Best to convert to MP4 - avi or m4v

[DeputyDawg]

I have some files which I need to convert over to mp4 to play in Itunes

I have duplicates, one in avi format the other m4v

Which one would be better to use for conversion? I would like priority to be best quality. But if equal then disk space is my next concern.

Thanks

[jagabo]

You can just remux to mp4 with no loss of quality. Try AviDemux or ffmpeg.

[DeputyDawg]

thanks forgot to mention i'm using handbrake to convert

Btw when you said remix - which one should i use avi or m4v - assuming m4v

[DeputyDawg]

Using handbrake I did 2 tests

avi file size 562mb converted to mp4 with size of 420mb
m4v file size 376mb converted to mp4 with size of 404mb

Both were the same file (tv show in this example)

[jagabo]

thanks forgot to mention i'm using handbrake to convert

There may be no need to convert (reencode). If the codecs are acceptable you can simply remux -- take the compressed audio and video out of the AVI/M4V containers and putting them in an MP4 container -- like taking a cake out of one box (AVI, M4V) and putting in another (MP4), the cake is exactly the same as before. And remuxing is much faster than reencoding.

Btw when you said remix - which one should i use avi or m4v - assuming m4v

Whichever has better quality. Or codecs acceptable for remuxing into mp4.

[DeputyDawg]

COOL.. thanks ill look into that

HOPING this can be done in batch as I have a few of them (few dozen at least)

[DeputyDawg]

I just tried it on 2 files - avi and m4v

m4v worked well and took seconds and size stayed extremely close

avi file converted but when I try to play get a popup: "cannot decode"

Anyways, this is a great tool.. But without batch I will probably stick to handbrake-batch version

Thanks so much for your help

[butterw]

re-encoding isn't lossless.

Avidemux or ffmpeg can batch remux a folder of files.

[lingyi]

Go back to the basics. MP4 and AVI are containers. Saying you have a MP4 or AVI is meaningless as it can containe multiple different formats.

M4V is a format. Containers can contain (usually) multiple formats. MKV is also a container.
https://en.wikipedia.org/wiki/Comparison_of_video_container_formats

Imagine you buy a round cake from the bakery and take it out of the bakery box and put it in a large square container at home. You've remuxed the cake. Taken it from the original container and put it in another. The cake is still exactly the same (format).

However, all containers (MP4, AVi, MKV) are not supported by all playback devices.

You try to put the cake (in the square container) i the fridge but it won't fit. Incompatible container. So you move it a smaller round container and it now fits! Exact same cake, different container.

This is what you did with the M4V, remux.

With the AVI, you (re)encoded and that caused some incompatibility, highly likely with your player, not the format .

Back to the cake. (Re)encoding is taking the cake apart. Remove the frosting separate the layers, possibly squish the cake the make it smaller, then putting back together. The cake is fundamentally the same and will taste the same, other than possibly texture. Some people may not be bothered by the squished, ugly cake (compatible) and others will balk at the change (incompatible).

As for M4V. It's a proprietary Apple format. If you're using Apple products, they're likely highly compatible with an M4V in a remux MP4 or MKV container because it's an Apple format. If you put an AVI, (re)encoded or not into a MP4 or MKV container, your Apple products may not play it correctly because Apple products have a very limited set of allowed formats and containers.

Edit: Rereading the OP, I see it's converting an MP4 to M4V. Same basic caveat applies. Apple devices will love formats converted to M4V format. Non-Apple products, less so.


Edit 2: Dangit! Reread carefully lingyi! The OP wants to convert TO MP4. <OOPS!>

Bottom line. If you want to retain the original file quality, try to remux into a container first. If that doesn't work or want to (re)encode to shrink the file, you need to (re)encode to a compatible format and place the formatted file into a compatible container.

Edit: Regarding formats. There are dozens, if not hundreds of variations in how a video file can be encoded. A prime example is the numerous posters asking why one MP4 or MKV will play on their smart TV, but another won't.