Split .png file into multiple smaller files

[philipgoyal]

Currently, a single .png thumbnail sheet is created, irrespective of the video duration or chosen thumbnail interval. This can result in large a .png file (e.g. 20MB for a 1 hour video with 10s interval). This could be problematic when the video is streamed on a website.

It would be preferable to have the option to create several thumbnail sheets, numbered sequentially, based on an optional argument. Specifically, if e.g. "thumbnail-sheet-size" is set to e.g. 2 MB, then the code will split sheets so that each is no more than (roughly) 2MB is size.

[ArtyomVancyan]

Hi @philipgoyal, seeing your activities and passion for contributing to the project is lovely. The issue you described is solved using the --compress option. Whether you set it or not, the final size of the .png cannot be more than 8K. Although if you have such an issue, you can fix it using the --compress option of the CLI or the compress property if you use Python API. And related to the streams, yes - we can process stream formatted files such as .ogv, but I am not sure if it is possible to have a stream as an input.

[philipgoyal]

Hi @ArtyomVancyan, many thanks for creating this project—I've been looking for a thumbnail generator that generates .vtt files for use with e.g. Plyr, so I'm happy to contribute in any small way that I can. I've tried the compress option, setting generator.compress (in the Python script) to several values between 0.01 and 1.00. But the movie.png file size did not change at all (it's 17.6MB based on 5s interval from a video that's 103.4MB). The video file and generated files (.png and .vtt) are here <https://www.dropbox.com/sh/cqooo6ivylo67o6/AABN3mNjotilpUmWURlPzigna?dl=0>. The full settings are: generator = Generator(inputs) generator.base = " " generator.compress = 1 generator.skip = False # overwrite existing thumbnails generator.interval = 5 generator.compress = 1.00 # also tried between 0.01 and 1.00 generator.generate() Also: is there any possibility of enabling creation of multiple .png files as I suggested? A previous online service ("videohop <https://www.videohop.com.au/>", no longer operational) created multiple thumbnail sheets, which were then referenced in a single .vtt file.

[ArtyomVancyan]

The image size is directly proportional to the count of frames in the image and the quality of each frame. After all, I got 76.3kB by setting the compress value to 0.01. Can you please delete the generated result and try again with generator.compress = 0.01? It should work.

[philipgoyal]

Thank you—erasing the previously generated results seems to have been necessary to get this to work (even though I set generator.skip = False). I now get: 22.9 MB with compress = 1.0 17.5 MB with compress = 0.2 3.9 MB with compress = 0.1 0.8MB with compress = 0.05