[FFmpeg-trac] #2074(undetermined:new): decoded frame picture type does not match packet flags

[FFmpeg]

#2074: decoded frame picture type does not match packet flags
-------------------------------------+-------------------------------------
             Reporter:  mrhines      |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:  1.0.1
  undetermined                       |               Blocked By:
             Keywords:  key frame,   |  Reproduced by developer:  0
  decode, mpeg2                      |
             Blocking:               |
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:

 I'm routine decoding an MPEG2 video, like this:

     avcodec_decode_video2(codecCtx, frame, &got_frame, &packet)

 .. and upon encountering a key frame, I perform a sanity check, like this:

     if(got_frame && (packet.flags & AV_PKT_FLAG_KEY))
          printf("picture type: '%c'\n",
 av_get_picture_type_char(frame->pict_type));

 .. which prints out:

          picture type 'P'

 Perhaps my layman's understanding of video is wrong, but doesn't "key
 frame" == 'I' frame? Is this output valid?

 Confirming with:
          ffprobe -show_frames sample.mpg

 Shows:
          [FRAME]
              ... snip ...
          key_frame=1
              ... snip ...
          pict_type=I
              ... snip ...
          [/FRAME]

 Am I missing something?

 How to reproduce:
 {{{
 % run avcodec_decode_video2() for a while until you hit a keyframe packet
 and then perform the sanity check
 ffmpeg version 1.0 (also confirmed on trunk with 'git checkout master'
 built on Ubuntu Linux 12.04
 }}}
 Patches should be submitted to the ffmpeg-devel mailing list and not this
 bug tracker.

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2074>
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