On 04/10/17 23:16, wm4 wrote: > On Wed, 4 Oct 2017 23:01:47 +0100 > Mark Thompson <[email protected]> wrote: >>> >>> In addition to this, should there be an AVCodec flag that tells the API >>> user whether this decoder can do half-transparent software fallback? >>> Half-transparent as in it can call get_format mid-stream to reconfigure >>> it to sw decoding. >>> >>> Or would such a flag be redundant with AVCodecHWConfig.hwaccel? >> >> Is there any decoder which does support software output formats but doesn't >> support this case from the point of view of the user? (Including in the >> other tine.) >> >> I think all decoders which offer a software format in get_format() are >> required to be able to do this - if they can't then they need to filter the >> list provided to get_format(). > > Well, as an API user I'd definitely want to know whether this is a true > hwaccel or not, because a true hwaccel will have 1. API-visible > software fallback, and 2. doesn't require the API user to do any sort > of explicit software fallback. > > A simple AVCodec flag whether something is a builtin decoder or an > external wrapper might help too with this. Personally I don't really > want to guess.
It sounds like this is more what you want. Is not the problem you are actually trying to solve that some external decoders have narrower codec support that the internal ones? (E.g. you feed any hardware decoder an 11-bit YUV 4:2:2 H.264 stream and it immediately explodes.) The flag directly on the decoder hwconfig doesn't really help, because software output is possible on many of these decoders (though it may just be the driver downloading it internally) so the flag should be set. - Mark _______________________________________________ libav-devel mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-devel
