Avidemux Formats?

[ramosis]

Please help a total novice!

Under Formats Drop Down List there are various options, amongst them: MPEG-PS and MPEG-TS and MPEG VIDEO.

Please explain the difference between these three formats.

Many Thanks

Ramosis

[edDV]

MPEG video = MPG <--- think letter or video stream.
http://en.wikipedia.org/wiki/MPEG-2

PS = Program Stream (as used for DVD VOB) <--- think letter with other things stapled*.
http://en.wikipedia.org/wiki/MPEG_program_stream

TS = m2t = Transport Stream (as used for digital TV broadcast) <--- think stapled letter with others placed in a Fed-EX envelope (rugged packet stream fit for long distance shipment).
http://en.wikipedia.org/wiki/MPEG_transport_stream

MTS = m2ts = Random access Transport Stream (as used for Blu-ray and AVCHD) <--- think X-Ray machine reading docs in an envelope without opening it.
http://en.wikipedia.org/wiki/.m2ts


* like audio, subtitles, angle shots

[ramosis]

Thanks for the help! So I gather to copy a MPEG video from a Hard Drive to a DVD I should use Format Mpeg-PS

[edDV]

Thanks for the help! So I gather to copy a MPEG video from a Hard Drive to a DVD I should use Format Mpeg-PS

Two choices. You can copy an MPG file to a DVDR disc and many players will play it directly. If you want a spec DVD playable on all players, you need to "author" the MPG video plus audio etc. into a VOB program stream in a VIDEO-TS folder.

[yoda313]

Just to add to eddvs last post - if the mpg isn't dvd compliant it will need to be reencoded. Chances are if this was recorded with a capture device it is PROBABLY dvd compliant. There shouldn't be too much loss if any from mpg to dvd (fyi if it is already dvd compliant there will be no quality loss upon authoring as it will be encapsulated properly into vobs in the proper format for dvd playback). Depends on the bitrate and the quality of the source you are using. (fyi avstodvd is a great program to use to author a dvd from multiple formats - it can also encode directly from said formats)

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@eddv - great descriptions you gave for the various mpeg formats. I love the analogy. Very vivid.

[Cornucopia]

I didn't get the "X-ray machine" part, though.

Scott

[edDV]

I didn't get the "X-ray machine" part, though.

Scott

It was a stretch to show a random access to frame analogy.

[Bonie81]

@edDV
nice one!

[hech54]

I use MPEG-PS exclusively.

[ramosis]

Thanks guys, but now I have another issue.

I tried saving the final product but got the following error msg.........'The first frame is not intra frame............File was not saved'

What does this mean and how do i resolve it?

Also what is the difference between....Save and Save Project?

Much Thanks

[hech54]

Thanks guys, but now I have another issue.

I tried saving the final product but got the following error msg.........'The first frame is not intra frame............File was not saved'

What does this mean and how do i resolve it?

Also what is the difference between....Save and Save Project?

Much Thanks

You cut/edited the video and you didn't cut on a key frame. You can only save a video (without re-encoding) if you only cut on key frames.

[edDV]

Save Project

Saves settings.

[ramosis]

OK, This Key Frame cutting is giving me a headache! How do I know when I'm not cutting on a key frame?

[locotus]

In the bottom of the avidemux gui you'll see a title name frame, at its side a letter appear
when you move the scroll bar, when you find and I you have gotten your key frame.
It's a very, very boring business.

[ramosis]

K I see "Frame Type" I (2 or sometimes 3, 4, 5 or 6) is this what you are referring to? So what would tell me if I'm on a key frame?

[Cornucopia]

For now, ignore the # part in parentheses. If it says Frame Type: I, that's a key frame (aka "Intra"-frame). The other 2 types of frames are delta-frames ("P" = Predicted, "B" = Bi-directional Predicted). The sequence such as IBBPBBPBBPBBPBB...etc makes up a GOP (Group of Pictures).

Without re-encoding, one can only edit on GOP boundaries (aka between the end of one GOP and the beginning of the new GOP). This would be like:

...I_B_B_P_B_B_P_B_B_P_B_B_P_B_B_ X I_B_B_P_B_B_P_B_B_P_B_B_P_B_B_...

This was using a standard MPEG2 NTSC GOP length.

Scott

[Hoser Rob]

It's not that complex re avidemux usage. If you want to seek to a point where you can cut, don't use the single frame step button. Use the one that jumps to the next key frame.

Re encoding to force an I-frame isn't something I'm totally familiar with. There isn't any way to do it that I know of in the tools I use ... stress "that I know of". I'd be happy to hear differently.

I`ve found you can generally force key frames at scene changes by reencoding with the number of consecutive b-frames limited (but > 0!) and setting a closed GOP. That sounds kludgy to me and I'm certainly open to suggestions. As long as they don't involve some other program that requires 3rd party codecs.