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by towolf
Sat Dec 07, 2013 3:34 pm
Forum: Camera board
Topic: Official V4L2 driver
Replies: 557
Views: 461544

Re: Official V4L2 driver

Finally Arch Linux Arm for Rpi uploaded the latest kernel and I can test. I find the latency improved compared to piping raspivid into Gstreamer (it ranges from 150 to 200 msec over two wireless links). Preserving the V4l2 timestamps via Gstreamer over RTP seems to work as well. There’s always a sli...
by towolf
Thu Dec 05, 2013 2:52 pm
Forum: Camera board
Topic: STICKY: New features for raspistill command
Replies: 106
Views: 116316

Re: New features for raspistill command

Tell that to the dudes who spent years trying to painstakingly clean-room reverse engineer the Broadcom wireless drivers to write open source kernel drivers. Then some blokes at Broadcom decided the Android business was worth opening up the driver for. Suddenly the sacred business secrets and regula...
by towolf
Wed Dec 04, 2013 7:15 pm
Forum: Camera board
Topic: SD Card Full
Replies: 6
Views: 1120

Re: SD Card Full

Or plug the card into a Linux PC.
by towolf
Wed Dec 04, 2013 5:08 pm
Forum: Camera board
Topic: Official V4L2 driver
Replies: 557
Views: 461544

Re: Official V4L2 driver

I think that the control you mentioned should be a good fit. Judging by the documentation and your needs you should use it. Changing the documentation not to list specific codecs would be a great idea. The following presentation may help you while writing the v4l2 codec driver. It is a presentation...
by towolf
Wed Dec 04, 2013 4:40 pm
Forum: Camera board
Topic: Official V4L2 driver
Replies: 557
Views: 461544

Re: Official V4L2 driver

I will have a look for PPS/SPS controls in there. V4L2_CID_MPEG_VIDEO_REPEAT_SEQ_HEADER looks plausible - do you agree? Ah you meant on the V4L side. I think so, yes. But if this control rally needs exposing I don't know. I think V4L2_CID_MPEG_VIDEO_REPEAT_SEQ_HEADER is the right control. I think i...
by towolf
Wed Dec 04, 2013 2:57 pm
Forum: Camera board
Topic: Official V4L2 driver
Replies: 557
Views: 461544

Re: Official V4L2 driver

6by9 wrote:I will have a look for PPS/SPS controls in there. V4L2_CID_MPEG_VIDEO_REPEAT_SEQ_HEADER looks plausible - do you agree?
Ah you meant on the V4L side. I think so, yes. But if this control rally needs exposing I don't know.
by towolf
Wed Dec 04, 2013 2:48 pm
Forum: Camera board
Topic: Official V4L2 driver
Replies: 557
Views: 461544

Re: Official V4L2 driver

Definitely inline pps/sps headers as in raspivid if possible. This is essential for streaming live. Or any other H264 encoding options. QP instead of bitrate would be appreciated as well. I'm restricted by what V4L2 can expose and control. We do have a good relationship with one of the V4L2 maintai...
by towolf
Wed Dec 04, 2013 1:18 pm
Forum: Camera board
Topic: Official V4L2 driver
Replies: 557
Views: 461544

Re: Official V4L2 driver

- Extra controls to mimic those exposed with raspistill. Do-able if they are available through the V4L2 API. The initial aims were to get the basic framework running with some parameters. Adding extras should be relatively trivial (extra array values in controls.c). AWB modes (we don't do full colo...
by towolf
Tue Dec 03, 2013 9:02 pm
Forum: Camera board
Topic: Official V4L2 driver
Replies: 557
Views: 461544

Re: Official V4L2 driver

Use

Code: Select all

configure --prefix=/usr
by towolf
Tue Dec 03, 2013 7:17 pm
Forum: Camera board
Topic: Official V4L2 driver
Replies: 557
Views: 461544

Re: Official V4L2 driver

jbeale, use the overlay preview from the v4l tool. Use guvcview -o (note the -o) only to control the settings.

Using the preview built into guvcview will be slow.
by towolf
Tue Dec 03, 2013 5:52 pm
Forum: Camera board
Topic: Official V4L2 driver
Replies: 557
Views: 461544

Re: Official V4L2 driver

I don't know if guvcview is available on raspbian. It's a GTK GUI program that allows you to control the stuff with sliders. guvcview -o just shows the controls with no preview. My Apple LCD at work has these: brightness (int) : min=-127 max=127 step=1 default=0 value=0 contrast (int) : min=0 max=64...
by towolf
Tue Dec 03, 2013 5:36 pm
Forum: Camera board
Topic: Official V4L2 driver
Replies: 557
Views: 461544

