Re: YUV Overlay

Do you happen to have ffmpeg installed?  I'm not really sure how best 
to list a Perl module dependency on a C library.  Alien::ffmpeg seems to 
recompile the whole library, which shouldn't be necessary for people who 
already have ffmpeg installed.

The code for drawing on top of the overlay is on github:

https://github.com/frezik/UAV-Pilot/blob/master/lib/UAV/Pilot/SDL/VideoOverlay/Reticle.pm

The "after 'init_video_overlay'" sub gets and stores the RGB color 
mapping.  Drawing the lines is done in process_video_overlay().

Thanks,
Timm

On 05.08.2013 09:50, Tobias Leich wrote:
> Hi, I am unable tun run that script either:
>
> $ perl bin/uav_video_display
> perl: symbol lookup error:
> 
> /usr/local/lib/perl/5.14.2/auto/UAV/Pilot/Video/H264Decoder/H264Decoder.so:
> undefined symbol: av_init_packet
>
> Do you have an example of your line-drawing problem somewhere?
>
> Am 05.08.2013 15:58, schrieb [email protected]:
>> Well, that's a bug.  I'll have to update that script with the right
>> module name.  Thanks for letting me know.
>>
>> That script only dumps the video to a file without displaying it.  
>> The
>> script 'uav_video_display', released with version 0.5, is the
>> important one here.
>>
>> I ended up solving my overlay issue by doing most of it in C.  I
>> probably needed to do this, anyway, as doing it with Perl
>> datastructures would have meant creating an SV for each value in the
>> three YUV channels and pushing them onto an AV.  720p is 0.9
>> megapixels, so that would have been a very expensive operation to do
>> 30 times a second to handle realtime video.
>>
>> The C technique is used in the recently released UAV::Pilot v0.5.
>>
>> I have run across a new problem when trying to draw on top of the 
>> YUV
>> overlay.  I can draw a line using the RGB colorspace, but it shows 
>> up
>> black.  Maybe I need to convert RGB to YUV?  Or perhaps draw on a
>> separate surface and blit that on top?
>>
>> Thanks,
>> Timm
>>
>> On 05.08.2013 08:41, Tobias Leich wrote:
>>> Hi, I installed UAV-Pilot right now, but it explodes like:
>>> $ bin/uav_video_dump
>>> Can't locate UAV/Pilot/Control/ARDrone/Video/FileDump.pm in @INC 
>>> (@INC
>>> contains: /etc/perl /usr/local/lib/perl/5.14.2
>>> /usr/local/share/perl/5.14.2 /usr/lib/perl5 /usr/share/perl5
>>> /usr/lib/perl/5.14 /usr/share/perl/5.14 /usr/local/lib/site_perl .) 
>>> at
>>> bin/uav_video_dump line 9.
>>> BEGIN failed--compilation aborted at bin/uav_video_dump line 9.
>>>
>>> Is there something I can do in order to test your example script?
>>>
>>> Cheers, FROGGS
>>>
>>> Am 24.07.2013 22:53, schrieb [email protected]:
>>>> I've made a simplified, standalone example:
>>>>
>>>> http://pastebin.com/dPPNc8VL
>>>>
>>>> The big array at the top is a single YUV420P frame.  Expected 
>>>> behavior
>>>> is to display that frame in a window for 5 seconds, and then quit. 
>>>> If
>>>> I comment out the overlay handling, it displays a green 
>>>> background.
>>>>
>>>> I've verified that I'm running SDL 2.540.
>>>>
>>>> Thanks,
>>>> Timm
>>>>
>>>> On 24.07.2013 08:17, Kartik Thakore wrote:
>>>>> Can we run this with out needing ARDdrone?
>>>>>
>>>>> On Wed, Jul 24, 2013 at 8:22 AM, <[email protected]> wrote:
>>>>>
>>>>>> Short on time at the moment, but I have the complete code on a
>>>>>> github repo:
>>>>>>
>>>>>> https://github.com/frezik/UAV-Pilot [2]
>>>>>>
>>>>>> The relevant code is in UAV::Pilot::SDL::Video, and the decoding
>>>>>> happens in the xs file for UAV::Pilot::Video::H264Decoder.  The 
>>>>>> test
