[FFmpeg-devel] [PATCH v4 1/1] avutils/hwcontext: When deriving a hwdevice, search for existing device in both directions

[Anton Khirnov]

Quoting Soft Works (2021-11-26 19:43:58)
> Maybe I'm missing something, but hw device contexts are refcounted.
> What happens in hwdevice_ctx_free() is this:
> 
> av_buffer_unref(&ctx->internal->source_device);

IIUC this only happens after the parent device is freed. My concern is
the following situation:
- the caller creates a parent hwdevice
- the caller derives a child from it, which may acquire some additional
  resources beyond what the parent holds
- the caller unrefs all his references to the child, but the child does
  not get freed because the parent still holds a reference to it

Since av_hwdevice_ctx_create_derived() has a flags parameter, we might
want to introduce a flag to control this behavior.

-- 
Anton Khirnov