping.
    Last message repeated 110 times
frame=   44 fps=0.0 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   frame=   56 fps= 52 q=28.0 size=       0kB time=00:00:00.12 bitrate=   3.2kbits/frame=   69 fps= 43 q=28.0 size= Error while decoding stream #2:1: Cannot allocate memory.26 bitrate=1445.6kbits/s speed=1.35x     00:01.16 bitrate=   0.3kbits/s speed=0.542x    
    Last message repeated 10 times
Error while decoding stream #2:1: Cannot allocate memory.26 bitrate=1536.6kbits/s speed=1.27x    
    Last message repeated 37 times
Error while decoding stream #2:1: Cannot allocate memory.68 bitrate=1531.0kbits/s speed=1.24x    
    Last message repeated 39 times
Error while decoding stream #2:1: Cannot allocate memory.60 bitrate=1419.2kbits/s speed=1.27x    
    Last message repeated 9 times
frame=  739 fps= 37 q=-1.0 Lsize=    4778kB time=00:00:29.44 bitrate=1329.4kbits/s speed=1.49x    
video:4682kB audio:85kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.223951%
[libx264 @ 0x7fc833831e00] frame I:7     Avg QP:16.70  size: 97405
[libx264 @ 0x7fc833831e00] frame P:379   Avg QP:22.09  size:  8715
[libx264 @ 0x7fc833831e00] frame B:353   Avg QP:25.96  size:  2291
[libx264 @ 0x7fc833831e00] consecutive B-frames: 34.9%  1.1%  9.3% 54.7%
[libx264 @ 0x7fc833831e00] mb I  I16..4: 14.9% 38.0% 47.1%
[libx264 @ 0x7fc833831e00] mb P  I16..4:  2.4%  3.4%  0.5%  P16..4: 32.4%  7.8%  3.0%  0.0%  0.0%    skip:50.5%
[libx264 @ 0x7fc833831e00] mb B  I16..4:  0.2%  0.3%  0.0%  B16..8: 28.4%  1.6%  0.2%  direct: 0.6%  skip:68.5%  L0:52.1% L1:45.1% BI: 2.9%
[libx264 @ 0x7fc833831e00] 8x8 transform intra:51.1% inter:69.4%
[libx264 @ 0x7fc833831e00] coded y,uvDC,uvAC intra: 47.1% 69.1% 21.1% inter: 7.0% 11.1% 0.3%
[libx264 @ 0x7fc833831e00] i16 v,h,dc,p: 26% 30% 13% 31%
[libx264 @ 0x7fc833831e00] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 24% 22% 22%  4%  5%  5%  5%  6%  6%
[libx264 @ 0x7fc833831e00] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 22% 17% 11%  8%  9%  9%  8%  9%  8%
[libx264 @ 0x7fc833831e00] i8c dc,h,v,p: 48% 21% 23%  9%
[libx264 @ 0x7fc833831e00] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 0x7fc833831e00] ref P L0: 80.1%  9.7%  8.2%  2.1%
[libx264 @ 0x7fc833831e00] ref B L0: 93.6%  5.5%  0.9%
[libx264 @ 0x7fc833831e00] ref B L1: 96.6%  3.4%
[libx264 @ 0x7fc833831e00] kb/s:1297.28
[aac @ 0x7fc833851c00] Qavg: 805.732

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