On Sat, Feb 15, 2014 at 8:00 PM, Tim Walker <tdskywal...@gmail.com> wrote: > On 15 Feb 2014, at 19:53, Vittorio Giovara <vittorio.giov...@gmail.com> wrote: > >> On Sat, Feb 15, 2014 at 7:31 PM, Tim Walker <tdskywal...@gmail.com> wrote: >>> On 15 Feb 2014, at 19:02, Vittorio Giovara <vittorio.giov...@gmail.com> >>> wrote: >>>> On Sat, Feb 15, 2014 at 3:24 PM, Tim Walker <tdskywal...@gmail.com> wrote: >>>>> On 12 Feb 2014, at 00:13, Vittorio Giovara <vittorio.giov...@gmail.com> >>>>> wrote: >>>>> >>>>> Is there a chance that the packet has been used before and already >>>>> contains side data? Or is it necessarily a new packet with no side data >>>>> to begin with? >>>> >>>> Well you have an array of side data in avpacket and >>>> av_packet_new_side_data takes care of (re)allocation. >>>> Side data is also correctly passed during copy_props so all should be fine. >>>> Vittorio >>> >>> But: >>> - av_packet_new_side_data always adds side data >>> - av_packet_new_side_data always adds it to the end of the array >>> - av_packet_get_side_data always returns the first side data of a given type >>> >>> So if you add side data of type T to an AVPacket which already has side >>> data of type T, you'll get the >>> correct pointer back in libavcodec, but libavcodec users will never be able >>> to get that side data, since >>> there will be another side data of the same type earlier in the side data >>> array. >>> >>> This is only an issue if the AVPacket may already contain side data of the >>> same type, hence my question. >> >> Ah well good point, bug I guess this is a bug true for *any* side data no? > > Yes. This is e.g. why I added ff_side_data_update_matrix_encoding() in > 5b4797a21db900b7d509660b7a4d49829089b004
ok but that is something for a separate patch, assuming it's actually needed here (this sida data is added only once and i'm not even sure mov supports changing this atom live). Cheers, Vittorio _______________________________________________ libav-devel mailing list libav-devel@libav.org https://lists.libav.org/mailman/listinfo/libav-devel
