Recherche avancée

Sur d’autres sites (9894)

• How can I stream then play YUV format with/without VLC/FFMPEG ?

  13 janvier 2023, par orfruit

  I'm able to play a local YUV file through VLC (as expected)

  


  .\vlc.exe --demux rawvideo --rawvid-fps 25 --rawvid-width 480 --rawvid-height 360 --rawvid-chroma I420 out.yuv


  


  Also FFPLAY is playing well

  


  .\ffplay.exe -f rawvideo -pixel_format yuv420p -video_size 480x360 out.yuv


  


  Conversion to YUV was done with FFMPEG

  


  .\ffmpeg.exe -i "video.mp4" -c:v rawvideo -pixel_format yuv420p out.yuv


  


  However, I'm not able o stream it and play'it over local network.
I know, it sounds crazy :) but I plan to use VLC as a monitor/debugger for some YUV data.

  


  The original MP4 file is streamed/played fine with VLC (test on the same computer)

  


  .\vlc.exe "video.mp4" --sout="#std{access=http, mux=ts, dst=:55555/}"
.\vlc.exe http://192.168.0.174:55555/


  


  So the big question !
How can I stream the YUV format and VLC recognise an play it as well ?

  


  All that I tried with VLC is not playable.

  


  Thanks for any hints !

  


• Failed to convert web-saved .wemb audio to .wav by using php "shell_exec" and javascript

  30 mai 2022, par Anirbasgnaw

  I'm working on an online experimenter which could record participants' audio from the browser. The audio data I get has an extension of .wemb, so I plan to use ffmpeg to convert it to .wav while I save the data.

  


  I tried to use PHP's shell_exec but nothing happens when I run the scripts. Then I found that my echo and print_r also did not work. I'm new to PHP and javascript, so I''m really confused now.

  


  Below are the relevant codes, I really appreciate it if you could help !

  


  write_data.php :

  


  <?php
  $post_data = json_decode(file_get_contents('php://input'), true); 
  // the directory "data" must be writable by the server
  $name = "../".$post_data['filename'];
  $data = $post_data['filedata'];
   // write the file to disk
  file_put_contents($name, $data);
  
  $INPUT = trim($name) . ".webm";
  $OUTPUT = trim($name) . ".wav";
  echo "start converting...";

  // check if ffmprg is available
  $ffmpeg = trim(shell_exec('which ffmpeg'));
  print_r($ffmpeg);
  // call ffmpeg
  shell_exec("ffmpeg -i '$INPUT' -ac 1 -f wav '$OUTPUT' 2>&1 ");
?>


  


  javascript :

  


    saveData: function(fileName,format){
    // save  as json by default
    if (!format){ format = 'json';}
    // add extension to filename
    fileName = `${fileName}.${format}`
    // create saveData object using fetch
    let saveData = [];
    if (format == 'json') {
        saveData = {
          type: 'call-function',
          async: true,
          func: async function(done) {
            let data = jsPsych.data.get().json();
            const response = await fetch("../write_data.php", {
              method: "POST",
              headers: {
                "content-type": "application/json"
              },
              body: JSON.stringify({ filename: fileName, filedata: data })
            });
            if (response.ok) {
              const responseBody = await response.text();
              done(responseBody);
            }
          }
        }
    } else {
        saveData = {
          type: 'call-function',
          async: true,
          func: async function(done) {
            let data = jsPsych.data.get().csv();
            const response = await fetch("../write_data.php", {
              method: "POST",
              headers: {
                "content-type": "application/json"
              },
              body: JSON.stringify({ filename: fileName, filedata: data })
            });
            if (response.ok) {
              const responseBody = await response.text();
              done(responseBody);
            }
          }
        }
    }
    return saveData;
  },


  


• I have a ffmpeg command to concatenate 300+ videos of different formats. What is the proper syntax for the concat complex filter ?

  25 avril 2022, par jokoon

  I plan to concatenate a large amount of video files of different formats and resolution, some without sound, and add a short black screen "pause" of about 0.5s between each.

  


  I wrote a python script to generate such command.

  


  I created a 0.5s video file using ffmpeg.exe -t 0.5 -f lavfi -i color=c=black:s=640x480 -c:v libx264 -tune stillimage -pix_fmt yuv420p blank500ms.mp4.

  


  I then added a silent audio to it with -f lavfi -i anullsrc -c:v copy -c:a aac -shortest

  


  I now have the problem of adding a blank audio track for streams without one, but I don't want to generate new file, I want to add it to my complex filter.

  


  This is my complex script and generate command.

