Using H.264 Encoding For FLV Files

Today I was asked to fix a problem with an existing website where a FLV was stopping quarter way in its playback. This problem only occurred in IE 7 with Windows Vista. Every other browser seemed to work fine.

First step I took was to isolate the problem. I remade the FLV from source just to see that nothing like a cue point was in there that shouldn’t be. No dice. So I tried another FLV that I knew worked and sure enough it played all the way through. From there I opened Adobe Media Encoder and started getting creative with the encoding settings.

I tried it without audio and it played all the way through. That made sense, because the one that I tested with didn’t have audio either. So the problem was now isolated to an audio problem. Some forums had vaguely familiar sounding fixes, but nothing solid that worked for me. Once again I changed bitrate and channel settings for the FLV sound. No dice. The audio options for FLV are pretty limited and I was running out of things to test for. So I thought about who does this kind of thing successfully all day; they must have a process. I figured that if anyone was encoding things right it was probably YouTube.

I checked YouTube and using this Safari trick grabbed the FLV file that YouTube generates. In my test, the YouTube video worked in IE 7 with Vista. I opened the FLV in QuickTime player. You can only do this if you have a plugin like Perian installed. I checked the movie properties. It was H.264/AAC audio. Even the CS4 Media Encoder can’t make an FLV like that. The options are only Sorenson Spark or On2 VP6. It can make a F4V this way, whatever the hell that is. In any event, that F4V had the settings that I needed, so I encoded one of those. No dice. FLV player wouldn’t play a F4V. The hillbilly in me figured I’ll just change the extension. Why the fuck not? Holy shit, it worked.

So, if you want to make an FLV file that is H.264, just make a F4V file with Adobe Media Encoder and then change the file extension.