why this MP4 is not smooth during play?

[marcorocchini]

Hi cats,

please consider this source:

https://dl.dropboxusercontent.com/u/39871584/test.avi

I try to encode it to MP4 using ffmpeg:

ffmpeg.exe -y -i test.avi -c:v libx264 -profile:v high422 -level:v 4.1 -g 33 -bf 2 -b:v 7900k -an -aspect 16:9 out.mp4

but I see that out.mp4 don't playback fine in vlc, betweenn the graphic and video there is a kind of "jump" of the image

https://dl.dropboxusercontent.com/u/39871584/out.mp4

How can I resolve? thanks

[Baldrick]

Try set the framerate with -r 25 ?

Replace 25 with the actual framerate.

[marcorocchini]

Try set the framerate with -r 25 ?

Replace 25 with the actual framerate.

sorry but it don't resolve

[marcorocchini]

https://dl.dropboxusercontent.com/u/39871584/out.mp4

this mp4 in my vlc playback wrong

the problem is present between the dissolve from graphic, and the video

[poisondeathray]

You need to encode TFF, not progressive . VLC playback yadif 2x or bob

Or bob deinterlace and make it 1080p50

[jagabo]

You still don't understand the difference between interlaced and progressive video?

[marcorocchini]

You need to encode TFF, not progressive . VLC playback yadif 2x or bob

Or bob deinterlace and make it 1080p50

ah

BOB deinterlace = -vf yadif=1:0 ?

[marcorocchini]

however yes: in this case I need to get progressive output, but seems I cannot find "bob" filter in ffmpeg

[marcorocchini]

I have try

ffmpeg.exe -y -i test.avi -c:v libx264 -profile:v high422 -level:v 4.1 -g 33 -bf 2 -vf yadif=1:0 -r 50 -b:v 7900k -an -aspect 16:9 out.mp4

but I don't know if is correct, and however playback remains wrong

[jagabo]

Yes, yadif in mode one is a smart bob. Not as good as QTGMC() in most cases.

[marcorocchini]

ffmpeg.exe -y -i test.avi -vf yadif=1:0 -r 50 -c:v libx264 -profile:v high422 -level:v 4.1 -g 33 -bf 2 -b:v 7900k -an -aspect 16:9 out.mp4

I have insert the yadif but in vlc I still see playback is not fine

[jagabo]

I wonder if the ffmpeg docs are backward regarding the field order. In every other version of Yadif order=0 is BFF.

[marcorocchini]

I cannot resolve

I have try:

ffmpeg.exe -y -i test.avS -c:v libx264 -profile:v high422 -level:v 4.1 -g 33 -bf 2 -b:v 7900k -an -aspect 16:9 out.mp4

where test.avS is:

LoadCPlugin("v:\automazioneclip\core\yadif.dll")
ffvideosource("v:\test.avi")
AssumeBFF()
Yadif(mode=1)
assumefps(50)

but this don't resolve the problem, in the output mp4 I cannot see the dissolve, is there a "jump" in replace of dissolve

[jagabo]

Your video is TFF. AssumeTFF() or Yadif(mode=1, order=1).

<edit>

I went back to post #11 and found that the yadif parameters were correct. Unlike every other version of Yadif order=0 is TFF in ffmpeg. The file it produced worked fine in several players I tried -- except VLC which jumps suddenly from the titles to somewhere in the middle of the clip. If I encode directly with the x264 cli encoder there are still some problems when the bitrate and complexity is too high. It looks to me like this is a problem with VLC.

[marcorocchini]

ahn, thanks

only to do a proof I would try use

-b:v 7900k -minrate 7900k -maxrate 7900k -bufsize ?


How have to be calculate the bufsize considering a bitrate of 7900k?

[marcorocchini]

ffmpeg.exe -y -i audiosfilata.wav -i sfilata.avi -c:v libx264 -profile:v high422 -level:v 4.1 -g 33 -bf 2 -vf yadif,colormatrix=bt709:bt601 -b:v 8000k -minrate 8000k -maxrate 8000k -bufsize 8000k -c:a libmp3lame -b:a 320k -aspect 16:9 output8000.mp4

this seems work, but I don't know if the bufsize=8000k is correct

[jagabo]

bufsize depends on your playback device's limitations. Why are you setting min, max, and average bitrates all the same? Are you aiming for constant bitrate encoding? That's the worst possible encoding method.

[marcorocchini]

I know but I'm not able to calculate final size in VBR mode. However I have a uncompressed .avi file of 460 GB that have duration of 1hour and 15 minutes, HD 1920x1080 25fps 4:2:2. I would like encode it into mp4 so that it fit

- in a 4,7GB dvd

- in a 9Gb dvd

For example, to create a MP4 of 4.37Gb how I have to set min max and average rate? thanks

[poisondeathray]

Same answer, use a bitrate calculator . Not necessarily one for DVD-video, but a generic one

eg this one is similar to the one in megui
https://www.videohelp.com/software/Bitrate-calculator

If it's not intended for a device (it probably isn't if you're using 4:2:2) , you usually don't want to set min/max or buffer or VBV settings. The more restrictions, the lower the potential quality

The only important one is average bitrate, because that is what is used in the equation

Filesize = average bitrate * running time

[jagabo]

duration of 1hour and 15 minutes - in a 4,7GB dvd

It's simple algebra:

running time = 1 hour 15 minutes = 4500 seconds
file size = 4.7 GB = 4,700,000,000 bytes = 37,600,000,000 bits

bitrate = file size / running time:

37,600,000,000 / 4500 = 8,355,556 bits/sec = 8356 kbits/sec

Subtracting a few percent for the container overhead leaves about 8200 kbits/sec. Subtract 384 kbps for audio (typical for 5.1 AC3) leaves you with about 7800 kbps for the video.

[poisondeathray]

Let me guess the response:

"cats" don't do algebra

<insert cat gif>

[marcorocchini]

oh ______

[newpball]

oh ______


[Attachment 31007 - Click to enlarge]

Hahaha!