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Messages - sharpmusic

#1
Quote from: Digital Corpus on May 25, 2013, 10:01:34 AM
Your error was in notation. Upper case 'B' is bytes, lower case 'b' is in bits.

g3gg0 does plan on returning back to the 7D's development, but his focus lies on the RAW video development and regular life (I assume). Right now ML is running off of the slave CPU in the 7D. As far as he can tell, now RAW stream touches the slave. So, for the time being, maybe until the end of time, we will not have RAW video. However, we will get a good copy of ML. In earlier tests I've recorded 220+ Mbps h.264 video with CRB 20 on my Samsung 16 GB cards.

Yes sir, video and audio data rates have always been measured in bits hence CBR (constant bit rate, and High bit rate)
#2
Quote from: feureau on May 24, 2013, 05:42:36 AM
That's megabit not megabytes.

89.6 Mbps = 11.2 MBps. About 1/8th of a raw 1080 24p feed.

Your math is good but someone please correct me if I'm wrong but "All" canon cameras are measured in bits not bytes.  Hence the term CBR=Constant bit rate, and I believe that's one of the reasons we install Magic Lantern to attain a higher "bit" rate, not bytes.  Even in the panasonic GH2 ptools hacks that attain 72Mbps, again measured in only bits as with most audio and video data rate analysis.


Bytes are usually used for the storage required here is the constant bitrate formula for RAW (uncompressed video):

Storage and Data Rates for Uncompressed Video

Constant bitrate formula: Uncompressed data rate = color depths * vertical resolution * horizontal resolution * refresh frequency
Examples
24bit @ 1080i @ 30fps :24*1920*1080*30=1.49 Gbps.
24bit @ 1080p @ 60fps :24*1920*1080*60=2.98 Gbps.
The storage and data rates for the widely-used YCbCr 4:2:2 chroma subsampling uncompressed video are listed below:
525 NTSC uncompressed
8 bit @ 720 x 486 @ 29.97fps = 20 MB per/sec, or 70 GB per/hr.
10 bit @ 720 x 486 @ 29.97fps = 27 MB per/sec, or 94 GB per/hr.
#3
According the software media info I evaluated ML footage on my 7D and I am getting 89.6 Mbps on a UDMA6 card no less.

General
Complete name                            : Z:\Desktop\MVI_0285.MOV
Format                                   : MPEG-4
Format profile                           : QuickTime
Codec ID                                 : qt 
File size                                : 438 MiB
Duration                                 : 41s 8ms
Overall bit rate                         : 89.6 Mbps
Encoded date                             : UTC 2013-05-11 14:42:01
Tagged date                              : UTC 2013-05-11 14:42:01

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : [email protected]
Format settings, CABAC                   : No
Format settings, ReFrames                : 1 frame
Format settings, GOP                     : M=1, N=15
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 41s 8ms
Bit rate                                 : 89.6 Mbps
Width                                    : 1 920 pixels
Height                                   : 1 080 pixels
Original height                          : 1 088 pixels
Display aspect ratio                     : 16:9
Original display aspect ratio            : 16:9