php - 使用 ffmpeg 将 mp4 转换为 x264 时数据无效，但将 flv 转换为 x264 时很好

Question

我有一个 PHP 脚本，可以将上传的视频转换为 x264，如果我上传 FLV，它可以正常工作，但对于 MP4，它不起作用，这是命令和输出:

命令:
ffmpeg -y -i ../../flv/rjaRGKzSMtksUJ4kGbsLMYEcr.mp4 -crf 0 -vcodec libx264 -movflags faststart ../../flv/rjaRGKzSMtksUJ4kGbsLMYEcr.mp4 2>&1
输出:

ffmpeg version N-67321-ge5054c8 Copyright (c) 2000-2014 the FFmpeg developers
  built on Nov  1 2014 12:53:28 with gcc 4.8.2 (GCC) 20140120 (Red Hat 4.8.2-16)
  configuration: --extra-libs=-ldl --enable-gpl --enable-nonfree --enable-libfdk_aac --enable-libmp3lame --enable-libvorbis --enable-libvpx --enable-libx264
  libavutil      54. 11.100 / 54. 11.100
  libavcodec     56. 10.100 / 56. 10.100
  libavformat    56. 11.101 / 56. 11.101
  libavdevice    56.  2.100 / 56.  2.100
  libavfilter     5.  2.100 /  5.  2.100
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  3.100 / 53.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '../../flv/rjaRGKzSMtksUJ4kGbsLMYEcr.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2mp41
    creation_time   : 2018-10-08 12:03:53
    encoder         : Lavf56.15.102
  Duration: 00:03:03.08, start: 0.023129, bitrate: 1647 kb/s
    Stream #0:0(und): Video: mpeg4 (Simple Profile) (mp4v / 0x7634706D), yuv420p, 720x404 [SAR 1:1 DAR 180:101], 1547 kb/s, 24 fps, 24 tbr, 12288 tbn, 24 tbc (default)
    Metadata:
      creation_time   : 2018-10-08 12:03:53
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 95 kb/s (default)
    Metadata:
      creation_time   : 2018-10-08 12:03:53
      handler_name    : SoundHandler
[libx264 @ 0x1f0a080] using SAR=1/1
[libx264 @ 0x1f0a080] using cpu capabilities: MMX2 SSE Cache64
[libx264 @ 0x1f0a080] profile High 4:4:4 Predictive, level 3.0, 4:2:0 8-bit
[libx264 @ 0x1f0a080] 64 - core 142 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x1:0x111 me=hex subme=7 psy=0 mixed_ref=1 me_range=16 chroma_me=1 trellis=0 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=0 chroma_qp_offset=0 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=2 keyint=250 keyint_min=24 scenecut=40 intra_refresh=0 rc=cqp mbtree=0 qp=0
Output #0, mp4, to '../../flv/rjaRGKzSMtksUJ4kGbsLMYEcr.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2mp41
    encoder         : Lavf56.11.101
    Stream #0:0(und): Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 720x404 [SAR 1:1 DAR 180:101], q=-1--1, 24 fps, 12288 tbn, 24 tbc (default)
    Metadata:
      creation_time   : 2018-10-08 12:03:53
      handler_name    : VideoHandler
      encoder         : Lavc56.10.100 libx264
    Stream #0:1(und): Audio: aac (libfdk_aac) ([64][0][0][0] / 0x0040), 44100 Hz, stereo, s16, 128 kb/s (default)
    Metadata:
      creation_time   : 2018-10-08 12:03:53
      handler_name    : SoundHandler
      encoder         : Lavc56.10.100 libfdk_aac
Stream mapping:
  Stream #0:0 -> #0:0 (mpeg4 (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (aac (native) -> aac (libfdk_aac))
Press [q] to stop, [?] for help
[mpeg4 @ 0x2004420] ac-tex damaged at 1 1
[mpeg4 @ 0x2004420] Error at MB: 47
[mpeg4 @ 0x2004420] concealing 1170 DC, 1170 AC, 1170 MV errors in P frame
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x1ed3ec0] stream 1, offset 0xee5b: partial file
../../flv/rjaRGKzSMtksUJ4kGbsLMYEcr.mp4: Invalid data found when processing input
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x1ed3ec0] stream 0, offset 0xef98: partial file
../../flv/rjaRGKzSMtksUJ4kGbsLMYEcr.mp4: Invalid data found when processing input
[mp4 @ 0x1f08f40] Starting second pass: moving the moov atom to the beginning of the file
frame=    3 fps=0.0 q=-1.0 Lsize=     116kB time=00:00:00.12 bitrate=7585.3kbits/s dup=1 drop=0    
video:113kB audio:2kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.171168%
[libx264 @ 0x1f0a080] frame I:1     Avg QP: 0.00  size:113785
[libx264 @ 0x1f0a080] frame P:2     Avg QP: 0.00  size:   518
[libx264 @ 0x1f0a080] mb I  I16..4: 38.4%  0.0% 61.6%
[libx264 @ 0x1f0a080] mb P  I16..4:  0.2%  0.0%  0.1%  P16..4:  1.2%  0.1%  0.2%  0.0%  0.0%    skip:98.3%
[libx264 @ 0x1f0a080] 8x8 transform intra:0.0% inter:3.1%
[libx264 @ 0x1f0a080] coded y,uvDC,uvAC intra: 91.6% 88.7% 88.7% inter: 0.7% 0.2% 0.2%
[libx264 @ 0x1f0a080] i16 v,h,dc,p: 46% 53%  1%  0%
[libx264 @ 0x1f0a080] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 44% 40%  3%  2%  3%  2%  2%  2%  2%
[libx264 @ 0x1f0a080] i8c dc,h,v,p:  2% 55% 43%  0%
[libx264 @ 0x1f0a080] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 0x1f0a080] kb/s:7348.61

如您所见，那里有一些错误。我已经尝试了几个不同的 mp4 文件，来自不同的来源，所以这不是视频文件的问题。

我也试过没有 -movflags faststart选项，也尝试使用 -q:v 0而不是 -crf 0 ，没有任何效果，但如上所述，它适用于 FLV -> MP4，我在这里做错了什么？

PS:“没有任何效果”是指生成的 MP4 在浏览器中播放 1 帧并停止。

Answer 1

FFmpeg 不会就地编辑文件，因此输入不能与输出相同 - 直到最近*这没有被检查，所以只要存在覆盖标志，ffmpeg 就会静默执行这样的指令。

写入与输入不同的文件。

*2018-09-17