Quoting Marton Balint (2020-05-18 20:32:53) > > > On Mon, 18 May 2020, Anton Khirnov wrote: > > > Quoting Marton Balint (2020-05-16 15:52:22) > >> Hi, > >> > >> As you may know, a recent patchset enabled AVCodecContext->profile > >> constants to reside in encoders. > >> > >> In order to make a full transition to avctx->profile even in existing > >> encoders which might use a private profile setting, we have to make sure > >> only supported avctx->profile values are passed to encoders. > >> > >> The fact that avctx->profile is not validated is already an issue, and > >> assertions/segmentation faults can already happen in existing encoders > >> (e.g.: aac, mpeg) if unsupported values are passed. > >> > >> AVCodec have a .profiles attribute which supposed to contain the list of > >> supported profiles. However this is problematic because > >> - AVCodecContext->profile is not validated against this list > >> - not all encoders define the list > >> - even if there is a list it might be defined as NULL_IF_CONFIG_SMALL > >> - some encoders support more or less than its currently defined list > > > > All of these sound like bugs that can and should be fixed. > > > >> - AVCodec->profiles contains AVProfiles which supposed to have a textual > >> representation of each profile, which can cause profile name > >> duplications/inconsistencies against libavcodec/profiles.c if the list > >> is different to the one in codecs profile list. > > > > Why should it be different? Isn't that a bug that should be fixed? > > The list can be different because possibly not all the profiles which are > recognized by the decoder is supported by the encoder. Also the encoder > can define pseudo profiles which it can support, for example the AAC > encoders have support for FF_PROFILE_MPEG2_AAC_LOW which is LC profile > with some features disabled.
Don't understand - I would think AVCodec.profiles would list the profiles supported by that specific AVCodec instance. Is that not the case? -- Anton Khirnov _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
