Opened 11 years ago

Closed 11 years ago

Last modified 11 years ago

#2376 closed defect (fixed)

Documentation for -avoid_negative_ts is too vague

Reported by: dbuitenh Owned by:
Priority: minor Component: documentation
Version: unspecified Keywords: pts
Cc: Blocked By:
Blocking: Reproduced by developer: yes
Analyzed by developer: yes

Description (last modified by dbuitenh)

Currently it says: "Shift timestamps to make them positive. 1 enables, 0 disables, default of -1 enables when required by target format."

This fails to cover a few important details:

  • How does it interact with the various async and vsync algos?
  • How does it interact with -copyts?
  • How does it interact with non-monotonic timestamps with both of the above?

Change History (6)

comment:1 by dbuitenh, 11 years ago

Description: modified (diff)

comment:2 by Michael Niedermayer, 11 years ago

There are no specific interactions iam aware of, all combinations should work. If something doesnt work, please be more specific.

comment:3 by Michael Niedermayer, 11 years ago

Or said differently, which specific case is vague ?
if you ask for constant frame rate through vsync and shifting timestamps to avoid negative ones theres nothing contradicting nor is there is you ask for timestamps to be copied and shifted so they arent negative. But iam happy to clarify any cases that need clarification, i just need to know which cases people find unclear.

comment:4 by dbuitenh, 11 years ago

If example, if you do -copyts and -avoid_negative_ts, which takes precedent?

If you do -vsync 0 -avoid_negative_ts, which is applied first?

If you do -vsync 0, is avoid_negative_ts ignored?

What about -copyts -vsync 1 -avoid_negative_ts? -async 1 -copyts -avoid_negative_ts?

The interaction between these sorts of flags is not at all clear to anyone without prior knowledge of the code.

comment:5 by Stefano Sabatini, 11 years ago

Analyzed by developer: set
Reproduced by developer: set
Resolution: fixed
Status: newclosed

Should be fixed since:

commit 9c22039c158c47c03df6c1e3b820fdf727a6c9c2
Author: Michael Niedermayer <>
Date:   Mon Mar 18 23:17:16 2013 +0100

    doc: Document the order in which avoid_negative_ts is applied compared to other timestamp options
    Also try to document the rational behind it.
    This might fix Ticket2376
    Signed-off-by: Michael Niedermayer <>

and following commits.

comment:6 by Carl Eugen Hoyos, 11 years ago

Priority: normalminor
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