[Live-devel] openRTSP producing bad video files

[Ron McOuat]

On the Axis cameras if you go to Setup then pick Video & Image on the 
left menu and sub item Image you should find a setting for the max 
framerate. If it is set to unlimited it will go at a best effort rate 
which varies by model depending on processor speed and resolution 
requested. I would set an actual value in here that the camera is 
capable of sustaining, check the datasheet at www.axis.com for your 
camera model. As a test I would choose CIF or 320x240 resolution 
depending on camera model and maybe 10 fps and see if that works for 
recording and playback in mplayer. The settings you put into the Image 
form define the MPEG4 stream. My 207MW is set to unlimited and QuickTime 
is playing the stream from the camera using rtsp://... but QuickTime 
windows Movie Inspector and Movie Properties do not reveal a frame rate. 
Changed the setting to limit it to 5 fps still reveals no frame rate 
value that I could find, testing on version 7.5 on Mac OS X Leopard 
10.5.4. Using openRTSP to record and playing the .mov file back Movie 
Inspector shows the frame rate I used on the openRTSP command line. The 
SDP description from the camera did have 5.0 fps in the result which 
matches. Setting the camera back to unlimited, the SDP says 30.0 fps as 
listed by openRTSP debug output.

Playing the .mov file in QuickTime with camera and openRTSP set to 30 
fps and w 1280, h 720 plays the movie back several times too fast - I 
have the time display from the camera turned on so the time on the video 
is known. The QuickTime time scrub bar is advancing at normal time but 
the movie is over showing the last frame while the time bar is still 
advancing showing it is playing back. I tried the same in VLC and 20 sec 
of video plays in 2 sec watching the video content window but the scrub 
bar plays at the correct speed for 20 sec.

Changed the camera to 320 x 240 at 5 fps, recorded again using openRTSP 
with correct w, h and f parameters and the video plays back at 2x speed 
but the scrub bar moves at the correct speed for the movie duration in 
both VLC and QuickTime. This is with the 2008.07.25 version of live555.

I found some movies I recorded from Axis cameras using openRTSP a year 
ago and they play back correctly, the scrub bar and the frames are in 
sync and visually the time recorded in the movie advances at the correct 
time scale in QuickTime and VLC.

Something has changed. I have saved most of the versions of live555 
between those 2 times so it would be possible for me to do a binary 
search on the revisions to see at what version the behavior of recorded 
.mov files changed. Not tonight, need some ZZZs, it is late here, if 
anyone wants the .mov recorded tonight that plays back too fast let me know.

Ron

Mike Mueller wrote:
> On Thu, Aug 28, 2008 at 03:51:29PM -0700, Ross Finlayson wrote:
>   
>>> I am having a problem with openRTSP recording video from a few Axis
>>> video cameras.  I'm basically running openRTSP like this:
>>>
>>>   openRTSP -q -b 80000 -w 704 -h 480 -f 30 rtsp://url > foo.mov
>>>
>>> When I play foo.mov in mplayer, it's jerky and plays too fast, where 10
>>> seconds of wall time will go by in 4 to 6 seconds.
>>>       
>> It sounds like your "-f" (frame rate) parameter is wrong.  Perhaps it  
>> should be 15, or 12 frames-per-second?  You need to get that correct.
>>     
>
> I did try 15 with similar results.  I can try other values tomorrow I
> suppose.  Is it possible that the mpeg4 stream actually has a variable
> framerate?
>
>