FFmpeg 分割大文件 [英] FFmpeg splitting large files

问题描述

我需要快速将一个大型视频文件拆分成多个片段，并且没有错误的文件.基本思想是，我有一个 2GB 的视频文件，我想将其更改为多种格式.我读过一些编码器在编码为不同格式时不能使用超过 1 个核心.所以我有了将大文件(非常快)拆分为 4/8 块的想法，具体取决于我在各个服务器上可用的内核数量.将每个片段重新编码为新格式，并使用这些格式按顺序显示视频.

I need to split a large video file into multiple pieces quickly and without files with errors. The basic idea is, I have a 2GB video file which I want to change to multiple formats. I have read some encoders can not make use of more than 1 core when encoding to a different format. So I had the idea to split the large file (which is very quick) into 4/8 pieces depending on how many cores I have available on individual servers. re-encode each piece to a new format and use these to display video in sequence.

所以

testfile.mp4

testfile.mp4

变成

1. testfile_piece_1.mp4
2. testfile_piece_2.mp4
3. testfile_piece_3.mp4
4. testfile_piece_4.mp4

然后可以单独转换这些.

these can then be individually be converted.

解决方案不应特定于格式.但是我发现 mp4 文件有问题.

The solution should not be format specific. However I have found issues with mp4 files.

我已经尝试过下面的命令，它运行得非常好而且速度很快，但是创建的文件有错误.

I have tried the command below, which works really well and fast but creates files with errors.

ffmpeg -i testfile.mp4 -ss 00:00:00 -t 00:20:00 -c copy testfile_piece_1.mp4

当我在 VLC 上播放 testfile_piece_1.mp4 时，它工作正常.将拆分文件转换为不同高度和宽度的 mp4 文件时会出现问题.我会收到类似于moov atom not found"的错误

When I play the testfile_piece_1.mp4 on VLC it works fine. An issue arises when converting the split file to a different height and width mp4 file. I would get an error similar to "moov atom not found"

我尝试添加 -movflags faststart 没有运气

I tried adding -movflags faststart with no luck

然后我遇到了这个库 https://code.google.com/archive/p/moovrelocator/ 解决了 moov 问题，但随后我会收到关于 aac 的错误打开输出流 #0.0 的编码器时出错 - 可能参数不正确，例如比特率、速率、宽度或高度"

I then came across this library https://code.google.com/archive/p/moovrelocator/ which fixed the moov issue but I would then get an error with regards to aac "Error while opening encoder for output stream #0.0 - maybe incorrect parameters such as bit_rate, rate, width or height"

另一种拆分文件的方法没用，但涉及重新编码文件.对于较小的文件大小来说还不错，但 2GB 的文件可能需要几天才能完成.

The other way of splitting the files is useless but involved re-encoding the file. not too bad for smaller file size but the 2GB file would probably take days to complete.

有没有办法在不产生错误文件的情况下快速拆分 Largr 文件?我已经为此努力了好几天，但都没有运气.

Is there a way to split the largr file quickly without producing files with errors? I have been working on it for days with no luck.

用于评论的控制台输出 - FFmpeg 拆分大文件

Console output for comment - FFmpeg splitting large files

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/usr/share/nginx/html/uploads/testfile01.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf56.36.100
  Duration: 00:05:02.08, start: 302.120000, bitrate: 3254 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709)                                  , 1920x1080 [SAR 1:1 DAR 16:9], 3252 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (de                                  fault)
    Metadata:
      handler_name    : VideoHandler
[libx264 @ 0x165ffc0] width not divisible by 2 (853x480)
Output #0, mp4, to '/usr/share/nginx/html/uploads/testfile01_480.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf56.36.100
    Stream #0:0(und): Video: h264, none, q=2-31, 128 kb/s, SAR 2560:2559 DAR 0:0                                  , 25 fps (default)
    Metadata:
      handler_name    : VideoHandler
      encoder         : Lavc56.41.100 libx264
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
Error while opening encoder for output stream #0:0 - maybe incorrect parameters                                   such as bit_rate, rate, width or height

