avformat/avio: Add Metacube support

[ffmpeg] / doc / mailing-list-faq.texi

\input texinfo @c -*- texinfo -*-
@documentencoding UTF-8

@settitle FFmpeg Mailing List FAQ
@titlepage
@center @titlefont{FFmpeg Mailing List FAQ}
@end titlepage

@top

@contents

@chapter General Questions

@section What is a mailing list?

A mailing list is not much different than emailing someone, but the
main difference is that your message is received by everyone who
subscribes to the list. It is somewhat like a forum but in email form.

See the @url{https://lists.ffmpeg.org/pipermail/ffmpeg-user/, ffmpeg-user archives}
for examples.

@section What type of questions can I ask?

@itemize
@item
@url{https://lists.ffmpeg.org/mailman/listinfo/ffmpeg-user/, ffmpeg-user}:
For questions involving unscripted usage or compilation of the FFmpeg
command-line tools (@command{ffmpeg}, @command{ffprobe}, @command{ffplay}).

@item
@url{https://lists.ffmpeg.org/mailman/listinfo/libav-user/, libav-user}:
For questions involving the FFmpeg libav* libraries (libavcodec,
libavformat, libavfilter, etc).

@item
@url{https://lists.ffmpeg.org/mailman/listinfo/ffmpeg-devel/, ffmpeg-devel}:
For discussions involving the development of FFmpeg and for submitting
patches. User questions should be asked at ffmpeg-user or libav-user.
@end itemize

To report a bug see @url{https://ffmpeg.org/bugreports.html}.

We cannot provide help for scripts and/or third-party tools.

@anchor{How do I ask a question or send a message to a mailing list?}
@section How do I ask a question or send a message to a mailing list?

First you must @ref{How do I subscribe?, subscribe}. Then all you have to do is
send an email:

@itemize
@item
Email @email{ffmpeg-user@@ffmpeg.org} to send a message to the
ffmpeg-user mailing list.

@item
Email @email{libav-user@@ffmpeg.org} to send a message to the
libav-user mailing list.

@item
Email @email{ffmpeg-devel@@ffmpeg.org} to send a message to the
ffmpeg-devel mailing list.
@end itemize

@chapter Subscribing / Unsubscribing

@anchor{How do I subscribe?}
@section How do I subscribe?

Email @email{ffmpeg-user-request@@ffmpeg.org} with the subject
@emph{subscribe}.

Or visit the @url{https://lists.ffmpeg.org/mailman/listinfo/ffmpeg-user/, ffmpeg-user mailing list info page}
and refer to the @emph{Subscribing to ffmpeg-user} section.

The process is the same for the other mailing lists.

@section How do I unsubscribe?

Email @email{ffmpeg-user-request@@ffmpeg.org} with subject @emph{unsubscribe}.

Or visit the @url{https://lists.ffmpeg.org/mailman/listinfo/ffmpeg-user/, ffmpeg-user mailing list info page},
scroll to bottom of page, enter your email address in the box, and click
the @emph{Unsubscribe or edit options} button.

The process is the same for the other mailing lists.

Please avoid asking a mailing list admin to unsubscribe you unless you
are absolutely unable to do so by yourself. See @ref{Who do I contact if I have a problem with the mailing list?}

Note that it is possible to temporarily halt message delivery (vacation mode).
See @ref{How do I disable mail delivery without unsubscribing?}

@chapter Moderation Queue
@anchor{Why is my message awaiting moderator approval?}
@section Why is my message awaiting moderator approval?

Some messages are automatically held in the @emph{moderation queue} and
must be manually approved by a mailing list admin:

These are:

@itemize

@item
Messages that exceed the @ref{What is the message size limit?, message size limit}.

@item
Messages from users whose accounts have been set with the @emph{moderation flag}
(very rarely occurs, but may if a user repeatedly ignores the rules
or is abusive towards others).
@end itemize

@section How long does it take for my message in the moderation queue to be approved?

The queue is not checked on a regular basis. You can ask on the
@t{#ffmpeg-devel} IRC channel on Freenode for someone to approve your message.

@anchor{How do I delete my message in the moderation queue?}
@section How do I delete my message in the moderation queue?

