Video Contact Sheet for Ruby
I do like the results of the "Video Contact Sheet *NIX" but the Script is written as a Shell Script and naturally this makes it hard to understand and extend.
vcs.rb has several applications in mind
- It should be usable as a library in rails to make video captures easy.
- It should be usable as a simple script imitating the original vcs script.
- Capturing single frames from a video
- Gathering meta information from a video. (streamio replacement)
require 'vcs.rb'
video = VCSRuby::Video.new 'video.mkv'
sheet = video.contact_sheet
sheet.format = :jpg
sheet.sheet.initialize_geometry(3,3,nil)
sheet.signature = nil
sheet.thumbnail_width = 320
sheet.initialize_filename('out.jpg')
sheet.build
frame = video.frame VCSRuby::TimeIndex.new('1:22')
frame.filename = "frame.jpg"
frame.capture_and_evade # evade blank framesgem install vcs_ruby
You will only need the CaptureSheet class from the VCSRuby Module. All other classes are only helper classes to create a Capture Sheet easily for you.
The library uses MiniMagick to use ImageMagick and we use directly libav, ffmpeg or mplayer whatever you have on your System.
To extract the images from the videos you can select your preferred capturer. Currently there are the following 3 options:
- LibAV
- FFMPEG
- MPlayer
# encoding: utf-8
require "vcs"
video = VCSRuby::Video.new "video.avi"
if video.valid?
# Fields on .info: duration, bit_rate, size, format, extension, raw (hash, depends on capturer)
puts "Video duration: #{video.info.duration}"
# Supports multiple streams
puts "Video codec: #{video.video_streams.first.codec}"
# Fields on a video stream: width, height, codec, color_space, bit_rate, frame_rate, aspect_ratio, raw (hash, depends on capturer)
puts "Video frame rate: #{video.video.frame_rate}"
# Supports multiple streams:
puts "Audio codec: #{video.audio_streams.first.codec}"
# Fields on a audio stream: codec, channels, channel_layout, sample_rate, bit_rate, raw (hash, depends on capturer)
puts "Audio sample rate: #{video.video.sample_rate}"
endIt is pretty simple to include the Contact Sheet into CarrierWave, however the processing will be done after the upload which might take quite some time. It is recommendet to use something like carrierwave_backgrounder to make the processing not during the upload.
Here is a working example in Carrierwave:
# encoding: utf-8
require "vcs"
class VideoUploader < CarrierWave::Uploader::Base
include CarrierWave::MiniMagick
storage :file
def store_dir
"uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
end
version :contact_sheet do
process :contact_sheet_processor
end
def contact_sheet_format end
:png
end
def cs_url
"#{File.dirname(url)}/#{File.basename(url,'.*')}.#{contact_sheet_format}"
end
def contact_sheet_processor
# input
directory = File.dirname(current_path)
tmpfile = File.join(directory, 'tmpfile')
File.rename(current_path, tmpfile)
# output
new_name = File.basename(current_path, '.*') + '.' + contact_sheet_format.to_s
current_extenstion = File.extname(current_path).gsub('.', '')
encoded_file = File.join(directory, new_name)
# create cs
cs = VCSRuby::ContactSheet.new tmpfile
cs.initialize_filename(encoded_file)
cs.format = contact_sheet_format
cs.title = model.name
cs.signature = nil
cs.thumbnail_width = 320
cs.timestamp = false
cs.softshadow = false
cs.build
# without this lines processed video files will remain in cache folder
self.filename[-current_extenstion.size..-1] = contact_sheet_format.to_s
self.file.file[-current_extenstion.size..-1] = contact_sheet_format.to_s
File.delete(tmpfile)
end
endThe cs_url alternative gives you the right path. This is not very nice though. A solution to just correct the url would be appreciated.
<%= image_tag @video.video.contact_sheet.cs_url %>Video Contact Sheet Ruby 1.1.9
-i, --interval [INTERVAL] Set the interval [INTERVAL]
-c, --columns [COLUMNS] Arrange the output in <COLUMNS> columns.
-r, --rows [ROWS] Arrange the output in <ROWS> rows.