  


  The command (there are line returns, because I send this with the python subprocess module)

  


  ffmpeg.exe
-i
input0.mp4
-i
input1.mp4
-i
input2.mp4
-i
input3.mp4
-i
input4.mp4
-i
input5.mp4
-i
input6.mp4
-i
input7.mp4
-i
input8.mp4
-i
input9.mp4
-i
input10.mp4
-f
lavfi
-i
anullsrc
-filter_complex_script
C:/filter_complex_script.txt
-map
"[final_video]"
-map
"[final_audio]"
output.mp4


  


  The complex_filter_script :

  


  [0]fps=24[fps0];
[fps0]scale=480:270:force_original_aspect_ratio=decrease,pad=480:270:(ow-iw)/2:(oh-ih)/2,setsar=1,setpts=PTS-STARTPTS[rescaled0];
[1]fps=24[fps1];
[fps1]scale=480:270:force_original_aspect_ratio=decrease,pad=480:270:(ow-iw)/2:(oh-ih)/2,setsar=1,setpts=PTS-STARTPTS[rescaled1];
[2]fps=24[fps2];
[fps2]scale=480:270:force_original_aspect_ratio=decrease,pad=480:270:(ow-iw)/2:(oh-ih)/2,setsar=1,setpts=PTS-STARTPTS[rescaled2];
[3]fps=24[fps3];
[fps3]scale=480:270:force_original_aspect_ratio=decrease,pad=480:270:(ow-iw)/2:(oh-ih)/2,setsar=1,setpts=PTS-STARTPTS[rescaled3];
[4]fps=24[fps4];
[fps4]scale=480:270:force_original_aspect_ratio=decrease,pad=480:270:(ow-iw)/2:(oh-ih)/2,setsar=1,setpts=PTS-STARTPTS[rescaled4];
[5]fps=24[fps5];
[fps5]scale=480:270:force_original_aspect_ratio=decrease,pad=480:270:(ow-iw)/2:(oh-ih)/2,setsar=1,setpts=PTS-STARTPTS[rescaled5];
[6]fps=24[fps6];
[fps6]scale=480:270:force_original_aspect_ratio=decrease,pad=480:270:(ow-iw)/2:(oh-ih)/2,setsar=1,setpts=PTS-STARTPTS[rescaled6];
[7]fps=24[fps7];
[fps7]scale=480:270:force_original_aspect_ratio=decrease,pad=480:270:(ow-iw)/2:(oh-ih)/2,setsar=1,setpts=PTS-STARTPTS[rescaled7];
[8]fps=24[fps8];
[fps8]scale=480:270:force_original_aspect_ratio=decrease,pad=480:270:(ow-iw)/2:(oh-ih)/2,setsar=1,setpts=PTS-STARTPTS[rescaled8];
[9]fps=24[fps9];
[fps9]scale=480:270:force_original_aspect_ratio=decrease,pad=480:270:(ow-iw)/2:(oh-ih)/2,setsar=1,setpts=PTS-STARTPTS[rescaled9];
[10]fps=24[fps10];
[fps10]scale=480:270:force_original_aspect_ratio=decrease,pad=480:270:(ow-iw)/2:(oh-ih)/2,setsar=1,setpts=PTS-STARTPTS[rescaled10];
[10]split=10[blank0][blank1][blank2][blank3][blank4][blank5][blank6][blank7][blank8][blank9];
[rescaled0:v][0:a][blank0][rescaled1:v][1:a][blank1][rescaled2:v][2:a][blank2][rescaled3:v][3:a][blank3][rescaled4:v][4:a][blank4][rescaled5:v][5:a][blank5][rescaled6:v][11:a][blank6][rescaled7:v][11:a][blank7][rescaled8:v][11:a][blank8][rescaled9:v][11:a][blank9]concat=n=22:v=1:a=1[final_video][final_audio]


  


  As you can see, some video use [11:a], because it's a silent audio stream.

  


  input10.mp4, mapped to [10] and then split (or "cloned") into blanked0 to 9, is a short pause separator.

  


  ffmpeg tells me the error

  


  [Parsed_split_55 @ 000001591c33b280] Media type mismatch between the 'Parsed_split_55' filter output pad 1 (video) and the 'Parsed_concat_56' filter input pad 5 (audio)
[AVFilterGraph @ 000001591bf1e6c0] Cannot create the link split:1 -> concat:5
Error initializing complex filters.
Invalid argument


  


  I'm a bit lost when it comes to using the [X:Y:Z] syntax, and how the order matter in the concat argument list.

  


  I'm open to any other suggestion to solve my problem. I would rather do this in a single command, without intermediate file.

  


  EDIT :

  


  For details, I already wrote a large concat+xstack filter that worked well with 8GB of memory.

  


  In this case, there are a lot of inputs, but those inputs are small, most of them are between 1 and 10MB, so it would probably not generate out-of-memory problems, although I'm not certain.