Seeing as the DVD format only uses MPEG-2, does it mean that if you want to burn a video to DVD there will always be some compression/loss of quality?
It depends on what format and codec the original footage contains. If the original footage is less compressed than the export then yes.
It depends on what format and codec the original footage contains. If the original footage is less compressed than the export then yes.
Please could you expand on that a bit more?
Hi Jack,
Different camera types can use different formats, so let's say that you are using a camcorder filming in mp4 in High definition, and you want to export to dvd for playing on a normal dvd player, then the footage will have to be exported to standard definition mpeg2 as that is required for dvd playback.
That's keeping it very simple, but in fact there are settings in most cameras for whether you want to record at higher or lower data rates. If for example you are recording in 4K mp4 at 100mbs, then there will be considerable reduction in quality to export to a dvd in standard definition. If on the other hand the camera has a setting for SD recording, then the compression required will be less, but of course you are starting with much lower quality.
In PAL land where I am, 4K/UHD is 3840x2140 pixels, HD is 1920x1080 pixels, and SD is 768x576 pixels, so as you can see, reducing down to SD for dvd is going to involve considerable compression.
Hope that helps,
Roger
In PAL land where I am, 4K/UHD is 3840x2140 pixels, HD is 1920x1080 pixels, and SD is 768x576 pixels, so as you can see, reducing down to SD for dvd is going to involve considerable compression.
I would not use the word "compression".... because I can compress something and decompress it without lossing anything... ala winzip.
In case of DVD there will be reduced in "pixel per inch" or "reduced in clarity" from HD.
Hi
To clarify more there are two different parameters being used here both of which have an effect on the image quality.
Compression - is usually determined by the bitrate measured in kilobits (or megabits) per second.
With low compression ie a higher the rate the better the image quality as more detail is preserved in the video, however the down side is the video file sizes are larger
With high compression ie lower bitrate the image quality is poorer as less detail is preserved in the video, however the upside is that the file sizes are smaller.
Compression settings are always a compromise between maintaining a good quality image while trying to keep the file size down to a reasonable size.
Resolution - this is the image size measured in pixels(colour dots).
UHD is 3840x2160 pixels, Full HD is 1920x1080 pixels, HD is 1280x720 pixels and SD is 768x576 pixels.
Note: the term 4K is misused in describing a video resolution - it does not have a specified vertical resolution - technically, 4K is a horizontal resolution of 4,096 pixels, the vertical resolution depends on the context of use. ie. is it a 16:9 aspect ratio video or 1.9:1 (Cinema 4K).
As an example - if your source video is UHD and you are creating a DVD then your are 'throwing away' all the extra pixels, ie detail, and clarity - the UHD video image uses a total of 8,217,600 pixels, a DVD (PAL) 414,720 or 345,600 pixels (NTSC).
The image quality is going to suffer depending on the final resolution of the video- the worst case is UHD to NTSC DVD where you are effectively using only 4.2% of the original image pixels.
HTH
John EB
To try to clarify what John has said still further it might be helpful to say that increased compression and reduction in resolution are entirely separate. So you could reduce an MPEG4 UHD image to an MPEG2 SD file with decreased, or no change in compression.
Reducing resolution is a pure mathematical calculation removing pixels to re scale the image, whereas compression involves the encoder assessing each frame to decide which areas of the image have pixels similar enough, that the block of pixels can be encoded as being identical without having to save the information (data) about each pixel's differences. This as you can imagine is quite inaccurate/subjective, creating varying degrees of quality loss, especially if the encoder is poorly designed or configured and as the target compression level increases.