ERROR: `convert` has no method matching convert(::Type{AVFrame}) in v"0.4-dev"

[maxruby]

In julia dev v0.4.0, opencamera complains about "convert" of ::Type{AVFrame}.

julia> f = opencamera()
[avfoundation @ 0x7fd0fc89a200] Selected pixel format (yuv420p) is not supported by the input  
device.
[avfoundation @ 0x7fd0fc89a200] Supported pixel formats:
[avfoundation @ 0x7fd0fc89a200]   uyvy422
[avfoundation @ 0x7fd0fc89a200]   yuyv422
[avfoundation @ 0x7fd0fc89a200]   nv12 
[avfoundation @ 0x7fd0fc89a200]   0rgb
[avfoundation @ 0x7fd0fc89a200]   bgr0 
ERROR: `convert` has no method matching convert(::Type{AVFrame})

julia> close(f)
ERROR: f not defined

[lucasb-eyer]

Getting that in openvideo too (after fixing #49):

 julia> v = VideoIO.openvideo("/home/beyer/data/bbenfold/TownCentreXVID.avi")
ERROR: `convert` has no method matching convert(::Type{AVFrame})
 in VideoReader at /home/beyer/.julia/v0.4/VideoIO/src/avio.jl:303
 in VideoReader at /home/beyer/.julia/v0.4/VideoIO/src/avio.jl:281
 in VideoReader at /home/beyer/.julia/v0.4/VideoIO/src/avio.jl:364
 in openvideo at /home/beyer/.julia/v0.4/VideoIO/src/avio.jl:482

[lucasb-eyer]

I think it's because the function AVFrame is not defined for newer versions of ffmpeg. If I grep for it, all I find is:

><((("> ag 'function AVFrame'                                                                                                                                                 lb
src/libav/AVUtil/v53/LIBAVUTIL.jl
22:function AVFrame()

src/libav/AVCodecs/v54/LIBAVCODEC.jl
5:function AVFrame()

src/libav/AVCodecs/v53/LIBAVCODEC.jl
5:function AVFrame()

src/ffmpeg/AVUtil/v52/LIBAVUTIL.jl
26:function AVFrame()

src/ffmpeg/AVCodecs/v53/LIBAVCODEC.jl
7:function AVFrame()

compare to:

julia> VideoIO.versioninfo()
Using ffmpeg
AVCodecs version 56.1.100
AVFormat version 56.4.101
AVUtil version 54.7.100
SWScale version 3.0.100
AVDevice version 56.0.100
AVFilters version 5.1.100

[maxruby]

Actually, I find AVFrame() in

src/ffmpeg/AVUtil/v54/LIBAVUTIL.jl
src/ffmpeg/AVUtil/v52/LIBAVUTIL.jl

Now, the following sequence of calls for AVFrame()

using VideoIO 
     using AVUtil
           AVUtil/src/AVUtil.jl
                include(w("LIBAVUTIL.jl"))
                          => function AVFrame()

According to this, AVFrame() should be loaded. However, the conversion is still a problem with Type{AVFrame}, which we need to locate in the code.

[maxruby]

The error is most definitely at lines 296 and 299 in src/avio.jl

    # Type AVFrame is indeed defined in VideoIO
    julia> typeof(VideoIO.AVFrame)
    DataType

    # However, initializing it as a vector in function VideoReader() fails
    julia> aVideoFrame = [VideoIO.AVFrame()]
    ERROR: `convert` has no method matching convert(::Type{AVFrame})

    julia> aTargetVideoFrame = [VideoIO.AVFrame()]
    ERROR: `convert` has no method matching convert(::Type{AVFrame})

Something about the conversion of AVFrame in v0.4-dev is the source of the failure. Lets see if we can fix this.

[maxruby]

Sorry, I have 2 separate installations of VideoIO (one with v0.3 which works fine and a second one under v0.4-dev). The one associated with v0.4-dev was missing AVFrame(). I added AVFrame() alone to

 src/ffmpeg/AVUtil/v54/LIBAVUTIL.jl

This fixed the problem and now opencamera() works. Can you try it on your side with openvideo() to confirm this works for you too?

[lucasb-eyer]

I was about to suggest trying to call AVFrame() in the terminal :) Yes, that works. I didn't want to just copy-paste it over from v52 because I wonder

1. Why it's not there in the first place; is it supposed to be added automatically by the wrapping script, or has it always been added manually?
2. If it's to be added manually, isn't there a better place to add it, so it doesn't need to be duplicated code for all versions? I don't know much at all about VideoIO's internals.

[maxruby]

It should be relatively easy to reduce duplication in VideoIO but I would suggest to wait until #47 is processed. Regarding AVFrame, it is a custom function likely added manually to LIBAVUTIL.jl

[kmsquire]

Just to verify: yes, AVFrame was added by hand. I also added it by hand to src/ffmpeg/AVUtil/v54/LIBAVUTIL.jl, as @maxruby did above, and committed that change as part of 26b301cb. Can you run Pkg.update() and see if this is fixed?

@maxruby, sorry, this is going to screw up your pull request.

Since both of you have push access, please feel free to push fixes for things like these in the future. If you're unsure, you can always just make a pull request, but anything obviously wrong can be fixed again in the future.

(Obviously, if you don't have time for a fix, a bug report is still welcome!) Cheers, and sorry for the delay.

[lucasb-eyer]

It works, thanks.

I forgot I had push access, sorry^^

[kmsquire]

No worries--glad it's fixed!

Somewhat related, at some point, there was discussion of moving a few repositories to a JuliaImages (or some such) organization. I'll try to get that discussion going again this week.

[lucasb-eyer]

Sounds good, please ping when you do.