Editing when mpg is your only source, while avoiding rerendering

[Jon.G]

I have one nearly 4 hour video clip of a fireplace loop. The program is supposed to start with a fade in from black, wide angle shot, which then zooms into the fireplace. It then loops about 5-6 minutes of the log burning, cross fading to keep the loop going, which you can notice the fade of the log going to a previously burnt phase. Every 15 minutes, the camera pans out to the wide angle shot, crossfades back to the start and zooms back in to the log. At the 90 minute and 3 hour mark, it breaks for a station ID. The audio consists of Christmas music, but the brief station IDs has it's own sound.....it is this that is causing the precision to be important, I need the station ID animation to match the audio.

The 4 hour recording off of TV missed the beginning and end. I was able to obtain the music that would have gone with this, and make a full soundtrack. So, since this is a loop, I can patch the beginning and end by going to the point after the first station ID, because that also contains the starting point of this loop, fade in from black to the wide angle shot that then zooms in to the 5/6 minute loop. I then need to make a new ending by using a part of before the first station ID, because that zooms out and fades to black before the station ID as well.

But, to keep the station IDs lining up right, I need my new beginning and ending clips to be timed right, or within a few frames. So, that's why I've been using vegas, to make my cut, shift drag, and then figure out how much I need for each new beginning and end, and have it be the right time. I was hoping to use vegas only to determine where the cuts need to be made, and then mpg2cut2 to figure out what frames I can cut on, and have it still time out right. I could re-encode with vegas, but I don't want to re-encode, which is why I'm trying to create 3 clips out of the same clip, and then join them. I really don't want to do any re-encoding at all. I should be able to use mpg2cut2 to edit the original clip into new beginnings and endings that time out right, but.....since the time readout in vegas doesn't match the time readout in mpg2cut2, I can't make accurate edits in mpg2cut2.


What is really throwing me off is that my clip is reading time differently in different programs. When I find the frame I want to edit at in vegas, and go to that same frame in mpg2cut2, and the time is different. The first black frame after the station id according to vegas is 01:28:40 frame 6, in mpg2cut2 01:28:41 frame 19, over a second difference! I don't know what is causing this. I seem to always run into issues with my odd specific things I set out to do in video, that always seem to find inconsistencies in different programs, which suggests buginess in the software to me, I'm not looking to attack these things, but it is extremely frustrating when the tools I go to use consistently don't seem to work right.

What would cause these timing issues? Is there better software I can use? I know that a tmpenc rendering program was recommended, but I want to try using free software or software I already own, and I still want to try and do this without any rerendering, which should be possible if my frames land close enough to where they need to be.

[poisondeathray]

wow sounds exciting a fireplace loop! j/k

vegas can actually smart render mpeg2 , if you have it set up perfectly (but it can be "finicky") . The project settings and render settings have to match exactly the specs of the input clip . ("smart rendering" means no re-encoding, only a few frames around the cutsite within the affected GOP are re-encoded . You will know it's working when it renders pass through sections extremely fast and a screen will say "smart rendering: no recompression required" or something like that)

Sometimes error handling is the cause for the discrepancies. Different programs handle junk frames slightly differently. Some may treat them as "black" frames, some might drop them entirely . That might cause the timing discrepancies

Videoredo is a good stable smart rendering program if you're looking for alternative MPEG2 editor

One potential problem with MPG2CUT2 , is it's not frame accurate . It can only cut on GOP boundaries

[Jon.G]

Ok, I'm not sure how to smart render with vegas.

[poisondeathray]

Sometimes it's difficult to get smart rendering working in vegas. You have to go in the advanced render settings and use the same settings as the input clip. Everything has to match (b frames, GOP size, dc precision, ... I mean every little fricken detail. One thing "off" will often cause it to re-encode). Tools like gspot and mediainfo can be helpful here for the input clip

[poisondeathray]

Also, make sure options=>preferences=>general tab => "enable no-recompress long-GOP rendering" should be checkmarked

Videoredo is much less finicky. It works with all MPEG2 streams, all the time . No fiddling, no mess

[Jon.G]

Not sure how I'm supposed to match the settings. Especially since I've got 3 different bit rates supposedly at the same time.

Could I get more of a detailed how to here?

I've tried to post the mediainfo and gspot screen captures, but the forum keeps failing to let me post that.

Mediainfo says it's 2 105 Kbps, gspot says it's 2468 kb/s, but then it also says its 3362 kbps.


Ugh....is there no standards or consistencies in video software? I really don't understand how anyone can get anything done in video editing with all these inconsistencies I continue to find everywhere I turn.....audio editing has none of these inconsistencies. What is going on here?

[poisondeathray]

Not sure how I'm supposed to match the settings. Especially since I've got 3 different bit rates supposedly at the same time.

