user5089: Is the assumption in the title true?
What is preventing the use of ffmpeg when producing a movie or broadcast quality material?
Are there any prominent or well known users of ffmpeg?
What is used instead of ffmpeg? Quicktime pro? Final Cut Pro/Adobe Premiere/Avid media composer?
Edit:
One interesting indication of ffmpeg usage could be job offer listings from major media firms where they are looking for ffmpeg skills.

user2836: The main reason is support, usability and control.  First, lets clarify that FFMPEG is an encoder, QuickTime Pro is a video utility that happens to include multiple encoders and Final Cut Pro is a non-linear editor and has nothing to do with encoders other than the fact it can output to an encoder (generally QuickTime I believe).
For big budget commercial projects, the emphasis is going to be on having the highest possible quality encoding which often will involve manual review of the content and tweaking the way things are encoded to minimize artifacts and maximize the quality.  Commercial encoders or even proprietary ones used internally by encoding houses have far more control, support and development than ffmpeg.  It's great for a free tool, but it isn't a high end commercial product.
For smaller commercial projects, you may find some users, but most often people use the encoders that come with their NLEs at that level (such as QuickTime Pro or Adobe Media Encoder).  The main reason at that level is convenience since they are tied directly in to the NLEs and are easy to configure and behave well with good quality results.
I can't guarantee that there aren't any production chains that use FFMPEG or a modified form of it, but in general, it is worth simply pointing out that not all encoders are created equally and while ffmpeg does very, very well for being free, it isn't the best option in all cases all the time, even if for business reasons rather than technical ones.

user1950: I use it in my professional production chain all the time. Last week I was using it to batch through dozens of videos that needed subtitles burnt-in. It would have taken me weeks of tedious labour with Final Cut, it took me a couple of minutes burning the srts in with ffmpeg, and I was able to automatically rename the files and compress them for the various playback devices at the same time, and keep editing in the background.
I'd say unfamiliarity with the command line is the major reason most people don't use it. Typy-typy is too scary, they need clicky-clicky. Though there are definitely some areas - archival preservation for one, where it is one of the main tools of choice. In any situation where you need to automate video manipulation or conversion there is really nothing that beats it.

user1760: FFmpeg is probably being used more than you believe. I think the BBC uses it for some workflows, there is evidence that Laika and Weta may use it, and there is a fork called FFmbc which is targeted for professional broadcast usage.
YouTube probably uses FFmpeg to decode as shown by some unique decoding issues (but this was several years ago that I read about this and I'm not sure of the current status).
Also see the FFmpeg Projects page for a small list of who uses FFmpeg in their projects.

user10516: I work as an assistant editor on feature films, and use ffmpeg all the time, primarily for two purposes:

Transcoding files to be uploaded for producers to view on digital dailies systems (Dax, PIX, etc). I've written up shell scripts that accept property-of and recipient strings as command line input, along with target bitrate, and then generate the desired files with a watermark made from those inputs. It's convenient, faster than AME, and more stable than a Compressor cluster. When I figure out how to do SMPTE timecode and feet+frames burn-ins with ffmpeg, my use of the application will expand further. 
Transcoding files for editorial whose original video or audio are in codecs or formats not supported by AME or Compressor. For example, clips needed for temp can be pulled from BDR or DVDR video discs, ingested into an mkv file, and then from there transcoded with ffmpeg to editorial-ready DnxHD or Prores.

I don't use ffmpeg for any sort of final or critical output, and I only use it in a few limited ways that I've extensively tested. But in answer to the original question - I do use ffmpeg a ton on both film and TV work, and think it's a great tool that helps me get through many of my regular tasks quickly and well. I couldn't guess how many other people in features or TV are using it. I frequently recommend ffmpeg to other AE's, but most folk have a command-line aversion.
ffmpeg's use in professional film and broadcast settings is probably also limited by the learning curve of not just the application's own syntax(es) but also the exposed complexity of video formats. Sometimes in ffmpeg a user has to know a ton about source and target codec in order to get things done. Use Compressor or AME to transcode from one codec to another and you'll never have to deal with perusing a long list of different YUV pixel formats, or having to make sure that your target file's height is divisible by 2 to avoid an x264 error. Those of us who enjoy learning arcana and carving our way to solutions are probably silently using ffmpeg at work. 

