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• Unable to stream swf file with ffserver

  12 août 2014, par user993766

  I’m trying to stream swf w/ flv video & mp3 audio & have had some issues. I believe my ffmpeg command line is fine, I think the problem is with my ffserver configuration. If I comment out the audio configuration, I get video output fine. If I have both, I only get audio - no video. However, upon stopping my input stream, audio will stop and video will start playing(at a faster speed than normal). Saving my ffmpeg to a file & viewing on mplayer yields both audio & video playing at the correct rate.

  Before posting an entire output dump, can anyone tell me if anything is blatantly wrong with my code ?

  FFMPEG is taking in an MPEG2 TS from a digital video tuner, transcoding to flv & mp3 :

  ffmpeg -i /dev/dvb/adapter0/dvr0 -c:v flv -r 15 -c:a mp3 -b:a 128k -ac 1 -ar 44100 http://localhost:8090/feed1.ffm

  My ffserver conf file is :

  Port 8090
  
  BindAddress 0.0.0.0
  
  MaxHTTPConnections 2000
  
  MaxClients 1000
  
  MaxBandwidth 16000
  
  CustomLog -
  
  
  
  <feed>
  
  File /tmp/feed1.ffm
  
  FileMaxSize 5M 
  
  </feed>
  
  
  
  <stream>
  
  Feed feed1.ffm
  
  Format swf
  
  
  
  AudioCodec libmp3lame
  
  AudioBitRate 128k
  
  AudioChannels 1
  
  AudioSampleRate 44100
  
  #AVOptionAudio flags +global_header
  
  
  
  #AVOptionVideo flags +global_header
  
  VideoCodec flv
  
  VideoFrameRate 15
  
  VideoBufferSize 80000
  
  VideoBitRate 100
  
  VideoQMin 1
  
  VideoQMax 5
  
  VideoSize 720x480
  
  PreRoll 0
  
  
  
  </stream>

  I’ve tried all kinds of permutations, adjusting QMax, video size, framerate & VideoBufferSize. Nothing seems to work. Any & all help appreciated !

• Server Move For multimedia.cx

  1er août 2014, par Multimedia Mike — General

  I made a big change to multimedia.cx last week : I moved hosting from a shared web hosting plan that I had been using for 10 years to a dedicated virtual private server (VPS). In short, I now have no one to blame but myself for any server problems I experience from here on out.

  The tipping point occurred a few months ago when my game music search engine kept breaking regardless of what technology I was using. First, I had an admittedly odd C-based CGI solution which broke due to mysterious binary compatibility issues, the sort that are bound to occur when trying to make a Linux binary run on heterogeneous distributions. The second solution was an SQLite-based solution. Like the first solution, this worked great until it didn’t work anymore. Something else mysteriously broke vis-à-vis PHP and SQLite on my server. I started investigating a MySQL-based full text search solution but couldn’t make it work, and decided that I shouldn’t have to either.

  Ironically, just before I finished this entire move operation, I noticed that my SQLite-based FTS solution was working again on the old shared host. I’m not sure when that problem went away. No matter, I had already thrown the switch.

  How Hard Could It Be ?
  We all have thresholds for the type of chores we’re willing to put up with and which we’d rather pay someone else to perform. For the past 10 years, I felt that administering a website’s underlying software is something that I would rather pay someone else to worry about. To be fair, 10 years ago, I don’t think VPSs were a thing, or at least a viable thing in the consumer space, and I wouldn’t have been competent enough to properly administer one. Though I would have been a full-time Linux user for 5 years at that point, I was still the type to build all of my own packages from source (I may have still been running Linux From Scratch 10 years ago) which might not be the most tractable solution for server stability.

  These days, VPSs are a much more affordable option (easily competitive with shared web hosting). I also realized I know exactly how to install and configure all the software that runs the main components of the various multimedia.cx sites, having done it on local setups just to ensure that my automated backups would actually be useful in the event of catastrophe.

  All I needed was the will to do it.

  The Switchover Process
  Here’s the rough plan :

  • Investigate options for both VPS providers and mail hosts– I might be willing to run a web server but NOT a mail server
  • Start plotting several months in advance of my yearly shared hosting renewal date
  • Screw around for several months, playing video games and generally finding reasons to put off the move
  • Panic when realizing there are only a few days left before the yearly renewal comes due

  So that’s the planning phase. BTW, I chose Digital Ocean for VPS and Zoho for email hosting. Here’s the execution phase I did last week :

  • Register with Digital Ocean and set up DNS entries to point to the old shared host for the time being
  • Once the D-O DNS servers respond correctly using a manual ‘dig’ command, use their servers as the authoritative ones for multimedia.cx
  • Create a new Droplet (D-O VPS), install all the right software, move the databases, upload the files ; and exhaustively document each step, gotcha, and pitfall ; treat a VPS as necessarily disposable and have an eye towards iterating the process with a new VPS
  • Use /etc/hosts on a local machine to point DNS to the new server and verify that each site is working correctly
  • After everything looks all right, update the DNS records to point to the new server

  Finally, flip the switch on the MX record by pointing it to the new email provider.

  Improvements and Problems
  Hosting on Digital Ocean is quite amazing so far. Maybe it’s the SSDs. Whatever it is, all the sites are performing far better than on the old shared web host. People who edit the MultimediaWiki report that changes get saved in less than the 10 or so seconds required on the old server.

