Author Topic: AVI turns to MKV in copy mode  (Read 78 times)

HMR

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AVI turns to MKV in copy mode
« on: January 06, 2018, 03:10:25 PM »
Hello everyone,
I suspect my question is lame but I'll still ask since my video formats knowledge is lame too.
I try to cut a piece from AVI file.
Use A/B markers, COPY option for both video and audio, save as.
But, I can only save to .mkv format, and get MKV file as a result.
Is it "uncompressed cut"? I don't want my videos to be re-encoded, just want a clear copy, with NO compression.
I thought output file format has to be same, in such case. AVI to AVI, MKV to MKV etc.
But this format difference at the end confuses me.
Some help/explanation would really help.
Thanks!!!

zakk

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Re: AVI turns to MKV in copy mode
« Reply #1 on: January 06, 2018, 05:47:54 PM »
I can only save to .mkv format
What do you mean ?

eumagga0x2a

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Re: AVI turns to MKV in copy mode
« Reply #2 on: January 06, 2018, 09:00:28 PM »
I can only save to .mkv format, and get MKV file as a result.

Sure you can change the default output container to something else, but MKV is just the best choice. MP4 is actually even better for some purposes (exact timing while MKV is limited to 1 millisecond accuracy), but much less flexible.

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Is it "uncompressed cut"? I don't want my videos to be re-encoded, just want a clear copy, with NO compression.

Most likely your videos are already compressed, otherwise they would easily occupy hundreds of gigabytes worth of disk space. Leaving the video and audio codec at the default setting "copy" means that compressed video and audio frames will be written to the output container without being first decoded and then reencoded – exactly as you wish.

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I thought output file format has to be same, in such case. AVI to AVI, MKV to MKV etc.

No, not at all. A container is just a structure to explain where the actual frames are stored. However, some containers impose limitations on codecs used to compress audio and video as well as on other features (e.g. MKV allows to store subtitles and supports also chapters, and the chapters may overlap if needed). AVI is a legacy container whose shortcomings make it incompatible with modern codecs. Avoid saving video as AVI as good as you can.