x264GUI encode result not satisfying

[ioncube]

Under win732bit
The following picture is the analysis of bitrateviewer:

After learning a great deal I want to ask some basic questions
1] Are the jitters (huge variation of bitrate) in the encoded files (relative to original .wmv) usual or they refer to poor results?
(I used CBR this should have given me a nice smooth bitrate histogram?)
2] Am I correct in setting level to 3.1 because this is enough to handle the input resolution & bitrate?
(http://en.wikipedia.org/wiki/H.264/MPEG-4_AVC#Levels)
3] Would you recommend me for CBR(currently used at 23) or 2pass(2500kb/s) or ABR(2500kb/s) for this file?
(I assume that the latter of the two will reduce jitters but increase filesize because bitrate is kept constant even in those frames where its not needed or willlnt produce influential results)
4] Provided that I want good result under ~260mb what are the setting I have to use?

[hello_hello]

For best quality the last thing you probably want to use is a constant bitrate. You want the encoder to distribute the bits where they're needed for best quality, otherwise to a certain extent the quality will vary while the bitrate remains constant. That's what CRF does. It attempts to maintain the same quality relative to the source. When using CRF encoding the bitrate will still vary even if the source is CBR because it's being re-compressed.

2 pass encoding works exactly the same way as CRF encoding. The encoder runs the first pass to work out how best to distribute the bits, then the second pass encodes it. If you run a CRF encode, then specify the resulting file size for a 2 pass encode, both encodes should distribute the bits in a very similar manner.

The basic idea is when using CRF encoding you're specifying the quality by specifying a CRF value, but the final file size is an unknown. 2 pass encoding lets you specify a file size, but the quality is the unknown factor. Unless file size is an issue for some reason, it's generally best to pick a CRF value which gives you the quality you're happy with and stick to it. If you want to ensure the file size remains at around 260MB, using 2 pass encoding is probably the way to go.

The AVC levels enforce certain encoder restrictions. Most devices will have specifications which state the highest AVC level they support. Some devices (mainly older ones) specify an AVC level along with additional bitrate restrictions. Level 3.1 will give you better compatibility with a few older devices but these days High Profile, Level 4.1 support is pretty standard.

[Cornucopia]

And of course you have "wider variations" in your output bitrate graphs - that's because you are using a more zoomed in scale!

Scott

[_Al_]

1) look into this way, ...., variation of bitrate have nothing to do with quality of video, ..., or,...., if it looks neat and flat it basically means two things, bitrate is wasted in some scenes or the opposite, not enough bitrate in some instances, real videos are a "living" thing and scenes need different bitrate in a given moment to keep relative quality the same ...

2) level 3.1 supports 1280x720, 25fps, it is all right, if you intend to play it back only with some media player, you can go higher , it will mean more HW power though, so it is up to you, if you wanna play it back on a cellphone you go easy and check your cellpohone first , maybe you can use base profile and level 3 so your device can handle that. If you use Megui or ripbot264 or many others, you choose device (Ipad ...) and it will choose the max specs for you.

3) jitter is all right, no need to worry

4)
If you need to go with final file size around 260MB you use that CRF 22, first picture, I doubt you can get better results using different mode for encoding, there was discussion here what it is better - CRF or 2pass VBR - (honestly I do not know what is better I think it does not matter), in your case CRF 22 , first picture or 2pass VBR average set to 2464kbps

[jagabo]

1] Are the jitters (huge variation of bitrate) in the encoded files (relative to original .wmv) usual or they refer to poor results?

Yes, bitrate variations are normal with CFR encoding. Different shots require different bitrates. Different encoders require different bitrates.

4] Provided that I want good result under ~260mb what are the setting I have to use?

Exact settings depend on the properties of the particular video.

[ioncube]

1)
If you need to go with final file size around 260MB you use that CRF 22, first picture, I doubt you can get better results using different mode for encoding, there was discussion here what it is better - CRF or 2pass VBR - (honestly I do not know what is better I think it does not matter), in your case CRF 22 , first picture or 2pass VBR average set to 2464kbps

Thnx you sir

[jagabo]

Of course, CRF=22 doesn't always work out to 2464 kbps. You will find a several fold difference with other videos with similar frame sizes and rates. But the result will always have a similar quality with the same CRF. I usually use CRF=18.

[_Al_]

I did not see your video , responses almost always change after viewing originals that need to be encoded. But most people make a mistake to keep higher resolution and push bitrate down. With your bitrate going down to 2500kbps you might get better result to go down with resolution to 960x540 for example.

You have to try to gently de-noise (neat video) , but I do not know what your video is, with resolution going down and compression ratio going up it is a good idea ,..,I'm talking about camcorder videos I do not re-encode movies. Video for web or heavily compressed video could undergo denoise "treatment" and still look ok, without much plastic feel, it is not that obvious or it suppresses blockiness which could be much worse at the end. If you'd do the same with 1080p video and denoise the heck out of it, it might not feel right.

[ioncube]

I did not see your video , responses almost always change after viewing originals that need to be encoded. But most people make a mistake to keep higher resolution and push bitrate down. With your bitrate going down to 2500kbps you might get better result to go down with resolution to 960x540 for example.

I want my video (which by the way are short clips) to run perfect at least on my 19' Viewsonic LCD having a resolution of 1440x900/16:10
IMO decreasing resolution willnt have any effect provided that I see videos such that they cover my whole screen area no matter what their resolution/aspect ratio is (my stretching them or such)
here are my vid info:

General
Complete name                  : D:\Trainers\Anton.wmv
Format                         : Windows Media
File size                      : 534 MiB
Duration                       : 14mn 16s
Overall bit rate mode          : Variable
Overall bit rate               : 5 226 Kbps
Maximum Overall bit rate       : 5 402 Kbps
Encoded date                   : UTC 2011-11-25 04:55:35.250
WM/EncodingSettings            : Lavf52.64.2

Video
ID                             : 1
Format                         : WMV2
Codec ID                       : WMV2
Codec ID/Info                  : Windows Media Video 8
Duration                       : 14mn 16s
Bit rate mode                  : Variable
Bit rate                       : 4 982 Kbps
Width                          : 1 280 pixels
Height                         : 720 pixels
Display aspect ratio           : 16:9
Frame rate                     : 25.000 fps
Nominal frame rate             : 30.000 fps
Bit depth                      : 8 bits
Bits/(Pixel*Frame)             : 0.216
Stream size                    : 509 MiB (95%)
Language                       : English (US)

Audio
ID                             : 2
Format                         : WMA
Format version                 : Version 2
Codec ID                       : 161
Codec ID/Info                  : Windows Media Audio
Duration                       : 14mn 16s
Bit rate mode                  : Constant
Bit rate                       : 280 Kbps
Channel(s)                     : 2 channels
Sampling rate                  : 44.1 KHz
Bit depth                      : 16 bits
Stream size                    : 28.6 MiB (5%)
Language                       : English (US)

[jagabo]

IMO decreasing resolution willnt have any effect provided that I see videos such that they cover my whole screen area no matter what their resolution/aspect ratio is (my stretching them or such)

The smaller the frame the less bitrate you need to keep relative quality. You won't be able to tell the difference between 1920x1080 and 1280x720 videos on your 1400x900 HDTV. Dropping down to 960x540 won't make that much difference, either in bitrate requirement or visual quality on your TV.