Timing Anomalies

[TheLaughingBuddha]

I am probably being really dumb here (again) but I cant get my head around this.
Between Magic and Vegas (which I use for post processing) I cant seem to get the length of my rendered scenes right.
If I render an 8 second scene in Magic and then drag that scene into Vegas it seems to be at a different length...only very slightly, but it throws off the whole project timeline.
I'm not sure if its Vegas or Magic or the fact I am not setting up the frame rate or something correctly between the 2...but I have to time stretch each rendered clip (by only a very small amount) to make it sync up in Vegas.
Again...sorry if I am missing something basic here...I am new to video work...also maybe, I should be posting this in the Vegas forums.
Regards.

[blackdot]

my first guess would indeed be different framerates. if you render something in magic at 30fps and then import that into a 24fps (for example) vegas project, it will have a different lenght.

[dj0le]

My guess is the issue is on the Vegas side. But to test it, you need to find the exact number of frames in your Magic mp4 output. Assuming you rendered at 60 fps, then that number should be 480.

I would use ffmpeg to probe the video for that information. Either of these 2 commands will work:

$ ffmpeg -i filename.mp4

This will return all the info about your mp4. near the bottom, for the video stream, it should show the exact time-length. It should be (00:00:08.00). This times 60 = 480. If it's anything else (for example - 00:00:08.23), then you have found your problem. This times 60 = 503 frames which will still show as 8 seconds but is just slightly longer.


$ ffprobe -v error -count_frames -select_streams v:0 -show_entries stream=nb_read_frames -of default=nokey=1:noprint_wrappers=1 filename.mp4

This will return the exact number of frames, which is hopefully 480. If so, your Magic mp4 is good.


If you don't use FFMPEG, I imagine Vegas has some sort of media utility that will give you the details as well. Either way, once you confirm the video you will know which side is the issue. If its 480 frames, Magic is fine and Vegas is the problem. If its any other number of frames, then it has to do with your Magic rendering.

[blackdot]

framerate and total amount of frames/duration should already be known, as one has to enter these values when exporting in magic.

also if ffmpeg seems too complicated you can also open your file in vlc then go to tools>media/codec-info.

[TheLaughingBuddha]

Yeah I tried doing by frames instead of seconds...so I will render like a set amount of frames and import those into Vegas after having set Vegas to the same Framerate....I use for audio codecs the K-lite standard codec pack...but I really have no clue what I'm doing here and all I know is whatever I render the Magic scenes as it all F's up in Vegas....50 frames a sec in Magic seems to work better than the standard 60.
The videos before working on them in Vegas seem to be fine though...I was just wondering if it was something silly that I am not doing.
Regards

[blackdot]

i dont know vegas, but in theory it should work like thi (example values) : export mmv scene as a 10s clip, 30fps, 1280x720, export as movie clip or better as image sequence. then open new vegas project, define it as 30fps and 1280x720. add your music into the audio layer, import your movie/imgsequence into the video layer. it should play as it's supposed to, it should be 10s. do your post processing, export and encode final thing to your liking.

the advantage of using an image sequence and adding the audio seperatly is, that you wont encode your stuff twice.

[Magic]

the advantage of using an image sequence and adding the audio seperatly is, that you wont encode your stuff twice.

Yup that's important, and another advantage is that each frame is its own file, so you don't run into any file size limits. For example, on Windows 7, the maximum file size is 4 GB, which is not a long video if the frames are uncompressed.

Just make sure that when you import an image sequence into Vegas, you manually specify the framerate that you set in Magic, because otherwise Vegas won't know. Frame rate is saved in video files but not in image sequences.

[Terry Payman]

A very small timing error suggests the issue is related to "drop frame". Professional TV broadcast kit often will work at a frame rate very slightly different from what you would expect, so a program like Vegas will certainly accommodate this, and perhaps even defaults to eg 59.94fps instead of 60fps without indication.

http://www.tvtechnology.com/media-syste ... fps/241737

Sorry I can't research in further detail at the moment.

[TheLaughingBuddha]

Thanks very much for the replies guys...I'm going to try the image sequencing tonight as I have not tried that option yet.
Regards