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• Merge video with ffmpeg

  17 mars 2017, par Björn

  I have tried this command :
  ffmpeg -i 'concat:10.mov|11.mov' -codec copy out.mov
  The output file out.mov only shows whats in the first movie (10.mov).

  Been googling for several hours and tried lots of things but nothing works. I want this done without re-encoding the files. Just merge with the same codec

  ffmpeg version 3.2.4 Copyright (c) 2000-2017 the FFmpeg developers
 built with Apple LLVM version 8.0.0 (clang-800.0.42.1)
 configuration: --prefix=/usr/local/Cellar/ffmpeg/3.2.4 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-vda
 libavutil      55. 34.101 / 55. 34.101
 libavcodec     57. 64.101 / 57. 64.101
 libavformat    57. 56.101 / 57. 56.101
 libavdevice    57.  1.100 / 57.  1.100
 libavfilter     6. 65.100 /  6. 65.100
 libavresample   3.  1.  0 /  3.  1.  0
 libswscale      4.  2.100 /  4.  2.100
 libswresample   2.  3.100 /  2.  3.100
 libpostproc    54.  1.100 / 54.  1.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7ff678802600] Found duplicated MOOV Atom. Skipped it
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'concat:10.mov|11.mov':
 Metadata:
   creation_time   : 2017-03-17T12:15:22.000000Z
   major_brand     : qt<br />
   minor_version   : 537134592
   compatible_brands: qt<br />
 Duration: 00:00:29.96, start: 0.000000, bitrate: 140810 kb/s
   Stream #0:0: Video: prores (apcn / 0x6E637061), yuv422p10le, 1280x720, 116735 kb/s, SAR 1:1 DAR 16:9, 50 fps, 50 tbr, 5k tbn, 5k tbc (default)
   Metadata:
     handler_name    : Telestream Inc. Telestream Media Framework - Local 99.99.999999
     encoder         : Apple ProRes 422
Output #0, mov, to 'out.mov':
 Metadata:
   compatible_brands: qt<br />
   major_brand     : qt<br />
   minor_version   : 537134592
   encoder         : Lavf57.56.101
   Stream #0:0: Video: prores (apcn / 0x6E637061), yuv422p10le, 1280x720 [SAR 1:1 DAR 16:9], q=2-31, 116735 kb/s, 50 fps, 50 tbr, 10k tbn, 5k tbc (default)
   Metadata:
     handler_name    : Telestream Inc. Telestream Media Framework - Local 99.99.999999
     encoder         : Apple ProRes 422
Stream mapping:
 Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
frame= 1498 fps=0.0 q=-1.0 Lsize=  426938kB time=00:00:29.94 bitrate=116815.8kbits/s speed=50.8x<br />
video:426930kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.001997%

  Any ideas ? Would make my life very much easier if I got this to work :)

• Why is ffmpeg's hstack so much slower than overlay and pad ?

  27 janvier 2021, par cgenco

  I'm using ffmpeg to stitch together two videos of people chatting into a video with each of them side-by-side, like this :

  


  

  


  Here's the command I'm currently using to get this done, which runs at 2.5x on my 13" M1 MacBook Pro :

  


  ffmpeg -y -i left.mp4 -i right.mp4 -filter_complex "
  [0:v] crop=w=in_w/2 [croppedLeft];
  [1:v][1:v] overlay=x=overlay_w/4 [shiftedRight];
  [shiftedRight][croppedLeft] overlay [vout];
  [0:a][1:a] amix [aout]
" -map "[vout]" -map "[aout]" -ac 2 out.mp4


  


  This command crops the left video to half of its original width (cropping so the video is centered), then shifts the right video a quarter of its width to the right, then overlays the left video on the left half of the output merged with the shifted right video.

  


  One day on my weekly fun-time read-through the FFmpeg filters documentation I stumbled on a filter named hstack, which is described as being "faster than using overlay and pad filter to create same output."

  


  My ex wife can affirm that there are few higher priorities in my life than going faster, so I altered my ffmpeg script to use hstack instead of two overlays :

  


  ffmpeg -y -i left.mp4 -i right.mp4 -filter_complex "
  [0:v] crop=w=in_w/2 [croppedLeft];
  [1:v] crop=w=in_w/2 [croppedRight];
  [croppedLeft][croppedRight] vstack [vout];
  [0:a][1:a] amix [aout]
" -map "[vout]" -map "[aout]" -ac 2 out.mp4


  


  ...but that command runs painfully slowly, like 0.1x. It takes multiple minutes to render a single second.

  


  So uhhh what's going on here ? Why is hstack taking so long when it's supposed to be faster ?

  


  I've tried this on both the M1 native build from OSXExperts (version N-99816-g3da35b7) and the standard ffmpeg from brew and hstack is just as slow on each.

  


• How can I use ffmpeg to create a seamless looping gif ? [closed]

  27 juin 2024, par DavidNyan10

  I have an MP4 file which contains animation repeating in a loop. Let's just say, for example, a video of rain. However, when loop is turned on, the video cuts off at the wrong place and does not make a nice smooth animation. The part where it loops is obvious. It's just that the video contains more than one cycle of the loop, but not an exact integer of the full cycle.

  


  My goal is to turn this video into a gif with a seamless loop. In other words, I want the last frame of the video to match the first frame.

  


  My approach : I found a "Seamless loop creator" website on Google, tried it out, and it worked REALLY well. I thought all my problems have been solved. But little did I know, I've been only looking at the few seconds at the beginning and at the end of the video, not paying attention to what's in the middle. The sneaky pesky little website cuts off the video right in the middle, stitch the "seamless transition" at the beginning and end of the video, and put an ugly cross-fade in the middle where the frames don't line up. That is stupid. This of course, isn't noticable on rain videos, but on videos like a character jumping, the crossfade is very visible.

  


  My second approach : I'd use FFMPEG to get the first frame of the video, then starting from the last frame of the video and backwards, it'd try to find a frame that matches exactly with the first frame.

  


  Steps :

  


  

  1. Get the first frame and save it as a PNG or something I don't know

  


  2. Reverse the original video

  


  3. Match the image to each frame of the video in step 2. It is now easier because it's not doing it backwards frame by frame.

  


  4. When a frame match is found, cut off all the frames before this matched frame.

  


  5. Reverse back the video

  


  


  Can I achieve something like this in ffmpeg, preferably a one-liner in windows cmd ?

  


  Follow-up question : Would it be better to leave the last frame the same as first frame or should I remove it ? For example, when it's looping, it would repeat that exact frame two times, is that good ? Or which one provides better results ? And if it's better to not include the last frame (the one that matches), how would I do it in my process above ?

  


  I tried ChatGPT, expecting a ready-made code. Put it in the command prompt and lost my original video file. Had to use a recovery tool because the file was overwritten.