From afbd4b7e093adf6d7a830b32759ca3ba8500363d Mon Sep 17 00:00:00 2001 From: Andrew Stone Date: Fri, 8 Aug 2014 13:09:23 -0400 Subject: lavf: add AVFormatContext/AVStream fields for signaling to the user when events happen. 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(). Signed-off-by: Anton Khirnov --- libavformat/avformat.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'libavformat/avformat.h') diff --git a/libavformat/avformat.h b/libavformat/avformat.h index 61ae6fab5e..5b29145a01 100644 --- a/libavformat/avformat.h +++ b/libavformat/avformat.h @@ -296,6 +296,11 @@ 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 or AVStream.event_flags + * will be updated to indicate if metadata changed. In order to detect metadata + * changes on a stream, you need to loop through all streams in the AVFormatContext + * and check their individual event_flags. * * - Demuxers attempt to export metadata in a generic format, however tags * with no generic equivalents are left as they are stored in the container. @@ -798,6 +803,14 @@ typedef struct AVStream { */ int nb_side_data; + /** + * 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 AVSTREAM_EVENT_FLAG_*. + */ + int event_flags; +#define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata. + /***************************************************************** * All fields below this line are not part of the public API. They * may not be used outside of libavformat and can be changed and @@ -1170,6 +1183,15 @@ typedef struct AVFormatContext { * @see AVCodecContext.strict_std_compliance */ int strict_std_compliance; + + /** + * Flags for the user to detect events happening on the file. 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. + /***************************************************************** * All fields below this line are not part of the public API. They * may not be used outside of libavformat and can be changed and -- cgit v1.2.3