<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=ISO-8859-1">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<meta http-equiv="CONTENT-TYPE" content="text/html;
charset=ISO-8859-1">
<p class="western" style="margin-bottom: 0cm">I am confused by
'filters'.</p>
<p class="western" style="margin-bottom: 0cm">I think that I
understand that a filter is any element which is not a source or a
sink and that a filter 'does something' to the data being passed
through it.</p>
<p class="western" style="margin-bottom: 0cm">For some filters, I
can
find information by looking at the 'GStreamer Good Plugins 1.0
Plugins Reference Manual' – but some, I am not sure what to look
for.</p>
<p class="western" style="margin-bottom: 0cm">I am trying to record
audio/video – but it appears that I am not getting the video
content I want.</p>
<p class="western" style="margin-bottom: 0cm">I initially had the
command</p>
<p class="western">gst-launch-1.0 v4l2src !
'video/x-raw,format=(string)I420,width=320,height=240,framerate=(fraction)25/1'
!
queue ! mux. alsasrc num-buffers=440 ! audioconvert !
'audio/x-raw,rate=44100,channels=2' ! queue ! mux. avimux name=mux
!
filesink location=test.avi</p>
<p class="western">and I got the result (including terminating with
a
Control-C)</p>
<p class="western">Setting pipeline to PAUSED ... </p>
<p class="western">Pipeline is live and does not need PREROLL ... </p>
<p class="western">Setting pipeline to PLAYING ... </p>
<p class="western">New clock: GstAudioSrcClock </p>
<p class="western">^CCaught interrupt -- handling interrupt. </p>
<p class="western">Interrupt: Stopping pipeline ... </p>
<p class="western">Execution ended after 6006542779 ns. </p>
<p class="western">Setting pipeline to PAUSED ... </p>
<p class="western">Setting pipeline to READY ... </p>
<p class="western">Setting pipeline to NULL ... </p>
<p class="western">Freeing pipeline ... </p>
<p class="western">A test.avi file was created and it contained the
audio, but the video was evidently not there (all I saw when I
played
the avi was a filmstrip large icon).</p>
<p class="western"><br>
</p>
<p class="western">I thought that the failure to record any video
could be a) the hardware of my capture card, b) the v4l2src plugin
or
c) one of the other plugins up to the filesink – so I attempted to
use videotestsrc to see if I got any video.</p>
<p class="western">I tried</p>
<p class="western">gst-launch -v videotestsrc num-buffers=25 !
'video/x-raw,format=(string)I420,width=320,height=240,framerate=(fraction)25/1'
!
queue ! mux. alsasrc num-buffers=440 ! audioconvert !
'audio/x-raw,rate=44100,channels=2' ! queue ! mux. avimux name=mux
!
filesink location=test.avi </p>
<p class="western">but I got</p>
<p class="western">WARNING: erroneous pipeline: could not link
videotestsrc0 to queue0</p>
<p class="western">I didn't expect it to help, but I removed the
'filter' </p>
<p class="western">video/x-raw,format=(string)I420,width=320,height=240,framerate=(fraction)25/1</p>
<p class="western">to leave</p>
<p class="western">gst-launch -v videotestsrc num-buffers=25 ! queue
! mux. alsasrc num-buffers=440 ! audioconvert !
'audio/x-raw,rate=44100,channels=2' ! queue ! mux. avimux name=mux
!
filesink location=test.avi</p>
<p class="western">which resulted in</p>
<p class="western">WARNING: erroneous pipeline: could not link
audioconvert0 to queue1 </p>
<p class="western">So, I removed the 'audio/x-raw ...' filter and it
now worked – insofar as I now had test video with some recorded
audio.</p>
<p class="western">I had assumed that the 2 'filters' were supposed
to determine the nature of the video and audio that I captured –
but this only works without them, so how can I configure how I
record?<br>
</p>
<p class="western">I do not know what to try to read regarding these
filters. I cannot see 'video' or 'video/x-raw' or 'audio' or
'audio/x-raw' in the documentation of plug-ins I have looked at.
I am probably looking in the wrong place.<br>
</p>
<p class="western"><br>
<br>
</p>
<p class="western">As to my video, here is a section of the output
of
dmesg</p>
<p class="western">[ 6.790578] bttv: driver version 0.9.19 loaded </p>
<p class="western">[ 6.790580] bttv: using 8 buffers with 2080k
(520 pages) each for capture </p>
<p class="western">[ 6.790613] bttv: Bt8xx card found (0) </p>
<p class="western">[ 6.790630] bttv: 0: Bt848 (rev 18) at
0000:03:02.0, irq: 23, latency: 32, mmio: 0xfdfff000 </p>
<p class="western">[ 6.790644] bttv: 0: using: ***
UNKNOWN/GENERIC *** [card=0,autodetected] </p>
<p class="western">[ 6.791304] tveeprom 6-0050: Huh, no eeprom
present (err=-6)? </p>
<p class="western">[ 6.791305] bttv: 0: tuner type unset </p>
<p class="western">[ 6.791423] bttv: 0: registered device video0 </p>
<p class="western">[ 6.791471] bttv: 0: registered device vbi0</p>
<p class="western">So Linux has seen the video card but I notice
that there my be a problem with a missing
eeprom, although I do have a /dev/video0. Could this explain the
lack of video?</p>
<title></title>
<meta name="GENERATOR" content="OpenOffice.org 3.4.1 (Win32)">
<style type="text/css">
<!--
@page { margin: 2cm }
P { margin-bottom: 0.21cm }
-->
</style>
<div class="moz-signature">-- <br>
--<br>
Ian Davidson<br>
<i>239 Streetsbrook Road, Solihull, West Midlands, B91 1HE</i><br>
--<br>
Facts used in this message may or may not reflect an underlying
objective reality. Facts are supplied for personal use only.<br>
Recipients quoting supplied information do so at their own risk.
Facts supplied may vary in whole or part from widely accepted
standards.<br>
While painstakingly researched, facts may or may not be indicative
of actually occurring events or natural phenomena.<br>
The author accepts no responsibility for personal loss or injury
resulting from memorisation and subsequent use.
</div>
</body>
</html>