[Libav-user] FF_COMMON_FRAME: coded_picture_number and display_picture_number

[Igor Fontana]

FFmpeg people,

sorry if inappropriate, but google failed hard on me and I couldn't find
this on archives.

In avcodec.h, FF_COMMON_FRAME, there are those two fields defined:

	...
	/**\
	 * picture number in bitstream order\
	 * - encoding: set by\
	 * - decoding: Set by libavcodec.\
	 */\
	int coded_picture_number;\
	/**\
	* picture number in display order\
	* - encoding: set by\
	* - decoding: Set by libavcodec.\
	*/\
	int display_picture_number;\
	...

After decoding a frame, coded_picture_number is set to "number of
pictures decoded so far", which does not match teh __real__ picture
number in some cases --- corrupted videos for instance. Is this
intended?

Also, display_picture_number is __always__ zero.

What I'm trying to achieve is to decode a video and detect lost frames.
If searching for jumps in this counters is not teh good way, could
someone, please, direct me?

-- 
Igor