Use Shrine to upload video files and generate thumbnails - amazon-s3

Question

I want to use the Shrine gem to upload video files, transcode, & generate thumbnails from the video.
I am trying to convert Erik Dahlstrand's Shrine-Rails-example from photos to videos. I am having trouble creating the video uploader. I based this code on Video isn't of allowed type (allowed types: video/mp4), Shrine, Rails
require "streamio-ffmpeg"
class VideoUploader < Shrine
ALLOWED_TYPES = %w[video/mp4 video/quicktime video/x-msvideo video/mpeg]
plugin :processing
plugin :versions
plugin :determine_mime_type
plugin :cached_attachment_data
plugin :remove_attachment
plugin :add_metadata
plugin :validation_helpers
plugin :derivation_endpoint, prefix: "derivations/video"
add_metadata do |io, context|
movie = Shrine.with_file(io) { |file| FFMPEG::Movie.new(file.path) }
{ "duration" => movie.duration,
"bitrate" => movie.bitrate,
"resolution" => movie.resolution,
"frame_rate" => movie.frame_rate }
end
movie.screenshot("video_thumb_007.jpg", seek_time: 5, resolution: '320x240')
metadata_method :duration
Attacher.validate do
validate_max_size 100.megabyte, message: "is too large (max is 100 MB)"
validate_mime_type_inclusion ALLOWED_TYPES
end
end
I get this error:
/var/folders/mm/_j8x4k2176jcv31zvbc497_c0000gp
/T/shrine20190607-24438-4f3jz2.m4v: No such file or directory
and in fact, there is no file in that location. So where is the file stored while waiting for upload??
Also, using the demo to upload photos to AWS (production env), the objects are stored in the bucket in a folder called 'photos'. Shrine uses the table name to name the folder apparently. Is possible to create alternative & nested folder names?
Thank you - seems like an amazing gem! Trying to understand it better!
Thx

Answer 1

Further delving into the documentation, I was able to solve this problem with only one remaining question - is it possible to control which folders in the AWS bucket the original and thumbs are uploaded to? Thx
Solution:
require "streamio-ffmpeg"
require "tempfile"
class VideoUploader < ImageUploader
plugin :add_metadata
plugin :validation_helpers
plugin :processing
plugin :versions
plugin :delete_raw
add_metadata do |io, context|
movie = Shrine.with_file(io) { |file| FFMPEG::Movie.new(file.path) }
{ "duration" => movie.duration,
"bitrate" => movie.bitrate,
"resolution" => movie.resolution,
"frame_rate" => movie.frame_rate
}
end
process(:store) do |io, context|
versions = {original: io}
io.download do |original|
screenshot1 = Tempfile.new(["screenshot1", ".jpg"], binmode: true)
screenshot2 = Tempfile.new(["screenshot2", ".jpg"], binmode: true)
screenshot3 = Tempfile.new(["screenshot3", ".jpg"], binmode: true)
screenshot4 = Tempfile.new(["screenshot4", ".jpg"], binmode: true)
movie = FFMPEG::Movie.new(original.path)
movie.screenshot(screenshot1.path, seek_time: 5, resolution: '640x480')
movie.screenshot(screenshot2.path, seek_time: 10, resolution: '640x480')
movie.screenshot(screenshot3.path, seek_time: 15, resolution: '640x480')
movie.screenshot(screenshot4.path, seek_time: 20, resolution: '640x480')
[screenshot1, screenshot2, screenshot3, screenshot4].each(&:open) # refresh file descriptors
versions.merge!(screenshot1: screenshot1, screenshot2: screenshot2, screenshot3: screenshot3, screenshot4: screenshot4)
end
versions
end
Attacher.validate do
validate_max_size 100.megabyte, message: "is too large (max is 100 MB)"
validate_mime_type_inclusion ALLOWED_TYPES
end
end