FFProbe incorrectly shows positive value for start time with no options flags

[vade]

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.

[Carl Eugen Hoyos]

For future tickets: Please do not report bugs against FFprobe if they are reproducible with FFmpeg (and don't forget to test current FFmpeg git head before reporting an issue).

This bug was fixed in 949444348b752664243681625f9f1d2c55b6dfaa - for the attached sample it currently cannot be tested because of ticket #5420.