You should have received an email with the subject @emph{Your message to <mailing list name> awaits moderator approval}.
A link is in the message that will allow you to delete your message
unless a mailing list admin already approved or rejected it.

@chapter Archives

@anchor{Where are the archives?}
@section Where are the archives?

See the @emph{Archives} section on the @url{https://ffmpeg.org/contact.html, FFmpeg Contact}
page for links to all FFmpeg mailing list archives.

Note that the archives are split by month. Discussions that span
several months will be split into separate months in the archives.

@section How do I reply to a message in the archives?

Click the email link at the top of the message just under the subject
title. The link will provide the proper headers to keep the message
within the thread.

Note that you must be subscribed to send a message to the ffmpeg-user or
libav-user mailing lists.

@section How do I search the archives?

Perform a site search using your favorite search engine. Example:

@t{site:lists.ffmpeg.org/pipermail/ffmpeg-user/ "search term"}

@chapter Other

@section Is there an alternative to the mailing list?

You can ask for help in the official @t{#ffmpeg} IRC channel on Freenode.

Some users prefer the third-party @url{http://www.ffmpeg-archive.org/, Nabble}
interface which presents the mailing lists in a typical forum layout.

There are also numerous third-party help sites such as
@url{https://superuser.com/tags/ffmpeg, Super User} and
@url{https://www.reddit.com/r/ffmpeg/, r/ffmpeg on reddit}.

@anchor{What is top-posting?}
@section What is top-posting?

See @url{https://en.wikipedia.org/wiki/Posting_style#Top-posting}.

Instead, use trimmed interleaved/inline replies (@url{https://lists.ffmpeg.org/pipermail/ffmpeg-user/2017-April/035849.html, example}).

@anchor{What is the message size limit?}
@section What is the message size limit?

The message size limit is 1000 kilobytes. Please provide links to larger files
instead of attaching them.

@section Where can I upload sample files?

Anywhere that is not too annoying for us to use.

Google Drive and Dropbox are acceptable if you need a file host, and
@url{https://0x0.st/, 0x0.st} is good for files under 256 MiB.

Small, short samples are preferred if possible.

@section Will I receive spam if I send and/or subscribe to a mailing list?

Highly unlikely.

@itemize
@item
The list of subscribed users is not public.

@item
Email addresses in the archives are obfuscated.

@item
Several unique test email accounts were utilized and none have yet
received any spam.
@end itemize

However, you may see a spam in the mailing lists on rare occasions:

@itemize
@item
Spam in the moderation queue may be accidentally approved due to human
error.

@item
There have been a few messages from subscribed users who had their own
email addresses hacked and spam messages from (or appearing to be from)
the hacked account were sent to their contacts (a mailing list being a
contact in these cases).

@item
If you are subscribed to the bug tracker mailing list (ffmpeg-trac) you
may see the occasional spam as a false bug report, but we take measures
to try to prevent this.
@end itemize

@section How do I filter mailing list messages?

Use the @emph{List-Id}. For example, the ffmpeg-user mailing list is
@t{ffmpeg-user.ffmpeg.org}. You can view the List-Id in the raw message
or headers.

You can then filter the mailing list messages to their own folder.

@anchor{How do I disable mail delivery without unsubscribing?}
@section How do I disable mail delivery without unsubscribing?

Sometimes you may want to temporarily stop receiving all mailing list
messages. This "vacation mode" is simple to do:

@enumerate
@item
Go to the @url{https://lists.ffmpeg.org/mailman/listinfo/ffmpeg-user/, ffmpeg-user mailing list info page}

@item
Enter your email address in the box at very bottom of the page and click the
@emph{Unsubscribe or edit options} box.

@item
Enter your password and click the @emph{Log in} button.

@item
Look for the @emph{Mail delivery} option. Here you can disable/enable mail
delivery. If you check @emph{Set globally} it will apply your choice to all
other FFmpeg mailing lists you are subscribed to.
@end enumerate

Alternatively, from your subscribed address, send a message to @email{ffmpeg-user-request@@ffmpeg.org}
with the subject @emph{set delivery off}. To re-enable mail delivery send a
message to @email{ffmpeg-user-request@@ffmpeg.org} with the subject
@emph{set delivery on}.

