FFmpeg Mailing List FAQ

## Table of Contents

## 1 General Questions

### 1.1 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 ffmpeg-user archives for examples.

### 1.2 What type of questions can I ask?

- ffmpeg-user: For questions involving unscripted usage or compilation of the FFmpeg command-line tools (`ffmpeg`, `ffprobe`, `ffplay`).
- libav-user: For questions involving the FFmpeg libav* libraries (libavcodec, libavformat, libavfilter, etc).
- ffmpeg-devel: For discussions involving the development of FFmpeg and for submitting patches. User questions should be asked at ffmpeg-user or libav-user.

To report a bug see https://ffmpeg.org/bugreports.html.

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

### 1.3 How do I ask a question or send a message to a mailing list?

First you must subscribe. Then all you have to do is send an email:

- Email ffmpeg-user@ffmpeg.org to send a message to the ffmpeg-user mailing list.
- Email libav-user@ffmpeg.org to send a message to the libav-user mailing list.
- Email ffmpeg-devel@ffmpeg.org to send a message to the ffmpeg-devel mailing list.

## 2 Subscribing / Unsubscribing

### 2.1 How do I subscribe?

Email ffmpeg-user-request@ffmpeg.org with the subject subscribe.

Or visit the ffmpeg-user mailing list info page and refer to the Subscribing to ffmpeg-user section.

The process is the same for the other mailing lists.

### 2.2 How do I unsubscribe?

Email ffmpeg-user-request@ffmpeg.org with subject unsubscribe.

Or visit the ffmpeg-user mailing list info page, scroll to bottom of page, enter your email address in the box, and click the 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 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 How do I disable mail delivery without unsubscribing?

## 3 Moderation Queue

### 3.1 Why is my message awaiting moderator approval?

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

These are:

- Messages that exceed the message size limit.
- Messages from users whose accounts have been set with the moderation flag (very rarely occurs, but may if a user repeatedly ignores the rules or is abusive towards others).

### 3.2 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 `#ffmpeg-devel` IRC channel on Freenode for someone to approve your message.

### 3.3 How do I delete my message in the moderation queue?

You should have received an email with the subject 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.

## 4 Archives

### 4.1 Where are the archives?

See the Archives section on the 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.

### 4.2 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.

### 4.3 How do I search the archives?

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

`site:lists.ffmpeg.org/pipermail/ffmpeg-user/ "search term"`

## 5 Other

### 5.1 Is there an alternative to the mailing list?

You can ask for help in the official `#ffmpeg` IRC channel on Freenode.

Some users prefer the third-party Nabble interface which presents the mailing lists in a typical forum layout.

There are also numerous third-party help sites such as Super User and r/ffmpeg on reddit.

### 5.2 What is top-posting?

See https://en.wikipedia.org/wiki/Posting_style#Top-posting.

Instead, use trimmed interleaved/inline replies (example).

### 5.3 What is the message size limit?

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

### 5.4 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 0x0.st is good for files under 256 MiB.

Small, short samples are preferred if possible.

### 5.5 Will I receive spam if I send and/or subscribe to a mailing list?

Highly unlikely.

- The list of subscribed users is not public.
- Email addresses in the archives are obfuscated.
- Several unique test email accounts were utilized and none have yet received any spam.

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

- Spam in the moderation queue may be accidentally approved due to human error.
- 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).
- 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.

### 5.6 How do I filter mailing list messages?

Use the List-Id. For example, the ffmpeg-user mailing list is `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.

### 5.7 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:

1. Go to the ffmpeg-user mailing list info page
2. Enter your email address in the box at very bottom of the page and click the Unsubscribe or edit options box.
3. Enter your password and click the Log in button.
4. Look for the Mail delivery option. Here you can disable/enable mail delivery. If you check Set globally it will apply your choice to all other FFmpeg mailing lists you are subscribed to.

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

### 5.8 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 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 via <mailing list name> added to their name and the 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.

## 6 Rules and Etiquette

### 6.1 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.

- Always show your actual, unscripted `ffmpeg` command and the complete, uncut console output from your command.
- Use the most simple and minimal command that still shows the issue you are encountering.
- 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.
- Use the latest `ffmpeg` build you can get. See the FFmpeg Download page for links to recent builds for Linux, macOS, and Windows. Or compile from the current git master branch.
- Avoid top-posting. Also see What is top-posting?
- 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.
- Do not send screenshots. Copy and paste console text instead of making screenshots of the text.
- Avoid sending email disclaimers and legalese if possible as this is a public list.
- Avoid using the `-loglevel debug`, `-loglevel quiet`, and `-hide_banner` options unless requested to do so.
- If you attach files avoid compressing small files. Uncompressed is preferred.
- 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.
- Configuring your mail client to break lines after 70 or so characters is recommended.
- Avoid sending the same message to multiple mailing lists.
- Please follow our Code of Conduct.

## 7 Help

### 7.1 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.

### 7.2 Why are my sent messages not showing up?

Excluding messages that are held in the moderation queue there are a few other reasons why your messages may fail to appear:

- 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.
- Check your spam folder.

### 7.3 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.

### 7.4 Who do I contact if I have a problem with the mailing list?

Send a message to ffmpeg-user-owner@ffmpeg.org.