avi format has smoother motion than mp4 or mkv ?

[Tom80112]

I've noticed that motion in mkv or mp4 format often fatigues my eyes like
it is skipping frames or something.

I've downloaded the same TV show in avi and mp4 format.
Motion when viewing the avi version seems consistently "easier on my eyes".
The mp4 in my example is twice the size so you would think it would have
more better motion but it doesn't. Both show the same frame rate 29.970

Can someone help me understand why? Does AVI encode motion better?
Here are the specs for each video. Based on the specs maybe someone help
me understand why avi seems to display smoother motion? Thanks...


The MP4:

Format                                   : MPEG-4
Format profile                           : Base Media
Codec ID                                 : isom
File size                                : 638 MiB
Duration                                 : 45mn 13s
Overall bit rate mode                    : Variable
Overall bit rate                         : 1 973 Kbps
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L4.0
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 3 frames
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 45mn 13s
Bit rate                                 : 1 841 Kbps
Maximum bit rate                         : 5 012 Kbps
Width                                    : 832 pixels
Height                                   : 464 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 29.970 fps
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.159
Stream size                              : 595 MiB (93%)
Writing library                          : x264 core 66 r1092 60f4cd8
Encoding settings                        : cabac=1 / ref=3 / deblock=1:-1:-1 / analyse=0x3:0x113 / me=umh / subme=9 / psy_rd=1.1:0.0 / mixed_ref=0 / me_range=16 / chroma_me=0 / trellis=0 / 8x8dct=1 / cqm=0 / deadzone=21,11 / chroma_qp_offset=-2 / threads=3 / nr=0 / decimate=1 / mbaff=0 / bframes=3 / b_pyramid=0 / b_adapt=2 / b_bias=0 / direct=3 / wpredb=1 / keyint=250 / keyint_min=25 / scenecut=40(pre) / rc=2pass / bitrate=1841 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / vbv_maxrate=25000 / vbv_bufsize=14000 / ip_ratio=1.40 / pb_ratio=1.30 / aq=1:1.00

The AVI:

Format                                   : AVI
Format/Info                              : Audio Video Interleave
File size                                : 350 MiB
Duration                                 : 44mn 49s
Overall bit rate                         : 1 091 Kbps
Writing application                      : VirtualDubMod 1.5.10.2 (build 2540/release)
Writing library                          : VirtualDubMod build 2540/release
Format                                   : MPEG-4 Visual
Format profile                           : Advanced Simple@L5
Format settings, BVOP                    : 2
Format settings, QPel                    : No
Format settings, GMC                     : No warppoints
Format settings, Matrix                  : Default (MPEG)
Codec ID                                 : XVID
Codec ID/Hint                            : XviD
Duration                                 : 44mn 49s
Bit rate                                 : 951 Kbps
Width                                    : 512 pixels
Height                                   : 384 pixels
Display aspect ratio                     : 4:3
Frame rate                               : 29.970 fps
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Compression mode                         : Lossy
Bits/(Pixel*Frame)                       : 0.161
Stream size                              : 305 MiB (87%)
Writing library                          : XviD 1.0.3 (UTC 2004-12-20)

[Cornucopia]

Container should have no bearing on viewability (barring individual system setup inadequacies).

Since both are 29.97p and both ~SD, it's more likely some difference in content preparation: frame blending, telecine...

Or bitstarving/compression artifacts.

Scott

[hello_hello]

I agree. If both were encoded to a decent quality there shouldn't be a difference in terms of motion due to the encoding itself. If they were originally 59.94fps interlaced and de-interlaced to 29.970 progressive for encoding, the de-interlacing quality might be more of a factor.

NTSC with badly (or incorrectly) removed pulldown can also be a cause of not so smooth motion (pulldown is used to convert film to 29.97fps NTSC). You can end up with frames being repeated occasionally while others are removed when they shouldn't have been.
https://en.wikipedia.org/wiki/Three-two_pull_down

[Tom80112]

You can end up with frames being repeated occasionally while others are removed when they shouldn't have been.
https://en.wikipedia.org/wiki/Three-two_pull_down

I think this is what I am seeing. Motion seems to split second pause then it jumps as if
frame 1 is repeated, 2 is missing, then 3 comes along. But with 30 frames per second
I wouldn't think the human eye could notice.

Yet when I eyeballed both versions of the TV show, I watched a slow pan of the
camera across a scene, the avi was smoother while the mp4 had a constant stuttery
look to the motion.

[jagabo]

You can end up with frames being repeated occasionally while others are removed when they shouldn't have been.
https://en.wikipedia.org/wiki/Three-two_pull_down

I think this is what I am seeing. Motion seems to split second pause then it jumps as if
frame 1 is repeated, 2 is missing, then 3 comes along.

That's not 3:2 pulldown. But there is virtually no 30p content. So what you have is most likely film content that has gone through 3:2 pulldown for TV, then badly deinterlaced to 29.97 progressive.

But with 30 frames per second I wouldn't think the human eye could notice.

You can easily see repeat/deleted frames at 30 fps.

Jerky playback has nothing to do with the MP4/MKV containers or the codecs used. It's how 24 frames per second film sources were converted to 59.94 interlaced fields per second for broadcast, then deinterlaced to 29.97 progressive frames per second.

http://www.100fps.com/

[hello_hello]

You could use a player such as MPC-HC to step through the frames one at a time to maybe get a better idea as to what's going on. Maybe open each version in a different instance of the player and step through them one frame at a time while comparing them to see what's different.

I've seen a reasonable amount of video that was originally film converted to NTSC where field matching was applied when it was re-encoded, but not decimated, so it ends up 29.970fps progressive with every fifth frame repeated. Either that or it was just created that way. That tends to be far more noticeable in respect to jerky motion than pulldown, at least to me.

Maybe it was simply a case of the video not being decoded correctly when the MP4 version was being encoded. Or maybe they were taken from different sources and the MP4 was taken from a bad capture, or the source had atrocities inflicted on it when it was broadcast.... being a TV show.

Co-incidentally, someone sent me a PM with a link to a sample they were trying to encode yesterday. The encode looked very "jittery". Stepping through frames there was a fairly consistent pattern of 3 unique frames, one repeated, two unique frames, one repeated.... but there were frames missing too as the frame rate was correct. The odd part was the source was simply 23.967fps progressive and I had no trouble re-encoding it, so for them it must have been a decoding issue (they were decoding via DirectShow).

[Tom80112]

Looking closer, it seems the avi is also using mp4 so it must be all in how
it was encoded. (which I did not do)

Another angle to consider, is it possible that my WDTV that I use to
play it on my TV is lacking the house power to play highly compressed
video smoothy? Or does the compression aspect have no effect when
being played back?