@anchor{Why is the mailing list munging my address?}
@section Why is the mailing list munging my address?

This is due to subscribers that use an email service with a DMARC reject policy
which adds difficulties to mailing list operators.

The mailing list must re-write (munge) the @emph{From:} header for such users;
otherwise their email service will reject and bounce the message resulting in
automatic unsubscribing from the mailing list.

When sending a message these users will see @emph{via <mailing list name>}
added to their name and the @emph{From:} address munged to the address of
the particular mailing list.

If you want to avoid this then please use a different email service.

Note that ffmpeg-devel does not apply any munging as it causes issues with
patch authorship. As a result users with an email service with a DMARC reject
policy may be automatically unsubscribed due to rejected and bounced messages.

@chapter Rules and Etiquette

@section What are the rules and the proper etiquette?

There may seem to be many things to remember, but we want to help and
following these guidelines will allow you to get answers more quickly
and help avoid getting ignored.

@itemize
@item
Always show your actual, unscripted @command{ffmpeg} command and the
complete, uncut console output from your command.

@item
Use the most simple and minimal command that still shows the issue you
are encountering.

@item
Provide all necessary information so others can attempt to duplicate
your issue. This includes the actual command, complete uncut console
output, and any inputs that are required to duplicate the issue.

@item
Use the latest @command{ffmpeg} build you can get. See the @url{https://ffmpeg.org/download.html, FFmpeg Download}
page for links to recent builds for Linux, macOS, and Windows. Or
compile from the current git master branch.

@item
Avoid @url{https://en.wikipedia.org/wiki/Posting_style#Top-posting, top-posting}.
Also see @ref{What is top-posting?}

@item
Avoid hijacking threads. Thread hijacking is replying to a message and
changing the subject line to something unrelated to the original thread.
Most email clients will still show the renamed message under the
original thread. This can be confusing and these types of messages are
often ignored.

@item
Do not send screenshots. Copy and paste console text instead of making
screenshots of the text.

@item
Avoid sending email disclaimers and legalese if possible as this is a
public list.

@item
Avoid using the @code{-loglevel debug}, @code{-loglevel quiet}, and
@command{-hide_banner} options unless requested to do so.

@item
If you attach files avoid compressing small files. Uncompressed is
preferred.

@item
Please do not send HTML-only messages. The mailing list will ignore the
HTML component of your message. Most mail clients will automatically
include a text component: this is what the mailing list will use.

@item
Configuring your mail client to break lines after 70 or so characters is
recommended.

@item
Avoid sending the same message to multiple mailing lists.

@item
Please follow our @url{https://ffmpeg.org/developer.html#Code-of-conduct, Code of Conduct}.
@end itemize

@chapter Help

@section Why am I not receiving any messages?

Some email providers have blacklists or spam filters that block or mark
the mailing list messages as false positives. Unfortunately, the user is
often not aware of this and is often out of their control.

When possible we attempt to notify the provider to be removed from the
blacklists or filters.

@section Why are my sent messages not showing up?

Excluding @ref{Why is my message awaiting moderator approval?, messages that are held in the moderation queue}
there are a few other reasons why your messages may fail to appear:

@itemize
@item
HTML-only messages are ignored by the mailing lists. Most mail clients
automatically include a text component alongside HTML email: this is what
the mailing list will use. If it does not then consider your client to be
broken, because sending a text component along with the HTML component to
form a multi-part message is recommended by email standards.

@item
Check your spam folder.
@end itemize

@anchor{Why do I keep getting unsubscribed from ffmpeg-devel?}
@section Why do I keep getting unsubscribed from ffmpeg-devel?

Users with an email service that has a DMARC reject or quarantine policy may be
automatically unsubscribed from the ffmpeg-devel mailing list due to the mailing
list messages being continuously rejected and bounced back.

Consider using a different email service.

@anchor{Who do I contact if I have a problem with the mailing list?}
@section Who do I contact if I have a problem with the mailing list?

Send a message to @email{ffmpeg-user-owner@@ffmpeg.org}.

@bye