decoder sometimes reporting pts values in incorrect order

[csab6597]

Decoding video data through C api I found that in some situations the frames coming out of the avcodec_receive_frame() function have their pts values not in the correct order, whilst the picture data itself seems to be in correct - that is display - order.
Check the video file provided. Have a look at the pts values by

ffprobe 02.mp4 -show_frames -select_streams 0

excerpt

...
[FRAME]
pts=478478
pkt_dts=480480
pict_type=P
coded_picture_number=478
[/FRAME]
[FRAME]
pts=479479
pkt_dts=481481
pict_type=P
coded_picture_number=479
[/FRAME]
[FRAME]
pts=481481
pkt_dts=482482
pict_type=B
coded_picture_number=481
[/FRAME]
[FRAME]
pts=480480
pkt_dts=483483
pict_type=P
coded_picture_number=480
[/FRAME]
[FRAME]
pts=482482
pkt_dts=484484
pict_type=P
coded_picture_number=482
[/FRAME]
...

You find that the pts values are in proper order up to codec_picture_number=479

Probably because suddenly a B frame is coming up, the next frame in the list is reported to be 481, but when looking at the raw image data in the AVFrame of that frame, it is indeed frame number 480 to be displayed. So the remedy for me right now is to swap the pts values between 480 and 481.

In the file provided this mixup will repeat again several times.

[csab6597]

uploaded sample media through ​http://streams.videolan.org/upload/