Bug#655890: [libav-devel] Bug#655890: libavcodec53: Breaks decoding using gst-ffmpeg

[Reinhard Tartler]

reassign 655890 libavcodec53,gstreamer0.10-ffmpeg
stop

On So, Jan 15, 2012 at 16:41:27 (CET), Anton Khirnov wrote:

[...]

> Setting custom get_buffer() for audio was not valid before
> avcodec_decode_audio3(), so IMO the proper solution would be to simply
> not do that for non-video streams.

Clarification from Justin, copied from irc channel #libav-devel with his
permission:

19:12 <ruggles> the documentation for AVCodecContext.get_buffer(), prior
                to the new audio API had this: "if CODEC_CAP_DR1 is not
                set then get_buffer() must call
                avcodec_default_get_buffer() instead of providing
                buffers allocated by some other means."
19:13 <ruggles> no audio decoders set CODEC_CAP_DR1 prior to the new
                api, therefore setting it to something other than
                avcodec_default_get_buffer() was contrary to the
                documented API
[...]
19:15 <ruggles> siretart: but i suppose we could be clearer in the
                current documentation that you cannot set a custom
                get_buffer() if using avcodec_encode_audio3()
19:15 <siretart> ruggles: I guess that would be helpful
19:16 <siretart> ruggles: I'm surprised that just setting get_buffer()
                 back to its default unbreaks gst-ffmpeg
19:16 <ruggles> because their custom get_buffer() never did anything
19:16 <ruggles> it was never called for audio in the first place
19:17 <ruggles> even if it actually did try to handle audio, it was
                pointless code that was never called
19:17 <siretart> "fun"


I have copied the debian gstreamer0.10-ffmpeg maintainer Sebastian Dröge
as well as the upstream gst-ffmpeg maintainer Edward Hervey in this
email.  Dear gst-ffmpeg maintainers, can you please comment on the
get_buffer API abuse as stated above? What do you propose to fix the issue?


(please use reply-to-all when answering; see
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=655890 for the full bug-log)

Cheers,
Reinhard


-- 
Gruesse/greetings,
Reinhard Tartler, KeyID 945348A4