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Tutorial - rewrap Canon DSLR mov files in MP4 container 4 better edit

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Neil Pollick
Tutorial - rewrap Canon DSLR mov files in MP4 container 4 better edit
on May 9, 2016 at 5:55:16 am

This is my summary of how to remux Canon DSLR mov files into a MP4 container, using the ffmpeg command line utility.
The instructions are simplified because I am no programmer. This method works well, it is very quick, much quicker than recoding/transcoding/converting. I went this why because I had been having trouble with mov
files myself, confirmed after reading many threads around the internet reporting Vegas will get sluggish if there are too many mov files on the timeline.

I was looking for a quick and cheap way to remux (rewrap) HD files from my DSLR so that I could edit in Vegas using full res files and be able to preview in Best quality. I haven't done extensive testing to prove that large projects are more responsive with Canon h254 mov files remuxed into an MP4 container, it may turn out the h254 codec is just too resource intensive, in ANY container. But I AM anticipating better performance during editing.

FFMPEG is a command line program, and the command line given in this post does batch remuxing of multiple files. Remux differs from recoding/encoding/transcoding in that it does not involve taking the stream out of the container, decoding it and then encoding it again, to pack it into the same or a different container.
Remuxing means you take whatever streams are inside the original container ("mov" in this case)and just put them verbatim into the alternative ("MP4" in this case)container. Remux is like "cut and paste", recoding/encoding/transcoding is like "cut, translate and paste"

Canon MOV files have a small problem in that their audio stream can not be transplanted into the mp4 container wholesale (that container does not support the Canon MOV audio stream). The video stream can be transplanted but the audio stream must be converted.

The whole thing, the remux of the video stream and the conversion of the audio stream can be done with a single line in a batch file, the line below. It is for remuxing multiple files in the same directory in one go.

FOR %%A IN (*.mov) DO ffmpeg -i %%A -vcodec copy -acodec aac -strict experimental -ab 256k %%~nA.mp4

That will remux each mov file into an MP4 container and convert the PCM audio stream into AAC (LC)
The number specified, in this case "256" refers to the desired Kbps of the audio stream in the new mp4 file (change as you wish)
The remux will not work without the switch "-strict experimental", it's needed because the "aac" encoder is still in experimental phase.
The string at the end is "%%~nA.mp4" to make sure that the remuxed files do not conatin ".mov" in their names, i.e. so they will be "MVI_1504.mp4" and not "" for example.
(using a syntax of "%%A.mp4" would yield a file name of "")
The beginning of the line "FOR %%A IN (*.mov)" defines the operator "%%A" as all and every mov file in the folder, that's why the string is repeated, with modification, as part of the outputted file name.

You must put a copy of the ffmpeg executable file in the same folder as the files you wish to remux (rewrap)
And you must put the batch file in that same folder too.
Running the batch file will result in a series of MP4 files sitting alongside the mov files in that folder. The mp4s should be approximately the same size as the original mov files.

I will be happy if people want to refine or expand these instructions. Please note though, that this method is working.

Thanks to Aleksey Tarasov on Creative Cow for putting me on to ffmpeg for this fucnction.

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