Doom9's Forum - View Single Post - x264 VBV -- Progressive download and Streaming

floz23 · 18th May 2009, 16:56

thanks everyone. What is the VBV_maxrate limited by? Frame, gop, or seconds?

I use this program to examine the bitrate of my resulting .mp4's
http://www.winhoros.de/docs/bitrate-viewer/

Even if I set a VBV_maxrate it seems that the maxrate is being respected only in regards to the GOP, and it seems to be about 200k higher than the maxrate. So for instance, if I set a maxrate of 1500k and a buffer of 4500k, when I use the bitrate viewer, it will show a rate of 1700k maximum bitrate when I put it on GOP mode. If I select frame or seconds mode, i still see huge spikes on the I frames.

Thanks for all the input, right now my website is running on purely progressive download, and I have to make a decision very soon to switch to a more advanced progressive solution like this one:
http://h264.code-shop.com/trac

Or go for a full-on wowza RTSP solution.

Regards,
-Adam

PS- I'm currently using MEGUI as a front-end to my encoding, and using automated 2-pass mode, using the VBV settings that are exposed in the GUI. I check the resulting command lines and they SEEM ok, but could MEGUI be giving me problems in my VBV experiments?

18th May 2009, 16:56	#8 \| Link
floz23 Registered User Join Date: Feb 2007 Posts: 14	thanks everyone. What is the VBV_maxrate limited by? Frame, gop, or seconds? I use this program to examine the bitrate of my resulting .mp4's http://www.winhoros.de/docs/bitrate-viewer/ Even if I set a VBV_maxrate it seems that the maxrate is being respected only in regards to the GOP, and it seems to be about 200k higher than the maxrate. So for instance, if I set a maxrate of 1500k and a buffer of 4500k, when I use the bitrate viewer, it will show a rate of 1700k maximum bitrate when I put it on GOP mode. If I select frame or seconds mode, i still see huge spikes on the I frames. Thanks for all the input, right now my website is running on purely progressive download, and I have to make a decision very soon to switch to a more advanced progressive solution like this one: http://h264.code-shop.com/trac Or go for a full-on wowza RTSP solution. Regards, -Adam PS- I'm currently using MEGUI as a front-end to my encoding, and using automated 2-pass mode, using the VBV settings that are exposed in the GUI. I check the resulting command lines and they SEEM ok, but could MEGUI be giving me problems in my VBV experiments?