Would source file determine whether or not a file will playback

[mdon]

My company develop flash based elearning and we recently came across an issue with some videos not playing back under certain parameters. The encoding I used was identical to hundreds of other videos that had always worked in the past, but as a part of trying to find an answer to the problem we requested the client (who had provided the source footage that was being encoded) send us the file in a different format, which we then encoded using the identical settings, this did not work, however as another test a colleague suggested that we screen record the original footage and then export the screen record, encoded using the identical settings. Much to my surprise this appears to have worked.

This went against all common sense to me as my understanding would have been, that the source footage would not affect the functionality of the output file. (provided that it was not corrupt) Can anybody shed some light onto why this may have happened.

I can provide more technical details as required

[Baldrick]

Are you sure you are using exact same encoding settings? Video codec, audio codec, frame rate, size etc? The source file should not matter if you are reconverting to same format.

Have you compared the files that doesn't work with the ones using for example mediainfo. Compare all properties.

[mdon]

Hi Baldrick, yes I use a preset setting in Adobe Media Encoder to ensure all the files are encoded exactly the same. I have Media info installed but aside from the obvious, video and audio bitrates, frame rates etc would there be any other particular info that I should look for that could prove relevant?

[Baldrick]

You could compare the encoder properties. View->Tree and under Encoding settings.

What happens if you convert with other software? Like any ffmpeg based encoder like handbrake, vidcoder, xmedia recode. Just to test. mp4 with h264/x264 works fine in flash.

[mdon]

One of the issues is that we have to get the videos below 1mb (insane I know) so the framework is set up particularly to work with flv file. Ive spoken to our development dept about using h264 in our flash course but for whatever reason, they have said they cant do it, we use .mp4 for mobile applications however. I think i attached two files with the details from media info. Aside from a slight variance in bit rate they are identical

[Baldrick]

Nope. No idea. Maybe some muxing problems.

What happens if you convert the video twice? First to some lossless/avi/mjpeg/mp4 format and the convert it again with adobe.