Mediainfo says it's 2 105 Kbps, gspot says it's 2468 kb/s, but then it also says its 3362 kbps.

The bitrates don't matter as much as the other settings. They just have to be in the same rough ballpark

But mediainfo is referring to different things, such as maxmium bitrate and average bitrate. It's not necessarily accurate anyway - it just scans the header, doesn't parse the file. gspot actually parses the file, so is more accurate for bitrate determination

Could I get more of a detailed how to here?

You have to try matching the settings . Sometimes it's very frustrating. Sometimes it doesn't work . Videoredo will solve all your problems and frustrations. It's one of "must haves" in my opinion if you work with MPEG2 in any large amounts

Ugh....is there no standards or consistencies in video software? I really don't understand how anyone can get anything done in video editing with all these inconsistencies I continue to find everywhere I turn.....audio editing has none of these inconsistencies. What is going on here?

Of course there are standards and consistencies. You're dealing with a crappy source most likely. Probably has errors in it as well. Definitely not a professional acquisition source.

[Jon.G]

I don't see how videoredo is going to help me. I installed the trial version, and it won't even open my mpg, not a good start. And, this looks like another one of those basic editing tools that just works on one file to cut parts out.....I need to have 3 copies of the same file, and trim them, and join them together in one big file like detailed above, which is why I've been laying this out in vegas.

I either need a better solution, or a detailed guide on getting vegas to smart encode.

[Jon.G]

Here's some more info

[poisondeathray]

I don't see how videoredo is going to help me. I installed the trial version, and it won't even open my mpg, not a good start. And, this looks like another one of those basic editing tools that just works on one file to cut parts out.....I need to have 3 copies of the same file, and trim them, and join them together in one big file like detailed above, which is why I've been laying this out in vegas.

You can join clips by adding them to the joiner list . But it's not going to help you if you can't even open a video... I was going to say use the "quickstream fix" in videoredo which often fixes various stream errors and problems, but you can even open it LOL

mediainfo view=>text shows more info, but you have a custom matrix ; I can tell you right now that usually prevents vegas from smart rendering

Other smart rendering software include tmpgenc smart renderer, solveigmm video splitter

There is a free smart rendering one for MPEG2 , but it only works on elementary streams and not very user friendly (cuttermaran)

[Jon.G]

It seems to not like the fact that the version of the mpg I'm trying to work on is silent. Apparently the fine folks at videoredo aren't familiar with the concept of an mpg video that has no audio.

So, I went back to my version with the audio, figuring I can strip the audio off later. It wanted me to run the quickstream fix, I ran that, opened the fixed file, the program froze when I tried to work on it.

So, I forced it closed, reopened it, opened the fixed file again, it ran into trouble again and suggested another quickstream fix.


Is there a tool that will actually fix whatever it is that is causing all my timing issues and crashes? The video plays fine. The video lets me rerender it fine. But, simple editing and joining and viewing of frames with a consistent time reference seems to be damn near impossible.

[poisondeathray]

It seems to not like the fact that the version of the mpg I'm trying to work on is silent. Apparently the fine folks at videoredo aren't familiar with the concept of an mpg video that has no audio.

So, I went back to my version with the audio, figuring I can strip the audio off later. It wanted me to run the quickstream fix, I ran that, opened the fixed file, the program froze when I tried to work on it.

So, I forced it closed, reopened it, opened the fixed file again, it ran into trouble again and suggested another quickstream fix.


Is there a tool that will actually fix whatever it is that is causing all my timing issues and crashes? The video plays fine. The video lets me rerender it fine. But, simple editing and joining and viewing of frames with a consistent time reference seems to be damn near impossible.

If videoredo can't fix it, probably nothing will. There is a chance projectx might be able to fix them

"Playing fine" in a software media player doesn't necessarily indicate anything - because video players have error correction and speedup tricks that "skip" over damaged parts.

Editing video , on the other hand , requires a higher level of frame accuracy and intact timestamps. I already mentioned differences in how some software handle damaged segments - some skip or drop frames, others keep corrupted frames, others render them as black. Others may even crash

Professional video sources don't have these problems. Even most 1st gen consumer sources don't have these problems. You're dealing with a crappy low bitrate recorded stream that probably has transmission errors. Don't blame the software for that one.

[Jon.G]

AAARRRRGGGGHHHHH......

I give up!

I almost had it, but my station IDs won't line up.

If I even just open the original file, select it all, and do a save as.....it messes with it. The original and saved files from videoredo won't line up, which means it's messing with my audio, and I will not have something messing with my audio! If I am able to have a consistent audio stream, that suggests to me a component that has consistent timing, the software should deal with errors in a way that keeps true to the timing instead of dropping bad data. I suppose the source is the problem, but the software isn't dealing with it as I would expect it logically should.

The Yule Log broadcasts Christmas morning on antenna TV, I'll capture a new source then.