[mythtv] GetPreviewImage returns 404 not found

[Gordon McLellan]

I'm trying to troubleshoot a thumbnail generation problem, and have
been running the backend with different verbosities looking for clues.

I've stumbled across my best lead yet ... a http 404 response is sent
whenever mythweb calls /Myth/GetPreviewImage

logs:

2008-05-02 09:38:35.733 MythXML::ProcessRequest: GetPreviewImage : GET
/Myth/GetPreviewImage?ChanId=1059&StartTime=2008-05-02T09:00:00&Height=260&Width=320&SecsIn=64
HTTP/1.0
2008-05-02 09:38:35.734 HTTPRequest::SendResponse(xml/html) () :404
Not Found -> 192.168.2.30: 2
2008-05-02 09:38:35.736 MythXML::ProcessRequest: GetPreviewImage : GET
/Myth/GetPreviewImage?ChanId=1059&StartTime=2008-05-02T09:00:00&Height=0&Width=320&SecsIn=64
HTTP/1.0
2008-05-02 09:38:35.737 HTTPRequest::SendResponse(xml/html) () :404
Not Found -> 192.168.2.30: 2

I have tried manually calling GetPreviewImage, but I cannot find the
right syntax, or perhaps, the right port number.  I thought it was
6544, but that does not result in the same error in the logs:

# wget 'http://localhost:6544/getPreviewImage?ChanId=1059&StartTime=2008-05-02T09:00:00&Height=260&Width=320&SecsIn=64'
-O test.png

--09:49:57--  http://localhost:6544/getPreviewImage?ChanId=1059&StartTime=2008-05-02T09:00:00&Height=260&Width=320&SecsIn=64
Resolving localhost... 127.0.0.1
Connecting to localhost|127.0.0.1|:6544... connected.
HTTP request sent, awaiting response... 404 Not Found
09:49:57 ERROR 404: Not Found.

and in the log, perhaps this is a cached response?

2008-05-02 09:46:40.759 Preview: Grabbed preview
'/mnt/video/1059_20080502093800.mpg' 320x480 at 64s
2008-05-02 09:49:57.684 HTTPRequest::SendResponse(xml/html) () :404
Not Found -> 127.0.0.1: 2

All other aspects of myth seem to be working well... it's just this
nagging problem of no thumbnails in mythweb.

I have a master backend with no tuners, and a combination
slave/frontend with a pvr-500 in it.  The two seem to be talking
properly.  Both servers share a exported network path for storage of
the video and preview images.  Both systems have the full mythtv suite
installed.

Any thoughts?

Gordon

here's some basic info:

master backend is running Centos 5.1 64-bit
# mythbackend --version
Please include all output in bug reports.
MythTV Version   : 17180M
MythTV Branch    : branches/release-0-21-fixes
Library API      : 0.21.20080304-1
Network Protocol : 40
Options compiled in:
 linux release using_oss using_alsa using_arts using_jack
using_backend using_dbox2 using_dvb using_firewire using_frontend
using_hdhomerun using_iptv using_ivtv using_joystick_menu
using_libfftw3 using_lirc using_opengl_vsync using_opengl_video
using_v4l using_x11 using_xrandr using_xv using_xvmc using_xvmcw
using_xvmc_vld using_glx_proc_addr_arb using_bindings_perl
using_bindings_python using_opengl using_ffmpeg_threads
using_libavc_5_3 using_live

slave backend / frontend is running Ubuntu 8.04 32-bit
# mythbackend --version
Please include all output in bug reports.
MythTV Version   : 16838
MythTV Branch    : branches/release-0-21-fixes
Library API      : 0.21.20080304-1
Network Protocol : 40
Options compiled in:
 linux profile using_oss using_alsa using_arts using_jack
using_backend using_dbox2 using_dvb using_firewire using_frontend
using_hdhomerun using_iptv using_ivtv using_joystick_menu
using_libfftw3 using_lirc using_opengl_vsync using_opengl_video
using_v4l using_x11 using_xrandr using_xv using_xvmc using_xvmcw
using_xvmc_vld using_glx_proc_addr_arb using_bindings_perl
using_bindings_python using_opengl using_ffmpeg_threads
using_libavc_5_3 using_live