Tutorial: (Updated) Convert FLV to MP4 No Re-Encode + Fixed XSplit Sync Problems

The older MP4 tutorial I did like this taught you how to remove the RAW audio & video out of a FLV container and re-mux (re-contain) it into a MP4 container. This worked for MOST people fine, however I figured out the problem some people had with the files not being in sync.

XSplit does not record at a fixed frame rate, it records in VFR (Variable Frame Rate) I go over this more in the first tutorial out of this set of 2 (The MKV tutorial) and so in long files or in files with a lot of frame variance it was impossible to get proper video and audio sync.


Now this method I found will perfectly sync files using time codes and will just like the first tutorial prevent you from having to re-encode any of your files to preserve all the original quality and content.

The MP4 container will work perfectly well with normal video editors like Adobe Premiere or Sony Vegas, so if you needed a way to edit those FLV files from XSplit now you have the perfect way!


If you needed this information or just found the video entertaining please say thanks by giving it a thumbs up so that I may be motivated to continue to learn new things and teach them to you as I go.

See everybody in the next tutorials!

-ViciousXUSMC

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Closed Caption:

hey everybody how's it going suspicious
and welcome back to the second part of
my two-part tutorial series on
converting flv video files over to a new
format so if you're tuning in after the
first one the first was talking about
taking flv and moving it into an MKV
container did that one first because it
was an easier process to help introduce
you to this it was all graphic user
interface programs that anybody can use
by dragging and dropping files the
second tutorial this one here with the
mp4 is more complicated because the
program are using his command line run
that's when we're going slower and have
to get more detail but real quick before
i even get into that let me reiterate
real quickly
what's a special about these tutorials
one they were not modifying the raw
content of these video files the audio
and video files inside of this flv
container is being unmodified and Marie
maxing it as they call it into a new
container so we're not losing any of the
quality that's originally here we're not
actually converting it all just changing
the container that means no quality is
lost and it's much faster because the
computer is not going to have to process
and encode anything
the other thing that's very special
about these tutorials a first one and
this one here is that we're dealing with
files that are from xsplit these flv
files are variable frame rate that means
using pretty much any traditional method
of unboxing and relaxing these files
you're going to get audio and video out
of sync because the audio/video don't
run into the same pace without timecodes
the time codes were easy to use and kv
but this is the first and only method
I've ever found to do this with mp4
alright so watch the first one first if
any more information on the variable
frame rate in the timecodes that's why
there's two parts
this one was going to get into it what
we need for this one is one program is
called ffmpeg we're gonna go ahead and
go to internet browser and go to Google
and ffmpeg dot org go there you go to
downloads and i'm using windows so i'm
going to go down here to download the
Windows builds and 32-bit or 64-bit go
ahead and choose whichever one is proper
for your operating system get the static
bill just because it's easier so i
downloaded the latest 64-bit build and
it's on my desktop are ready right here
and we're going to do is go ahead and
extract it and give myself a folder with
all the stuff so here we go
it's i read me some presets some
licenses documentation and then the
bench here the actually Xie's this is I
mean no GUI no graphic user interface if
i was to double click the exe you're
just going to quickly see a command line
window flash open and close
that's usually a tall tale sign that you
have to run this program via command
line and that means you need to know the
script and already have that typed out
for you
this is what we're going to be running
for this particular project ffmpeg exe
is the program running is our input
input to flv is the name of our file for
input
c is for codec we're going to running
this codec copy
we're not going to be specifying any
codec to re-encode this video we're just
going to copy the original streams and
here is the key ingredient that makes
them the tutorial what expert user has
been looking for in needing forever
copy TS means copy timestamps and that
is what's going to keep the audio and
video in sync and then output is the
name of the output file so that's how
we're gonna do it now if you know
anything about command-line these have
to be the long pass to your files
this isn't going to do anything unless i
specify war ffmpeg is this will not work
I don't specify where the input file is
and this won't work in sa everywhere I
want this file to go and that's why I'm
gonna make this tutorial easy by showing
you some tricks on how to shorten this
up and then i'm going to like a small
bonus tutorial later on to show you how
to run this for a batch file a bat file
that way you can run
by double-clicking on an icon and not
typing this out and how to get your long
path so for today's tutorial here's what
we're going to do I'm going to go ahead
and drag this into my folder where I had
the video file want to work with and I'm
going to move my video file into where
the Exies at so here i am with the exe
and my video file there in the same
location on my computer that means when
i run this program I don't have to
specify the path for this because
they're in the same location we're going
to rename this to give it an easy name
i'm just going to name it's a tutorial
flv and here's my trick for the command
line i have to specify where ffmpeg is
at my computer if i go back one folder
and I hold down ctrl + shift + i right
click on my bin folder where that exe is
under my options are going to find open
a command window here if I click on that
i'm going to get a nice command line
window already with the path specified
where the exe is that will save us the
whole trouble of having to find this
path and type it out since the video
files already in here as well I don't
have to specify the path of that so
we're already ready to run that script i
showed you so it go back to that and
show you what that was again i'm going
to type in FF mpeg-dash I for input the
name is tutorial flv dash c4 codec the
codec is copy for both video and audio
not specifying audio or video so it can
do both and then i'm going to flag copy
timestamps and then the output i'll just
call this morning on tutorial again to
call it before tutorial not in p4
and as you can see here's the important
part
it's syncing all the time stamps to the
frame rate and that's why when this is
done in just a moment you're going to
see that the audio and video are in sync
this is a two hour long video file my
framerate vary anywhere from 24 to 30
frames per second and there was no way
to get the audio video and sink and a
static frame rate using something like
the average framerate just wasn't going
to happen and unlike the MKV tutorial
now that i'm using an mp4 container
this file is editable and your average
video editor like Sony Vegas or adobe
premiere and i'll show you that since
we're done is my background get Vegas
open more waiting
Vegas is open and we're just waiting for
us to finish and that's it guys and we
go ahead and analyze this show what we
got and close that out again the
tutorial coming up with shortly as a
bonus is I'm gonna teach you guys how to
find your long path most you probably
know how but I'm going to elaborate just
in case you don't instead of running
from a command window like this it's
going to be a file like a text file I
just double-click on it will run this is
gonna make it much easier for you if you
do this process often it's going to be
easier for you to customize it for your
own personal needs to be much more in
depth on this portion of this tutorial
so back in here where we had the exe
here's the flv that we use for input and
here is the output the mp4 file same
size as originally nothing changed no
quality was lost but now it's an mp4
container which works in Vegas so flv we
try that Vegas is going to spit out an
area that says it does not recognize
this format you can't use that file I
hate you go away i try mp4 it will drag
and drop right in and you can see that
the video and audio are the exact same
length completely in sync and that guy's
is what everybody has been waiting for
is finally a fix both tutorials are
using a hundred percent free programs
there's nothing to pay for no gimmicks
i'm not making anything off of it
I'm not so basically just sharing the
knowledge so the knowledge was useful
for you or you just enjoyed the tutorial
for any other reason
be sure to say thank you by giving a
thumbs-up and liking the video if you
want to learn more things like this from
a technological guy like me just
subscribe to my channel because i always
have new stuff coming out rather than
that i'm really you guys go
this was vicious and i'll see you next
time