[0:00] Sometimes in our computing life, we actually
make use of software without realizing that
[0:05] we're using a particular piece of software
- And one very good example of this is FFMPEG!
[0:11] FFMPEG is actually a command line utility
and its job is to do file format conversion.
[0:17] And, in that process, it can also do a number
of cool things.
[0:21] Now, because of the license of FFMPEG, it
is actually included in certain other pieces
[0:26] of software, you know, to do its job in the
background and as a result you may or may
[0:31] not realize that it's actually there, but
in fact it is!
[0:35] So what we're gonna do today is we're not
only gonna give FFMPEG the recognition it
[0:40] deserves, we're gonna learn how to actually
use it from the command line, that is the
[0:45] plain, vanilla FFMPEG running on your computer
from scratch!
[0:50] So yeah, I hope this interests you!
[0:52] After learning how to use FFMPEG I've actually
found it quite useful and indispensable in
[0:57] many situations, so yeah, I hope you think
the same!
[1:00] You're watching another random Wednesday episode
on 0612 TV!
[1:14] Hello and welcome back to another random Wednesday
episode!
[1:17] So FFMPEG!
[1:19] A very interesting tool - Let's begin by learning
how to install it, we'll then move on to the
[1:25] basics, and then to some more interesting
things you can do with this piece of software.
[1:31] Of course, as it turns out, it is much more
than a file format converter, but yeah, like
[1:36] I said, we'll see it when the time comes.
[1:39] First of course is how do we install this
program?
[1:42] Well, you can find a download link in the
video description, it will send you to the
[1:46] download page on the official FFMPEG site.
[1:49] You'll realize right off the bat that things
are a little bit complicated because there
[1:54] are three different versions of FFMPEG you
can choose from.
[1:57] But, they do tell you that if you've no idea
what you're supposed to do here just pick
[2:02] the static version, so that's what we're gonna
do!
[2:05] Basically the idea is the static version contains
all of FFMPEG in one .exe file, which, for
[2:12] our purposes is the most convenient!
[2:15] So I would recommend that as well.
[2:17] Go ahead and download the latest version for
whatever bitness your computer is, and you'll
[2:23] realize that what you end up with is an archive.
[2:27] Open the archive in an archive manager of
some sort.
[2:30] If you don't have one you can check out PeaZip,
which I will also link to in the video description.
[2:35] Within the archive, enter the "bin" folder,
and look for FFMPEG.
[2:40] That's really the only file you need, so extract
that to some location that you can remember,
[2:46] and we can begin converting!
[2:48] Now, if you intend to use FFMPEG from anywhere
on your computer, you might want to, you know,
[2:55] save it somewhere important, like in a Program
Files folder, and then link to it using the
[3:01] PATH variable.
[3:02] So what you're seeing onscreen right now are
the steps I've used to do that.
[3:06] I do actually have things set up this way
because well, it's just easier for me.
[3:12] Of course, this step is optional so if you
don't want to do that, then make sure FFMPEG
[3:16] is in the same folder as the video files you
want to work with.
[3:22] With that out of the way, let's move on to
the fun part, and that is to actually convert
[3:27] files with FFMPEG!
[3:29] Now, previously to this I know I mentioned
videos repeatedly, but as it turns out FFMPEG
[3:35] can also work with images and audio!
[3:38] Basically, well, it's a command line utility
you just tell it what file to process and
[3:43] what kind of output you want, and it just
does it!
[3:47] That's how amazing it is!
[3:48] So, let's actually try a very simple example
first of taking a video file and converting
[3:55] it from .avi to .mp4.
[3:56] Now, what you're seeing here is a folder in
which I have staged the files I want to work
[4:02] with throughout this video.
[4:03] You can open a command line very quickly on
a windows computer by first making sure no
[4:08] files are selected, then hold down shift,
right click empty space, and then click on
[4:14] "Open Command Window Here".
[4:17] That's convenient because the command window
opens in that particular folder, so you can
[4:21] get started right away.
[4:23] Here's what FFMPEG syntax looks like - You
start off by saying FFMPEG, then you say -i,
[4:31] which means "I'm about to specify an input
file", and then, you go ahead and specify
[4:36] the input file!
[4:38] So what we wanna do here is we wanna convert
an AVI file to MP4.
[4:42] So simply all you have to do is to actually
press space, and type out the new name of
[4:47] the file, making sure that the extension is
MP4.
[4:49] Hit enter, and, well, off it goes!
[4:54] FFMPEG is now converting an AVI file to MP4,
by just looking at the file extension of the
[5:00] filename you gave it.
[5:02] That is how simple FFMPEG actually is, and
a lot of the time when we want to convert
[5:07] between different file formats, that's really
all you need to do.
[5:11] But well, the time will come when you wanna
do something more complex, and that is where
[5:16] the command switches start to come in.
[5:19] Probably the first thing that concerns you
would be the quality of the file.
[5:24] You would probably want to be able to tweak
up the quality and what I'm gonna show you
[5:29] here works for MP4 and AVI respectively.
[5:33] Let's start with AVI.
[5:35] Now, there is a factor in image compression
called the quantizer that actually affects
[5:41] file quality, and it is linked to how it should
choose a bitrate, when it comes to variable
[5:47] bitrate encoding, but we won't go into too
much detail about that.
[5:52] Basically, all you need to know is that the
quantizer is a number.
[5:56] The smaller the number, the higher the quality.
[5:59] Of course, the higher the quality, the higher
the file size, so there's a trade-off you
[6:03] need to work with.
