- Joined
- May 1, 2013
- Messages
- 10,668
- Reaction score
- 6,561
- Location
- Dublin
- Country
- Ireland
- Dash Cam
- Street Guardian UK / EU / EEA Distributor
Well in DSLR, metering is the way how light exposure is calculated.
It's different for portraits vs landscape pictures.
For dashcam video, I'm not sure what's best. This option was not there in other cameras so just asking what's the best.
Doreen should have the answer.
Overall bit rate increased from 15.8mbps to 19.5mbps even though video and audio bit rate is unchanged???
How's that possible?
May be I need to take longer video for proper data.
This properties is from Mediainfo.
As for files, here is before with initial firmware.
General
Complete name : F:\NORMAL\2014-07-23-17-34-30.MOV
Format : MPEG-4
Format profile : QuickTime
Codec ID : qt
File size : 340 MiB
Duration : 3mn 0s
Overall bit rate mode : Variable
Overall bit rate : 15.8 Mbps
Encoded date : UTC 2014-07-23 17:34:30
Tagged date : UTC 2014-07-23 17:34:30
AMBA :
Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Main@L4.0
Format settings, CABAC : Yes
Format settings, ReFrames : 1 frame
Format settings, GOP : M=1, N=15
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 3mn 0s
Bit rate mode : Variable
Bit rate : 15.0 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 29.970 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.241
Stream size : 322 MiB (95%)
Title : Ambarella AVC / Ambarella AVC
Language : English
Encoded date : UTC 2014-07-23 17:34:30
Tagged date : UTC 2014-07-23 17:34:30
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Audio
ID : 2
Format : ADPCM
Codec ID : 11
Codec ID/Hint : Intel
Duration : 3mn 0s
Bit rate mode : Constant
Bit rate : 408 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Stream size : 8.76 MiB (3%)
Title : Ambarella AAC / Ambarella AAC
Language : English
Encoded date : UTC 2014-07-23 17:34:30
Tagged date : UTC 2014-07-23 17:34:30
***********************************************************
With new r328 firmware: It's a short clip I did inside the room but that should give the idea.
General
Complete name : F:\NORMAL\2014-07-26-08-36-32.MOV
Format : MPEG-4
Format profile : QuickTime
Codec ID : qt
File size : 40.0 MiB
Duration : 17s 217ms
Overall bit rate mode : Variable
Overall bit rate : 19.5 Mbps
Encoded date : UTC 2014-07-26 08:36:32
Tagged date : UTC 2014-07-26 08:36:32
AMBA :
Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Main@L4.0
Format settings, CABAC : Yes
Format settings, ReFrames : 1 frame
Format settings, GOP : M=1, N=15
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 17s 217ms
Bit rate mode : Variable
Bit rate : 15.0 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 29.970 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.241
Stream size : 31.0 MiB (77%)
Title : Ambarella AVC / Ambarella AVC
Language : English
Encoded date : UTC 2014-07-26 08:36:32
Tagged date : UTC 2014-07-26 08:36:32
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Audio
ID : 2
Format : ADPCM
Codec ID : 11
Codec ID/Hint : Intel
Duration : 17s 178ms
Bit rate mode : Constant
Bit rate : 408 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Stream size : 856 KiB (2%)
Title : Ambarella AAC / Ambarella AAC
Language : English
Encoded date : UTC 2014-07-26 08:36:32
Tagged date : UTC 2014-07-26 08:36:32
@
Overall bit rate increased from 15.8mbps to 19.5mbps even though video and audio bit rate is unchanged???
How's that possible?
Variable bit-rate changes it value automatically depending on scene. The more action, light- and colours changing around at some scene, - the more more data need to be processed, - the higher bit-rate is used.
At night ( pitch dark ) bit-rate is lower than at day.
There is some logical explanation to variable bit-rate ( to save flash memory ), but it puts more pressure on CPU to work harder and in real life those "savings" of memory card space are not significant vs how much more work CPU must do.