[Libav-user] Does the image2 demuxer work with a custom AVIOContext?

[Robert Krüger]

On Sun, Jan 12, 2014 at 8:21 PM, Hendrik Leppkes <h.leppkes at gmail.com> wrote:
> On Sun, Jan 12, 2014 at 8:02 PM, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:
>> Hendrik Leppkes <h.leppkes at ...> writes:
>>
>>> image2 requires to directly access the files itself.
>>
>> Thank you for correcting me!
>>
>>> There is also a image2pipe, which can read the data from a avio
>>> context, but in my experience it also didn't work properly because its
>>> designed for a "pipe" scenario where it doesn't know the file size,
>>> and therefor reads kinda blindly.
>>
>> Could you elaborate a little on the shortcomings of image2pipe?
>> I seem to remember that it is used often.
>> Or do you just mean that too many parsers are missing?
>
> Yeah it only works on img formats which have a parser to re-assemble
> full images, so its use is a bit limited.
> On the other hand, you can actually use it to pipe several images in
> one command into it (if you have a parser), so both use-cases can be
> useful i suppose.

Could you elaborate a bit what would be needed to make this work, i.e.
demuxing single images (not a series) like jpg, png, dpx and probably
others covered by the image2 demuxer with a custom AVIOContext that
has a size and in my case can also seek but without access to the
file?