[ffmpeg] [reprint] image mosaic: picture in picture with wheat

• The so-called picture in picture is to play another smaller video in one video . Lianmai is a product form of interactive live broadcast , It was during the live broadcast of the anchor , The audience initiates the connection , Other viewers can see the picture of connected viewers in the lower right corner of the anchor picture , Hear the voice of the anchor and the connected audience at the same time .

Reprint the great God tutorial

• A great god Advanced watermark

 Experimental material ：

ad_inner.mp4:  The resolution is only 180x120, It must be smaller than the video outside , Otherwise, you can't see two 
ad_BQ.mp4:  The resolution is 720x480

Picture in picture will appear in the upper left corner

ffmpeg -i ad_BQ.mp4 -vf "movie=ad_inner.mp4[inner]; [in][inner] overlay [out]" -y ad_merge.mp4

The lower right corner

• ffmpeg -i ad_BQ.mp4 -vf “movie=ad_inner.mp4 [lianmai]; [in][lianmai] overlay=main_w-overlay_w-20:main_h-overlay_h-20 [out]” ad_BQ_lianmai.mp4 -y

Left right merger

• Input ：left.mp4 and right.mp4 Two videos Output ：sidebyside.mp4
• ffmpeg -i left.mp4 -i right.mp4 -filter_complex “[0:v][1:v]hstack=inputs=2[v]; [0:a][1:a]amerge[a]” -map “[v]” -map “[a]” -ac 2 sidebyside.mp4