Theora - Revision history

Eplese: Elaborated on the causes.

2007-05-18T13:58:04Z

Elaborated on the causes.

← Older revision		Revision as of 13:58, 18 May 2007
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	== Outstanding Issues ==		== Outstanding Issues ==
	These are issues that exist with the existing Theora streamer version 1.0:		These are issues that exist with the existing Theora streamer version 1.0:
	* Frames with encoded sizes larger than around 100KB aren't transmitted ~~(or received) properly~~.		* Frames with encoded sizes larger than around 100KB aren't transmitted. This appears to be caused by an explicit check of the frame size at line 469 of theora_str's main.c.
	* An integer overflow exists in theora_str which causes ~~issues~~ streaming to ~~be interrupted~~ after 45 minutes (at 5 FPS).		* An integer overflow exists in theora_str which causes streaming to halt after 45 minutes (at 5 FPS). The delta variable used in the while loop at line 454 of theora_str's main.c becomes negative and causes a very long sleep in the program.
	* The -f/--fps option for theora_str doesn't work properly. The framerate must be throttled with the sclk option added to the configuration URL as mentioned above.		* The -f/--fps option for theora_str doesn't work properly. The framerate must be throttled with the sclk option added to the configuration URL as mentioned above.

Eplese at 00:44, 18 May 2007

2007-05-18T00:44:06Z

← Older revision		Revision as of 00:44, 18 May 2007
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	For example, to cut the framerate approximately in half, add "&sclk=24" to the		For example, to cut the framerate approximately in half, add "&sclk=24" to the
	URL.		URL.

			== Outstanding Issues ==
			These are issues that exist with the existing Theora streamer version 1.0:
			* Frames with encoded sizes larger than around 100KB aren't transmitted (or received) properly.
			* An integer overflow exists in theora_str which causes issues streaming to be interrupted after 45 minutes (at 5 FPS).
			* The -f/--fps option for theora_str doesn't work properly. The framerate must be throttled with the sclk option added to the configuration URL as mentioned above.

Eplese: Framerate adjustments.

2007-05-15T00:00:29Z

Framerate adjustments.

← Older revision		Revision as of 00:00, 15 May 2007
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	$ theorartp-client -i 1.2.3.5 -p 20000 -f output.ogg		$ theorartp-client -i 1.2.3.5 -p 20000 -f output.ogg
	</pre>		</pre>

			=== Framerate Adjustments ===
			By default the camera will stream as fast as possible which may not be
			desirable. The theora_str program has a -f/--fps option that appears to
			allow the framerate to be adjusted but this ends up corrupting the Theora
			stream, rendering it unusable.

			The maximum framerate is affected by the resolution of the frames, the
			exposure time, and the sensor clock. Of these three variables, the sensor
			clock is the only option that can be adjusted that won't dramatically affect
			the appearance of the frames.

			To adjust the sensor clock, add an sclk parameter to the URL with a value
			specified in megahertz. The default and maximum sensor clock is 48 MHz.
			For example, to cut the framerate approximately in half, add "&sclk=24" to the
			URL.

Eplese: Mention wget.

2007-05-14T22:29:00Z

Mention wget.

← Older revision		Revision as of 22:29, 14 May 2007
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	streamer. There are quite a few settings so it can take some time to adjust		streamer. There are quite a few settings so it can take some time to adjust
	them properly to get a good picture.		them properly to get a good picture.

			Instead of requesting the page through a browser, wget can be used to download
			short Theora clips from the camera. When processing web requests the camera
			will first capture the entire clip to RAM and then begin to send the clip
			over the network. Requesting a Theora clip of only a single frame can be used
			to quickly adjust the video parameters from a script without taking much time
			to capture any video.

