[FFmpeg-trac] #6725(avcodec:new): wrong timecode for dpx

[FFmpeg]

#6725: wrong timecode for dpx
------------------------------------+-----------------------------------
             Reporter:  shekh       |                    Owner:
                 Type:  defect      |                   Status:  new
             Priority:  normal      |                Component:  avcodec
              Version:  git-master  |               Resolution:
             Keywords:  dpx         |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
------------------------------------+-----------------------------------

Comment (by shekh):

 Replying to [comment:2 cehoyos]:
 > How can I reproduce this?

 Reproduce what, dpx with framerate? IDK, maybe FFMPEG can do this. Found
 #3511

 > `time_base` is not supposed to have an effect on decoding.

 My understanding (maybe incomplete):
 Image2 demuxer assumes default framerate "25" and derives time_base 1/25
 from it.
 Then it assigns sequentially increasing pts/dts to packets and frames, as
 well as packet/frame duration to 1/25, as well as stream duration to
 number of pictures (which makes sense assuming time_base).
 Therefore, if I derive framerate from timestamps and timebase, I get 25.
 But r_framerate says 15.

 Maybe more informative command:
 {{{
 ffprobe.exe -i "test.%%02d.dpx" -start_number 1 -show_frames
 }}}

 Notice pkt_duration_time=0.040000 (0.04 is 1/25)

 {{{
 [FRAME]
 media_type=video
 stream_index=0
 key_frame=1
 pkt_pts=0
 pkt_pts_time=0.000000
 pkt_dts=0
 pkt_dts_time=0.000000
 best_effort_timestamp=0
 best_effort_timestamp_time=0.000000
 pkt_duration=1
 pkt_duration_time=0.040000
 pkt_pos=N/A
 pkt_size=12748800
 width=2048
 height=1556
 pix_fmt=gbrp10le
 sample_aspect_ratio=N/A
 pict_type=?
 coded_picture_number=0
 display_picture_number=0
 interlaced_frame=0
 top_field_first=0
 repeat_pict=0
 [/FRAME]
 [FRAME]
 media_type=video
 stream_index=0
 key_frame=1
 pkt_pts=1
 pkt_pts_time=0.040000
 pkt_dts=1
 pkt_dts_time=0.040000
 best_effort_timestamp=1
 best_effort_timestamp_time=0.040000
 pkt_duration=1
 pkt_duration_time=0.040000
 pkt_pos=N/A
 pkt_size=12748800
 width=2048
 height=1556
 pix_fmt=gbrp10le
 sample_aspect_ratio=N/A
 pict_type=?
 coded_picture_number=0
 display_picture_number=0
 interlaced_frame=0
 top_field_first=0
 repeat_pict=0
 [/FRAME]
 [FRAME]
 media_type=video
 stream_index=0
 key_frame=1
 pkt_pts=2
 pkt_pts_time=0.080000
 pkt_dts=2
 pkt_dts_time=0.080000
 best_effort_timestamp=2
 best_effort_timestamp_time=0.080000
 pkt_duration=1
 pkt_duration_time=0.040000
 pkt_pos=N/A
 pkt_size=12748800
 width=2048
 height=1556
 pix_fmt=gbrp10le
 sample_aspect_ratio=N/A
 pict_type=?
 coded_picture_number=0
 display_picture_number=0
 interlaced_frame=0
 top_field_first=0
 repeat_pict=0
 [/FRAME]
 [FRAME]
 media_type=video
 stream_index=0
 key_frame=1
 pkt_pts=3
 pkt_pts_time=0.120000
 pkt_dts=3
 pkt_dts_time=0.120000
 best_effort_timestamp=3
 best_effort_timestamp_time=0.120000
 pkt_duration=1
 pkt_duration_time=0.040000
 pkt_pos=N/A
 pkt_size=12748800
 width=2048
 height=1556
 pix_fmt=gbrp10le
 sample_aspect_ratio=N/A
 pict_type=?
 coded_picture_number=0
 display_picture_number=0
 interlaced_frame=0
 top_field_first=0
 repeat_pict=0
 [/FRAME]
 }}}

--
Ticket URL: <https://trac.ffmpeg.org/ticket/6725#comment:3>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker