video - FFMpeg 命令在 php 脚本中从 avi 转换为 mp4

Question

下面的ffmpeg命令从avi文件转换为mp4文件确实创建了mp4文件，但它的质量根本就不行。拳头，文件大小不同，mp4要小很多，大约是avi文件的1/10。
其次，新创建的mp4播放时间短，只有0.1秒左右，而avi文件的播放时间约为60秒。

任何人都可以帮助我使用 ffmpeg 命令在下面的目录下从 avi 创建 mp4 文件吗？

for i in /xxxxxxx/xxxxxxx/*.avi; do
    ffmpeg -i "$i" -frames:v 1  "/xxxxxxx/xxxxxxx/$(basename "$i" .avi).mp4"
done     

尝试后记录:

[root@server-xxxxxxx-x ~]# for i in /xxxxxx/xxxxxxx/xxxxxxx/*.avi; do ffmpeg -i "$i" -pix_fmt yuv420p -movflags +faststart "/xxxxxx/xxxxxxx/xxxxxxx/$(basename "$i" .avi).mp4"; done
ffmpeg version 3.4 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-18)
  configuration:
  libavutil      55. 78.100 / 55. 78.100
  libavcodec     57.107.100 / 57.107.100
  libavformat    57. 83.100 / 57. 83.100
  libavdevice    57. 10.100 / 57. 10.100
  libavfilter     6.107.100 /  6.107.100
  libswscale      4.  8.100 /  4.  8.100
  libswresample   2.  9.100 /  2.  9.100
 Guessed Channel Layout for Input Stream #0.1 : mono
 Input #0, avi, from '/xxxxxx/xxxxxxx/xxxxxxx/09141944_5b9b910308858.avi':
  Metadata:
    creation_time   : 2018-09-14 00:18:07
    encoder         : CanonMVI06
   Duration: 00:00:04.20, start: 0.000000, bitrate: 12999 kb/s
    Stream #0:0: Video: mjpeg (MJPG / 0x47504A4D), yuvj422p(pc,    bt470bg/unknown/unknown), 640x480, 12384 kb/s, 30 fps, 30 tbr, 30 tbn, 30 tbc
     Stream #0:1: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, mono, s16, 705 kb/s
 File '/xxxxxx/xxxxxxx/xxxxxxx/09141944_5b9b910308858.mp4' already exists.    Overwrite ? [y/N]

                                                                                                                          y
 Stream mapping:
  Stream #0:0 -> #0:0 (mjpeg (native) -> mpeg4 (native))
  Stream #0:1 -> #0:1 (pcm_s16le (native) -> aac (native))
  Press [q] to stop, [?] for help
  [swscaler @ 0x3d75fa0] deprecated pixel format used, make sure you did set   range correctly
 Output #0, mp4, to '/xxxxxx/xxxxxxx/xxxxxxx/09141944_5b9b910308858.mp4':
  Metadata:
    encoder         : Lavf57.83.100
    Stream #0:0: Video: mpeg4 (mp4v / 0x7634706D), yuv420p, 640x480, q=2-31, 200 kb/s, 30 fps, 65521 tbn, 30 tbc
    Metadata:
      encoder         : Lavc57.107.100 mpeg4
     Side data:
      cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: -1
     Stream #0:1: Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 69 kb/s
     Metadata:
       encoder         : Lavc57.107.100 aac
  [mp4 @ 0x3d0e6e0] Starting second pass: moving the moov atom to the  beginning of the file17x
  frame=  126 fps=0.0 q=11.8 Lsize=     310kB time=00:00:04.20 bitrate= 603.3kbits/s speed=6.21x
  video:270kB audio:35kB subtitle:0kB other streams:0kB global headers:0kB  muxing overhead: 1.605194%
  [aac @ 0x3d36f40] Qavg: 2283.534
  ffmpeg version 3.4 Copyright (c) 2000-2017 the FFmpeg developers
   built with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-18)
   configuration:
   libavutil      55. 78.100 / 55. 78.100
   libavcodec     57.107.100 / 57.107.100
   libavformat    57. 83.100 / 57. 83.100
   libavdevice    57. 10.100 / 57. 10.100
   libavfilter     6.107.100 /  6.107.100
   libswscale      4.  8.100 /  4.  8.100
   libswresample   2.  9.100 /  2.  9.100
   Guessed Channel Layout for Input Stream #0.1 : mono
   Input #0, avi, from '/xxxxxx/xxxxxxx/xxxxxxx/09141945_5b9b913e87834.avi':
    Metadata:
     creation_time   : 2018-09-14 00:18:07
     encoder         : CanonMVI06
    Duration: 00:00:04.20, start: 0.000000, bitrate: 12999 kb/s
    Stream #0:0: Video: mjpeg (MJPG / 0x47504A4D), yuvj422p(pc,      bt470bg/unknown/unknown), 640x480, 12384 kb/s, 30 fps, 30 tbr, 30 tbn, 30 tbc
    Stream #0:1: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, mono,    s16, 705 kb/s

Answer 1

问题:您没有支持的编码器

您的 configuration行为空白。这意味着您没有启用 H.264/H.265 视频编码器。所以ffmpeg选择原生编码器mpeg4输出 MPEG-4 Part 2 视频。这是 HTML5 视频不支持的旧格式。

解决方案

编译

使用 --enable-libx264 编译或 --enable-libx265 .您还需要 --enable-gpl使用这些编码器。有关说明，请参阅本指南:

FFmpeg Wiki: Compile for RHEL/Fedora/CentOS

或下载

或者，一个简单的方法是 download已编译的 ffmpeg并将其放在您的 PATH 中的某个位置，例如 /usr/local/bin .或者，如果您希望它位于任意位置，请确保您的脚本提供可执行文件的完整路径。确保这个新的 ffmpeg被处决，而不是你的旧的，残废的。