	== Theora Streamer ==		== Theora Streamer ==

Andrey.filippov at 17:08, 14 May 2007

2007-05-14T17:08:55Z

← Older revision		Revision as of 17:08, 14 May 2007
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	We plan to [[Design_Ideas#FPGA_Theora_Encoder_for_Videoconferencing \| resume]] Ogg Theora project on the new 353 hardware - Axis ETRAX FS		We plan to [[Design_Ideas#FPGA_Theora_Encoder_for_Videoconferencing \| resume]] Ogg Theora project on the new 353 hardware - Axis ETRAX FS
	is faster so it will better handle streaming (the bottleneck of the Ogg Theora		is faster so it will better handle streaming (the bottleneck of the Ogg Theora
	implementation in Model 333.		implementation in Model 333).

	Combining MJPEG and Theora in the same FPGA would complicate things - my plan		Combining MJPEG and Theora in the same FPGA would complicate things - my plan

Andrey.filippov at 17:01, 14 May 2007

2007-05-14T17:01:18Z

← Older revision		Revision as of 17:01, 14 May 2007
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	around September 2007.		around September 2007.

	We plan to resume Ogg Theora project on the new 353 hardware - Axis ETRAX FS		We plan to [[Design_Ideas#FPGA_Theora_Encoder_for_Videoconferencing \| resume]] Ogg Theora project on the new 353 hardware - Axis ETRAX FS
	is faster so it will better handle streaming (the bottleneck of the Ogg Theora		is faster so it will better handle streaming (the bottleneck of the Ogg Theora
	implementation in Model 333.		implementation in Model 333.

Andrey.filippov at 16:57, 14 May 2007

2007-05-14T16:57:54Z

@@ Line 8: / Line 8: @@
 compressors.  Porting the Theora compressor to the 353 is targeted to begin
 around September 2007.
 == Web Interface ==

Eplese at 16:09, 14 May 2007

2007-05-14T16:09:05Z

← Older revision		Revision as of 16:09, 14 May 2007
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	can only support a single encoding algorithm, either MJPEG or Theora. The		can only support a single encoding algorithm, either MJPEG or Theora. The
	6.3.x series supports Theora and the 6.4.x and 6.5.x series support MJPEG.		6.3.x series supports Theora and the 6.4.x and 6.5.x series support MJPEG.

			The 353 camera has a larger FPGA with space for both Theora and MJPEG
			compressors. Porting the Theora compressor to the 353 is targeted to begin
			around September 2007.

	== Web Interface ==		== Web Interface ==

Eplese at 15:53, 14 May 2007

2007-05-14T15:53:41Z

New page

The model 333 camera is able to encode and stream video in Ogg Theora in
realtime. In order to encode in Theora the older 6.3.9 firmware must be
loaded onto the camera. Due to space limitations in the FPGA, each firmware
can only support a single encoding algorithm, either MJPEG or Theora. The
6.3.x series supports Theora and the 6.4.x and 6.5.x series support MJPEG.

== Web Interface ==
Once the 6.3.9 firmware is loaded and an IP address is configured, the web
interface on the camera is used to download short Theora clips for testing
and also to set the video parameters which are also used by the Theora
streamer. There are quite a few settings so it can take some time to adjust
them properly to get a good picture.

== Theora Streamer ==
The Theora streamer can be acquired from the SourceForge download site
and the file is Theora_str_1.0.tgz. This contains the source and compiled
binaries for the streamer (theora_str) and the receiver (theorartp-client).

For the following examples it's assumed that the streamer has an IP address of
1.2.3.4 and the receiver has an IP address of 1.2.3.5. The examples use
unicast rather than multicast for simplicity.

=== Streamer ===
This method uses HTTP to transfer the executable to the camera so a webserver
of some sort is required. In addition this is temporary and will be
completely lost when the camera is powered off.

<pre>
$ telnet 1.2.3.4
$ cd /tmp
$ wget http://webserver/theora_str
$ chmod +x theora_str
$ ./theora_str -a 1.2.3.5 -p 20000 -k 25
</pre>

This will download and run the streamer on the camera. The -p option is the
IP port and the -k is the number of interframes between intraframes
(keyframes) in the Theora stream.

=== Receiver ===
<pre>
$ theorartp-client -i 1.2.3.5 -p 20000 -f output.ogg
</pre>