H264 Compression Issue

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H264 Compression Issue

Postby Alpha » Sun Jun 24, 2018 2:15 am

I am very new to the media stuffs. For the Bandicam H264 CPU setting, What is the major different between "faster encode, balanced performance, smaller size" ?

I googled a bit, it sounds like it affects the speed when we play the file and the smaller size will take longer to digest the encode so the file size can be smaller. I tried them all, I can't really notice the speed difference when I play them. Is it only occurs on slower computer or mobile?

Source Video is - Didnt show - / 1.2 GB
Faster Encode. 9730 kbs / 3.9 GB
Balanced Performance. 6701 kbs / 2.7 GB
Smaller Size: 6018 kbs / 2.45 GB

The quality drops a bit in Balanced Performance & Smaller Size.

It is frustrating when I use 2 times of file size and the quality still drops by a lot compare to the source. Faster Encode looks similar to the source but it takes 4 GB tho. The problem really kicks in when 1 of my source is 3.7 GB wmv and the output file is 10 GB H264 mp4. This makes me wonder if I am using the wrong setting..

It looks like Balanced Performance not just dropped the encode speed, it also drops the quality?
Some people mentions "slower" is better than "ultra fast" for x264 although Badicam recommends ultra fast in the doc. I thought the logic is slower the better. I tried "slower" in x264 and it looks worse than ultra fast tho. I assume H264 is the same and I am quite confused right now :?

Also, many people say that x264 is obviously better than H264 while some people say they are basically the same thing except x264 is open source. In Bandicam help document, both H264 and x264 are listed as "Better". I tried them both but H264 is obviously better in quality output. I tried all other encode like Xvid, H264 CPU gives the better solution still but I am not quite sure about those speed options. x264 gives us a config interface to set, how about H264? Is there some other place for us to tune it left and right?

Any suggestion on how should I record it? I need to record quite a lot of videos, I don't want to have a wrong start. Thanks!
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Re: H264 Compression Issue

Postby FoxTwo » Sun Jun 24, 2018 8:07 am

I will be just speaking in general terms in this reply, so bear that in mind.

Usually "faster encode" will encode fast and sacrifice efficiency, hence making the file size bigger and quality not-as-good-as-it-could-be.

"Balanced" tries to do exactly that - have a tradeoff between encoding speed, quality and filesize.

"Smaller filesize" generally tends to mean that the encoder will take a longer time (slower encode) in an attempt to be efficient and increase quality, generally resulting in a smaller filesize.

All these are just general terms. Some codecs show no visual difference at some settings, some codecs will show a world of difference. You need to experiment yourself with the chosen codec to better understand what settings you should use.
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Re: H264 Compression Issue

Postby GameTipsAndMore Blog » Sat Jul 21, 2018 6:16 am

If I may pop in, FoxTwo is correct, the general/overall workings of video compression is that 'slower' is better quality, where it takes more time to analyze the video and changes between the frames (you stated that concept too, I see).

The complexity arises from the various settings and the configurations they can have.

For example, in AVC (h264/x264 MPEG-4 Part 10), you can have a Slow preset, but then something can be altered to a lower quality setting, say something that 'ignores little changes' between frames, so instead of quality being kept, it will 'smooth out' those areas of the video, which seems like an apparent loss of quality to human eyes [I hope I am saying the concept right, I'm getting tired at the moment, but wanted to pop in to help a bit if I could].

For example, one of your movies might have a lot of Film Grain in it (the darker, 'static' or 'fuzz' that appears in films, which makes them appear more 'film-like' (as opposed to TV) and increases apparent quality ('what seems like quality to human eyes, but isn't actually more detail in the source', is how I like to explain that).

If then, there is a setting that ignores the static, tries to eliminate it (to make the file smaller), the film-grain effect will be gone, but the result will look 'mushy' or 'muddled', to use subjective terms, and some people feel it will look worse than the original. This is normal in video compression however, and usually these choices/options in the codecs are there because they were originally designed for television and similar media, where the loss of fine detail doesn't matter as much [to the creators of the content] as does, say, the streaming synchronization/timing (where speed/accuracy is more important, in such things as television/telecasts, over fine detailed quality).

While normally choosing "Slower" or other similar presets, one of the things that can help with fine detail like Film Grain is, configure the preset option of "Grain" in the settings of AVC/264 compression, or select to turn off DCT skipping and P-frame skipping. These types of settings make MPEG-4 'NOT' ignore the little changes between frames, and will help keep fine detail like film grain. Another thing to try, is to lower the Deblocking processing in MPEG-4/AVC. Deblocking will try to hide the analysis areas of the video (where is processed the images and didn't have enough bitrate, so there is a hard-edge of change, which creates the look of little 'blocks' when things move in the video) by blurring these areas, to try hide these 'edges'. The higher deblocking settings will blur these 'edges' more, which results in a softer/blurrier image. Lower Deblocking settings can then improve the apparent quality (where it may 'look better' to human eyes, but is still pretty 'lossy' in mathematical comparison to the original). Setting the preset option "GRAIN" in the settings of AVC/264 encoding, automatically sets the Deblocking levels to "-3" (Minus Three), for example, to try to keep the fine detail of Film Grain.

The last thing I will sum up briefly to try help [for now, sorry I have an illness that makes me tired quickly], is the Bitrate. If you select Slower as a preset, but set the Bitrate much lower than the original (say, a 2500k bitrate, when the original is 8000k [to try make it fit some media, for example]), even though there is extra analysis and processing going on (in the Slower preset, to try to keep fine details), there will be an end result of loss of quality, since the Bitrate is not high enough to keep the fine changes between frames of the video. Compression Artifacting, such as Gibbs Effects ('ringing' or 'static' around edges, such as text) and Macroblocking (those little 'squares' in lower-bitrate video) will occur, which will make the video look 'worse quality' to human eyes [even if you don't know what the changes/worseness is, you will 'feel it is worse']. This is one way that a "Slower" setting can still 'look worse'.

Here is an example I captured back around c.2012 (recording the game RIFT by Trion, with Bandicam) showing what happens when the bitrate is set too low (and/or when the Deblocking setting is too low or off in AVC/MPEG-4 video post-compression/rendering with small bitrates) - it is a good example of the "Macroblocking" compression artifacts occurring [the 'little squares' I was talking about earlier], as well as an example of some of the loss in the details and edges when too low a bitrate is set:
Example - Low Bitrate Compression Artifacting, Macroblocking - The Game Tips And More Blog.png
Example - Low Bitrate Compression Artifacting, Macroblocking - The Game Tips And More Blog.png (882.49 KiB) Viewed 121 times

The above type of compression artifacting can also occur if you set Bandicam's 'Quality' setting too low; such as if you use CBR, setting the number value too small, or setting Bandicam's VBR 'Quality' setting too low (overall/ default (eg. setting "Quality 10")) - if you are seeing these types of compression artifacts ('glitches') in your video - even if they are not as bad as the above, I purposely made it worse to show the differences - setting your Bandicam 'Quality' setting higher will help get rid of these, as Bandicam is capable of much higher Quality than the above [if you have the hard drive room to spare and computer power to allow it; note that your video size will be larger as well, because it needs the data space to keep all the differences between frames and finer details, in the video data stream].

HTH for now, with a couple concepts anyway - keep researching it yes, and have fun learning how to make your videos look better, heh
("Hope That Helps!") ~ Troy from The Game Tips And More Blog
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