MMP: Minimalist Media Player

Occasionally, when Exporting your edited video from the Audio & Video Timeline Editor, FFmpeg will throw up all sorts of errors when trying to read your original video.

This can be very annoying when you've spent so long making your edits.

Most of these problems appear to be created by some less than ideal video editors/encoders which output a video file with some non-standard-looking (and numbered) streams encoded in the file.

Fortunately, in most cases, there is a very straight-forward solution: have FFmpeg copy the entire video to a new file.

FFmpeg can read in the video and output it in a standard format which it can then manipulate.

You will need to run FFmpeg from a command line. (A copy of FFmpeg.exe is shipped with each release of MMP)

Run the following command from a command prompt (it only takes a few seconds):

ffmpeg -i “B:\Movies\myVideo.flv” -c copy “B:\Movies\myVideo.mp4”

Obviously, if your video already has a .mp4 file extension, you'll need to give the output file a slightly different name.

The great news is that you can then reuse your original .mmp file (which contains your edits) against the new video file:

• If the only difference in file names is the file extension, you can simply open the new video file in MMP, go straight into the Audio & Video Timeline Editor (Ctrl-[E]) and Export your edits
• If you had to modify the name of the output video file slightly, simply rename the .mmp file so that it matches before opening the Audio & Video Timeline Editor

The above FFmpeg command will only copy one audio stream and one video stream from your video file.

If your video also contains subtitle streams (or multiple audio streams) and you want to copy them too, it just requires a slightly modified FFmpeg command:

ffmpeg -i “B:\Movies\myVideo.flv” -map 0 -c copy “B:\Movies\myVideo.mp4”

In the above parameter list, -map 0 instructs FFmpeg to include all the streams from the input file.

If the subtitles are “hard-baked” into the video stream (i.e. your video player can't turn them on and off) then the first command is all you need if there are no other streams you want to preserve.

A PDF file is a container for individual pages, often with a Table Of Contents index, embedded fonts, meta-data about the document (title, author, creation time, creation software), etc.

In a similar way, video files are also containers.

A video file can be made up of a video stream, any number (including zero) of audio streams, and any number (including zero) of subtitle streams.

Video players don't read from the start of a video file and play through to the end of the file.

Rather, they examine the contents of the video file container, select the video/audio/subtitle streams to play, and then play them concurrently.

This is what allows you to select different language audio, and different language subtitles to play with the moving images.

You need to bear this in mind when using FFmpeg to convert video files and formats.

For example, if you're copying a .mkv movie with 20 subtitle tracks, you may need to make your output video a .mkv too*.

FFmpeg may complain if you try to create a .mp4 from your .mkv, whilst retaining all the subtitle streams.
However, it won't be immediately obvious from the error messages that that's what the problem is.

By contrast, FFmpeg will let you do a straight -c copy from a .mkv to a .mp4, but you need to check whether you have lost any streams you wanted to retain.
Typically, this basic command will result in an output video with one video stream and one audio stream.

The Segments & Streams Panel in the Audio & Video Timeline Editor can help you as it lists all the streams in a video container file.

*Just to be clear, FFmpeg will allow you to create practically any type of output file from any type (and number) of input file(s), making various complex conversions as it goes.
However, you will be required to supply more [and more complex] parameters to override FFmpeg's basic assumptions about what you have and what you want.
All that is beyond the scope of this article which is simply to supply you with some basic FFmpeg operations to fix your Export.