W3Exchange / MP4 and h.264 bitrate setting ignored

myusername99 · 2008-03-23 06:33:54

I know this topic has been covered in several previous threads, but I couldn't find an answer other than the suggestion that SUPER is only a front end, the problem must be with ffmpeg, etc.

The issue is that no matter what bitrate setting I choose I can't get SUPER to encode lower than about 1300 kbps with the h.264 codec. I have tried unchecking top and high quality, to no avail.

On the other hand, the setting seems to work fine if I set it higher than about 1300 kbps, so it's not being completely ignored. I don't seem to have the problem with other codecs. I am using the latest version, March 22 build 30.

Whether or not this is an issue with SUPER or its underlying encoders, does anyone have any insight as to what the problem is? Are others able to reproduce the issue?

96crypt_mod · 2008-03-23 09:29:09

myusername99 wrote:
...The issue is that no matter what bitrate setting I choose I can't get SUPER to encode lower than about 1300 kbps with the h.264 codec. ...

of course you can

this is a VOB input
.........................................................................
SUPER © - Multimedia Analysis Box (by http://mediainfo.sourceforge.net )
Analyzing the source file VTS_01_00.VOB

General #0
Complete name : D:\0-new-disk-1\Video-Cap\Video\VTS_01_00.VOB
Format : MPEG-2 Program
Format/Family : MPEG-2
File size : 102 MiB
PlayTime : 2mn 17s
Bit rate : 6250 Kbps

Video #0
Codec : MPEG-2 Video
Codec/Family : MPEG-V
Codec profile : Main@Main
Codec settings, Matrix : Standard
PlayTime : 2mn 17s
Bit rate mode : CBR
Bit rate : 5240 Kbps
Nominal bit rate : 6000 Kbps
Width : 720 pixels
Height : 576 pixels
Display Aspect ratio : 4/3
Frame rate : 25.000 fps
Standard : PAL
Chroma : 4:2:0
Interlacement : Top Field First

Audio #0
Codec : AC3
Codec profile : Dolby Digital
Bit rate mode : CBR
Bit rate : 192 Kbps
Channel(s) : 2 channels
Channel positions : L R
Sampling rate : 48 KHz

Audio #1
Codec : AC3
Codec profile : Dolby Digital
Bit rate mode : CBR
Bit rate : 192 Kbps
Channel(s) : 2 channels
Channel positions : L R
Sampling rate : 48 KHz

Audio #2
Codec : AC3
Codec profile : Dolby Digital
Bit rate mode : CBR
Bit rate : 192 Kbps
Channel(s) : 2 channels
Channel positions : L R
Sampling rate : 48 KHz

Text #0
Codec : RLE

Text #1
Codec : RLE

Text #2
Codec : RLE

Text #3
Codec : RLE

Menu #0
Codec : DVD-Video
...............................................................................

encoded into MP4 [H.264, AAC] 10 sec sample

SUPER © - Multimedia Analysis Box (by http://mediainfo.sourceforge.net )
Analyzing the source file VTS_01_00.VOB.MP4

General #0
Complete name : D:\0-new-disk-1\Video-Cap\VTS_01_00.VOB.MP4
Format : MPEG-4
Format/Info : ISO 14496-1 version 2
Format/Family : MPEG-4
File size : 354 KiB
PlayTime : 9s 520ms
Bit rate : 304 Kbps
StreamSize : 10.9 KiB
Movie name : VTS_01_00.VOB.MP4
Performer : created with SUPER(C).v2008.bld.30
Encoded date : UTC 2008-03-23 16:28:03
Tagged date : UTC 2008-03-23 16:28:14
Comment : 2008-03-23 17:28:15
Writing application : eRightSoft

Video #0
Codec : AVC
Codec/Family : AVC
Codec/Info : H.264 (3GPP)
PlayTime : 10s
Bit rate : 204 Kbps
Width : 320 pixels
Height : 240 pixels
Display Aspect ratio : 4/3
Frame rate : 25.000 fps
Bits/(Pixel*Frame) : 0.106
StreamSize : 250 KiB
Encoded date : UTC 2008-03-23 16:28:03
Tagged date : UTC 2008-03-22 16:28:13

Audio #0
Codec : AAC LC
Codec/Family : AAC
Codec/Info : AAC Low Complexity
PlayTime : 9s 520ms
Bit rate mode : CBR
Bit rate : 64 Kbps
Channel(s) : 2 channels
Channel positions : L R
Sampling rate : 44.1 KHz
Resolution : 16 bits
StreamSize : 93.3 KiB
Encoded date : UTC 2008-03-23 16:28:03
Tagged date : UTC 2008-03-22 16:28:13

myusername99 · 2008-03-23 14:52:21

I noticed you shrunk the frame size down to 320x240 when encoding. Is that you got it down to only 204 kbps? Is that the only way to get a lower bit rate -- by changing the frame size?

I did a search on this forum and found several other threads mentioning this problem, but none had a real solution. Again, I am aware the might not be an issue with SUPER, but rather an issue with ffmpeg or x264. On the other hand, maybe there's some buried setting somewhere that I'm missing. Another forum hinted the problem may be related to the ffmpeg qmax setting, but I have no idea. Any ideas would be greatly appreciated!

