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• File type not recognized when using ffprobe with Python

  28 novembre 2017, par Damian

  This is my python script :

  #!/usr/bin/python3
  
  import os, sys, subprocess, shlex, re
  
  from subprocess import call
  
  
  
  def probe_file(filename):
  
      cmnd = ['ffprobe', '-show_packets', '-show_frames', '-print_format', filename]
  
      p = subprocess.Popen(cmnd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
  
      print filename
  
      out, err =  p.communicate()
  
      print "Output:"
  
      print out
  
      if err:
  
          print "Error:"
  
          print err
  
  
  
  probe_file(sys.argv[1])

  Being run with this command :

  python parse_frames_and_packets.py mux_test.ts

  And I’m getting the following error output :

  Unknown output format with name 'mux_test.ts'

  Can you not use .ts file types when using ffprobe with Python ? Because I’ve run ffprobe alone using this exact file and it worked correctly.

  Does anyone have any tips ?

  Edit :
  it seems to not recognize all types of video, not just transport stream (I just tried it with .avi and got the same response).

• Audio PTS is not equal but play time is equal

  20 juillet 2023, par KaGa Wu

  I have a video which has an dubbed Portuguese audio stream. The stream does not have the video head, like BGM of companies playing logos. So, the audio stream to delay some time play, it's first data package PTS is 9s. Then I transcode the audio stream to AAC, it's first package PTS is 2s. In my thinking the audio stream put the first data package in more front, it will play in more front originally, but it plays delay time is right !

  


  Here is the first package PTS, origin and transcoded.

  


  origin

  


  https://files.videohelp.com/u/302682/025_sisu_hevc_1920x800_30s_yuv420p_aac_copy.ts

  


  0x00458B74 Transport Packet { PID = 0x101, Payload = Yes (182), Counter = 15, Start indicator }
Adaptation Field ():
adaptation_field_length = 1
discontinuity_indicator = 0
random_access_indicator = 1
elementary_stream_priority_indicator = 0
PCR_flag = 0
OPCR_flag = 0
splicing_point_flag = 0
transport_private_data_flag = 0
adaptation_field_extension_flag = 0

0x00458B7A PES Packet { stream_id = 0xC0  (audio stream)}
packet_length = 2898
PES_scrambling_control = 0
PES_priority = 0
data_alignment_indicator = 0
copyright = 0
original_or_copy = 0
PTS_DTS_flags = 2
ESCR_flag = 0
ES_rate_flag = 0
DSM_trick_mode_flag = 0
additional_copy_info_flag = 0
PES_CRC_flag = 0
PES_extension_flag = 0
PES_header_data_length = 5
 PTS =  0:  0:  9: 570 (861 300)

0x00458B88 AAC Frame
id = 0
layer = 0
protection_absent = 1
profile = 1
sf_index = 3
private_bit = 0
channel_configuration = 6
original = 0
home = 0
copyright_identification_bit = 0
copyright_identification_start = 0
aac_frame_length = 285
adts_buffer_fullness = 2047
no_raw_data_blocks_in_frame = 0
SamplingRate = 48000
Channels = 6
Duration = 0.021333


  


  transcoded

  


  https://files.videohelp.com/u/302682/025_susi_hevc_1920x800_30s_yuv420p_aac_trans.ts

  


  0x000010E4 Transport Packet { PID = 0x101, Payload = Yes (182), Counter = 0, Start indicator }
Adaptation Field ():
adaptation_field_length = 1
discontinuity_indicator = 0
random_access_indicator = 1
elementary_stream_priority_indicator = 0
PCR_flag = 0
OPCR_flag = 0
splicing_point_flag = 0
transport_private_data_flag = 0
adaptation_field_extension_flag = 0

0x000010EA PES Packet { stream_id = 0xC0  (audio stream)}
packet_length = 467
PES_scrambling_control = 0
PES_priority = 0
data_alignment_indicator = 0
copyright = 0
original_or_copy = 0
PTS_DTS_flags = 2
ESCR_flag = 0
ES_rate_flag = 0
DSM_trick_mode_flag = 0
additional_copy_info_flag = 0
PES_CRC_flag = 0
PES_extension_flag = 0
PES_header_data_length = 5
 PTS =  0:  0:  1: 400 (126 000)

0x000010F8 AAC Frame
id = 0
layer = 0
protection_absent = 1
profile = 1
sf_index = 3
private_bit = 0
channel_configuration = 6
original = 0
home = 0
copyright_identification_bit = 0
copyright_identification_start = 0
aac_frame_length = 43
adts_buffer_fullness = 2047
no_raw_data_blocks_in_frame = 0
SamplingRate = 48000
Channels = 6
Duration = 0.021333


  


  I decode the origin video and transcoded video，and print screen of them.

  


• mpegts : relax restrictions on matching the packet start in read_header

  4 février 2015, par Anton Khirnov

  mpegts : relax restrictions on matching the packet start in read_header
  analyze() is currently called both when probing and from read_header().
  
  It determines the packet start by looking for the sync byte, followed by
  
  unset Transport Error Indicator and valid adaptation_field_control.
  This makes sense to do when probing, but once we already know the format
  
  is MPEG-TS, it is counterproductive to be so strict — e.g. in some
  
  files the TEI might be set and analyze() might get called with a smaller
  
  buffer than the one used for probing, resulting in a failure.
  

  • [DH] libavformat/mpegts.c