  Again, all problems are now my problems. A sore spot with the shared web host was general poor performance. The hosting company would sometimes complain that my sites were using too much CPU. I would have loved to try to optimize things. However, the cPanel interface found on many shared hosts don’t give you a great deal of data for debugging performance problems. However, same sites, same software, same load on the VPS is considerably more performant.

  Problem : I’ve already had the MySQL database die due to a spike in usage. I had to manually restart it. I was considering a cron-based solution to check if the server is running and restart it if not. In response to my analysis that my databases are mostly read and not often modified, so db crashes shouldn’t be too disastrous, a friend helpfully reminded me that, “You would not make a good sysadmin with attitudes like ‘an occasional crash is okay’.”

  To this end, I am planning to migrate the database server to a separate VPS. This is a strategy that even Digital Ocean recommends. I’m hoping that the MySQL server isn’t subject to such memory spikes, but I’ll continue to monitor it after I set it up.

  Overall, the server continues to get modest amounts of traffic. I predict it will remain that way unless Dark Shikari resurrects the x264dev blog. The biggest spike that multimedia.cx ever saw was when Steve Jobs linked to this WebM post.

  Dropped Sites
  There are a bunch of subdomains I dropped because I hadn’t done anything with them for years and I doubt anyone will notice they’re gone. One notable section that I decided to drop is the samples.mplayerhq.hu archive. It will live on, but it will be hosted by samples.ffmpeg.org, which had a full mirror anyway. The lower-end VPS instances don’t have the 53 GB necessary.

  Going Forward
  Here’s to another 10 years of multimedia.cx, even if multimedia isn’t as exciting as it was 10 years ago (personal opinion ; I’ll have another post on this later). But at least I can get working on some other projects now that this is done. For the past 4 months or so, whenever I think of doing some other project, I always remembered that this server move took priority over everything else.

• Transcoding Modern Formats

  17 août 2014

  I’ve noticed that this blog still gets a decent amount of traffic, particularly to some of the older articles about transcoding. Since I’ve been working on a tool in this space recently, I thought I’d write something up in case it helps folks unravel how to think about transcoding these days.

  The tool I’ve been working on is EditReady, a transcoding app for the Mac. But why do you want to transcode in the first place ?

  Dailies

  After a day of shooting, there are a lot of people who need to see the footage from the day. Most of these folks aren’t equipped with editing suites or viewing stations - they want to view footage on their desktop or mobile device. That can be a problem if you’re shooting ProRes or similar.

  Converting ProRes, DNxHD or MPEG2 footage with EditReady to H.264 is fast and easy. With bulk metadata editing and custom file naming, the management of all the files from the set becomes simpler and more trackable.

  One common workflow would be to drop all the footage from a given shot into EditReady. Use the "set metadata for all" command to attach a consistent reel name to all of the clips. Do some quick spot-checks on the footage using the built in player to make sure it’s what you expect. Use the filename builder to tag all the footage with the reel name and the file creation date. Then, select the H.264 preset and hit convert. Now anyone who needs the footage can easily take the proxies with them on the go, without needing special codecs or players, and regardless of whether they’re working on a PC, a Mac, or even a mobile device.

  If your production is being shot in the Log space, you can use the LUT feature in EditReady to give your viewers a more traditional "video levels" daily. Just load a basic Log to Video Levels LUT for the batch, and your converted files will more closely resemble graded footage.

  Mezzanine Formats

  Even though many modern post production tools can work natively with H.264 from a GoPro or iPhone, there are a variety of downsides to that type of workflow. First and foremost is performance. When you’re working with H.264 in an editor or color correction tool, your computer has to constantly work to decompress the H.264 footage. Those are CPU cycles that aren’t being spent generating effects, responding to user interface clicks, or drawing your previews. Even apps that endeavor to support H.264 natively often get bogged down, or have trouble with all of the "flavors" of H.264 that are in use. For example, mixing and matching H.264 from a GoPro with H.264 from a mobile phone often leads to hiccups or instability.

  By using EditReady to batch transcode all of your footage to a format like ProRes or DNxHD, you get great performance throughout your post production pipeline, and more importantly, you get consistent performance. Since you’ll generally be exporting these formats from other parts of your pipeline as well - getting ProRes effects shots for example - you don’t have to worry about mix-and-match problems cropping up late in the production process either.

  Just like with dailies, the ability to apply bulk or custom metadata to your footage during your initial ingest also makes management easier for the rest of your production. It also makes your final output faster - transcoding from H.264 to another format is generally slower than transcoding from a mezzanine format. Nothing takes the fun out of finishing a project like watching an "exporting" bar endlessly creep along.

  Modernization

  The video industry has gone through a lot of digital formats over the last 20 years. As Mac OS X has been upgraded over the years, it’s gotten harder to play some of those old formats. There’s a lot of irreplaceable footage stored in formats like Sorensen Video, Apple Intermediate Codec, or Apple Animation. It’s important that this footage be moved to a modern format like ProRes or H.264 before it becomes totally unplayable by modern computers. Because EditReady contains a robust, flexible backend with legacy support, you can bring this footage in, select a modern format, and click convert. Back when I started this blog, we were mostly talking about DV and HDV, with a bit of Apple Intermediate Codec mixed in. If you’ve still got footage like that around, it’s time to bring it forward !

  Output

  Finally, the powerful H.264 transcoding pipeline in EditReady means you generate beautiful deliverable H.264 more rapidly than ever. Just drop in your final, edited ProRes, DNxHD, or even uncompressed footage and generate a high quality H.264 for delivery. It’s never been this easy !

  See for yourself

  We released a free trial of EditReady so you can give it a shot yourself. Or drop me a line if you have questions.