-H, --height [HEIGHT] Set the output (individual thumbnail) height.
-W, --width [WIDTH] Set the output (individual thumbnail) width.
-A, --aspect [ASPECT] Aspect ratio. Accepts a floating point number or a fraction. (i.e. 16/19)
--from [FROM] Set starting time. No caps before this.
-t, --to [TO] Set ending time. No caps beyond this.
-f, --format [FORMAT] Formats: png, jpg, jpeg, tiff
-C, --capture [CAPTURER] Capturer: ffmpeg, libav, mplayer, any
-T, --title [TITLE] Set Title
-o, --output [FILE] File name of output. When ommited will be derived from the input filename. Can be repeated for multiple files.
-s, --signature [SIGNATURE] Change the image signature to your preference.
--no-signature Remove footer with signature
-l, --highlight [HIGHLIGHT] Add the frame found at timestamp [HIGHLIGHT] as a highlight.
--[no-]timestamp Add timestamp to thumbnails. Default: true
--[no-]shadow Add shadow to thumbnails. Default: true
--[no-]polaroid Add polaroid frame to thumbnail. Default: false
-p, --profile [PROFILE] Loads additional setting from profile.yml.
-q, --quiet Don't print progress messages just errors.
--continue Prints Error message and continues with next file (if any left)
-V, --verbose More verbose Output.
-v, --version Current Version
-h, --help Prints help
Examples:
Create a contact sheet with default values (4 x 4 matrix):
$ vcs video.avi
Create a sheet with vidcaps at intervals of 3 and a half minutes, save to
"output.jpg":
$ vcs -i 3m30 input.wmv -o output.jpg
Create a sheet with vidcaps starting at 3 mins and ending at 18 mins in 2m intervals
$ vcs --from 3m --to 18m -i 2m input.avi
Each Profile is a yml file which copies all or parts of the defaults.yml file to overwrite some part of the settings.
There are a few profiles delivered with the gem. [black, white, oldstyle]
twobytwo.yml
This Profile Makes a two by two contact sheet with a large 10px padding and red text on yellow background for the header part. Place this file directly into the dir and call it with --profile twobytwo
main:
rows: 2
columns: 2
interval: ~
padding: 10
style:
header:
color: Red
background: "#ffcc00"
| Options | Default | Description |
|---|---|---|
| main:rows: | 4 | Number of Rows |
| main:columns: | 4 | Number of Columns |
| main:interval: | ~ | Number of columns, default is ~ (nil) |
| main:padding: | 2 | Padding in pixels |
| main:quality | 95 | quality level [1-100] for jpeg images |
| filter:timestamp | true | Add a timestamp to the thumbnail |
| filter:polaroid | true | Add a polaroid frame to the thumbnail |
| filter:softshadow | true | Add a shadow to the thumbanil |
| style:header:font | DejaVuSans.ttf | font (name or file) for the header |
| style:header:size | 14 | Size of the font for the header |
| style:header:color | Black | Color of the text for the header |
| style:header:background | #afcd7a | Background color for the header |
| style:title:font | DejaVuSans.ttf | font (name or file) for the title |
| style:title:size | 33 | Size of the font for the title |
| style:title:color | Black | Color of the text for the title |
| style:title:background | White | Background color for the title |
| style:highlight:background | SlateGray | Background color for the highlight |
| style:contact:background | SlateGray | Background color for the contact sheet |
| style:timestamp:font | DejaVuSans.ttf | font (name or file) for the timestamp |
| style:timestamp:size | 14 | Size of the font for the timestamp |
| style:timestamp:color | White | Color of the text for the timestamp |
| style:timestamp:background | #000000aa | Background color for the timestamp |
| style:signature:font | DejaVuSans.ttf | font (name or file) for the signature |
| style:signature:size | 10 | Size of the font for the signature |
| style:signature:color | Black | Color of the text for the signature |
| style:signature:background | SlateGray | Background color for the signature |
| lowlevel:blank_evasion | true | try to avoid blank frames |
| lowlevel:blank_threshold | 0.08 | median image brightness |
| lowlevel:blank_alternatives | [ -5, 5, -10, 10, -30, 30, 0] | Array of seconds around interval |