[6:04] To set the quantizer for an output AVI file,
all you have to do is well, you call FFMPEG,
[6:10] you specify the input, and then you type -q,
followed by a number.
[6:16] This number is of course the quality setting
you want.
[6:19] Numbers between 20 and 30 is common, but if
you want a very high quality video, you can
[6:24] go as low as a single digit.
[6:27] If you want it to be lower quality you can
go as high as 50.
[6:31] Experiment!
[6:32] You'll be able to see the difference in the
different settings you choose.
[6:36] Do note that this only works when you're writing
a file with a .avi extension.
[6:41] If you're doing this for MP4 files, then you'll
want to specify the -crf value instead!
[6:48] So instead of -q you'll need to type -crf,
and then enter your number.
[6:53] I think this exists on a slightly different
scale from the -q flag, so yeah, be careful
[6:59] of that.
[7:00] The values are not necessarily the same!
[7:02] Once again, experiment!
[7:04] You know, look at the file size, look at the
quality and decide whether you want to bump
[7:08] it up or down.
[7:10] If you prefer finer control, you can also
specify the exact bitrate of the output file.
[7:16] Now, bitrates work for both audio and video
in a file, so you'll probably want to tell
[7:21] it whether you want to tell it whether you
want this to work on the video channel, or
[7:24] the audio channel.
[7:25] And to specify this, you'll want to enter
a colon, and then type v or a, depending on
[7:31] which stream you want to target.
[7:33] Then, give it a number.
[7:35] For example, if I want the video quality to
be 1000k, which is actually quite low, well,
[7:41] you can do that.
[7:42] I can even specify both audio and video bitrates
at the same time, and that will fix the two
[7:48] bitrates of the two different streams.
[7:51] This is of course only if you want finer control.
[7:53] So yeah, for the vast majority of use cases
I'd say you know, what you've learnt so far
[7:59] covers your bases, but let's say we want to
go a step further - Let's take a look at FFMPEG
[8:05] filters just for fun!
[8:07] Now, here's the deal - FFMPEG actually comes
bundled with a whole bunch of different filters!
[8:13] And they all have various effects on the video
itself.
[8:16] What I've done is, through the whole list
of video and audio filters, I've picked a
[8:20] total of five to go through with you.
[8:23] Two of them are for audio, and the remaining
three are for video, and these are the things
[8:28] you'd probably do the most often.
[8:30] So yeah, let's take it from the top.
[8:33] We're going slideshow mode again because we've
overrun!
[8:36] Let's quickly jump through the five filters.
[8:39] First, let's tweak the volume.
[8:42] To do this, simply add the following flag
to the FFMPEG call.
[8:46] The flag itself says we want to use a filter
on the audio channel, and its parameter says
[8:51] that we want to call the volume filter, with
a setting of two.
[8:56] The number we provide is actually a multiplier.
[8:59] So when we say volume=2, we are actually doubling
the volume.
[9:03] You can of course use decimal volumes, including
values smaller than 1 to reduce the volume.
[9:09] Next, channel remapping.
[9:12] Sometimes we accidentally record with a mono
mic into a stereo track, causing the sound
[9:17] to only go to the left channel.
[9:19] We can easily fix this by mapping the audio
from the left input channel to both the output
[9:24] channels.
[9:26] That's what this command call means!
[9:28] The left channel is 0 and the right channel
is 1.
[9:31] So what we're doing here is mapping the input
left channel to the output left channel, and
[9:36] then the input left channel to the output
right channel, thus creating an audio track
[9:41] that has sound on both sides.
[9:44] Let's move on to the video filters.
[9:47] First cropping.
[9:48] The syntax looks like this.
[9:51] Notice how we say -filter:v because we now
want to target video.
[9:56] We then say crop, and specify up to four parameters.
[10:00] The first two are width and height, which
specify the width and height of the output.
[10:05] The two remaining parameters are optional,
and they specify the upper left corner of
[10:09] the cropping.
[10:11] If unspecified, the cropping is centered.
[10:14] You can use arithmetic for this as well.
[10:16] For example, this statement means that we
want to crop the video to 2/3 of its original
[10:21] size.
[10:22] The variables in_w and in_h are available,
referring to the input width and height respectively.
[10:30] Next, video scaling.
[10:33] This looks very similar to the first two parameters
of the crop filter.
[10:37] Use w and h to set the width and height of
the output.
[10:41] You can also arithmetic like with cropping.
[10:44] The variables in_w and in_h are also available
here.
[10:49] In addition, if you'd like proportional scaling,
you can specify -1 for one of the input parameters.
[10:57] Its value will be determined from the length
you do provide.
[11:01] Finally rotation.
[11:04] Simply say rotate= and specify your angle.
[11:07] Unfortunately your angle needs to be specified
in radians.
[11:11] Luckily it's not that hard, since you can
just multiply by the constant PI/180.
[11:15] So the following statement refers to a clockwise
rotation of 45 degrees.
[11:23] The result of this operation looks something
like this.
[11:27] And there you have it!
[11:28] We've actually gone through a pretty comprehensive
beginners guide to installing and using FFMPEG.
[11:34] And we've even taken a look at some complex
features, in the form of some filters, but
[11:40] I've barely scratched the surface!
[11:43] Like I said, FFMPEG has a whole host of filters
and if you want to look at the full list,
[11:48] I will include the link in the video description
so you can find out more.
[11:52] That's all there is for this particular episode,
it does look like I've overrun a bit so sorry
[11:57] about that, but hopefully you've found this
video insightful anyway!
[12:01] Thank you very much for watching, and until
next time, you're watching 0612 TV with NERDfirst.net.