5089: <p>Is the assumption in the title true?</p>

<p>What is preventing the use of ffmpeg when producing a movie or broadcast quality material?</p>

<p>Are there any prominent or well known users of ffmpeg?</p>

<p>What is used instead of ffmpeg? Quicktime pro? Final Cut Pro/Adobe Premiere/Avid media composer?</p>

<p>Edit:</p>

<p>One interesting indication of ffmpeg usage could be job offer listings from major media firms where they are looking for ffmpeg skills.</p>
 2836: <p>The main reason is support, usability and control.  First, lets clarify that FFMPEG is an encoder, QuickTime Pro is a video utility that happens to include multiple encoders and Final Cut Pro is a non-linear editor and has nothing to do with encoders other than the fact it can output to an encoder (generally QuickTime I believe).</p>

<p>For big budget commercial projects, the emphasis is going to be on having the highest possible quality encoding which often will involve manual review of the content and tweaking the way things are encoded to minimize artifacts and maximize the quality.  Commercial encoders or even proprietary ones used internally by encoding houses have far more control, support and development than ffmpeg.  It's great for a free tool, but it isn't a high end commercial product.</p>

<p>For smaller commercial projects, you may find some users, but most often people use the encoders that come with their NLEs at that level (such as QuickTime Pro or Adobe Media Encoder).  The main reason at that level is convenience since they are tied directly in to the NLEs and are easy to configure and behave well with good quality results.</p>

<p>I can't guarantee that there aren't any production chains that use FFMPEG or a modified form of it, but in general, it is worth simply pointing out that not all encoders are created equally and while ffmpeg does very, very well for being free, it isn't the best option in all cases all the time, even if for business reasons rather than technical ones.</p>
 1950: <p>I use it in <em>my</em> professional production chain all the time. Last week I was using it to batch through dozens of videos that needed subtitles burnt-in. It would have taken me weeks of tedious labour with Final Cut, it took me a couple of minutes burning the srts in with ffmpeg, and I was able to automatically rename the files and compress them for the various playback devices at the same time, and keep editing in the background.</p>

<p>I'd say unfamiliarity with the command line is the major reason most people don't use it. Typy-typy is too scary, they need clicky-clicky. Though there are definitely some areas - archival preservation for one, where it is one of the main tools of choice. In any situation where you need to automate video manipulation or conversion there is really nothing that beats it.</p>
 1760: <p>FFmpeg is probably being used more than you believe. I think the BBC uses it for some workflows, there is evidence that Laika and Weta may use it, and there is a fork called FFmbc which is targeted for professional broadcast usage.</p>

<p>YouTube probably uses FFmpeg to decode as shown by some unique decoding issues (but this was several years ago that I read about this and I'm not sure of the current status).</p>

<p>Also see the <a href="http://ffmpeg.org/projects.html">FFmpeg Projects</a> page for a small list of who uses FFmpeg in their projects.</p>
 10516: <p>I work as an assistant editor on feature films, and use ffmpeg all the time, primarily for two purposes:</p>

<ul>
<li><p>Transcoding files to be uploaded for producers to view on digital dailies systems (Dax, PIX, etc). I've written up shell scripts that accept property-of and recipient strings as command line input, along with target bitrate, and then generate the desired files with a watermark made from those inputs. It's convenient, faster than AME, and more stable than a Compressor cluster. When I figure out how to do SMPTE timecode and feet+frames burn-ins with ffmpeg, my use of the application will expand further. </p></li>
<li><p>Transcoding files for editorial whose original video or audio are in codecs or formats not supported by AME or Compressor. For example, clips needed for temp can be pulled from BDR or DVDR video discs, ingested into an mkv file, and then from there transcoded with ffmpeg to editorial-ready DnxHD or Prores.</p></li>
</ul>

<p>I don't use ffmpeg for any sort of final or critical output, and I only use it in a few limited ways that I've extensively tested. But in answer to the original question - I do use ffmpeg a ton on both film and TV work, and think it's a great tool that helps me get through many of my regular tasks quickly and well. I couldn't guess how many other people in features or TV are using it. I frequently recommend ffmpeg to other AE's, but most folk have a command-line aversion.</p>

<p>ffmpeg's use in professional film and broadcast settings is probably also limited by the learning curve of not just the application's own syntax(es) but also the exposed complexity of video formats. Sometimes in ffmpeg a user has to know a ton about source and target codec in order to get things done. Use Compressor or AME to transcode from one codec to another and you'll never have to deal with perusing a long list of different YUV pixel formats, or having to make sure that your target file's height is divisible by 2 to avoid an x264 error. Those of us who enjoy learning arcana and carving our way to solutions are probably silently using ffmpeg at work. </p>
