Why does Video File enlarge so much after Editing

[FL-Artist]

I shot approx. a 3GB HD 1080 x 1290 video file recently, but when I edited it in my VSDC Editor, it grew to 8.5 GB. I exported it in the same MP4 format, and all I really did in editing, was lighten the whole video as it was a bit too dark. Is it possible this was responsible for the change in size? I try to keep my files as close to the original quality as I can, but this is the largest change I have seen in any of my files!

[jagabo]

MP4 is a container -- a logical box that holds video and audio. It's the codecs and properties of the video that determine the quality and size, not the container (though some containers do have more overhead than others). Different codecs have different abilities to compress. But for all codecs:

stream size = bitrate * running time

Or more literally, bitrate is defined as:

bitrate  = stream size / running time

The final file size is the sum of the size of the audio and video (and any other) streams plus a little overhead for the container.

If you want a smaller file use a lower bitrate. If you use two low a bitrate for a particular codec, or bad settings, the quality will not be good.

[FL-Artist]

Thanks for your Help! ..I am very new to Video Editing! ..Is there a way to determine how much to lower the bitrate in settings, without losing to much quality? And also is there a recommended file format I should be exporting to? I do a lot of posting of my HD 1080 x 1290 footage, mostly to social media sites.

[Bernix]

Hi,
firstly I thought that 1080x1290 was mistake, but you write it second time too. Is it some proprietary resolution or you simply exchange 1920 with 1290? I think you write it wrong and if so, first number should be Width x Height so usually writen 1920x1080. 1290 seems to me be bad format not 1290/8 nor 1290/4 do not result whole number.


Also you can post mediainfo text report of your source file and your exported file. Best is text form output. It will get bit better insight what codecs are used and what bitrates and other settings.



Bernix

[FL-Artist]

Yes I'm sorry ...I was copying it from a miswritten page it's W.1920 x H.1080

[Bernix]

Not sure, if you have read what I edited in my previous post. Download Mediainfo, and post here information from your source and exported file.
To your question. Most effective (quality with less bitrate) is x265 codec. Not sure if social media will accept this codec. But for sure will accept x264 videocodec with aac audio. Most people here are using constant rate factor CRF encoding. Lower number bigger filesize but better quality. And quality is subjective. Since you uploading it for social media, others can have different perception of quality. EDIT but social media i believe reencode this video after you uploaded it anyway. So try encode with CRF 18 preset medium. If not satisfied set lower number, if file is too big set higher number. You have to try personaly because for someone is 18 not enough for someone is 22 very good. The size in this type of encoding is unpredictable, depending on video content (fast motion for example etc.)


Bernix

[FL-Artist]

Yes Thanks, I didn't understand what Mediainfo was! I will download and try to work with it!

[jagabo]

Is there a way to determine how much to lower the bitrate in settings, without losing to much quality?

Not really. Some encoders have a constant quality setting. Instead of specifying the bitrate you specify the quality. The encoder then uses whatever bitrate is necessary to deliver that quality. The quality is pretty consistent across all different types of content so once you find a quality level you're happy with you can encode all your videos at that setting.

And also is there a recommended file format I should be exporting to? I do a lot of posting of my HD 1080 x 1290 footage, mostly to social media sites.

h.264 video and aac audio on MP4 is fine for that.

[FL-Artist]

Thanks for the Help! ..There is a lot more to exporting video than I had realized! Also I forgot to mention in my original question, I use a zoom H1N recorder, MP3 to capture my Audio, and then delete the audio on the video file, could this exchange greatly affect the outcome of the file size?

[jagabo]

You can use a tool like MediaInfo to see the size of the audio and video streams within the MP4 (or whatever) file. Typically, audio is far smaller than video. For example, with DVD the audio is usually on 5 percent of the file size (maybe 6000 kbps for the video, 250 kbps for the audio).