>>>>>> t/160_video_decode.t should run the decoding end of things. 
>>>>>> There's
>>>>>> a test video in t_data/ardrone_video_stream_dump.bin, though 
>>>>>> that
>>>>>> contains the PaVE headers from the UAV before each frame.  Those
>>>>>> headers can be stripped out by bin/uav_video_dump.
>>>>>>
>>>>>> I'll try to come up with a more concise example later this 
>>>>>> evening.
>>>>>>
>>>>>> Thanks,
>>>>>> Timm
>>>>>>
>>>>>> On 24.07.2013 01 [3]:00, Tobias Leich wrote:
>>>>>>
>>>>>>> Hi, can you paste a complete example please? Maybe with a link 
>>>>>>> to a
>>>>>>> test
>>>>>>> video file.
>>>>>>>
>>>>>>> What I would try first is SDL's latest release, which is 2.540 
>>>>>>> or
>>>>>>> so.
>>>>>>>
>>>>>>> Cheers, FROGGS
>>>>>>>
>>>>>>> Am 23.07.2013 23:44, schrieb [email protected]:
>>>>>>>
>>>>>>>> I'm working on a project involving decoding h.264 video frames 
>>>>>>>> with
>>>>>>>> ffmpeg and then outputting them to an SDL surface. From what 
>>>>>>>> I've
>>>>>>>> read, the YUV overlay is meant for this kind of job, but I'm 
>>>>>>>> having
>>>>>>>> trouble getting it to work with the Perl bindings.
>>>>>>>>
>>>>>>>> One thing that seems odd to me in the Perl docs is:
>>>>>>>>
>>>>>>>>     As of release 2.3 direct right to overlay is disable.
>>>>>>>>
>>>>>>>> Besides the typos, this troubles me because it seems that 
>>>>>>>> disabling
>>>>>>>> the feature makes the YUV overlay completely useless.
>>>>>>>>
>>>>>>>> Not to be deterred, I wrote this code:
>>>>>>>>
>>>>>>>>     SDL::Video::lock_YUV_overlay( $overlay );
>>>>>>>>     # The order of array indexen is correct, according to:
>>>>>>>>     # http://dranger.com/ffmpeg/tutorial02.html [1]
>>>>>>>>     my $pitches = $overlay->pitches;
>>>>>>>>     $$pitches[0] = scalar @{ $last_vid_frame[0] };
>>>>>>>>     $$pitches[2] = scalar @{ $last_vid_frame[1] };
>>>>>>>>     $$pitches[1] = scalar @{ $last_vid_frame[2] };
>>>>>>>>     my $pixels = $overlay->pixels;
>>>>>>>>     $$pixels[0] = $last_vid_frame[0];
>>>>>>>>     $$pixels[2] = $last_vid_frame[1];
>>>>>>>>     $$pixels[1] = $last_vid_frame[2];
>>>>>>>>     SDL::Video::unlock_YUV_overlay( $overlay );
>>>>>>>>
>>>>>>>>     SDL::Video::update_rects( $sdl, $bg_rect );
>>>>>>>>     SDL::Video::display_YUV_overlay( $sdl, $bg_rect );
>>>>>>>>
>>>>>>>> When I run this, I get an error about not being able to find 
>>>>>>>> the
>>>>>>>> pitches() method against the class "SDL::Overlay".  Eh?  (Same
>>>>>>>> thing
>>>>>>>> happens for the pixels() method if I put that call first.) I 
>>>>>>>> can
>>>>>>>> call
>>>>>>>> width() and format() and such just fine on that object.
>>>>>>>>
>>>>>>>> If needed, I can handle the overlay entirely at the C level.  
>>>>>>>> I may
>>>>>>>> end up doing that anyway; the C array that comes out of ffmpeg 
>>>>>>>> is
>>>>>>>> being transformed into a Perl array-of-arrays, which is going 
>>>>>>>> to
>>>>>>>> be an
>>>>>>>> expensive operation to do for 720p at 30 fps in realtime. But 
>>>>>>>> I'd
>>>>>>>> like
>>>>>>>> to try this at the Perl level for now.
>>>>>>>>
>>>>>>>> I might also have to convert the output from ffmpeg using
>>>>>>>> sws_scale().  It's coming out in YUV420P mode, and I'm using
>>>>>>>> YV12 to
>>>>>>>> init the overlay. But I'd like to get the above working before
>>>>>>>> messing
>>>>>>>> with that.
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>> Timm Murray
>>>>>
>>>>>
>>>>>
>>>>> Links:
>>>>> ------
>>>>> [1] http://dranger.com/ffmpeg/tutorial02.html
>>>>> [2] https://github.com/frezik/UAV-Pilot
>>>>> [3] tel:24.07.2013%2001
>>>>
>>