How Can I Use "VBR" (Variable Bitrate) in my videos

[MBlueSky]

Hi Friends,
I use "HandBrake" for Converting and Compressing my videos.
How can I convert videos to VBR (Variable Bitrate) videos while compressing?
Thanks in advance.

[jagabo]

I'm pretty sure Handbrake only does VBR encoding. Use Constant Quality or Avg Bitrate encoding.

[MBlueSky]

I'm pretty sure Handbrake only does VBR encoding. Use Constant Quality or Avg Bitrate encoding.

I tried both Average Bitrate and Constant Quality, but when I check the media info of the result video, it's constant bitrate.

[DB83]

One pass encoding or two ?

[MBlueSky]

One pass encoding or two ?

Two pass encoding with fast first pass

[johns0]

Maybe you are looking at constant for frame rate mode.

[MBlueSky]

Maybe you are looking at constant for frame rate mode.

No, I know, but I checked and there was only one bitrate value.

[johns0]

I wouldn't trust mediainfo on stats like that,i checked files i made and it also says constant bitrate for files i encoded with constant quality.

[DB83]

I just did a quick test using 'Average Bit Rate'


That is the number quoted in mediainfo. But the top report does state that overall bitrate mode is variable.

[pm-s]

[Attachment 60031 - Click to enlarge]

here.

[jagabo]

Use Bitrate Viewer to examine the bitrate. You'll see that it's VBR.

[LigH.de]

The better MediaInfo application: MediaInfo.NET by stax76, author of StaxRip.

Still, MediaInfo only reads values from container headers. And container headers (if there is a field at all) will only report an average or estimated bitrate. MediaInfo will not scan the whole video to produce statistics about the bitrate distribution, like Bitrate Viewer does.

But video encoded with modern codecs always has a variable bitrate because encoding frames with different content, or with efficient algorithms comparing the content of related frames, will always result in a different code size per frame. Only completely uncompressed video (raw RGB / YUV) may have exactly the same size for every frame.

Encoders with a CBR mode may try to keep the bitrate as constant as possible but won't achieve this goal exactly (at least not without filling the result with junk bytes to make it appear more constant than it really is).

[MBlueSky]

[Attachment 60038 - Click to enlarge]


[Attachment 60039 - Click to enlarge]

I did whatever you said, but I still have the problem. "Media Info" does show variable bitrates of media files. In the picture above you see, Media Info shows variable bitrate for one of my videos. Shall I use another video convertor for VBR?

[Alwyn]

Shall I use another video convertor for VBR?

Handbrake is only not putting the bitrate info in the file info; it's still VBR (see later posts).

Mediainfo:

General
Complete name : H:\Videohelp\bitrate\20210317 233635 Leo Dreaming-1(1).m4v
Format : MPEG-4
Format profile : Base Media / Version 2
Codec ID : mp42 (isom/iso2/avc1/mp41)
File size : 8.14 MiB
Duration : 16 s 534 ms
Overall bit rate : 4 128 kb/s
Encoded date : UTC 2021-07-26 08:24:52
Tagged date : UTC 2021-07-26 08:24:52
Writing application : HandBrake 1.3.3 2020061300

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Main@L4
Format settings : CABAC / 4 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 4 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 16 s 534 ms
Bit rate : 4 000 kb/s
Width : 1 232 pixels
Height : 656 pixels
Display aspect ratio : 1.85:1
Frame rate mode : Constant
Frame rate : 30.000 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.165
Stream size : 7.85 MiB (97%)
Writing library : x264 core 157 r2935 545de2f
Encoding settings : cabac=1 / ref=2 / deblock=1:0:0 / analyse=0x1:0x111 / me=hex / subme=6 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=0 / 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=1 / keyint=300 / keyint_min=30 / scenecut=40 / intra_refresh=0 / rc_lookahead=30 / rc=2pass / mbtree=1 / bitrate=4000 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / vbv_maxrate=20000 / vbv_bufsize=25000 / nal_hrd=none / filler=0 / ip_ratio=1.40 / aq=1:1.00
Encoded date : UTC 2021-07-26 08:24:52
Tagged date : UTC 2021-07-26 08:24:52
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Codec configuration box : avcC

Bitrateviewer:


[Attachment 60041 - Click to enlarge]

[Alwyn]

Mediainfo.Net:

G: MPEG-4, 8.14 MiB, 16 s 534 ms, 4 128 kb/s

V: AVC, Main@L4, 1232x656, 30 FPS, 4 000 kb/s

A: AAC LC, 132 kb/s, 1 channel, 44.1 kHz, Default


General

Complete name : H:\Videohelp\bitrate\20210317 233635 Leo Dreaming-1(1).m4v
Format : MPEG-4
Format profile : Base Media / Version 2
Codec ID : mp42 (isom/iso2/avc1/mp41)
File size : 8.14 MiB
Duration : 16s 534ms
Overall bit rate : 4128 Kbps
Encoded date : UTC 2021-07-26 08:24:52
Tagged date : UTC 2021-07-26 08:24:52
Writing application : HandBrake 1.3.3 2020061300

