Recherche avancée

Sur d’autres sites (6798)

• swscale/arm/yuv2rgb : re-order compute_rgba macro arguments

  28 mars 2016, par Matthieu Bouron

  swscale/arm/yuv2rgb : re-order compute_rgba macro arguments
  

  • [DH] libswscale/arm/yuv2rgb_neon.S

• avfilter/x86/vf_blend : reorganize init in order to add 16 bit version

  17 février 2018, par Martin Vignali

  avfilter/x86/vf_blend : reorganize init in order to add 16 bit version
  

  • [DH] libavfilter/x86/vf_blend_init.c

• Is it possible to merge multiple FFMPEG commands (cuts, slow down, watermark) into one in order to increase performance ?

  14 novembre 2022, par Nectarie PF

  I wrote a small piece of software in PHP, using FFMPEG commands via shell exec. The final purpose is to take a 7 seconds MP4 file from a GoPro and transform it in order to achieve a sort of boomerang effect :

  


  

  • crop the video to 1080 width/height

  


  


  ffmpeg -i ./files/video_small/$latestVideo -filter:v \"crop=1080:1080:420:0\" ./files/video_small/outcrop_$cod.mp4 2>&1");


  


  

  • first second should run normally

  


  


  ffmpeg.exe -t 1 -i ./files/video_small/outcrop_$cod.mp4 ./files/video_small/out1_$cod.mp4 2>&1");


  


  

  • the next two seconds will run at slow motion with a 2x factor

  


  


  ffmpeg.exe -ss 00:00:01 -t 2 -i ./files/video_small/outcrop_$cod.mp4 -filter_complex \"[0:v]setpts=2*PTS[v]\" -map \"[v]\" ./files/video_small/out2_$cod.mp4 2>&1");


  


  

  • the next second will speed up at 4x factor

  


  


  ffmpeg.exe -ss 00:00:03 -t 1 -i ./files/video_small/outcrop_$cod.mp4 -filter_complex \"[0:v]setpts=0.25*PTS[v]\" -map \"[v]\" ./files/video_small/out3_$cod.mp4 2>&1");


  


  

  • the next 2 seconds again slow motion

  


  


  ffmpeg.exe -ss 00:00:04 -t 2 -i ./files/video_small/outcrop_$cod.mp4 -filter_complex \"[0:v]setpts=2*PTS[v]\" -map \"[v]\" ./files/video_small/out4_$cod.mp4 2>&1");


  


  

  • final second again normal speed

  


  


  ffmpeg.exe -ss 00:00:06 -i ./files/video_small/outcrop_$cod.mp4 ./files/video_small/out5_$cod.mp4 2>&1");


  


  

  • concatenate the above parts to achieve the modified clip

  


  


  ffmpeg.exe -f concat -i ./files/video_small/files_$cod.txt -c copy  ./files/video_small/output1_$cod.mp4 2>&1");


  


  

  • then append the resulting clip in reverse

  


  


  ffmpeg -i ./files/video_small/output1_$cod.mp4 -filter_complex \"[0:v]reverse,fifo[r];[0:v][r] concat=n=2:v=1 [v]\" -map \"[v]\" ./files/video_small/output2_$cod.mp4 2>&1");


  


  

  • add watermark

  


  


  ffmpeg -i ./files/video_small/output2_$cod.mp4 -i ./files/watermark-video1080.png -filter_complex \"[0:v][1:v]overlay=(W-w)/2:10[outv]\" -map [outv] -c:v libx264 -crf 22 -preset veryfast ./files/video_small/output3_$cod.mp4 2>&1");


  


  

  • add audio (we can discard the original audio in any of the above steps)

  


  


  ffmpeg -i ./files/video_small/output3_$cod.mp4 -i ./files/video_small/sound-hip-hop.mp3 -map 0 -map 1:a -c:v copy -shortest ./files/video_small/output_final_$latestVideo 2>&1");


  


  Right now it runs ok, but I have a problem with performance, the whole process lasts about 50 seconds on my 8th gen i7.

  


  I am very new to the capabilities of ffmpeg and I was wondering if any of the below commands can be optimized or if any of the steps can be merged into one, as I can see the syntax is quite powerful.

  


  Thanks !

  


  I was expecting this to run a little bit faster, ideally half the time it takes right now.
As far as I have observed, the longest part is appending the resulting clip in reverse, perhaps I am adding something too heavy and unnecessary in the reverse filter.