Bit Rates

Started by Lumiére, January 12, 2013, 12:04:45 AM

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Lumiére

Pro video cameras record video in various bit rates such as 25mbps, 35mbps, 50mbps  so on.  What is original Canon video bit rate? i.e 60D
In ML  CBR mode what the adjustments [-16...+16]  point to in terms of  mbps.  Also is there a simple software to analyse video bit rate etc.
Canon 60D, Tascam DR-40, Audio-Technica wireless/shotgun mikes, Adobe Production Premium CS6

nanomad

Camera uses a VBR encoder, so the bitrate varies with the complexity of the scene
EOS 1100D | EOS 650 (No, I didn't forget the D) | Ye Olde Canon EF Lenses ('87): 50 f/1.8 - 28 f/2.8 - 70-210 f/4 | EF-S 18-55 f/3.5-5.6 | Metz 36 AF-5

Lumiére

OK, since there is not going to be a fixed bitrate on Canon like the video cameras it is not  important in my case to mess around with the bitrate function. Images out of 60D is already great. Many thanx for the reply.
Canon 60D, Tascam DR-40, Audio-Technica wireless/shotgun mikes, Adobe Production Premium CS6

1%

Digic IV encoders encode based on QP  value set via predicting the size of the next frame.
Digic V encoders encode based on fixed QP or target bit rate (which just changes QP).

There is no way to do real CBR because your scene will always be different, even to the point where camera cannot process encoding the scene at fixed quality and stops.

You can check out what its doing with bit rate viewer or avinaptic. Default rates will have high (low quality) QPs.

Lumiére

Canon 60D, Tascam DR-40, Audio-Technica wireless/shotgun mikes, Adobe Production Premium CS6

Lumiére

Here is some tests I made for those interested in bitrate subject. I downloaded  Mediainfo which is a great tool. And tested some video footage as follows:
Canon 60D  1920x1080  25fr     color space 4.2.0      overall bitrate   45.8 Mbps
                     720x1280   50fr     color space 4.2.0      overall bitrate  47.3 Mbps
Nikon 5100   720x1280   50fr     color space  4.2.0     overall bitrate   12 Mbps ( poor Nik)
  Lets remember  HDV is 25 Mbps,  full HD minimum broadcast requirement is 35 Mbps,  BBC broadcast requirement is 50 Mbps  (color space 4.2.2)
All these figures make Canon a winner at 45.8 Mbps very close to 50.   :)
Canon 60D, Tascam DR-40, Audio-Technica wireless/shotgun mikes, Adobe Production Premium CS6

1%

It can go a bit higher than that.

alMalsamo

Quote from: Lumiére on January 12, 2013, 06:22:16 PM
                     720x1080   50fr     color space 4.2.0      overall bitrate  47.3 Mbps
Nikon 5100   720x1080   50fr     color space  4.2.0     overall bitrate   12 Mbps ( poor Nik)

720x1080?  What kind of aspect ratio is that... taller video than it is wide by 360 pixels?

Maybe you mean 1280x720?

Lumiére

Sorry its  1280x720  of course. Just my typing error.  Its been corrected.
Canon 60D, Tascam DR-40, Audio-Technica wireless/shotgun mikes, Adobe Production Premium CS6