Decreasing Bitrate — How Can I Make it Look as Smooth as This Video?

[Sham 69]

This video is at 600x480 with a bitrate of about 270kbps. Usually videos with such a low bitrate at this resolution look atrocious, but this one looks way better than it should.

How can I decrease the bitrate of my videos to get similar results? What settings should I choose?

[butterw]

It would be useful to post a 20s clip of your own that looks atrocious, so it might be possible to make suggestions on how to improve the result.

With modern codecs and a clean source, you can get a decent enough result at 270kbps @480p. 
The source here was likely poor and has been heavily smoothed.

[Sham 69]

1920x1080 2500kbps degraded to 640x480 270kbps.
This one isn't too bad but is comparatively sharper (pixelated?) than the former video.
https://drive.google.com/file/d/1qsiUnPLQPjsojb6riexsoa70V7XHuAqT/view?usp=sharing

[butterw]

The video was displayed as 360x480 h264 on my machine. It has Lossy compression artefacts: blocking.

You certainly need to avoid re-compression when dealing with low bitrate bitrate video. Increasing the resolution and bitrate would help.

HD sources are relatively recent. The content may have been broadcast and captured in HD, it still comes from an old source.   

 

[Sham 69]

I usually degrade my videos to something like 640x480 with 1200 bitrate for lower file size, but just wanted to know if I was missing out on something that would make the videos look better. I use Avidemux on default settings and average bitrate.

It's interesting that your display gave you 360x480, you're saying that it was taller than wide? Do you know why that happened? I just play videos on VLC.

[Sham 69]

I'm re-encoding the Kate Bush video in 720x540 350kbps right now. The 5:4 ratio looks wrong.

[butterw]

I usually degrade my videos to something like 640x480 with 1200 bitrate for lower file size, but just wanted to know if I was missing out on something that would make the videos look better. I use Avidemux on default settings and average bitrate.

It's interesting that your display gave you 360x480, you're saying that it was taller than wide? Do you know why that happened? I just play videos on VLC.

I viewed the video in the Google Drive player. It displays correctly, but the resolution is claimed to be 360p, 480x360, not sure why. The downloaded video is indeed 640x480 h264.

You do better with higher bitrate, higher resolution, slower encoding parameters (ex: x264 --slower).
x265 would perform better than x264.
The compressibility of video, varies a lot, but it is typically quite poor for old or noisy sources. I would suggest trying crf mode (ex crf=23) to see what your filesize comes out as, instead of forcing 270kbps.

For old sources, some filtering is typically required.
your video:

Code Select Expand

Bit rate                       : 270 kb/s
Width                          : 640 pixels
Height                         : 480 pixels
Display aspect ratio           : 4:3
Frame rate                     : 25.000 FPS
Chroma subsampling             : 4:2:0
Bit depth                      : 8 bits
Scan type                      : Progressive
Bits/(Pixel*Frame)             : 0.035
Writing library                : x264 core 157 r2969
Encoding settings              : cabac=1 / ref=3 / deblock=1:0:0 / analyse=0x3:0x133 / me=hex / subme=7 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=6 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=2pass / mbtree=1 / bitrate=270 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / aq=1:1.00

Kate Bush: 1.25 would not be a common AR for Video, it may not be the original Aspect Ratio, change the output AR to see if you like it better.