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metadope

Member

From: Florida (mostly)

Registered: 2017-06-30

Posts: 3

Website

[SOLVED] ffmpeg 2:7.1-7 regression (probesize and analyzeduration)

ffmpeg 2:7.1-7 has an apparent regression. A nasty new bug. I don't know if it is/was introduced by changes upstream, or if it is a packaging issue, or a an anomaly specific to my machine.

Before I report upstream to the ffmpeg Trac, I thought I'd ask for a little help here. Due to the nature of the bug (which affects the transcoding of huge VOB files, i.e. from a dvdbackup), I am hoping a fellow archlinux user, familiar with ffmpeg, can do a sanity check and confirm what I found in the transition from 2:7.1-6 to this newer release: Two ffmpeg command-line switches that are essential to the proper parsing of concatenated VOB files no longer work-as-designed.

Here's a typical command that can illustrate the issue:

{me@myAMD:/mnt/iso/1/VIDEO_TS $ ffprobe -analyzeduration 4000 -probesize 4000 'concat:VTS_03_1.VOB|VTS_03_2.VOB|VTS_03_3.VOB'
ffprobe version n7.1 Copyright (c) 2007-2024 the FFmpeg developers
  built with gcc 14.2.1 (GCC) 20250207

With previous releases of ffmpeg this command would normally take several seconds to complete. Increasing the value of the parameters (analzeduration and probesize had a direct corresponding increase in the time taken to complete the probe. This is often a necessary step/precursor to building a proper ffmpeg command line for the transcoding of DVD backups to single-file MP4s (as one example).

The new release finishes immediately, and fails to parse the concatenation. Increasing the values does not have any effect.

[mpeg @ 0x64f9f2058140] Stream #1: not enough frames to estimate rate; consider increasing probesize
[mpeg @ 0x64f9f2058140] start time for stream 1 is not set in estimate_timings_from_pts
[mpeg @ 0x64f9f2058140] stream 1 : no TS found at start of file, duration not set
[mpeg @ 0x64f9f2058140] Could not find codec parameters for stream 1 (Video: mpeg2video, none): unspecified size
Consider increasing the value for the 'analyzeduration' (4000) and 'probesize' (4000) options
Input #0, mpeg, from 'concat:VTS_03_1.VOB|VTS_03_2.VOB|VTS_03_3.VOB':
  Duration: 00:38:36.72, start: 0.229367, bitrate: 8199 kb/s
  Stream #0:0[0x1bf]: Data: dvd_nav_packet
  Stream #0:1[0x1e0]: Video: mpeg2video, none, 90k tbr, 90k tbn
  Stream #0:2[0xa0]: Audio: pcm_dvd, 48000 Hz, stereo, s16, 1536 kb/s
Unsupported codec with id 98312 for input stream 0

Last edited by metadope (2025-03-20 07:45:16)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 24,301

Re: [SOLVED] ffmpeg 2:7.1-7 regression (probesize and analyzeduration)

A change of the pkgrel (the -7 at he end) normally means a rebuild to satisfy dependencies with no changes to the underlying source code. In this case a rebuild for compat with svt-av1. Since you don't appear to be dealing with av1 files, it's very unlikely that this particular bump on it's own has caused the issue.

metadope

Member

From: Florida (mostly)

Registered: 2017-06-30

Posts: 3

Website

Re: [SOLVED] ffmpeg 2:7.1-7 regression (probesize and analyzeduration)

How embarrassing... [SOLVED]

I jumped to the wrong conclusion, misremembering the command line parameter's syntax.

This is/was a false positive 'regression' caused by me having a senior moment-- the strange behavior I erroneously reported here and attributed to the newest ffmpeg package was actually the result of me forgetting to postfix an 'M' to my numbers

me@myAMD:/mnt/iso/1/VIDEO_TS $ ffprobe -analyzeduration 4000M -probesize 4000M 'concat:VTS_03_1.VOB|VTS_03_2.VOB|VTS_03_3.VOB'

Can we delete this thread?

Sorry for the noise!