Video

ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Main@L4
Format settings : CABAC / 4 Ref Frames
Format settings, CABAC : Yes
Format settings, ref frames : 4 frame
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 16s 534ms
Bit rate : 4000 Kbps
Width : 1232 pixel
Height : 656 pixel
Display aspect ratio : 1.85:1
Frame rate mode : CFR
Frame rate : 30.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bit
Scan type : Progressive
Bits/(Pixel*Frame) : 0.165
Stream size : 7.85 MiB (97%)
Writing library : x264 core 157 r2935 545de2f
Encoding settings : cabac=1 / ref=2 / deblock=1:0:0 / analyse=0x1:0x111 / me=hex / subme=6 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=0 / 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=1 / keyint=300 / keyint_min=30 / scenecut=40 / intra_refresh=0 / rc_lookahead=30 / rc=2pass / mbtree=1 / bitrate=4000 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / vbv_maxrate=20000 / vbv_bufsize=25000 / nal_hrd=none / filler=0 / ip_ratio=1.40 / aq=1:1.00
Encoded date : UTC 2021-07-26 08:24:52
Tagged date : UTC 2021-07-26 08:24:52
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
CodecConfigurationBox : avcC

Audio

ID : 2
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 16s 533ms
Bit rate mode : CBR
Bit rate : 132 Kbps
Channel(s) : 1 channel
Channel layout : C
Sampling rate : 44.1 KHz
Frame rate : 43.066 fps (1024 SPF)
Compression mode : Lossy
Stream size : 270 KiB (3%)
Title : Mono
Default : Yes
Alternate group : 1
Encoded date : UTC 2021-07-26 08:24:52
Tagged date : UTC 2021-07-26 08:24:52

[MBlueSky]

I used bitrateviewer and it shows VBR. But it's strange for me that for one of my videos both MediaInfo and bitrateviewer show VBR,


[Attachment 60043 - Click to enlarge]

But for the videos that I convert, MediaInfo shows constant bitrate and bitrateviewer shows variable bitrate!!!


[Attachment 60044 - Click to enlarge]

[jagabo]

MediaInfo isn't telling you the video is constant bitrate. It's only reports what the mp4 header indicates. Some programs include more detailed information than others.

[MBlueSky]

[Attachment 60038 - Click to enlarge]

"Media Info" does show variable bitrates of media files. In the picture above you see, Media Info shows variable bitrate for one of my videos.

What about this?!!!

[jagabo]

Just because MediaInfo reports only one bitrate doesn't mean the file is constant bitrate. It only means the header doesn't show any other bitrate information. You can't assume that means constant bitrate.

[Alwyn]

Here's the Mediainfo report from a MOV:

General
Complete name : F:\Family Videos\2021\20201130_193152.MOV
Format : MPEG-4
Format profile : QuickTime
Codec ID : qt 0000.00 (qt )
File size : 31.6 MiB
Duration : 17 s 175 ms
Overall bit rate mode : Variable
Overall bit rate : 15.4 Mb/s
Encoded date : UTC 2020-11-30 11:31:53
Tagged date : UTC 2020-11-30 11:32:10
Writing library : Apple QuickTime
com.apple.quicktime.make : Apple
com.apple.quicktime.model : iPad (5th generation)
com.apple.quicktime.software : 14.2
com.apple.quicktime.creationdate : 2020-11-30T19:31:52+0800

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4
Format settings : CABAC / 1 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 1 frame
Format settings, GOP : M=1, N=30
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 17 s 175 ms
Bit rate : 15.3 Mb/s
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Variable
Frame rate : 29.970 (29970/1000) FPS
Minimum frame rate : 28.571 FPS
Maximum frame rate : 30.000 FPS

[LigH.de]

MediaInfo only reports the fields available in the header. Some headers contain both a value for an average and a maximum bitrate. Other containers don't, so MediaInfo can't display fields not present. The video still has a variable bitrate, just the header doesn't report that. You need to gather statistics to prove it.

[Alwyn]

It's a "characteristic" of Handbrake's encoding of the MP4. Here's a file encoded by my video editor (MEP):

General
Complete name : H:\Videohelp\bitrate\MEP Test.mp4
Format : MPEG-4
Format profile : Base Media
Codec ID : isom (isom/avc1)
File size : 10.5 MiB
Duration : 14 s 80 ms
Overall bit rate mode : Variable
Overall bit rate : 6 245 kb/s
Encoded date : UTC 2021-07-26 14:11:22
Tagged date : UTC 2021-07-26 14:11:22

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L3.1
Format settings : CABAC / 3 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 3 frames
Format settings, GOP : M=3, N=25
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 14 s 80 ms
Bit rate mode : Variable
Bit rate : 6 109 kb/s
Maximum bit rate : 8 000 kb/s
Width : 720 pixels
Height : 576 pixels
Display aspect ratio : 4:3
Frame rate mode : Constant
Frame rate : 25.000 FPS
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.589
Stream size : 10.3 MiB (98%)
Language : English
Encoded date : UTC 2021-07-26 14:11:22
Tagged date : UTC 2021-07-26 14:11:22
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Codec configuration box : avcC

[LigH.de]

The MP4, MOV, 3GPP and 3GPP2 containers are all related to the ISO Base Media File Format. There is a basic format specification with a few mandatory header fields, and several extended format specifications with additional header fields. One application creates files with a simple header, another application creates files with a more detailed header. But all applications creating a file with MPEG-4 video tracks will create variable bitrate, it is in the nature of MPEG-4 video not to have a constant bitrate (due to efficient encoding).

[MBlueSky]

Thank you all my friends

[DB83]

And for clarity I ran the test clip I created - and referred to above - through bitrateviewer.


mediainfo simply quoted the average bit rate I set in handbrake. I was most surprised to see the variance over only 2 minutes as reported in the app. And the actual average bit rate reported was not as set. Close but not the same.


Of course some codecs/encoders allow you to set minimum/maximum/avg. Are these more efficient ? I guess not.

[jagabo]

Of course some codecs/encoders allow you to set minimum/maximum/avg. Are these more efficient ? I guess not.

It's not about efficiency, it's about playback hardware and streaming requirements.

[DB83]

I guess we are both from an age when a 'stream' was a thing where you got your feet wet