On Wed, 23 Mar 2016 22:15:12 +0100 Michael Niedermayer <mich...@niedermayer.cc> wrote:
> On Wed, Mar 23, 2016 at 09:51:46PM +0100, wm4 wrote: > > On Wed, 23 Mar 2016 21:36:35 +0100 > > Michael Niedermayer <mich...@niedermayer.cc> wrote: > > > > > On Wed, Mar 23, 2016 at 08:44:41PM +0100, wm4 wrote: > > > > On Wed, 23 Mar 2016 18:37:25 +0100 > > > > Michael Niedermayer <mich...@niedermayer.cc> wrote: > > > > > > > > > On Wed, Mar 23, 2016 at 06:06:37PM +0100, wm4 wrote: > > > > > > On Wed, 23 Mar 2016 17:51:11 +0100 > > > > > > Michael Niedermayer <mich...@niedermayer.cc> wrote: > > > > > > > > > > > > > On Wed, Mar 23, 2016 at 02:02:11PM +0100, wm4 wrote: > > > > > > > > It's not practical to keep this with the new decode API. > > > > > > > > --- > > > > > > > > ffmpeg.c | 7 ------- > > > > > > > > ffmpeg.h | 1 - > > > > > > > > 2 files changed, 8 deletions(-) > > > > > > > > > > > > > > its not practical in ffmpeg.c but libavcodec should be able to > > > > > > > easily > > > > > > > check that a decoder which doesnt declare AV_CODEC_CAP_SUBFRAMES > > > > > > > doesnt decode "subframes" > > > > > > > Can you move this check into libavcodec ? > > > > > > > i think otherwise nothing would be checking for missing > > > > > > > AV_CODEC_CAP_SUBFRAMES anymore > > > > > > > > > > > > > > > > > > > What's the point of this check? > > > > > > > > > > to keep track of / detect the cases that put multiple decodable frames > > > > > in a packet. > > > > > > > > > > Whats the point of that? > > > > > there where several IIRC > > > > > one is that when too many frames are put in a packet > > > > > latency increases, another is that seeking granularity is worse > > > > > (if its not even one packet for the whole file ...) > > > > > > > > It's true that too many frames in a packet isn't ideal, but that's not > > > > what the code checks. > > > > > > > > It checks if an audio decoder not marked with AV_CODEC_CAP_SUBFRAMES > > > > consumes partial packets. > > > > > > yes, but a check that checks "if a decoder not marked with > > > AV_CODEC_CAP_SUBFRAMES consumes partial packets". Is a simple and > > > zero overhead way of detecting some (not all) cases where there are > > > multiple frames in a packet. One cant look at a sequence of bytes > > > that could be any arbitrary format/codec and say > > > "thats more than 1 frame" it requires codec specific code, > > > the decoders already do what is needed for some cases, for the others > > > there is (please correct me if iam wrong which might be) no easy > > > way except maybe running the parser if one exists over it but that > > > would not be zero overhead > > > > > > > > > > That might be useful as debug check in > > > > libavcodec or so, or by properly reviewing patches for new decoders. > > > > > > Iam not sure if i understand what you mean exactly but this somehow > > > sounds like an implication that people would not review patches > > > properly. > > > Thats a serious accusation if thats what was meant. Either there is > > > a problem then it should be pointed to very specifically so it can be > > > solved or such implications shouldnt be made at all. > > > > Well, I'm not sure what else this check is useful for. A new audio > > decoder will need explicit code to handle multiframe audio by returning > > the exact number of bytes parsed, instead of e.g. > > "return avpkt->size;". So it should be pretty obvious whether a decoder > > does this? > > yes, though there may be corner cases where it has to do that > and it might be more robust. > > > > > > > Anyway, I could move this check to avcodec_decode_audio4(), would that > > be ok? > > yes and thanks! > So I actually tried this, and it turns out at least shorten (and maybe many more codecs) raises this warning, because it doesn't set AV_CODEC_CAP_SUBFRAMES. And nobody ever cared. Give me a reason why I should, instead of sending a patch to deprecate AV_CODEC_CAP_SUBFRAMES? _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
