Video 两个文件的ffmpeg concat会导致视频格式错误

我正在处理两个视频，如下所示：

ffmpeg -i video-raw/455848793538790988_duration18.051.mp4 -b:v 993k -b:a 128k -vf "scale=720x1280:force_original_aspect_ratio=decrease,pad=720:1280:(ow-iw)/2:(oh-ih)/2,setsar=1:1" video-proc/455848793538790988_duration18.051.mp4

及

然后对concat运行以下命令：

ffmpeg-f concat-safe 0-i video concat/dogs-2021-04-17-06-46-id-1.txt-c:v copy-c:a copy./output.mp4

生成的视频可以正常启动，但当进入第二个视频时，图像会卡住，声音会变慢

ffprobe结果如下所示：

处理前：

ffprobe video-raw/14425661295137552_duration11.666.mp4 

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'video-raw/14425661295137552_duration11.666.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.45.100
  Duration: 00:00:11.68, start: 0.000000, bitrate: 565 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709), 640x800 [SAR 1:1 DAR 4:5], 462 kb/s, 30 fps, 30 tbr, 90k tbn, 60 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 93 kb/s (default)
    Metadata:
      handler_name    : SoundHandler

ffprobe video-proc/14425661295137552_duration11.666.mp4
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'video-proc/14425661295137552_duration11.666.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.45.100
  Duration: 00:00:11.70, start: 0.000000, bitrate: 1133 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 720x1280 [SAR 1:1 DAR 9:16], 993 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 130 kb/s (default)
    Metadata:
      handler_name    : SoundHandler

关于第二个问题：

ffprobe video-raw/455848793538790988_duration18.051.mp4

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'video-raw/455848793538790988_duration18.051.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.45.100
  Duration: 00:00:18.07, start: 0.000000, bitrate: 655 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, smpte170m/bt709/bt709), 576x1024 [SAR 1:1 DAR 9:16], 585 kb/s, 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (HE-AACv2) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 62 kb/s (default)
    Metadata:
      handler_name    : SoundHandler

处理后：

ffprobe video-raw/14425661295137552_duration11.666.mp4 

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'video-raw/14425661295137552_duration11.666.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.45.100
  Duration: 00:00:11.68, start: 0.000000, bitrate: 565 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709), 640x800 [SAR 1:1 DAR 4:5], 462 kb/s, 30 fps, 30 tbr, 90k tbn, 60 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 93 kb/s (default)
    Metadata:
      handler_name    : SoundHandler

ffprobe video-proc/14425661295137552_duration11.666.mp4
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'video-proc/14425661295137552_duration11.666.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.45.100
  Duration: 00:00:11.70, start: 0.000000, bitrate: 1133 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 720x1280 [SAR 1:1 DAR 9:16], 993 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 130 kb/s (default)
    Metadata:
      handler_name    : SoundHandler

第二个呢

ffprobe video-proc/455848793538790988_duration18.051.mp4
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'video-proc/455848793538790988_duration18.051.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.45.100
  Duration: 00:00:18.19, start: 0.000000, bitrate: 1044 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 720x1280 [SAR 1:1 DAR 9:16], 923 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 112 kb/s (default)
    Metadata:
      handler_name    : SoundHandler

---

有什么想法吗？怎么了？这两个视频在处理后分别播放得非常完美，但在concat之后就没有了。Reddit上的社区最终回答了这个问题

---

问题是，即使在处理命令之后，两个输入的FPS都不相同，所以我为处理命令添加了“-R 30”以强制FPS为30，而CONTAT工作得像魔术

，因为您已经预处理每个输入，考虑使用CONTAT过滤器。然后您可以在一个命令中完成所有操作。有关示例，请参见