When using the MainConcept H.264/AVC encoder in MEP, I am quite confused with the encoding options that are available. There is Constant Bitrate, Variable Bitrate, Constant Quantizer, & Target Quality. What do each of these options mean and which one provides the best video quality output?
There is little to gain if the source file is a variable bit rate to encode at a constant bit rate.
Individual frames seldom contain exactly the same amount of data in each frame, so using a variable bitrate allows the end file to be physically smaller than using a constant bit rate without losing quality beyond the normal encoding degradation. A constant quantizer stops faster scenes (more action) from reducing the bitrate from what it would be doing normally, which is taking information away where your eye doesn't perceive it, but it will increase the file size with little to no gain quality wise. Target quality is the how close to the original it can take the conversion with the added compression from transcoding.
There is no gain in quality to be had in my opinion from using H.264 over MP4. You just get smaller file sizes.
In fact, from a quality point of view, I prefer MP4.
There is little to gain if the source file is a variable bit rate to encode at a constant bit rate.
Individual frames seldom contain exactly the same amount of data in each frame, so using a variable bitrate allows the end file to be physically smaller than using a constant bit rate without losing quality beyond the normal encoding degradation. A constant quantizer stops faster scenes (more action) from reducing the bitrate from what it would be doing normally, which is taking information away where your eye doesn't perceive it, but it will increase the file size with little to no gain quality wise. Target quality is the how close to the original it can take the conversion with the added compression from transcoding.
There is no gain in quality to be had in my opinion from using H.264 over MP4. You just get smaller file sizes.
In fact, from a quality point of view, I prefer MP4.
Hi, thanks for your help.
The thing with Target Quality though is that when I select it, I have no idea what to type in it. By default it usually has something like 24-25-27 but I have no idea what that means or how it affects the video quality.
Also, isn’t MP4 just a container?
Sorry, I meant to type MPEG4.
On Target quality, that would be tough to suggest as too low and it may not work at all leaving a blank video and too high will not render any improvements while only increasing file size.
Welcome to the frustrating world of working with video editing.
Hi
. . . . I have no idea what to type in it. . . . .
If you want to learn more of what they do there are plenty of resources on the Internet, however, as you have been advised many times before - do no touch these settings, it is very easy to make the video quality worse if you deviate from the default export settings - they are already optimised and should not need changing.
HTH
John EB
I will second that after much fruitless fettling.
Sometimes in some settings where you get an 'auto' option, you can improve things by selecting 'Best' or 'better' instead, but that's about it. Messing around with bit rates often ends with less than optimum quality output. There are definite relationships between minimum and maximum bit rates that you can't narrow or extend without crashing the encoding process or ending up with blank or stuttering video. Similarly messing with GOP structures is equally unadvisable at all in my limited experience.
I think the problem is that older formats are always going to look bad on new equipment. It's the reason to film in 4k or 6k now before 8k becomes mainstream. And it will. Progress will always be continuous with shorter and more rapid time frames between formats. Where possible older formats with less resolution possibly need enhancing before they are re-encoded go be preserved on new formats, but that would need specialist programming. There are fractal programs for enhancing stills but I'm not aware of anything for old video footage that possibly came originally from 16mm film stock anyway. Look at the problems the BBC had with converting old Dr Who programs. They are barely watchable even with the resources they have. My old VHS tapes played back on an old TV look dreadful even without editing.
The other problem is the more you edit and convert video, the more your eyes will pick up on the imperfections between the two outputs that most people would not see. That's why I prefer the cinema to watching a film on a large screen TV. Once we train our brains to see something one way there is little going back without seeing the imperfections that were always there but not noticable until something better came along. I'm already fed up with 1080p.
Sorry, I meant to type MPEG4.
On Target quality, that would be tough to suggest as too low and it may not work at all leaving a blank video and too high will not render any improvements while only increasing file size.
Welcome to the frustrating world of working with video editing.
Which part of MPEG-4 are you referring to?
Hi
. . . . MPEG-4 . . . .
MPEG-4 has many 'parts' ie specification levels see this article on Wikipedia.
It not advisable to touch these settings as you may render your exports unplayable on some devices, leave the level settings as is or set them to auto.
HTH
John EB
There is little to gain if the source file is a variable bit rate to encode at a constant bit rate.
Individual frames seldom contain exactly the same amount of data in each frame, so using a variable bitrate allows the end file to be physically smaller than using a constant bit rate without losing quality beyond the normal encoding degradation. A constant quantizer stops faster scenes (more action) from reducing the bitrate from what it would be doing normally, which is taking information away where your eye doesn't perceive it, but it will increase the file size with little to no gain quality wise. Target quality is the how close to the original it can take the conversion with the added compression from transcoding.
There is no gain in quality to be had in my opinion from using H.264 over MP4. You just get smaller file sizes.
In fact, from a quality point of view, I prefer MP4.
So isn’t Constant Quantizer effectively the same as Constant Bitrate??
Hi
. . . . .Constant Quantizer effectively the same as Constant Bitrate . . . .
No, they are 2 independant settings.
See this article on what Quantization does.
In a nutshell if you use Constant Quantizer settings you are stopping the encoder determining the best settings depending on the degree of fine detail in the video.
As has been advised do not touch these settings - there is nothing to be gained.
John EB
There is little to gain if the source file is a variable bit rate to encode at a constant bit rate.
Individual frames seldom contain exactly the same amount of data in each frame, so using a variable bitrate allows the end file to be physically smaller than using a constant bit rate without losing quality beyond the normal encoding degradation. A constant quantizer stops faster scenes (more action) from reducing the bitrate from what it would be doing normally, which is taking information away where your eye doesn't perceive it, but it will increase the file size with little to no gain quality wise. Target quality is the how close to the original it can take the conversion with the added compression from transcoding.
There is no gain in quality to be had in my opinion from using H.264 over MP4. You just get smaller file sizes.
In fact, from a quality point of view, I prefer MP4.
So is “Target Quality” the equivalent of “Constant Quality” then?
No. They have two different jobs as described so can't be equivalent to each other.
You have to realise that playing around with these settings is like taking a photo manually. There are lots of options with hundreds of permutations that won't work well together and possibly only one that will give the desired result.
I personally don't think it will matter if you chose a different software or went through all the various permutations available, you would probably end up very close to one of the presets.