Return media attachment dimensions

[siuying]

MediaAttachment currently do not return dimension of the image/video. This prevent the view from properly sized the placeholder.

If the api optionally return media dimension, we can make the client render the preview at proper size:

---

• I searched or browsed the repo’s other issues to ensure this is not a duplicate.

[ashfurrow]

Did some brief research into this, Paperclip has a companion gem for storing the asset dimensions in a database column: https://github.com/teeparham/paperclip-meta Beyond a basic db migration, it looks like it would require "rebuilding thumbnails", and I'm not sure what's involved in that.

[siuying]

The dimension field can be optional, then we don't need to worry about rebuilding thumbnails -- a rebuild task can be added later if someone really want all media have dimensions.

[ashfurrow]

Tried for a while to get this, but it's beyond my abilities at the moment. If someone else could take a look, that'd be 💯

[siuying]

I'm looking into it!

[siuying]

Tried to add paperclip-meta, but it conflicts with paperclip-av-transcoder. I don't really want to monkey patch it, so I write some custom code to do that instead.

1. Add a field file_meta to MediaAttachment
2. For images, find the meta data using Paperclip::Geometry
3. For video, paperclip-av-transcoder will set the meta data
4. Render meta field in _media.rabl

Note:

file_meta is json type, which require newer postgresql (9.4)

Result is something like:

 [
   {
      "media_attachments" : [
         {
            "id" : 4,
            "type" : "image",
            "remote_url" : "",
            "meta" : {
               "original" : {
                  "width" : 600,
                  "size" : "600x400",
                  "height" : 400,
                  "aspect" : 1.5
               },
               "small" : {
                  "aspect" : 1.49812734082397,
                  "height" : 267,
                  "size" : "400x267",
                  "width" : 400
               }
            },
            "url" : "http://127.0.0.1:3000/system/media_attachments/files/000/000/004/original/3416fc5188c656da.jpg?1493138517",
            "preview_url" : "http://127.0.0.1:3000/system/media_attachments/files/000/000/004/small/3416fc5188c656da.jpg?1493138517",
            "text_url" : "http://127.0.0.1:3000/media/4hfW3Kt4U9UxDvV_xug"
         },
         {
            "text_url" : "http://127.0.0.1:3000/media/0vTH_B1kjvIvlUBhGBw",
            "preview_url" : "http://127.0.0.1:3000/system/media_attachments/files/000/000/003/small/23519a5e64064e32.png?1493138030",
            "meta" : {
               "fps" : 15,
               "duration" : 5.06,
               "width" : 320,
               "size" : "320x180",
               "height" : 180,
               "length" : "0:00:05.06",
               "aspect" : 1.77777777777778
            },
            "url" : "http://127.0.0.1:3000/system/media_attachments/files/000/000/003/original/23519a5e64064e32.mp4?1493138030",
            "remote_url" : "",
            "type" : "gifv",
            "id" : 3
         }
      ],
   }
]

[ashfurrow]

Nice work @siuying !