Re: YUV Overlay

Yes.  For my own testing purposes, it's not always convenient to 
connect to the ARDrone, so I overrode much of the behavior in Mock 
classes.

For decoding the video stream to a file, you can do:

$ uav_video_dump --in t_data/ardrone_video_stream_dump.bin --out 
/tmp/ardrone_video_stream_dump.h264

And then play the out file in a mplayer or vlc.  Mplayer might need you 
to manually set the -fps option (set to "25", I think), or it will 
mangle the output.

Playing the video in real time should work with:

$ uav_video_display --in t_data/ardrone_video_stream_dump.bin

Which should pop up the SDL window, and then dump a bunch of error 
messages to the console. This is the one I'm trying to get working here.

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