Converting between audio and video formats.

[JEW UNIT NY]

Hey everybody! I have a question about converting video and audio formats. How does it work? 

 

Lets say the source is 480p using an MP4 container and want to "convert" it into a 720p/1080p using a mkv/avi file. How does that work and why does the file size increase? Will it increase the quality of the video?

 

Sorry if this is in the wrong forum ...There should be a Techquickie about it.  

[Enderman]

it takes the 480p video image by image and stretches it to fit 720p

this makes the file larger because its more pixels, but the quality worse because 480p doesnt properly scale to 720p which means a lot of the pixels will be rounded and averaged colour values, making the image blurry

even if you upscaled it to 960p (2 times 480) you would end up with the exact same quality because its just stretching the image to fit a size 2x larger

 

upscaling does not add in pixels, it just stretches the image

[JEW UNIT NY]

How about changing containers with the same resolution? 

[WobblyMusicStand]

How about changing containers with the same resolution? 

 

Changing containers might change the file size depending on the compression algorithms that the two different codecs use. But it won't make the video look any better because it cannot recreate information that has already been removed/doesn't exist. The best that could happen is you end up with a video of the same quality. The worst is that the process of transitioning will degrade the quality.

 

You also have to watch that both of the formats are being encoded at the same bitrate. If you convert if to a different container and don't maintain the source bitrate you will be guaranteed a lower quality render.

[JEW UNIT NY]

Thanx...I might not go into that territory then ...Thanx guys

[-TesseracT-]

Changing containers might change the file size depending on the compression algorithms that the two different codecs use. But it won't make the video look any better because it cannot recreate information that has already been removed/doesn't exist. The best that could happen is you end up with a video of the same quality. The worst is that the process of transitioning will degrade the quality.

You also have to watch that both of the formats are being encoded at the same bitrate. If you convert if to a different container and don't maintain the source bitrate you will be guaranteed a lower quality render.

There are programs that can extract audio and video tracks from the container so that you can put them in a new one without loosing quality.

[.spider.]

How about changing containers with the same resolution?

Changes nothing except that the file is a few kbyte smaller or bigger due to overhead caused by the container.

Also you could get problems if the codec isn't supported by the container you should make sure that the container properly supports the codec.