Question

请问帮助我了解如何在ffmpeg编码过程中匹配音频和视频持续时间，以将用于无限循环mpeg破折号传输（mp4box）的视频串联起来。

我的问题发生在ffmpeg编码期间：

在concat / encode处理之前，为每个视频进行音频编码和时基一致性的第一步：

ffmpeg -y -i "$f" -c copy -video_track_timescale 90k -c:a aac -b:a 384k -ar 44100 -ac 2 -shortest -af aresample=async=1 ../buffer/${NAME}_buffer.mp4

然后进行concat / encode处理，以获取封闭GOP的总持续时间（以秒为单位）例如：减少373.5持续时间以获得372.000持续时间：

ffmpeg -f concat -safe 0 -y -i list.txt -loop 1 -i ../logo/logo.png -c:a copy -c:v libx264 -x264opts keyint=$GOP:min-keyint=$GOP:no-scenecut -bf 0 -r $FPSC -b:v 4800k -maxrate 9600k -bufsize 19200k -profile:v main -crf 22 -filter_complex "[0:v][1:v]overlay=main_w-overlay_w-10:10,scale=1920:1080,setsar=1" -t $TOTDUR 1080set.mp4

结果

VIDEO FORMAT CONTAINER DURATION:
372.000000
VIDEO STREAM DURATION:
372.000000
AUDIO FORMAT CONTAINER DURATION:
372.006000

我需要帮助来理解为什么音频持续时间比视频持续时间要多6毫秒以及如何解决。我读到关于loop_stream应该有帮助吗？非常感谢！

视频信息下方：

Metadata:
    major_brand     : isom
    minor_version   : 1
    compatible_brands: isomavc1
    creation_time   : 2007-05-09T07:55:25.000000Z
  Duration: 00:01:29.22, start: 0.000000, bitrate: 7490 kb/s
    Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 1920x816, 7403 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 47.95 tbc (default)
    Metadata:
      creation_time   : 2007-05-09T07:55:25.000000Z
      handler_name    : GPAC ISO Video Handler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 94 kb/s (default)
    Metadata:
      creation_time   : 2007-05-09T07:55:29.000000Z
      handler_name    : GPAC ISO Audio Handler

  Metadata:
    major_brand     : isom
    minor_version   : 1
    compatible_brands: isomavc1
    creation_time   : 2007-07-17T09:18:37.000000Z
    genre           : Trailer
    artist          : Fox
    title           : The Simpsons Movie
    date            : 2007
  Duration: 00:02:17.25, start: 0.000000, bitrate: 8591 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x800, 8486 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 47.95 tbc (default)
    Metadata:
      creation_time   : 2007-07-17T09:18:37.000000Z
      handler_name    : GPAC ISO Video Handler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, 5.1, fltp, 107 kb/s (default)
    Metadata:
      creation_time   : 2007-07-17T09:18:45.000000Z
      handler_name    : GPAC ISO Audio Handler
    Stream #0:2: Video: mjpeg (Progressive), yuvj420p(pc, bt470bg/unknown/unknown), 101x150 [SAR 72:72 DAR 101:150], 90k tbr, 90k tbn, 90k tbc (attached pic)

  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42isomavc1
    creation_time   : 2013-12-01T03:59:56.000000Z
    genre           : Trailer
    artist          : Warner Bros.
    title           : Gravity - 2K Trailer
    encoder         : HandBrake 0.9.9 2013051800
    date            : 2013
  Duration: 00:02:27.07, start: 0.000000, bitrate: 20296 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 2048x858, 20149 kb/s, 23.98 fps, 23.98 tbr, 90k tbn, 47.95 tbc (default)
    Metadata:
      creation_time   : 2013-12-01T03:59:56.000000Z
      encoder         : JVT/AVC Coding
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 153 kb/s (default)
    Metadata:
      creation_time   : 2013-12-01T03:59:56.000000Z
    Stream #0:2: Video: mjpeg (Baseline), yuvj420p(pc, bt470bg/unknown/unknown), 102x150 [SAR 72:72 DAR 17:25], 90k tbr, 90k tbn, 90k tbc (attached pic)

音频视频持续时间匹配，用于无限虚线循环伪实时播放

0 个答案: