How to measure bitrate changes

P

Petanque

Active member
Hi,

In a previous thread, it was noted that Final Cut Pro was not a reliable source for measuring data rate (which was reading 17 mb/s after patch). How can one get a reliable reading from an affordable (StreamEye is $1795) and mac friendly program (can't download the 30 day trial- only for windows, as is Bitrate Viewer)?

Thanks.
 
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OSD of ffdshow codec have that possibility - realtime overlaying
or
winhoros.de/docs/bitrate-viewer/
or
many on that forum use "Elecard StreamEye Studio"
 
I use DGAVCIndex in DGAVCDec for mts files.
the tool is used to create .dga files for maiking .mts file available in Avisynth by clicking the "save". normally, but it also make a log file about the .mts file like that:

Stream Type: Transport [192]
Profile: High
Level: 4
Frame Size: 1920x1080
SAR: 1:1
Display Size: 1920x1080
Frame Rate: 23.971235 fps
Colorimetry: BT.709* [2]
Frame Structure: Frame
Frame Type: not yet
Coded Number: 252
Playback Number: 252
Frame Repeats: 0
Field Repeats: 0
Bitrate: 25.015
Bitrate (Avg): 25.136
Bitrate (Max): 27.976
Audio Stream: 1100: AC3 2/0 48 192
Elapsed: 0:00:00
Remain: 0:00:00
FPS:
Info: Finished!



It's free. but I don't know about mac...
 
If you are looking for an overall rate you can just calculate it based on file size and total clip time.

I've noticed that the overall rate is remarkably constant even though the ratio of bandwidth devoted to I frames versus P frames can change considerably based on various parameters. Settings that affect image detail - such as fast shutter speeds, high sharpening values, and low NR settings - can raise the amound of bandwidth devoted to I frames by as much as 50%. That means less bandwidth is devoted to P frames and that will affect image quality between I frames.

Chris
 
I think Microsoft affers a Windows virtual machine for Mac, and there are others - some free. Couldn't you get the Windows version working with one of them? I don't think the program is doing anything special, just parsing a video stream file.

Chris
 
cbrandin said:
I think Microsoft affers a Windows virtual machine for Mac, and there are others - some free. Couldn't you get the Windows version working with one of them? I don't think the program is doing anything special, just parsing a video stream file.

Chris
Click to expand...
Thanks for the help Chris, VLC does it too, I've got my readings. I removed the Windows virtual machine from my mac, thinking I'd never use it... oh, hindsight.

Rob
 
This program works like a charm on my iMac, that someone listed on a post (which I can't find but thank you whoever you are): http://mediainfo.sourceforge.net/en

The program gives an overall Mbps rate, with simple dragging and dropping the mts file into it. I'm using the recommend c settings that are listed on the 3.36 firmware, and depending on the shot, I get anywhere from 16 Mbps to 27 Mbps, with a manual lens, ISO 400. Not as high as I thought, but higher. Thankfully, I had some old Private folders from the pre-hacked GH1, and none of those were going much above 10 Mbps on average (with only one or two files even hitting 13) -- so there is DEFINITELY an improvement.

I however have to use VLC to watch the actual mts file -- just for the statistics from the media information window -- since the picture kinda blows. Then I can watch the whole thing bitrate change, but it's in kbps.
 
rjk2000 said:
This program works like a charm on my iMac, that someone listed on a post (which I can't find but thank you whoever you are): http://mediainfo.sourceforge.net/en

The program gives an overall Mbps rate, with simple dragging and dropping the mts file into it. I'm using the recommend c settings that are listed on the 3.36 firmware, and depending on the shot, I get anywhere from 16 Mbps to 27 Mbps, with a manual lens, ISO 400. Not as high as I thought, but higher. Thankfully, I had some old Private folders from the pre-hacked GH1, and none of those were going much above 10 Mbps on average (with only one or two files even hitting 13) -- so there is DEFINITELY an improvement.

I however have to use VLC to watch the actual mts file -- just for the statistics from the media information window -- since the picture kinda blows. Then I can watch the whole thing bitrate change, but it's in kbps.
Click to expand...
Wicked! Thanks man, exactly what I was after.
 
cbrandin said:
If you are looking for an overall rate you can just calculate it based on file size and total clip time.
Click to expand...
+1

No extra software required. GH1 gives you the time, Finder/Explorer/Dolphin/Nautilus/whatever file browser you have on your computer gives you the file size.

Plus you know that this number is definitely the average bitrate of the file. Not a transient bitrate for a few frames...not a metadata "bitrate" that might be guessed or incorrect...rather the true average bitrate.

J
 
jaydil said:
+1

No extra software required. GH1 gives you the time, Finder/Explorer/Dolphin/Nautilus/whatever file browser you have on your computer gives you the file size.

Plus you know that this number is definitely the average bitrate of the file. Not a transient bitrate for a few frames...not a metadata "bitrate" that might be guessed or incorrect...rather the true average bitrate.

J
Click to expand...
Come on guys, that's too obvious. Math? What is this, the 90's? Why use a calculator when some dude's made a complicated computer program with fancy windows?
Sarcasm makes me feel less stupid...
 
Hehe...not your fault. :)

Fancy windows...or lots of forum posts....will fool most people. ;)

Wouldn't it be great if these forums had a legal obligation for each poster to guarantee they are who they say they are, and whether they are affiliated with Panasonic, or a competing manufacturer, or a distributor, retailer, etc.

The signal:noise ratio on this forum would go waaaay up. :) That would be nice. There is so much stupid marketing crap here right now. :(

J
 
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