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With all the measurements I've done with the images from my webcam
( the API <br>
calls: <i>th_encode_ycbcr_in</i> and <i>th_encode_packetout</i> take <b>80
ms </b>when there <br>
is a lot of motion from the webcam ), I've come to the conclusion that
I can only <br>
encode around 10-12 frames/sec without any other image processing ( YUV
conversion, etc).<br>
<br>
<br>
Mircea Gliga wrote:
<blockquote cite="mid:4B1D0BD7.7030008@integrasoft.ro" type="cite">I'm
evaluating some video codecs for a online conference system. I'm
encoding images (640x480)<br>
from a webcam. I've been playing around with theora and xvid. <br>
First of all, using theora, the decoded image looks strange: <a
moz-do-not-send="true"
href="http://integrasoft.ro/%7Emgliga/theora/comparison.png">http://integrasoft.ro/~mgliga/theora/comparison.png</a>.<br>
On the left side the image from the webcam, on the right side the image
from the <br>
webcam encoded, and then decoded using theora. As you can see there are
some strange <br>
colors overs there ( looks like edge detection <span
class="moz-smiley-s5"><span> :-D </span></span> ).<br>
Then I measured how long does it take for Theora to encode an image
(<i>th_encode_ycbcr_in</i> and <i><br>
th_encode_packetout</i> calls).<br>
<br>
int TIMER_t0 = GetTickCount();<br>
int ret = th_encode_ycbcr_in( (th_enc_ctx*)m_encoderHandler, ycbcr);<br>
ogg_packet op;<br>
th_encode_packetout((th_enc_ctx*)m_encoderHandler,0,&op)>0 <br>
int TIMER_t1 = GetTickCount();<br>
printf( "Timer : %d \n",TIMER_t1 - TIMER_t0 );<br>
<br>
On average: <b>80 ms</b>.<br>
<br>
Using XVID I've obtained between <b>20-25 ms</b> for an image.
That's 60ms longer using Theora.<br>
I don't know if I am doing something wrong while initializing the
encoder, or that's the way it <br>
supposed to be. The encoder initialization used by me can be found
here: <a moz-do-not-send="true"
href="http://integrasoft.ro/%7Emgliga/theora/comparison.png">http://integrasoft.ro/~mgliga/theora/theora_init.cpp</a><br>
<br>
Used hardware/software:<br>
Processor Pentium(R) Dual-Core CPU E5200 @ 2.50GHz, 2400
Mhz, 2 Core(s), 2 Logical Processor(s)<br>
Installed Physical Memory (RAM) 2.00 GB<br>
OS Name Microsoft® Windows Vista™ <br>
<br>
<br>
Any ideas or suggestions are welcomed.<br>
<br>
<pre class="moz-signature" cols="72">--
Mircea Gliga
</pre>
</blockquote>
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