[FFmpeg-trac] #5540(undetermined:new): FFProbe incorrectly shows positive value for start time with no options flags

[FFmpeg]

#5540: FFProbe incorrectly shows positive value for start time with no options
flags
-------------------------------------+-------------------------------------
             Reporter:  vade         |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:  git-
  undetermined                       |  master
             Keywords:  ffprobe,     |               Blocked By:
  start_time, start_pts,             |  Reproduced by developer:  0
             Blocking:               |
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:

 Some files with negative start times for audio produce a positive start
 time for ffprobe output without any flags:

 ffprobe -input file

 produces a start time field which is positive for the above file. However,

 ffprobe -show_streams -select_streams a -input file  shows the correct
 negative audio start time.

 How to reproduce:

 Download a file produced by ffmpeg libraries:

 https://www.dropbox.com/s/9jfwmyt4p83dx2e/_mezzanine_transcode.mp4?dl=0

 The file produces the following :

 {{{
 ffprobe _mezzanine_transcode.mp4
 ffprobe version 3.0.1 Copyright (c) 2007-2016 the FFmpeg developers
   built with Apple LLVM version 7.3.0 (clang-703.0.29)
   configuration: --enable-gpl --enable-nonfree --extra-
 ldflags=-L/usr/local/lib --extra-cflags=-I/usr/local/include --enable-
 libx264
   libavutil      55. 17.103 / 55. 17.103
   libavcodec     57. 24.102 / 57. 24.102
   libavformat    57. 25.100 / 57. 25.100
   libavdevice    57.  0.101 / 57.  0.101
   libavfilter     6. 31.100 /  6. 31.100
   libswscale      4.  0.100 /  4.  0.100
   libswresample   2.  0.101 /  2.  0.101
   libpostproc    54.  0.100 / 54.  0.100
 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '_mezzanine_transcode.mp4':
   Metadata:
     major_brand     : isom
     minor_version   : 512
     compatible_brands: isomiso2avc1mp41
     encoder         : Lavf57.25.100
   Duration: 00:00:04.72, start: 0.021333, bitrate: 11200 kb/s
     Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv,
 bt709), 1920x1080 [SAR 1:1 DAR 16:9], 11026 kb/s, 25 fps, 25 tbr, 25k tbn,
 100 tbc (default)
     Metadata:
       handler_name    : VideoHandler
     Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz,
 stereo, fltp, 248 kb/s (default)
     Metadata:
       handler_name    : SoundHandler
 }}}

 However, the same version of ffprobe with the following arguments properly
 shows the negative start time for the same file, unlike the above default
 ffprobe output.

 {{{
 ffprobe -show_streams -select_streams a _mezzanine_transcode.mp4
 ffprobe version 3.0.1 Copyright (c) 2007-2016 the FFmpeg developers
   built with Apple LLVM version 7.3.0 (clang-703.0.29)
   configuration: --enable-gpl --enable-nonfree --extra-
 ldflags=-L/usr/local/lib --extra-cflags=-I/usr/local/include --enable-
 libx264
   libavutil      55. 17.103 / 55. 17.103
   libavcodec     57. 24.102 / 57. 24.102
   libavformat    57. 25.100 / 57. 25.100
   libavdevice    57.  0.101 / 57.  0.101
   libavfilter     6. 31.100 /  6. 31.100
   libswscale      4.  0.100 /  4.  0.100
   libswresample   2.  0.101 /  2.  0.101
   libpostproc    54.  0.100 / 54.  0.100
 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '_mezzanine_transcode.mp4':
   Metadata:
     major_brand     : isom
     minor_version   : 512
     compatible_brands: isomiso2avc1mp41
     encoder         : Lavf57.25.100
   Duration: 00:00:04.72, start: 0.021333, bitrate: 11200 kb/s
     Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv,
 bt709), 1920x1080 [SAR 1:1 DAR 16:9], 11026 kb/s, 25 fps, 25 tbr, 25k tbn,
 100 tbc (default)
     Metadata:
       handler_name    : VideoHandler
     Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz,
 stereo, fltp, 248 kb/s (default)
     Metadata:
       handler_name    : SoundHandler
 [STREAM]
 index=1
 codec_name=aac
 codec_long_name=AAC (Advanced Audio Coding)
 profile=LC
 codec_type=audio
 codec_time_base=1/48000
 codec_tag_string=mp4a
 codec_tag=0x6134706d
 sample_fmt=fltp
 sample_rate=48000
 channels=2
 channel_layout=stereo
 bits_per_sample=0
 id=N/A
 r_frame_rate=0/0
 avg_frame_rate=0/0
 time_base=1/48000
 start_pts=-1024
 start_time=-0.021333
 duration_ts=226304
 duration=4.714667
 bit_rate=248195
 max_bit_rate=318903
 bits_per_raw_sample=N/A
 nb_frames=221
 nb_read_frames=N/A
 nb_read_packets=N/A
 DISPOSITION:default=1
 DISPOSITION:dub=0
 DISPOSITION:original=0
 DISPOSITION:comment=0
 DISPOSITION:lyrics=0
 DISPOSITION:karaoke=0
 DISPOSITION:forced=0
 DISPOSITION:hearing_impaired=0
 DISPOSITION:visual_impaired=0
 DISPOSITION:clean_effects=0
 DISPOSITION:attached_pic=0
 TAG:language=und
 TAG:handler_name=SoundHandler
 [/STREAM]
 }}}
 Patches should be submitted to the ffmpeg-devel mailing list and not this
 bug tracker.

--
Ticket URL: <https://trac.ffmpeg.org/ticket/5540>
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