Converting flv into mp4 help

[Lovecraft]

I am currently working on a project where I need to take 36 flv files and string them together using my Adobe Premiere Elements 8.0. After discovering that Premiere cannot view flv files, I tried converting them the files in to mp4 using VLC. To convert them, I opened up “convert/save” and placed the first file into “file selection” and hit “convert/save button”. In the source box I have “example.flv”, while in the destination box I have “example.mp4” and checked the “display the output” box then pressing start.

The problem is that when I open “example.mp4” in Premiere, I find that the second half of the audio file is missing in all 36 converted files. In VLC the audio is present the entire length of the file, but is extremely choppy.

I have a very limited grasp on computers and have only been able to this much through guessing. I have tried looking for a solution on the forms myself, but I am afraid that many of the terms escaped my grasp.

[Jean-Baptiste Kempf]

What OS are you on?

[Lovecraft]

windows 7

[Lovecraft]

hello?

[Jean-Baptiste Kempf]

You should use mpeg-ps for premiere

[Lovecraft]

I'm sorry, I don't know what you mean.

[Lovecraft]

can i have some help?

[l a n]

Hello,

if you don't know much about computers, video and audio codecs you should either start learning or ask a friend or someone in your neighborhood who knows about computers.

First thing to understand: The FLV file format is a container that contains an audio stream and a video stream.
Personally, I would not convert the FLV because it decreases the quality of the video.

I'd extract the video stream and audio stream with the program FLV-Extract:
http://moitah.net/download/latest/FLV_Extract.zip
Then you get three files: video.aac, video.264 and the timecodes. AAC is "Advanced Audio Coding" and H264 is a standard for video encoding - you can look that up in Wikipedia if you want.
H264 is already an MP4 format.

Then you have to multiplex the unmodified audio and video stream together with MP4Box:
http://www.videohelp.com/tools/My-MP4Box-GUI
I think that MP4Box can also append the video to an existing MP4 file. That means you can join your 36 FLV files if you append every stream.
Maybe you have to set the frames per second (FPS) of the video by hand.

Maybe your "Adobe Premiere" is also able to multiplex the video.aac and video.264. But I only use free and open software for video conversion.