Handbrake and converting video without losing quality

[Aeropars]

Hi all,

I've registered today because I'm a little confused by the behaviour of handbrake and the quality settings I can select. Let me elaborate....

I've shot some HD video footage using a consumer grade camera which has resulted in a variable frame rate. To edit it using a trial version of premiere pro, I've had to convert it using handbrake to constant frame rate as well as changinc the audio to AAC from PCM. That much I understand and I've done it successfully.

I've been playing with the quality slider to get the right settings so that i do not lose any quality and observed that after I get past a certain point (around 12) I don't see any difference in the file size so seem to hit a wall on the quality front. I understand that if I put it down to 0 (lossless) i should see a great increase in filesize because of the way its unpacking the video and then re-encoding but with lossless compression.

I'm also noticing that some files seem to output marginally larger form the original but then others are smaller.

I'm a little confused by how this is working to say the least. Also, using mediainfo I'm seeing that, even on lossless, there are some differences in the reported bitrate.

Could anyone give me a bit of an education as to what I am seeing here?

Many thanks for your help in advance.

[LigH.de]

In general: To not lose any quality, you would have to not convert the video at all. When the video is compressed into a lossy format (e.g. MPEG-4 AVC = H.264 or MPEG-H HEVC = H.265), every conversion will reduce the quality further. Keeping the amount of loss unnoticeably low may require more bitrate than the original video, except for a video encoder which is far more efficient than hardware encoders in consumer cameras. In case of the x264 encoder for H.264 video, a quality value (CRF = constant rate factor) of 12 is indeed "archival grade".

Variable frame rate is an additional issue for many video converters and editors; many applications assume a constant frame rate, commercial software just as much as freeware. Sometimes, the video is merely flagged as having VFR, although there is hardly any fluctuation through the whole playing time; this may simply be related to the ability of the container to support it, if required. But if MediaInfo reports a wide range of frame rates, then it may indeed require additional care...

[Aeropars]

Thanks for the reply.

So am I right in saying that if I did code using anywhere between lossless and 12 then that's the best I am going to get in terms of losing minimal quality?

I've done a quick look at a few clips and I've seen 17mb/s as the lowest and 35 mb/s as the highest.

At the moment I'm not actually using the footage for projects, just trying to get as professional look as I can with the equipment I have (DSLR and iPhone)

Thanks again.

[_Al_]

Just realize extremes.
A static shot, some quite scene where nothing is going on, using tripod, nothing is moving and encode it RF18 using handbrake.
Then you record something hand held, shake with camcorder, pan with it, or if objects would be moving all the time, texture of the background is not defined (grass , trees with millions of twittering leaves), or recording a footage with lots of noise in it, then encode again RF 18.
Your encoded footage would be much larger. To keep same relative quality would need more bitrate.

If you shoot with cheap camcorder with very short times, everything is sharp and pronounced, bitrate can skyrocket if you encode it and keeping solid CRF (RF in Handbrake). If you used some DSLR with shallow depth of field, longer times, bitrate drastically drops down if you encode footage like that.

[poisondeathray]

DSLR and iPhone

The DSLR should be CFR . Only the iphone should be VFR

So am I right in saying that if I did code using anywhere between lossless and 12 then that's the best I am going to get in terms of losing minimal quality?

I've done a quick look at a few clips and I've seen 17mb/s as the lowest and 35 mb/s as the highest.

Some handbrake settings may be limiting the bitrate. It might be using maxrate and bufsize for device compatiblity. You might have to change some settings if you want higher quality

[Aeropars]

Thanks again for the response.

COuld you tell me what settings I should be looking at to increase quality?

[poisondeathray]

If you're using low crf values like 1-12 and still only seeing 35Mb/s for 1920x1080 typical phone video despite lowering the value (not simple content like blank screen or cartoons) , it suggests you have encoding restrictions in handbrake (maxrate capping)

In the video tab, you can set the profile and level to "auto" and it will be unrestricted. Or if you want to place some restrictions , you might set profile to high and level at 4.1 or 4.2 . Restrictions are there to ensure video is compliant for devices, so it will playback correctly

But newer versions of premiere can actually decode almost all x264 settings and profiles, even true lossless YUV . (--qp 0 or --crf 0) , and it's actually decoded as YUV as well

At some crf value, it will become larger than the original, because the compression refers to the original decoded to uncompressed frames. Thus it will be smaller than uncompressed, but larger than the original . There are diminishing returns, you have to ask yourself if a filesize a few times larger than the original , that looks the same, but technically lower in quality is worth it.

[Aeropars]

Thats perfect. Many thanks for the explanation. I was targeting a filesize the same as the original really but I've no logic for what that was. I just thought it would be good enough quality if its at about that filesize.