YouTube API v3 upload video and set snippet etc.

youtube-upload.html

<!-- More info at http://stackoverflow.com/questions/25595930/youtube-api-v3-over-http-post-cant-set-snippet-while-uploading-a-video-title/ -->

<form id="upload-yt-video" action="https://www.googleapis.com/upload/youtube/v3/videos?part=snippet&access_token=YOUR_TOKEN_HERE" method="post" enctype="multipart/form-data">
  <input type="text" name="title" placeholder="Video title">
  <textarea name="description" placeholder="Video description"></textarea>
  <input type="file" accept="video/*" name="videoFile">
  <input type="submit" value="Upload Video">
</form>

<!-- load jQuery -->
<!-- load jQuery form plugin https://github.com/malsup/form -->

<script>
  var YOUTUBE_API_TOKEN = 'YOUR_TOKEN_HERE';
  var YOUTUBE_VID_CATEGORY_ID = 24; // "entertainment" as an example
  var YOUTUBE_VID_PRIVACY_STATUS = 'unlisted';
  
  $('#upload-yt-video').ajaxForm({
    success: function(res, status) { 
      if (status !== 'success' || ! res.id) {
        console.error('problem uploading the video, response status:', status, 'response:', res);
        return;
      }
  
      console.log('form submission successful, video uploaded to youtube! response:', res);
  
      updateYouTubeVideo({
        id: res.id,
        token: YOUTUBE_API_TOKEN,
        title: $('#upload-yt-video [name=title]').val(),
        description: $('#upload-yt-video [name=description]').val()
      }, function(err, res) {
        if (err) {
          console.error('problem uploading the video - error while updating video attributes after upload:', err);
        }
        else {
          console.log('video updated! upload complete. response:', res);
        }
      });
    },
    error: function() {
      console.error('form submission failed', arguments);
    }
  });
  
  function updateYouTubeVideo(args, cb) {
    if (!args || !args.id || !args.token) {
      console.error('missing args: must at least include id and token');
      return;
    }
  
    var apiArgs = {
      id: args.id,
      snippet: {
        description: args.description || '',
        title: args.title || 'Video ' + new Date().toDateString(),
        categoryId: YOUTUBE_VID_CATEGORY_ID
      },
      status: {
        privacyStatus: YOUTUBE_VID_PRIVACY_STATUS
      }
    };
  
    $.ajax({
      type: 'PUT',
      url: 'https://www.googleapis.com/youtube/v3/videos?part=snippet,status',
      contentType: 'application/json',
      headers: {
          Authorization: 'Bearer ' + args.token
      },
      data: JSON.stringify(apiArgs),
      dataType: 'text',
      success: function(data) {
        if ($.type(data) === "string") data = JSON.parse(data);
        cb(null, data);
      },
      error: function(request, err){
        cb(err);
      }
    });
  }
</script>