Hi, I知 a novice video editor. I have an hour worth of MPEG-2, 720x480 video clips that total 3.87GB.
I知 using Sony Movie Studio 13 to add some chapter markers and a menu to put on a DVD.
When I render/export, however, the resulting video and audio files drop to 2.6GB. I知 selecting the highest possible quality settings. There's no significant video quality loss to my untrained eye, but I would still like to preserve as much of the original data as possible.
These clips are already DVD compliant, so I thought the output should be the same size as the original. Is this file size reduction normal for Movie Studio, or am I doing something wrong? Is it possible to maintain the file size or avoid the re-encode altogether? Thanks for any advice.
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filesize = average bitrate * running time
But that includes audio & video (it also includes overhead, accessory streams, but they are usually small in comparison)
This means the bitrate of your original was larger than the version you encoded.
You can use mediainfo, gspot , or bitrate viewer to check bitrates
In the encoding settings , you can increase the average bitrate and bump up the minimum bitrate, also check the differences in audio
If the sources are to DVD spec already, and you're only adding chapter markers and menus, you shouldn't be re-encoding at all.
You might have to re-encode at least some sections when chapters points don't coincide with I frames . I've had to do this before
I don't think the studio version does mpeg2 smart rendering like the pro version
Vegas Pro 12 and Movie Studio Platinum 13 both have the following paragraph in online Help re smart rendering.
In order to perform smart rendering, the width, height, frame rate, field order, profile, level, and bit rate of the source media, project settings, and rendering template must match. Frames that have effects, compositing, or transitions applied will be rendered.
The formats are the same, but some are only in Pro of course.
Last edited by vkmast; 21st Mar 2014 at 10:17.
You do not have to make chapter markers in Vegas, do it in DVD authoring software. Perhaps you have I frame every 15 frames or so in video - every half a second, so you place chapter and DVD authoring should correct its position to nearby I-frame. This way you do not need re-encode video again.
Thanks for the responses. I discovered that Movie Studio's default bitrate is significantly lower than the source file's bitrate. Is it possible to automatically set Movie Studio to preserve the original bitrate without adjusting it manually every time?
Since all I'm really doing is authoring, I'm wondering if it would be better to put the MPEG-2 clips directly into DVD Architect and add chapter markers and menu. Will this avoid the rendering process completely? I don't really understand what smart rendering is. Is it possible to add subtitles to video in DVD Architect?
Last edited by smrpix; 22nd Mar 2014 at 11:31.
In your first screenshot, you have a box marked "Adjust source media to better match project or render settings" ticked. I may be wrong but I suspect that this is causing your already DVD compliant files to be re-rendered at a lower bitrate. Untick that box and see what happens then.
to try to smart render in Vegas (does not always work) I checked bitrate in Mediainfo and selected that in Vegas template, it cannot be smaller, but anyway, as I said , not always it worked
Movie Studio, but Movies Studio insists on rendering the MPEG-2 files. That's why I tried adding subtitles and chapter markers in DVD Architect. But DVD Architect doesn't have a text track for video compilations(only audio and video), so I haven't been able to find a way to set a duration for text in DVD Architect. I can add text, but it stays there for the entire clip.
These are DVD-compliant MPEG-2 clips, so I was really hoping Movie Studio would be able to smart render. I tried unchecking the box as Richard_G suggested, but still no change. I even tried adding and exporting the completely untouched MPEG-2 clips just to see if it would smart render, but it still insists on rendering. Has anyone had success with smart rendering?
In order to "convince" vegas to smart render mpeg2 (at least for the pro version), every little detail has match the source file. This means both the project settings and export settings. vkmast in post #5 listed some of the parameters that must match
You can use gspot and mediainfo to identify some of the characteristics of the source file
Last edited by poisondeathray; 23rd Mar 2014 at 12:58.
You can always upload 5 sec sample for others to try, any sample, you can shoot your floor, whatever.
In the past I tried some camcorder mpeg2 samples and I was successful couple of times but in some cases I was not.
Using HV30 camcorder for example, I shoot 30p and I have to run those videos through ReStream to make it real progressive so Vegas would smart render it as progressive as well, so that helped a bit, so as I said post sample and somebody might have an idea, you never know ...
It smart renders in the pro version. You will know it's working when the preview goes black and it says "no recompression required"
The settings changed from the DVD Architect NTSC preset:
1) field order: upper field first
2) maxmimum bps 9,100,000
3) average bps 8,900,00
2nd tab advanced settings:
1) use closed GOPS, none short
2) DC coefficient 8
3) VBV buffesize 112
Sony Vegas 8.0c Pro I could not make it render smart, even with pdr's advice .
Sony Vegas 10.0 Pro , it rendered smart, but not using 2pass VBR, but using:
-DVD Architect NTSC video preset as well
-upper field first
it rendered smart (except couple of frames at the beginning) , I did not had to change anything in advanced tab
Here, VPro 10 worked with _Al_'s settings, VPro 12 as well with pdr's settings. Vegas Movie Studio Platinum 11 did the job with the pdr ones. MSP 12 showed some flashes of "no compression required" but did not really work. I could not find settings in MSP 13 (32 or 64-bit) to smart render here.
Thanks for all the input. Smart rendering worked.
The only problem now is that it seems to be ignoring my settings for VBR and reducing the bit rate. It re-encodes if I raise the bit rate to anything significantly above the original. Constant bit rate works fine, but that makes the file size too large.
It might not be very evident from that one 5-second clip, but when I put multiple clips together there's a pretty noticeable drop in file size. Did anyone else notice this when smart rendering that clip?
Is this necessarily a bad thing, or is this the idea of smart rendering?
Did you factor in audio & video + container overhead in your size calculation? or video only ?
You can also try bumping up the minimum bitrate (don't touch the maximum or average, or it will re-encode)
Please forgive my ignorance, but what is container overhead? The output file (with audio) is 3.55GB, compared with 3.87GB for the original. I was using max bitrate of 9,100,000 and Avg bitrate of 8,900,000. Adjusting the minimum bit rate doesn't seem to have much effect.
I'm not sure why it's changing the file size, since smart rendering doesn't involve re-encoding.
Constant bit rate makes the file bigger, but it will still fit on a DVD. So I guess I'll use that for now, but I'd still like to be able to use VBR to achieve a certain file size. Thanks.
Container overhead is the for the program stream (mpg) . Different containers can have significant overhead. Transport streams can be 5-10% of the size
An elementary video stream (.m2v) is video only, no container. That's what you should be comparing. You can demux the original to compare the video stream ONLY (no audio, no container, no subs, video ONLY)
Those bitrate settings only affect if certain frames are re-encoded. For example if you put in markers, or other edits. So "using VBR to achieve a certain filesize" doesn't really make any sense unless you are re-encoding the entire thing or the vast majority
Some versions of vegas might need to re-encode the first few frames of some clips depending on how those clips have their GOP arranged . Look at some of the comments above .
2pass VBR will come closer to those VBR bitrate settings (on those sections that are re-encoded), compared to 1pass VBR. CBR will pad the data, even if it's not necessary - it's a waste of bitrate usually although CBR may be preferrable in some scenarios
Last edited by poisondeathray; 27th Mar 2014 at 17:02.