x264 + Mediacoder + VBV + Maxrate = Bug

[thiagoprado]

Originally Posted by Dark Shikari

Now that's interesting--this is the first VBV bug I have seen in a long time that occurs even with threads and B-frames off. I will look into debugging this tonight or tomorrow.

If you are using two-pass, you may be able to get away with commenting out line 933 in encoder/ratecontrol.c:

if( h->mb.i_mb_x != h->sps->i_mb_width - 1 || !rc->b_vbv)

This completely disables all row-based ratecontrol and relies solely on 2pass VBV for VBV accuracy. It is not guaranteed to avoid underflow, but it should eliminate your problem for now.

How can I do this? Get the original code and then build x264?

[Dark Shikari]

Originally Posted by thiagoprado

How can I do this? Get the original code and then build x264?

Sure, or ask someone to build such a modified version for you.

A proper description of this modification would be "disable row-based VBV handling".

[LoRd_MuldeR]

Originally Posted by thiagoprado

How can I do this? Get the original code and then build x264?

Exactly.

[thiagoprado]

Originally Posted by LoRd_MuldeR

Use the x264 CLI encoder with Avisynth input and you can use whatever deinterlace filter you prefer

The problem is that I need bach encode. I have 700 movies to encode

[LoRd_MuldeR]

Originally Posted by thiagoprado

The problem is that I need bach encode. I have 700 movies to encode

Ever heard of batch/script files?

Also you can use a GUI like MeGUI, which uses Avisynth input too, offers job control (batch processing) and offers all options you'll need.

[thiagoprado]

Originally Posted by LoRd_MuldeR

Ever heard of batch/script files?

Also you can use a GUI like MeGUI, which uses Avisynth input too, offers job control (batch processing) and offers all options you'll need.

Since this solution still use x264 I will get same problem? Correct?

[LoRd_MuldeR]

Originally Posted by thiagoprado

Since this solution still use x264 I will get same problem? Correct?

Yes, as said before: All tools that use the x264 encoder will give identical output for identical input (and identical encoder settings).

However Avisynth allows you to use the pre-processing filters of your choice, including your preferred deinterlacer

[thiagoprado]

Originally Posted by Dark Shikari

Sure, or ask someone to build such a modified version for you.

A proper description of this modification would be "disable row-based VBV handling".

I will try to build myself.

With this patch the vbv-maxrate / bufzie will still work?
I will be able to set the x264 to use VBV at 250Kbps with maximum 500Kbps?

Thanks

[Dark Shikari]

Originally Posted by thiagoprado

I will try to build myself.

With this patch the vbv-maxrate / bufzie will still work?

Yes, but it will only be remotely reliable in 2-pass mode.

[J_Darnley]

If you don't have a build environment already setup, here is a build with Dark Shikari's change: http://users.telenet.be/darnley/x264...thiagoprado.7z

[Guest]

The VBV bufsize is ridiculously low. It has no relation to bitrate. It's determined by the HW of your player. Find out what your player has and set it appropriately.

[Dark Shikari]

Originally Posted by neuron2

The VBV bufsize is ridiculously low. It has no relation to bitrate. It's determined by the HW of your player. Find out what your player has and set it appropriately.

A 1 second VBV is unreasonable?

[thiagoprado]

Worked!!! Worked!!!

Thanks!!!!

[thiagoprado]

I thought bufsize is the time in seconds maxrate can be used.

Ex: maxrate 500 / bufzise 500 - One second of 500Kbps peak
maxrate 500 / bufsize 1000 - Two seconds of 500Kbps peak

I'm using JW Player with Flash Media Streaming 3.5

[thiagoprado]

Thanks Dark Shikari for the help and for the build.

It's incredilble how fast a problem was fixed.

I bought the Flash Media Server ($990) and I still don't get an awnser for a question posted one month ago.

[Dark Shikari]

Originally Posted by thiagoprado

I thought bufsize is the time in seconds maxrate can be used.

Ex: maxrate 500 / bufzise 500 - One second of 500Kbps peak
maxrate 500 / bufsize 1000 - Two seconds of 500Kbps peak

I'm using JW Player with Flash Media Streaming 3.5

Are you actually streaming the H.264, or just using progressive download?

If you're using progressive download, you don't need VBV.

[thiagoprado]

Originally Posted by Dark Shikari

Are you actually streaming the H.264, or just using progressive download?

If you're using progressive download, you don't need VBV.

Streaming

[Guest]

Originally Posted by Dark Shikari

A 1 second VBV is unreasonable?

I haven't looked at the particulars of his stream. I was just saying that it is small compared to what typical HW provides.

[Dark Shikari]

Originally Posted by thiagoprado

Streaming

If you're encoding beforehand and not in real-time, why do you need to stream instead of progressive download?

IMO progressive download avoids most of these annoyances and is much easier for both the user and server.

[thiagoprado]

Security, time seek and bandwidth control.

It's a pay-per-view site.