{"id":44461,"date":"2019-04-08T03:01:41","date_gmt":"2019-04-07T17:01:41","guid":{"rendered":"http:\/\/www.rjmprogramming.com.au\/ITblog\/?p=44461"},"modified":"2019-04-05T16:12:43","modified_gmt":"2019-04-05T06:12:43","slug":"batch-ffmpeg-image-scaling-and-cropping-tutorial","status":"publish","type":"post","link":"https:\/\/www.rjmprogramming.com.au\/ITblog\/batch-ffmpeg-image-scaling-and-cropping-tutorial\/","title":{"rendered":"Batch ffmpeg Image Scaling and Cropping Tutorial"},"content":{"rendered":"
\"Batch<\/a>

Batch ffmpeg Image Scaling and Cropping Tutorial<\/p><\/div>\n

We’re adding “Scaling” functionality onto the “Cropping” functionality of yesterday’s Batch ffmpeg Image Cropping Primer Tutorial<\/a> today.<\/p>\n

For now, we are also harnessing the power of running this changed<\/a> PHP help_ffmpeg.php<\/a> within a web browser by showing you both input and output images in data URI<\/a> form. Why data URI? Data URI makes your work transportable, as any data URI formed image does not reference a domain of any sort. Sounds good in emails, doesn’t it? This data URI usage might be a “bridge” from the local web server usage we’ve started out on (and may remain on) to other realms in that within the web browser you can Windows right click or Mac OS X two finger gesture on this data URI image of interest and get a copy of it or display it somewhere else or … who knows …<\/p>\n

\"You<\/p>\n

… the water temperature’s pretty good at the moment!<\/p>\n

In amongst the new scaling functionality, and again we’d like to thank https:\/\/www.oodlestechnologies.com\/blogs\/Crop-and-scale-image-using-ffmpeg<\/a> for their excellent heads up, we allow for scaling to a user defined width and height, but maintaining the original image’s “Aspect Ratio”<\/a>.<\/p>\n

\n

Previous relevant Batch ffmpeg Image Cropping Primer Tutorial<\/a> is shown below.<\/p>\n

\"Batch<\/a>

Batch ffmpeg Image Cropping Primer Tutorial<\/p><\/div>\n

Putting together presentations based on slides which are images you may come across the desire to apply batch image manipulations to a whole set of images, in the same way. When we presented Gimp Batch Image Manipulation Primer Tutorial<\/a> you would have seen this in play with the Gimp<\/a> image editor’s Bimp batch processing functionality part.<\/p>\n

Today we write some PHP to do this with an exec<\/a> invocation of the great ffmpeg<\/a>, which we will show you code for on rjmprogramming.com.au but no “live run” links on this occasion. “Live run” for us happens on (the Apache\/PHP\/MySql local web server) MAMP<\/a>, a setup we enthusiastically recommend for any Mac OS X (or macOS) users out there developing web applications, where …<\/p>\n

HTTP:\/\/localhost:8888\/<\/code><\/p>\n

… URL (at a web browser address bar) corresponds to a (local) web server folder (MAMP’s “Document Root”) called (for us) …<\/p>\n


\n\/Applications\/MAMP\/htdocs\/
\n<\/code><\/p>\n

… and the user performing today’s PHP help_ffmpeg.php<\/a> can define an image file(specification) relative to that “Document Root” basis above, and processing via PHP’s file specification specialist, glob<\/a>. It’s all relative, really.<\/p>\n

We’ll be adding to this, but today we start out on this exploration with some cropping functionality, the heads up for we’d like to thank https:\/\/www.oodlestechnologies.com\/blogs\/Crop-and-scale-image-using-ffmpeg<\/a> … ta, muchly! One last thing is that ffmpeg is Open Source and you can read about compiling this desktop application yourself by referring to the links explaining how to do this at Video via Slide Images and Back Again via ffmpeg Primer Tutorial<\/a>.<\/p>\n

\n

Previous relevant Gimp Batch Image Manipulation Primer Tutorial<\/a> is shown below.<\/p>\n

\"Gimp<\/a>

Gimp Batch Image Manipulation Primer Tutorial<\/p><\/div>\n

Gimp is a great graphics editor with a huge number of methods to subtlely or not so subtlely adjust your images, no matter where they have come from (some of today’s came from Mac OS X screen captures via the Grab application and some came from a digital camera).<\/p>\n