【FFmpeg】MultitrackMP4file：合并俩mp4为asinglefragmented.mp4

• 【测试源】bbb_sunflower_1080p_30fps_normal.mp4 等下载地址

Multi-track MP4 file

• 双声道 AAC LC 音频

// Generate a scaled down to 320x240 video + 2 channel AAC LC audio from the source file.ffmpeg -i bbb_sunflower_1080p_30fps_normal.mp4 -c:v libx264 -crf 36 -vf scale=320:240 -c:a libfdk_aac -ac 2 -t 24 bbb1.mp4


• 另一个 个文件：

// Generate a file with the original video scaled down to 320x240 and