连接视频 Audio/Video 不同步:非单调 TDS 输出

Concatenating videos Audio/Video out of sync : Non-monotonous TDS output

我正在尝试使用 ffmpeg 添加两个视频,但输出 video/audio 不同步(并快进)。目标是将 intro.mp4 放在原始文件 clip.flv

之前

我的做法是

  1. clip.flv 的格式更改为 clip.mp4
ffmpeg -i clip.flv -q 0 -c copy clip.mp4
  1. 连接 intro.mp4clip.mp4
ffmpeg -f concat -safe 0 -i filesToJoin.txt -c copy combinedvideo.mp4

我在命令#2 的输出日志中看到了这个

[mp4 @ 0x3ebcd60] Non-monotonous DTS in output stream 0:0; previous: 392311, current: 391925; changing to 392312. This may result in incorrect timestamps in the output file.
frame= 1566 fps=0.0 q=-1.0 Lsize=    8711kB time=00:00:48.86 bitrate=1460.2kbits/s speed= 272x    
video:7363kB audio:1294kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.619341%

文件元数据

原始源文件clip.flv元数据

  Metadata:
    encoder         : Lavf57.83.100
  Duration: 00:00:40.09, start: 0.010000, bitrate: 1632 kb/s
    Stream #0:0: Video: h264 (High), yuv420p(progressive), 1280x720, 1500 kb/s, 30 fps, 30 tbr, 1k tbn, 60 tbc
    Stream #0:1: Audio: aac (LC), 44100 Hz, stereo, fltp, 160 kb/s

中间文件intro.mp4元数据

  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42mp41
    creation_time   : 2020-06-02T10:36:51.000000Z
  Duration: 00:00:13.21, start: 0.000000, bitrate: 484 kb/s
    Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709), 1280x720 [SAR 1:1 DAR 16:9], 130 kb/s, 30 fps, 30 tbr, 30k tbn, 60k tbc (default)
    Metadata:
      creation_time   : 2020-06-02T10:36:51.000000Z
      handler_name    : Alias Data Handler
      encoder         : AVC Coding
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 317 kb/s (default)
    Metadata:
      creation_time   : 2020-06-02T10:36:52.000000Z
      handler_name    : Alias Data Handler

文件clip.mp4元数据

    Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.83.100
  Duration: 00:00:40.01, start: 0.000000, bitrate: 1635 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720, 1500 kb/s, 30 fps, 30 tbr, 16k tbn, 60 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 160 kb/s (default)
    Metadata:
      handler_name    : SoundHandler

我尝试过的东西

ffmpeg -i clip.mp4 -video_track_timescale 30000 clip_ts30000.mp4

更新:我尝试了一种解决方法,将视频转换为中间格式 .MTS,然后连接视频,然后将输出视频转换为 .mp4 作为最终输出。

# Step 1: Convert to MTS format
ffmpeg -i clip.flv -q 0 clip.MTS
ffmpeg -i intro.mp4 -q 0 intro.MTS

# Step 2: Concat clip.MTS and intro.MTS
ffmpeg -f concat -i filesToSync.txt -c copy out.MTS

# Step 3: Convert the output back to mp4
ffmpeg -i out.MTS -q 0 out.mp4

此解决方法适用于具有怪癖的此特定用例:对最终输出文件应用更多 ffmpeg 操作会出现错误 - 未指定的像素格式。