Difference between revisions of "Talk:Live CD"

Latest revision as of 11:39, 25 November 2007

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I'm confused about "netcamconfig" and "netcardconfig".

Is the "netcardconfig" from original Knoppix or is is modified too?

And what is "flashit MPlayer..."?

--Andrey.filippov 12:06, 28 September 2005 (MDT)

It is possible to use wiki formatting: asterisk(s) in the beginning of the line make UL, space as the first character - PRE

>netcardconfig

It is modified, it has operations with bridge and checks for ip uniqueness.

>asterisk(s)

It looks a little differently

Andrey, how do you insert a signature?

There is a button above the textarea (second to the right). Or you just put --~~~~ manually

--Andrey.filippov 13:55, 28 September 2005 (MDT)

OK!

--Sergey Khlutchin 14:02, 28 September 2005 (MDT)

I have found that I can not edit different sections of one page simultaneously in different windows. At the second submit there is a undo of the first :-( .

--Sergey Khlutchin 14:10, 28 September 2005 (MDT)

If it is the case - maybe use "includes" {{included_name}}?

It will be possible to have separate files for subsections but see them on the same page. It will also be possible to embedd the same text (and keep it current) into diffrently formatted pages (what Ilya did by copiing)?

--Andrey.filippov 14:39, 28 September 2005 (MDT)

Maybe the "Live CD" page insert to Manual?

--Ilya 13:27, 10 October 2005 (MDT)

maybe --Sergey Khlutchin 13:41, 10 October 2005 (MDT)

New template for navigation

I've added new template for navigation header of the manual. Ilya, look the top of this article.

--Sergey Khlutchin 14:48, 22 October 2005 (CDT)

2GB limit for avi

Here is a discussion about recording avi files with mencoder.

Standard avi files has 2GB limit. See article about avi file limits. In this section i offer method to split video to several files.

Some dropouts may be because of a new call of mencoder opens new RTSP session before recording. I have rewrited rtsp server in the camera to reduce the time of session initialization. New server (qrtsp) now is only in 313 branch. One-two frames everyone may be droped.

Later I have made this splitting in my plug-in for Mozila/Firefox. It has example HTML page, which can be used to record and watch a stream simultaneously You may Download and install the debian package into our Knoppix: http://savannah.nongnu.org/download/genres/genres_0.7.2_i386.deb Then edit file /usr/share/doc/genres/example/drag-test.html: replace 'default.avi' to 'rtsp://camera:7070/' and width=1600 to actual width. And open this in Firefox. You can scroll video picture with mouse dragging (as in acrobat reader) when it is bigger than the window. "Record" link prompts to input a template of file names. Template can contain fields wich will be replaced to current date, time and camera address.

I have an idea on how to start second mencoder before the first will be finished. A special program can monitor output of mplayer and start new instance when is necessary to record given number of frames to complette current file.

Sergey

I was thinking it may be possible to hack the avi encoder/decoder plugin for mplayer/mencoder such that is uses an int64_t for file length, rather than an int32_t. This would produce non-standard avi's which could only be played back by the hacked version of mplayer, but it should enable >2GB files.

--Salsaman 15/11/05

I not like nonstandard formats when standard exists. It is better to use other standard of file format non avi, maybe ogg or mov or other. I don't know is it possible to write files >2GB on FAT32 under linux, but if it is possible maybe windows don't process it. So this is not solves the problem in all. I think the splitting is more common solution.

--Sergey Khlutchin 07:40, 15 November 2005 (CST)

It will bi nice to have a timestamp for each frame (FPGA now supports precise timing and it should not be very difficult to add code to add timing data to the beginning of each frame by FPGA) but it is likely that MJPEG RTP stream format has no room for such info. When splitting stream we need to start new seccion first, and end the previous one later)

Yet another solution is to hack mencoder such that it itself splits video to files with given number of frames. It will be faster without creation of new process and opening new rtsp session.

--Sergey Khlutchin 00:16, 18 November 2005 (CST)

I emailed my contact on the mplayer team, and he told me the 2GB limit is no longer an issue in mplayer, since mplayer now supports openDML (an extension to avi which supports larger files).

I think this support is automatic in the latest version of mplayer/mencoder.

For older versions of mencoder, you can use: mencoder -saveidx <index_file>

and then: mplayer -loadidx <index_file>

This will save/load the index from a separate file, thus getting around the 2GB limit.

--Salsaman 05/12/05

Timestamps

RTP standard common header has 32 bit field for timestamp in 1/90000 of second from some base time. So maximum time is 47721 seconds or 13 hours. Now this field I calculate in the streamer on frame per second value and errors is summed. I can take it from a special field in the camera frame buffer. We can send base time in special packet or with http and rtsp.

--Sergey Khlutchin 11:22, 15 November 2005 (CST)

Nice - probably it will be easier to add timestamp in the driver where it calculates pointers in the DMA buffer (put it just ahead of the frame length).

Dump mencoder and write a separate stream recorder?

I'm not sure mecoder (contrary to Mplayer) works well just for the RTP stream recording. Even it's name includes "encoder" - the main purpose of this program is to re-code from one format to the another.

What is important for us - the DVR function, just saving the RTP incoming stream(s) as is(are), avoiding frame drops and using as low resources as possible and being able to serve as many cameras in parallel as possible. In some cases the same computer will be used to visualize the stream(s) - likely with reduced resolution/frame rate and with lower priority - only using resources that are left free by the recording.

The DVR software should also provide capabilities to split recording in multiple files (with no time gaps - overlap is acceptable), support pause, support Apple Quicktime (.mov) format in addition to (or instead of) the Microsoft .avi one. Anyway standard Windows player does not support AVI with Motion JPEG inside (at least it did not work for me) so it is better to provide .mov container that will be played as is by the Apple Quicktime.

--Andrey.filippov 11:53, 29 November 2005 (CST)

to upgrade if we continue to maintain User_Documentation

--Polto 20:34, 25 Nov 2007 (GMT)

to restore / upgrade and point to both Knoppix & Ubuntu based CD/DVD --Polto 20:39, 25 Nov 2007 (GMT)