图片处理技巧， image magick 与音频处理

使用 image magick， 修改图片背景色

➜  src git:(main) ✗ convert    /Users/jzd/Movies/A_a/Clang/src/Cache_t.png    \
        -fill   white    -fuzz 20% \
        -draw 'color 0,0 floodfill' \
        output_color.png

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ffmpeg

ss ： seek second

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ffmpeg -ss 15 -i /Users/jzd/Music/10_nobody.mp3 -acodec copy output.mp3

ffmpeg 裁剪音频

创建，减去开头 15 秒的，音频

➜  Music ffmpeg -ss 15   -i     /Users/jzd/Music/10_nobody.mp3      -acodec copy   output.mp3



Input #0, mp3, from '/Users/jzd/Music/10_nobody.mp3':
  Metadata:
    artist          : 可可英语
    title           : 可可英语 kekenet.com
    TLEN            : 000000040647
  Duration: 00:00:40.67, start: 0.000000, bitrate: 64 kb/s
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, fltp, 64 kb/s
File 'output.mp3' already exists. Overwrite? [y/N] y
Output #0, mp3, to 'output.mp3':
  Metadata:
    TPE1            : 可可英语
    TIT2            : 可可英语 kekenet.com
    TLEN            : 000000040647
    TSSE            : Lavf58.45.100
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, fltp, 64 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
size=     201kB time=00:00:25.64 bitrate=  64.2kbits/s speed=3.28e+03x    
video:0kB audio:201kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.164049%

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循环播放的另一思路：

ffmpeg -i "concat:nobody.mp3|nobody.mp3|nobody.mp3" -acodec copy out.mp3

把该音频文件，多次拼接在其后

➜  Music ffmpeg -i "concat:nobody.mp3|nobody.mp3|nobody.mp3" -acodec copy out.mp3




[mp3 @ 0x7feb1a019600] Audio packet of size 337 (starting with 49443304...) is invalid, writing it anyway.
    Last message repeated 1 times
size=     603kB time=00:01:17.04 bitrate=  64.1kbits/s speed=9.02e+03x    
video:0kB audio:602kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.054623%