x264 + Mediacoder + VBV + Maxrate = Bug

[thiagoprado]

I'm trying to encode to streaming using a average bandwidth of 250Kbps.
But I would like to put a cap to limit the bitrate at 512Kbps.
So I used this setting:

# ".\codecs\x264.exe" "$(SourceFile)" --no-psnr --no-ssim --keyint 250 --min-keyint 25 --level 51 --vbv-maxrate 480 --vbv-bufsize 480 --me umh --merange 16 --no-fast-pskip --non-deterministic --subme 1 --ref 1 --partitions all --8x8dct --bframes 5 --direct auto --mixed-refs --trellis 2 --b-pyramid --weightb --deblock -2:-1 --bitrate $(VideoBitrate) --qcomp 0.6 --vbv-bufsize 480 --threads auto --stats "$(PassLogFile)" --pass 1 -o NUL

# ".\codecs\x264.exe" "$(SourceFile)" --no-psnr --no-ssim --keyint 250 --min-keyint 25 --level 51 --vbv-maxrate 480 --vbv-bufsize 480 --me umh --merange 16 --no-fast-pskip --non-deterministic --aq-mode 1 --aq-strength 1.0 --b-adapt 2 --ref 6 --subme 7 --psy-rd 1:0 --partitions all --8x8dct --bframes 5 --direct auto --mixed-refs --trellis 2 --b-pyramid --weightb --deblock -2:-1 --bitrate $(VideoBitrate) --qcomp 0.6 --vbv-bufsize 480 --threads auto --stats "$(PassLogFile)" --pass 2 -o "$(DestFile)"

And got this terrible result when changing from one frame to other (no fade):




So I thought the problem was the to low cap and removed the vbv-maxrate and vbv-bufsize

And got this perfect transition and a peak bitrate at 604:




Then I used the vbv-maxrate and vbv-bufsize at 700Kbps (96Kbps above the peak rate).

And got the same problem:




After I did a lot of tests (cap with 800, 900, 1000Kpbs) and got the same result.

It is a bug? How can I set the vbv-maxrate above the peak bitrate and still get a bad result?
Why the peak bitrate remained at 555Kbps if I used the vbv_maxrate at 700Kbps?

Configuration:

Intel Q8200
Windows Vista Ultimate 64
Medicoder x64


Links to the encoded movies:

http://www.thiagoprado.com.br/10_pap...er_500_500.mp4
http://www.thiagoprado.com.br/10_papeis_lider_0_0.mp4
http://www.thiagoprado.com.br/10_pap...er_700_700.mp4

[Dark Shikari]

You're using an ancient version of x264, from years before VBV handling was modernized.

What is with this proliferation of MediaCoder users "reporting bugs" with ancient x264 builds anyways? We had one yesterday too.

[LoRd_MuldeR]

Also "rc=abr" is a bad choice, I think. You better go with 2-Pass, especially when VBV is involved.

[Dark Shikari]

Originally Posted by LoRd_MuldeR

Also "rc=abr" is a bad choice, I think. You better go with 2-Pass, especially when VBV is involved.

Not with a version of x264 so old that it is from before 2pass VBV existed

[LoRd_MuldeR]

Originally Posted by Dark Shikari

Not with a version of x264 so old that it is from before 2pass VBV existed

But given he follows the advice and updates to a recent revision of x264, he should also consider using 2-Pass instead of ABR...

[thiagoprado]

Sorry guys, I'm using 2-pass with vbr.

I download the latest x264 build from the x264.nl and replaced the codec from the Mediacoder. I did the test with the original Mediacoder x264 and with the build 1114. Got the same result.

[LoRd_MuldeR]

Originally Posted by thiagoprado

Sorry guys, I'm using 2-pass with vbr.

Your first post said something different:
... / rc=abr / ...

Also check the line "Writing library" in MediaInfo's report

[Dark Shikari]

Originally Posted by thiagoprado

Sorry guys, I'm using 2-pass with vbr.

Doesn't look like it to me.

[thiagoprado]

Sorry I wrote a wrong settings.

Correct

# ".\codecs\x264.exe" "$(SourceFile)" --no-psnr --no-ssim --keyint 250 --min-keyint 25 --level 51 --vbv-maxrate 480 --vbv-bufsize 480 --me umh --merange 16 --no-fast-pskip --non-deterministic --subme 1 --ref 1 --partitions all --8x8dct --bframes 5 --direct auto --mixed-refs --trellis 2 --b-pyramid --weightb --deblock -2:-1 --bitrate $(VideoBitrate) --qcomp 0.6 --vbv-bufsize 480 --threads auto --stats "$(PassLogFile)" --pass 1 -o NUL

# ".\codecs\x264.exe" "$(SourceFile)" --no-psnr --no-ssim --keyint 250 --min-keyint 25 --level 51 --vbv-maxrate 480 --vbv-bufsize 480 --me umh --merange 16 --no-fast-pskip --non-deterministic --aq-mode 1 --aq-strength 1.0 --b-adapt 2 --ref 6 --subme 7 --psy-rd 1:0 --partitions all --8x8dct --bframes 5 --direct auto --mixed-refs --trellis 2 --b-pyramid --weightb --deblock -2:-1 --bitrate $(VideoBitrate) --qcomp 0.6 --vbv-bufsize 480 --threads auto --stats "$(PassLogFile)" --pass 2 -o "$(DestFile)"

[thiagoprado]

Links to the encoded movies:

http://www.thiagoprado.com.br/10_pap...er_500_500.mp4
http://www.thiagoprado.com.br/10_papeis_lider_0_0.mp4
http://www.thiagoprado.com.br/10_pap...er_700_700.mp4

[Dark Shikari]

I checked out the first video; it looks fine to me. Is there any particular frame # you're having issues with?

[thiagoprado]

00:01:12;25 to 00:01:12;26
00:01:13;21 to 00:01:13;22
00:01:19;21 to 00:01:19;22

In videos vbv_500_500 and vbv_700_700, vbv_0_0 is perfect.

Thanks

[Dark Shikari]

Does the bug go away if you:

a) Don't use threads?
b) Don't use B-frames?

[lexor]

Originally Posted by Dark Shikari

Does the bug go away if you:

a) Don't use threads?
b) Don't use B-frames?

I would add:
c) decoder is too old/problematic (get latest ffdshow from the try-outs thread)

[Dark Shikari]

Originally Posted by lexor

I would add:
c) decoder is too old/problematic (get latest ffdshow from the try-outs thread)

No, it's an encoder issue.

[shon3i]

Try this build http://www.mediafire.com/?3nozdw0ozn1

[Dark Shikari]

Originally Posted by shon3i

Try this build http://www.mediafire.com/?3nozdw0ozn1

No, the fix in that build was already put into official x264.

[thiagoprado]

I did with no b-frames. Same problem.
I don't know how to disable threads. I can only set 0 (auto) or 1, 2, 3...
I also did with the suggested build and got the same problem.

I read in other post a similar problem with fade transition, but I'm having with dry cuts.

Thanks

[LoRd_MuldeR]

Originally Posted by thiagoprado

I don't know how to disable threads. I can only set 0 (auto) or 1, 2, 3...

Using "--threads 1" will disable multi-threading...

[thiagoprado]

1) With vbv-maxrate and vbv-bufsize 480 to 900Kbps = Problem
2) With vbv-maxrate and vbv-bufsize 480 to 900Kbps + no b-frames + no threads = Problem
3) With vbv-maxrate and vbv-bufsize 0 = Perfect
4) With vbv-maxrate and vbv-bufsize 3000Kbps (incredible high to this bitrate and out of my bandwidth) = Perfect