Rendered video much greater in size than individual components

syedkaleelawn-m wrote on 1/26/2018, 4:57 PM

I am using Vegas Movie Studio Platinum edition on a Windows 10 PC running on AMD Phenom II X4 processor, GTS 450 GPU and 4 GB RAM.

I have a screen recorded video of 3 mins duration mp4 format, 1366x768 resolution, 60fps, without any audio. The file size is just 4 MB.

I have a separate speech audio file that is of mp3 format 2 min duration 48kbps bit rate and 0.5 MB file size.

I have another music audio that is of mp3 format, 2 min duration and 1 MB size.

I added one line watermark text.

I merged all of these into a single video file by rendering as mp4 Internet 1280x720 format 30fps. The output file size is 32 MB. I was wondering how the file size could be more than 5x the size of all individual components put together. Is this normal or am I doing something wrong?

Also the final rendered video is not as sharp as the original one. Is it because of the small change in resolution and fps?

Comments

Former user wrote on 1/26/2018, 5:13 PM

Two things affect file size, length of program and bitrate. You probably used a much larger bitrate to render than the original source.

syedkaleelawn-m wrote on 1/26/2018, 6:01 PM

Two things affect file size, length of program and bitrate. You probably used a much larger bitrate to render than the original source.

Thanks David. You are right. I am using a very high bit rate of 16,000,000 bps where as the source file is only ~850 kbps.

syedkaleelawn-m wrote on 1/26/2018, 6:06 PM

Try this:

1, Set your projectsettings to match your source.
2. Do your edits and
3. Render as... with this customized template where you have to enter the bitrate that matches your sourcefile.

Thanks Cornico for the detailed steps. I did all of those to adjust bit rate same as my source file. The file size is much smaller now. But, the video quality has gone down drastically. I could hardly see anything! When I check the properties of source file and output file, they have exactly same resolution with bps in same ballpark around 800kbps. But why is the output video quality very poor? Is there any other parameter that affects video quality? The fps of output is at 30 fps though the source is at 60 fps and the template I customized for rendering is set to 60 fps.

syedkaleelawn-m wrote on 1/26/2018, 6:37 PM

I think your sourcefile has a very low bitrate itself.
Where and how do you compare between the sourcefile and the rendered output?
Can you publish here the MediaInfo and Vegas Properties as requested HERE.
Also helpfull for us is a small part of your sourcefile uploaded to a cloudservice so we can look at it and maybe do some testing.

 

I was using the default windows file properties (details tab) to compare the files.

Below is the link to my source file.
https://drive.google.com/open?id=1OB1kmqCVMFZBtPPfBpu551uYyYaG_uvp

If you could help me in figuring out how can I render this source file with same properties and file size, without any loss in quality, it would be most helpful.

Musicvid wrote on 1/26/2018, 9:14 PM

If you could help me in figuring out how can I render this source file with same properties and file size, without any loss in quality, it would be most helpful.

Since your source file cannot be smart rendered in Vegas, this is done in Windows, not Vegas.

Ctrl+C, Ctrl+V

Former user wrote on 1/26/2018, 9:32 PM

Bitrate is part of what determines quality. If you start with a source file at a low bitrate, it can never be any better, and is usually worse. MP4 is called a "lossy" format, meaning in order to make smaller size files, they discard video data. If you keep bitrates high, from the first source, you can retain "perceived visual quality" in some cases, but once quality is lost, it cannot be returned. And if you continue to render to other "lossy" formats, it will keep getting worse. The point being, if your video quality is not that great, rendering to the same properties, etc will make it worse. It is just the way compression for video works.

Musicvid wrote on 1/27/2018, 4:55 AM

My grandfather would say, "You can't make a silk purse from a sow's ear."

3POINT wrote on 1/27/2018, 6:15 AM

First, when you reduce framerates from 60 fps to 30 fps, disable resample.

Second use good old WindowsMedia codec to render your project with following settings:

Which gives following wmv.file with good quality and almost same file size as original. Maybe you can also further reduce the audio bitrate to make file even smaller.

.