[FFmpeg-devel] [PATCH] doc/codecs: Updates for skip_alpha / field_order

Stefano Sabatini stefasab at gmail.com
Fri Oct 18 23:51:46 CEST 2013


On date Friday 2013-10-11 20:02:47 +0200, Michael Niedermayer encoded:
> From: Timothy Gu <timothygu99 at gmail.com>
> 
> Merged-by: Michael Niedermayer <michaelni at gmx.at>
> Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> ---
>  doc/codecs.texi |   16 ++++++++++------
>  1 file changed, 10 insertions(+), 6 deletions(-)
> 
> diff --git a/doc/codecs.texi b/doc/codecs.texi
> index 74dd775..2e9d106 100644
> --- a/doc/codecs.texi
> +++ b/doc/codecs.texi
> @@ -1064,19 +1064,23 @@ Set/override the field order of the video.
>  Possible values:
>  @table @samp

>  @item progressive
> -Progressive video
> +Progressive video.
>  @item tt
> -Interlaced video, top field coded and displayed first
> +Interlaced video, top field coded and displayed first.
> +
>  @item bb
> -Interlaced video, bottom field coded and displayed first
> +Interlaced video, bottom field coded and displayed first.
> +
>  @item tb
> -Interlaced video, top coded first, bottom displayed first
> +Interlaced video, top coded first, bottom displayed first.
> +
>  @item bt
> -Interlaced video, bottom coded first, top displayed first
> +Interlaced video, bottom coded first, top displayed first.
>  @end table

unrelated?

Also I prefer as it was before, since they are not complete sentence
(the rule is: if not a complete sentence no need to put a final dot,
*unless* there is a following sentence).

>  
>  @item skip_alpha @var{integer} (@emph{decoding,video})
> -causes alpha plane not to be decoded, like "gray" which skips chroma.
> +Set to 1 to disable processing alpha (transparency). Default is 0.
> +like "gray" which skips chroma.

This is utterly confusing, indeed I can just guess what this is all
about.

So with skip_alpha no alpha component is decoded (processed). But how
is "gray" related if it has no alpha component? I believe you mean
like in the case of encoding to gray, when the alpha component is
skipped by the encoder so there is no point into decoding/processing
it in the first place. (BTW do we have a corresponding skip_chroma
option?)
-- 
FFmpeg = Fantastic and Fascinating Monstrous Problematic Emblematic Gem


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