By the way, I am using an MS42 (a Microsoft MPEG4 codec) source file that is 640x480, 29.97 fps, and has ~3800 kbps video bitrate. I am encoding into MP4/h.264 keeping the frame size and frame rate the same -- just changing the bitrate. The output files are perfect otherwise, but whether I set the video bitrate to 128 kbps or 1008 kbps, my output file always has about 1300 kbps video rate.

Thanks again!

96crypt_mod · 2008-03-23 15:14:27

every setting has a logical reason
reducing VBitrate is mainly to reduce file size (and quality)
why would someone who is willingly trying to reduce filesize would keep a high VideoScaleSize
knowing that the filesize of a 640:480 file is 4 times larger than the same at 320:240

therefore, if you really want to reduce filesize, the impact of a lower VideoScaleSize is
even more important that the VBitrate.
not to mention that a 320:240 looks much better than a 640:480 both @ 200KBps
due to heavy the pixelization in the 640:480 at low bitrates
afterall, DirectX job is to render full screen of the 320:240..

myusername99 · 2008-03-23 15:37:01

96crypt_mod wrote:
every setting has a logical reason
reducing VBitrate is mainly to reduce file size (and quality)
why would someone who is willingly trying to reduce filesize would keep a high VideoScaleSize
knowing that the filesize of a 640:480 file is 4 times larger than the same at 320:240

therefore, if you really want to reduce filesize, the impact of a lower VideoScaleSize is
even more important that the VBitrate.
not to mention that a 320:240 looks much better than a 640:480 both @ 200KBps
due to heavy the pixelization in the 640:480 at low bitrates
afterall, DirectX job is to render full screen of the 320:240..

Very good point. If file size reduction was my true goal, I would simply change the frame size. But my goal is to have no noticeable quality difference when re-encoding these files. My untrained eye cannot tell any difference in quality between the 1300 kbps h.264 and the original M4S2 at 3800 kbps, even when blown up on my big screen TV (granted it was over a crappy s-video connection). So I'd like to keep it at 640x480 and just reduce the bitrate until I start noting quality decline.

I did find out some more info, however. When I put h.264 in the AVI container, the bitrate comes out almost perfectly. And, of course, the big difference with that is mencoder vs. ffmpeg. So there's more evidence of a bug in ffmpeg. But ffmpeg is just such a huge, well-established program that I have a hard time believing that's the whole story.

Thanks again for your quick responses in this matter, by the way!

96crypt_mod · 2008-03-23 15:43:34

what version of SUPER(C) are you using
what is your operating system

myusername99 · 2008-03-23 16:00:46

96crypt_mod wrote:
what version of SUPER(C) are you using
what is your operating system

I am using Vista Business SP1, and the just released version of SUPER, March 22, build 30 (I'm the one who was asking about when the SP1-compatible version was coming. And I am happy to report that other than this bitrate issue, it works great with Vista SP1!)

Another test result: I transcoded the original M4S2, 3800 kbps file using 128 kbps as the desired video bitrate and ended up with 1300 kbps in the output file. I then took THAT MP4/h.264 file and encoded IT, again with the 128 kbps bitrate setting. That one was about 1000 kbps.

Maybe I have to run several passes?

Once again, thank you!

myusername99 · 2008-03-23 19:50:21

Just tested with a wmv source file and flv source file...SUPER transcoded both to MP4/h.264 correctly with the requested bitrate!

Now I am confused, because it seems that the issue may be related to the source M4S2 codec that my Casio camera uses to create videos.

But I can't help but thinking there is some "limiter" setting that prevents you from setting a bitrate too low.

myusername99 · 2008-03-25 07:43:27

Any new info on this? I definitely think it has to do with some ffmpeg setting (or bug) because I have the same problem with Mediacoder if I specify ffmpeg, while x264 and mencoder work as expected.

One more issue I noticed...why is the "tagged date" a day behind the "encoded date" in your file above? The "tagged date" is always in the past for my files as well.

96crypt_mod wrote:
Encoded date : UTC 2008-03-23 16:28:03
Tagged date : UTC 2008-03-22 16:28:13

#1 2008-03-23 06:33:54

MP4 and h.264 bitrate setting ignored

#2 2008-03-23 09:29:09

Re: MP4 and h.264 bitrate setting ignored

myusername99 wrote:

#3 2008-03-23 14:52:21

Re: MP4 and h.264 bitrate setting ignored

#4 2008-03-23 15:14:27

Re: MP4 and h.264 bitrate setting ignored

#5 2008-03-23 15:37:01

Re: MP4 and h.264 bitrate setting ignored

96crypt_mod wrote:

#6 2008-03-23 15:43:34

Re: MP4 and h.264 bitrate setting ignored

#7 2008-03-23 16:00:46

Re: MP4 and h.264 bitrate setting ignored

96crypt_mod wrote:

#8 2008-03-23 19:50:21

Re: MP4 and h.264 bitrate setting ignored

#9 2008-03-25 07:43:27

Re: MP4 and h.264 bitrate setting ignored

96crypt_mod wrote:

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