Opened 5 years ago

Closed 5 years ago

#3207 closed defect (fixed)

FFmpeg outputs invalid ASS files

Reported by: gjdfgh Owned by:
Priority: normal Component: undetermined
Version: unspecified Keywords: sub ass
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no

Description

ffmpeg -i test.sub out.ass produces an ASS file with this header:

[Events]
Format: Layer, Start, End, Style, Text

The "Format:" line, as well as all events following it, is semi-invalid. While it does look like the ASS format is flexible about the headers, and libass actually parses this, it's not accepted by most other ASS readers, such as the (very important) vsfilter.

FFmpeg should output standard headers instead.

Here's an example of users actually running into this problem: http://www.cccp-project.net/forums/index.php?topic=6826.0

It's possible that libass will drop the header parsing in the future to avoid compatibility problems with real-world scripts.

Change History (6)

comment:1 Changed 5 years ago by ubitux

So does vsfilter only accept the events in the following form Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text?

Is the Style header also affected?

Any other incompatibilities?

comment:2 Changed 5 years ago by gjdfgh

Is the Style header also affected?

Yes. Note that it might accept older variants, SSA at least.

Any other incompatibilities?

Not that I know of.

comment:3 Changed 5 years ago by plorkyeran

The headers assumed by VSFilter for SSA are:
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, TertiaryColour, BackColour, Bold, Italic, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, AlphaLevel, Encoding
Format: Marked, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text

and for ASS:
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text

Last edited 5 years ago by plorkyeran (previous) (diff)

comment:4 Changed 5 years ago by ubitux

  • Keywords subtitles ass added

comment:5 Changed 5 years ago by cehoyos

  • Keywords sub added; subtitles removed

comment:6 Changed 5 years ago by ubitux

  • Resolution set to fixed
  • Status changed from new to closed
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