控制台输出2

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/usr/share/nginx/html/uploads/testfile.mp4':
  Metadata:
    major_brand     : dash
    minor_version   : 0
    compatible_brands: iso6avc1mp41
    creation_time   : 2016-01-24 04:26:37
  Duration: 01:15:58.08, start: 0.000000, bitrate: 3163 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 3161 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc (default)
    Metadata:
      creation_time   : 2016-01-24 04:26:37
      handler_name    : VideoHandler
[segment @ 0x1197060] Codec for stream 0 does not use global headers but container format requires global headers
[mp4 @ 0x11512a0] Codec for stream 0 does not use global headers but container format requires global headers
Output #0, segment, to '/usr/share/nginx/html/uploads/testfile%02d.mp4':
  Metadata:
    major_brand     : dash
    minor_version   : 0
    compatible_brands: iso6avc1mp41
    encoder         : Lavf56.36.100
    Stream #0:0(und): Video: h264 (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 3161 kb/s, 25 fps, 25 tbr, 12800 tbn, 25 tbc (default)
    Metadata:
      creation_time   : 2016-01-24 04:26:37
      handler_name    : VideoHandler
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
[mp4 @ 0x11512a0] Codec for stream 0 does not use global headers but container format requires global headers
[mp4 @ 0x11512a0] Codec for stream 0 does not use global headers but container format requires global headers
[mp4 @ 0x11512a0] Codec for stream 0 does not use global headers but container format requires global headers
[mp4 @ 0x11512a0] Codec for stream 0 does not use global headers but container format requires global headers
[mp4 @ 0x11512a0] Codec for stream 0 does not use global headers but container format requires global headers
[mp4 @ 0x11512a0] Codec for stream 0 does not use global headers but container format requires global headers
[mp4 @ 0x11512a0] Codec for stream 0 does not use global headers but container format requires global headers
[mp4 @ 0x11512a0] Codec for stream 0 does not use global headers but container format requires global headers
[mp4 @ 0x11512a0] Codec for stream 0 does not use global headers but container format requires global headers
[mp4 @ 0x11512a0] Codec for stream 0 does not use global headers but container format requires global headers
[mp4 @ 0x11512a0] Codec for stream 0 does not use global headers but container format requires global headers
[mp4 @ 0x11512a0] Codec for stream 0 does not use global headers but container format requires global headers
[mp4 @ 0x11512a0] Codec for stream 0 does not use global headers but container format requires global headers
[mp4 @ 0x11512a0] Codec for stream 0 does not use global headers but container format requires global headers
[mp4 @ 0x11512a0] Codec for stream 0 does not use global headers but container format requires global headers

推荐答案

使用段复用器将输入分成段:

Use the segment muxer to break the input into segments:

ffmpeg -i testfile.mp4 -c copy -f segment -segment_time 1200 testfile_piece_%02d.mp4

这将在关键帧处拆分源，因此片段的长度可能不会正好是 1200 秒.并且时间戳不会重置，因此某些玩家将无法播放第二个和后面的片段.如果需要可玩性，插入-reset_timestamps 1.

This will split the source at keyframes, so segments may not be exactly 1200 seconds long. And the timestamps aren't reset, so some players will fail to play the 2nd and latter segments. If playability is needed, insert -reset_timestamps 1.

并行编码后，可以先创建一个文本文件seg.txt，像这样拼接生成的片段

After the parallel encoding, you can stitch the generated segments by first creating a text file seg.txt like this

file 'encoded_testfile_piece_00.mp4'
file 'encoded_testfile_piece_01.mp4'
file 'encoded_testfile_piece_02.mp4'
file 'encoded_testfile_piece_03.mp4'

然后运行

ffmpeg -f concat -i seg.txt -c copy -fflags +genpts encoded_full.mp4

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