Re: Official V4L2 driver

Normally you can enumerate the controls a v4l driver exposes. Does this v4l tool have a command line option like "list controls"?
by towolf
Tue Dec 03, 2013 4:34 pm
Forum: Camera board
Topic: Official V4L2 driver
Replies: 557
Views: 461544

Re: Official V4L2 driver

It's a kernel driver that is written according to the standard video2linux specification. Most software on Linux requires video4linux drivers. The cludge with piping video to other software is unnecessary now. Provided it works properly. And proper timestamps allowing VFR, and easy muxing, e.g., wit...
by towolf
Tue Dec 03, 2013 4:14 pm
Forum: Camera board
Topic: Official V4L2 driver
Replies: 557
Views: 461544

Re: Official V4L2 driver

Sweet! I've been waiting for this. Gonna test soon.

Why does it say "Authored 10 months ago" on GitHub?
by towolf
Fri Nov 29, 2013 12:58 am
Forum: Camera board
Topic: Minimizing latency with streaming encoded h264?
Replies: 38
Views: 13958

Re: Minimizing latency with streaming encoded h264?

Because scaling reduces sharpness. It's such a minor crop, image quality should take precedence. I think you'd be hard pushed to see any degradation when scaling down like this. We've certainly done something similar for production devices, and the notoriously extremely difficult to pass quality te...
by towolf
Wed Nov 27, 2013 3:55 pm
Forum: Camera board
Topic: Minimizing latency with streaming encoded h264?
Replies: 38
Views: 13958

Re: Minimizing latency with streaming encoded h264?

Because scaling reduces sharpness. It's such a minor crop, image quality should take precedence.
by towolf
Wed Nov 27, 2013 11:44 am
Forum: Camera board
Topic: Minimizing latency with streaming encoded h264?
Replies: 38
Views: 13958

Re: Minimizing latency with streaming encoded h264?

Please also consider a video mode that captures full frame (2592x1944), bins this 2x2 to 1296x972, and then central crop to yield 1280x720.

This would give maximum quality wide 720p.

Really still holding my thumbs hoping this will be possible.
by towolf
Fri Nov 15, 2013 9:26 pm
Forum: Camera board
Topic: New raspivid test release - please try.
Replies: 59
Views: 18884

Re: New raspivid test release - please try.

Code: Select all

omxplayer <(cat *.h264)
Bash process substitution.

This segmentation is sweet. If only we could get a container format with timestamps now to make auto-gain with variable frame rates feasible.






( ... And full sensor video ...)
by towolf
Thu Nov 14, 2013 6:05 pm
Forum: Camera board
Topic: PoC: Poor man's high framerate full HD motion detection
Replies: 25
Views: 14292

Re: PoC: Poor man's high framerate full HD motion detection

Looking at the motion vectors in the H264 is more promising than just bit allocation. Just more image noise after an ISO switch would inflate the bitrate.
by towolf
Thu Nov 14, 2013 5:59 pm
Forum: Camera board
Topic: Simple time-lapse with raspivid
Replies: 6
Views: 4068

Re: Simple time-lapse with raspivid

You can pipe video through ffmpeg and let it write neatly segmented video chunks that can be gaplessly concatenated later.
by towolf
Wed Nov 13, 2013 2:11 pm
Forum: Camera board
Topic: Minimizing latency with streaming encoded h264?
Replies: 38
Views: 13958

Re: Minimizing latency with streaming encoded h264?

Here's a blog post that elucidates how encoding strategies can lower coding latencies:

http://x264dev.multimedia.cx/archives/249

The relevant part is described as "Periodic Intra Refresh".
by towolf
Wed Nov 13, 2013 1:25 pm
Forum: Camera board
Topic: live camera
Replies: 16
Views: 14399

Re: live camera

donde wrote: The camera will be on for 2 hours + ! Not a good idea
Says who?
by towolf
Tue Nov 12, 2013 11:12 am
Forum: Camera board
Topic: live camera
Replies: 16
Views: 14399

Re: live camera

You’re trying to run mplayer on the raspberry. The command you used has to be run on your local box.
by towolf
Fri Nov 01, 2013 7:46 pm
Forum: Camera board
Topic: Streaming Raspberry Pi Camera H264 into HTML over RTMP
Replies: 199
Views: 247653

Re: Streaming Raspberry Pi Camera H264 into HTML over RTMP

HLS was not made for the real-time type of live streaming. Only the TV type of live.
by towolf
Tue Oct 29, 2013 8:26 pm
Forum: Camera board
Topic: tmpfs questions
Replies: 7
Views: 6624

Re: tmpfs questions

/dev/shm is for shared memory not for user files.

If you want /tmp to be a ramdisk put this line into /etc/fstab:

Code: Select all

tmpfs           /tmp            tmpfs   defaults,noatime,nosuid   0       0

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