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• Output a video with "slide up" transition using more than 100 images in FFMPEG ?

  9 juillet 2021, par Joseph Ladera Fugata

  I have more than a hundred images of the same size and format that my company wants to display at the big 9:16 (rotated 16:9) screen outside the front gate. It's supposed to be easy but they required me to have it slide from top to bottom, meaning that it should look like a smooth auto scroll effects. I searched here and there but no luck.

  


  I have tried xfade like this :

  


  ffmpeg -loop 1 -i input.txt -filter_complex
"xfade=transition=slideup:duration=10:offset=0,format=yuv420p" output.mp4


  


  It didn't do anything just a bunch of error referring to the inputs. Which is supposed to be just 2 images in the first place.

  


  The next thing I tried was using Concat from someone named @Gyan at his reply HERE and here's my version of the code :

  


  ffmpeg -y -f concat -safe 0 -i input.txt
-vf tile=1x%img_count%,loop=%_my_loop_count_var%:1:0,
crop=iw:ih/%img_count%:0:clip((t-%_start_time%)/%sec_per_img%*ih/%img_count%\,0\,ih*%img_count_minus_one%/%img_count%)
-r 25 -c:v libx264 -preset ultrafast output.mp4


  


  When I played with it, it gives a different output even do the image are all the same dimensions.

  


  I found someone on youtube used this but it is using bash and I am on windows. Unless someone here can convert it to a batch script would be great. I look into it and it seems like he's just V-stacking them kinda like what I did but there's more. I know I could have gone through win bash but I doubt the script will run on a non-Unix environment just by having bash, and I'm not yet familiar with Cygwin either.

  


  I also did tried other options posted by others here, I just forgot to bookmark them, but non of them works on more than a hundred images.

  


  I love to hear a response if anyone can help.

  


• Node.js Webm live stream server : issues with tag

  10 décembre 2013, par breathe0

  I'm using Node.js as stream server to stream realtime Webm videos that is sent by FFMPEG (executed from another application, the stream is done via HTTP) and received by a webapp that uses the tag.

  This is what I'm doing : FFMPEG streams the received frames using the following command :

  ffmpeg -r 30 -f rawvideo  -pix_fmt bgra -s 640x480 
  
  -i \\.\pipe\STREAM_PIPE -r 60 
  
  -f segment  -s 240x160 -codec:v libvpx  -f webm 
  
  http://my.domain.com/video_stream.webm

  (the stream comes from an application that uses the Kinect as source and communicates with FFMPEG through a pipe, sending one frame after another)

  When the webapp connects, it receives immediately this response from the server :

  HTTP/1.1 200 OK
  
  X-Powered-By: Express
  
  content-type: video/webm
  
  cache-control: private
  
  connection: close
  
  Date: Fri, 06 Dec 2013 14:36:31 GMT

  and a Webm header (previously stored on the server, with the same resolution and frame rate of the source stream and tested as working on VLC) is immediately appended. Then the webapp starts to receive the data streamed by FFMPEG. Here is a screenshot of Mkvinfo GUI showing the fields of the header :

  

  However, even if the Network tab of the Chrome console shows that there is an actual stream of data (meaning that what is streamed is not completely garbage, otherwise the connection would be dropped), the player doesn't display anything. We tried to manually prepend our header to the dumped video received by the webapp and VLC plays it just fine, but this is not happening with the tag.

  What can cause this problem ? Are we missing something about the encoding on the FFMPEG side or we stored wrong values on the header (or they're not enough) ?

  PS : I cannot rely on an extern stream server.

  PPS : We tried the following experiments :

  • substituting the video header with the one stored in the server makes the video playable on both vlc and video tag
  • if we dump the video that is already started (without an header) and we prepend the video header stored in the server or even its original header, the video is playable in VLC but not on the tag (we're carefully prepending the header just before the beggining of the cluster).

• Q.For encoding error of ffmpeg

  21 mars 2016, par 社畜根性

  I ran the following command.

  ffmpeg -i test.mp4 -threads 2 -codec:v libx264 -s:v 1280x720 -aspect:v 16:9 -b:v 256k -map 0 -f segment -segment_format mpegts -segment_time 10 -segment_list stream.m3u8 streamfiles/stream%03d.ts

  Execution result

  ffmpeg version N-75926-gce0834b Copyright (c) 2000-2015 the FFmpeg developers
  
    built with gcc 4.6 (Debian 4.6.3-14+rpi1)
  
    configuration: --arch=armel --target-os=linux --enable-shared --enable-gpl --enable-libx264 --enable-nonfree
  
    libavutil      55.  3.100 / 55.  3.100
  
    libavcodec     57.  5.100 / 57.  5.100
  
    libavformat    57.  3.100 / 57.  3.100
  
    libavdevice    57.  0.100 / 57.  0.100
  
    libavfilter     6. 11.100 /  6. 11.100
  
    libswscale      4.  0.100 /  4.  0.100
  
    libswresample   2.  0.100 /  2.  0.100
  
    libpostproc    54.  0.100 / 54.  0.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'test.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf56.40.100
  
    Duration: 00:00:03.28, start: 0.000000, bitrate: 10159 kb/s
  
      Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080, 10156 kb/s, 25 fps, 25 tbr, 1200k tbn, 2400k tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
  Illegal instruction

  The result is that an error occurred.
  Someone told me that it’s an error if you do not put the option to ./configure of libx264. That option is the --extra-cflags='-march=armv6' --extra-ldflags='-march=armv6'. Otherwise it would use the instruction of unsupported.

  So I ran ./configure with the option, then I ran the make and now I’m getting an error message :

  common/arm/quant-a.S: Assembler messages:
  
  common/arm/quant-a.S:362: Error: selected processor does not support ARM mode `rbit r1,r1'
  
  common/arm/quant-a.S:363: Error: selected processor does not support ARM mode `rbit r1,r1'
  
  Makefile:217: recipe for target 'common/arm/quant-a.o' failed
  
  make: *** [common/arm/quant-a.o] Error 1

  I do not know the meaning of this error. How should you deal me this error ?

  I use the machine is Raspberry PI B+ and my OS is Raspbian. I want to use ffmpeg and libx264.

  Any advice and suggestions will be greatly appreciated.