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• avutil/timestamp : introduce av_ts_make_time_string2 for better precision

  17 mars 2024, par Marton Balint

  avutil/timestamp : introduce av_ts_make_time_string2 for better precision
  av_ts_make_time_string() used "%.6g" format, but this format was losing
  
  precision even when the timestamp to be printed was not that large. For example
  
  for 3 hours (10800) seconds, only 1 decimal digit was printed, which made this
  
  format inaccurate when it was used in e.g. the silencedetect filter. Other
  
  detection filters printing timestamps had similar issues. Also time base
  
  parameter of the function was *AVRational instead of AVRational.
  Resolve these problems by introducing a new function, av_ts_make_time_string2().
  We change the used format to "%.*f", use a precision of 6, except when printing
  
  values near 0, in which case we calculate the precision dynamically to aim for
  
  a similar precision in normal form as with %.6g.  No longer using scientific
  
  representation can make parsing the timestamp easier for the users, we can
  
  safely do this because the theoretical maximum of INT64_MAX*INT32_MAX still
  
  fits into the string buffer in normal form.
  We somewhat imitate %g by trimming ending zeroes and the potential decimal
  
  point characters. In order not to trim "inf" as well, we assume that the
  
  decimal point string does not contain the letter "f". Note that depending on
  
  printf %f implementation, we might trim "infinity" to "inf".
  Thanks for Allan Cady for bringing up this issue.
  Signed-off-by : Marton Balint <cus@passwd.hu>
  

  • [DH] doc/APIchanges
  • [DH] libavutil/Makefile
  • [DH] libavutil/timestamp.c
  • [DH] libavutil/timestamp.h
  • [DH] libavutil/version.h

• ffmpeg make a movie with multiple numbers in filename [closed]

  22 juillet 2024, par NNN

  I have the following four files

  


  mov_00_00.png
mov_00_01.png
mov_01_00.png
mov_01_01.png


  


  I can make a movie using

  


  ffmpeg.exe -i mov_%02d_00.png -filter:v "setpts=10*PTS" out.mp4

  


  But this does not consider the files ending with 01.png.

  


  I tried

  


  ffmpeg.exe -i mov_%02d_%02d.png -filter:v "setpts=10*PTS" out.mp4


  


  But it says

  


  [in#0 @ 0000021982d69000] Error opening input: No such file or directory
Error opening input file mov_%02d_%02d.png.
Error opening input files: No such file or directory


  


  What command line magic do I need to use to make this work ? Thanks.

  


  Edit : I'm using the Windows version under WSL and the glob option is not supported.

  


• Using ffmpeg.wasm to convert an image with V360 filter without installing node.js

  6 mars 2024, par mcgyver

  I can't figure out if the problem is in my setup of ffmpeg.wasm, or in ffmpeg processing of my image, or somewhere else.

  


  I have this command line which I know does work :

  


  ffmpeg -i input.jpg -vf v360=fisheye:e:ih_fov=180:iv_fov=180 -y output.jpg


  


  I would like to implement this conversion in a web page unsing ffmpeg.wasm, so I forked this repo into mine and started playing : I edited the original transcode.html ending up in something completely standalone and functioning in github pages out of the box : transcode.html

  


  Starting from there, I split the original code in 3 parts :

  


  

  • setupFFmpeg : preloads ffmpeg stuff - ok

  


  • setName : store the data of the file selected by the user - ok

  


  • transcode : the remaining of the original code, the parts which executes the ffmpeg command, which I changed from video prcoessing to image processing. - not working

  


  


  My current file :

  


  https://github.com/jumpjack/ffmpeg.wasm-gh-pages/blob/main/public/f2e-001.html

  


  The core part, the not working one :

  


  const transcode   = async () => { 
        await ffmpeg.exec(['-hide_banner', '-i', filename, '-filter_complex', filterString,  'output.jpg']); //Execute ffmpeg command line 
        const data = await ffmpeg.readFile('output.jpg'); // Read output file from ffmpeg virtual filesystem
console.log("=== DATA=",data);
        const imgOutput = document.getElementById('myimage');
        imgOutput.src = URL.createObjectURL(new Blob([data.buffer], { type: 'image/jpeg' })); // put output into html page
      }


  


  (filterString is v360=fisheye:e:ih_fov=180:iv_fov=180 )

  


  the console.log("=== DATA=",data) ; line is never reached, I see this output :

  


  f2e.html:41 Input #0, png_pipe, from 'fisheye-mono.png':
f2e.html:41   Duration: N/A, bitrate: N/A
f2e.html:41   Stream #0:0: Video: png, rgb24(pc), 540x541 [SAR 1:1 DAR 540:541], 25 fps, 25 tbr, 25 tbn
f2e.html:41 Stream mapping:
f2e.html:41   Stream #0:0 (png) -> v360:default
f2e.html:41   v360:default -> Stream #0:0 (mjpeg)
f2e.html:41 [swscaler @ 0xe0a340] deprecated pixel format used, make sure you did set range correctly
f2e.html:41     Last message repeated 1 times
    Last message repeated 2 times
    Last message repeated 3 times
    Last message repeated 3 times
f2e.html:41 Output #0, image2, to 'output.jpg':
f2e.html:41   Metadata:
f2e.html:41     encoder         : Lavf59.27.100
f2e.html:41   Stream #0:0: Video: mjpeg, yuvj444p(pc, progressive), 1080x541 [SAR 1:1 DAR 1080:541], q=2-31, 200 kb/s, 25 fps, 25 tbn
f2e.html:41     Metadata:
f2e.html:41       encoder         : Lavc59.37.100 mjpeg
f2e.html:41     Side data:
f2e.html:41       cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: N/A


  


  I don't undrestand if this is an issue of the web page or of ffmpeg : why do I get all these data about video converting, if I use a .png file as input ?

  


  Sometimes this list also finishes with a "memory error" :

  


  Uncaught (in promise) RuntimeError : memory access out of bounds

  


  Please note that I don't want to install node.js or anything else on my PC, the page must work standalone ; I am currently trying it online, I wonder if it could work also locally, but I doubt, due to cors restrictions.