[MPlayer-DOCS] CVS: main/DOCS/xml/en faq.xml,1.77,1.78

The Wanderer inverseparadox at comcast.net
Tue Jun 28 11:29:15 CEST 2005

Guillaume Poirier CVS wrote:

> +Newer versions of <application>MEncoder</application> can directly
> +generate MPEG-2 files that can be used as a base to create a (S)SVCD and

Redundant S, either in or out of the parentheses.

Also, this is still not really satisfactory WRT "a"/"an". The "a" which
is present works when the following construction is parsed as "VCD", but
not when it's parsed as "SVCD", and for "an" the reverse is true; in
effect, whichever form you choose will only be right half of the time.
If we're going to insist on using the correct form of the indefinite
article (which I wouldn't necessarily say we should, given that this is
an acronym whose expansion does not have the problem), I see no way to
avoid this without being more verbose (i.e., saying something like "a
VCD or SVCD").

> +are likely to be playable out of the box on all platforms (for example
> +to share a video from a digital camcorder with your computer-illiterate
> +friends).

Comma after "example" would be better, I think.

Heh. In my partially completed response to the first pre-commit version
of this, I ignored the lack of hyphenation because other people don't
usually agree with me - but here it's been corrected after all. ^_^

> +<screen>
> +mencoder -of mpeg -oac toolame -toolameopts br=224 -srate 44100 \
> +-af-adv force=1 -ovc lavc -mpegopts format=xsvcd -vf harddup -ofps 25 \
> +-lavcopts vcodec=mpeg2video:mbd=2:keyint=25:vrc_buf_size=917:vrc_minrate=600:vbitrate=2500:vrc_maxrate=2500 \
> +<replaceable>in.avi</replaceable> -o <replaceable>xsvcd.mpg</replaceable>
> +</screen>
> +This will convert the input file <replaceable>in.avi</replaceable> into
> +the output file <replaceable>xsvcd.mpg</replaceable>, converting the
> +audio with <systemitem class="library">toolame</systemitem> at 224kbps
> +and the video with <systemitem class="library">libavcodec</systemitem>.
> +</para><para>

Since you specifically explain the audio bitrate, you should probably
also specifically explain more information about the video options used,
just for consistency.

> +Please note that in order to make the GOP structure SVCD compliant the
> +<option>keyint</option> option should be 15 for PAL and 18 for NTSC,
> +although very often files with much longer GOPs play correctly (25 should
> +never lead to any problem).
> +Also, even though leaving out <option>-ofps</option> should work in most
> +cases PAL requires <option>-ofps</option> 25 and NTSC
> +<option>-ofps</option> 30000/1001.

This is ambiguous. Is it that "leaving out -ofps should work in most
cases" but "PAL requires" etc., or that "leaving out -ofps should work"
but "in most cases PAL requires" etc.? (Yes, I know the answer, but Joe
Average FAQ Reader won't necessarily.)

In the former case you want a comma after "cases", in the latter case
the comma goes after "work".

In addition, you should probably say "NTSC requires" just as with "PAL
requires" - it's clear what you mean anyway but it's not quite proper

> +</para><para>
> +As far as the audio is concerned, SVCD only support MPEG-1 layer II audio,

Either "SVCDs only support" or "SVCD only supports".

> +therefore you have to use either
> +<systemitem class="library">toolame</systemitem>,
> +<systemitem class="library">twolame</systemitem>, or as a last resort
> +<systemitem class="library">libavcodec</systemitem>'s MPEG-1 layer II
> +encoder (as its quality is far from being as good as the former two
> +libraries).

Since you're listing more than two items, "either" isn't really 
appropriate; "one of" would work as a drop-in replacement.

> +Both <systemitem class="library">toolame</systemitem> and
> +<systemitem class="library">twolame</systemitem> follow the same syntax,
> +so you depending on which one you managed to install, the example only
> +requires a small chance, but if you need to use

ITYM "change".

Also, to avoid a run-on sentence, try something like "change. If you do
need to use" - the important part is splitting the sentence, the rest
just helps things fit with that change.

> +<systemitem class="library">libavcodec</systemitem>'s MPEG-1 layer II
> +encoder, replace
> +<screen>
> +-oac toolame -toolameopts br=224
> +</screen>
> +by
> +<screen>
> +-oac lavc -lavcopts acodec=mp2:abitrate=224

Does "-toolameopts" in fact work even if youre actually using twolame?
If not, you should probably add a comment about the change needed in
that sitation as well.

> +</screen>
> +</para><para>
> +The resulting file <replaceable>xsvcd.mpg</replaceable> is an extended

Either put commas around the name 'xsvcd.mpg', or remove the word
"file". Given the degree of commage in the rest of the sentence, I'd
recommend either the latter (which has its own problems) or:

> +SVCD (that is why it is called xsvcd), mainly because it does not contain
> +scan offsets, so if you need to generate an SVCD image out of it, you
> +should pass it to

splitting the setntencee before "so" and dropping the "so".

       The Wanderer

Warning: Simply because I argue an issue does not mean I agree with any
side of it.

A government exists to serve its citizens, not to control them.

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