On Wed, Aug 6, 2014 at 12:46 PM, wm4 <[email protected]> wrote: > On Wed, 06 Aug 2014 08:18:22 +0200 > Anton Khirnov <[email protected]> wrote: > >> >> On Tue, 5 Aug 2014 12:58:47 -0400, Andrew Stone <[email protected]> wrote: >> > The only flags, for now, indicate if metadata was updated and are set >> > after each call to >> > av_read_frame(). This comes with the caveat that, on stream start, it >> > might not be set properly >> > as packets might be buffered in AVFormatContext.packet_buffer before being >> > given to the user >> > in av_read_frame(). >> > --- >> > doc/APIchanges | 4 ++++ >> > libavformat/avformat.h | 14 ++++++++++++++ >> > libavformat/version.h | 2 +- >> > 3 files changed, 19 insertions(+), 1 deletion(-) >> > >> > diff --git a/doc/APIchanges b/doc/APIchanges >> > index 261993b..a677e42 100644 >> > --- a/doc/APIchanges >> > +++ b/doc/APIchanges >> > @@ -13,6 +13,10 @@ libavutil: 2013-12-xx >> > >> > API changes, most recent first: >> > >> > +2014-xx-xx - xxxxxxx - lavf 55.21.0 - avformat.h >> > + Add AVFormatContext.event_flags for signaling to the user when events >> > + have happened in the stream. >> > + >> > 2014-07-xx - xxxxxxx - lavu 53.19.0 - avstring.h >> > Make name matching function from lavf public as av_match_name(). >> > >> > diff --git a/libavformat/avformat.h b/libavformat/avformat.h >> > index ab2081a..6b25d6a 100644 >> > --- a/libavformat/avformat.h >> > +++ b/libavformat/avformat.h >> > @@ -296,6 +296,10 @@ struct AVFormatContext; >> > * - sorting -- a modified version of a tag that should be used for >> > * sorting will have '-sort' appended. E.g. artist="The Beatles", >> > * artist-sort="Beatles, The". >> > + * - Some protocols and demuxers support metadata updates. After a >> > successful >> > + * call to av_read_packet(), AVFormatContext.event_flags will be >> > updated to >> > + * indicate if metadata was updated. Currently, only file >> > (AVFormatContext) >> > + * and stream (AVStream) metadata change. >> > * >> > * - Demuxers attempt to export metadata in a generic format, however >> > tags >> > * with no generic equivalents are left as they are stored in the >> > container. >> > @@ -1177,6 +1181,16 @@ typedef struct AVFormatContext { >> > * @see AVCodecContext.strict_std_compliance >> > */ >> > int strict_std_compliance; >> > + >> > + /** >> > + * Flags for the user to detect events happening on the stream. Flags >> > must >> > + * be cleared by the user once the event has been handled. >> > + * A combination of AVFMT_EVENT_FLAG_*. >> > + */ >> > + int event_flags; >> > +#define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call >> > resulted in updated metadata for the whole file. >> > +#define AVFMT_EVENT_FLAG_STREAM_METADATA_UPDATED 0x0002 ///< The call >> > resulted in updated metadata for a stream. >> >> My original suggestion in the last thread was to have a separate set of flags >> for each stream (+global). That way you can see which stream exactly got >> updated. >> Or is there some specific reason to put all the flags here? >> > > You have a point. IMO the event flags should allow the user to know > what exactly changed, without having to compare old and new metadata > manually (because that would be a pain). If the event flags aren't > per-AVStream, it's harder to tell which AVStream changed metadata. > > An _additional_ change flag in the AVFormatContext itself could still > be useful, so you don't have to iterate over all streams every time > just to check flags. But then maybe it should be something like > AVFMT_EVENT_FLAG_STREAM_EVENTS_UPDATED?
A flag to indicate that a flag has been set? That seems like a bit too much. I would honestly rather iterate the streams. _______________________________________________ libav-devel mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-devel
