Your English is excellent -- no worries!
Export from Camtasia as a lossless AVI file (using the Lagarith or UT codec), edit that in Pr, and then export to H.264 from Pr. Part of the problem is that you are encoding the screen recording once to H.264 in Camtasia, then encoding the H.264 again to H.264 in Pr. That causes an unnecessary loss of quality. There are probably some export settings in Pr that are adding to the loss of quality. If you post a screen shot of your Pr export settings for H.264, we may be able to spot something you can change to get better results. We also need to know the dimensions and frame rate of your video from Camtasia as well as your sequence settings in Pr.
If all else fails, you can encode to a visually lossless MOV file using the Photo-JPEG codec and use Handbrake to encode to H.264 using the x264 encoder.
All of this info assumes you are using a Windows computer and not a Mac.
Hi Jeff, thanks for your answer. Let me explain a little better.
I have Mac, but these videos are produced by chemestry professionals in theyr homes and sent to me (the original files, not encoded), and all of them use Windows. Camtasia for Mac is not compatible with Camtasia for Windows, so i run Camtasia on a Virtual Machine, and then send the video to Premiere in OSX.
Resolution is maintained across softwares (1280x800 30fps).
With what you've told me i managed to finally produce a Quicktime Photo-JPEG codec video, wich is almost 22gb and looks great because its uncompressed. But when i produce the video in Premiere still generates a bad quality mp4 and those "heartbeats" i was talking about. Here you can see a new example https://dl.dropboxusercontent.com/u/51216709/prueba2.mp4 you can see the heartbeats from 0:13, the quality of the previous animation isnt important.
For this case i reduced the min bitrate to 0,19, the lower value Premiere allows, because i really want to reduce the filesize
Here you can see the settings https://dl.dropboxusercontent.com/u/51216709/premiere.jpg
Maybe you can help me to get a better image, or eliminate those annoying heartbeats
Thanks again for your answer
- Uncheck all of the boxes at the bottom of the export settings dialog. In this case, you don't need Maximum Render Quality or Frame Blending, and you certainly don't want to use your Preview files. If you've rendered any portion of your timeline while editing, Use Preview Files will probably destroy the video quality.
- If you still get the "heartbeat" effect after that, try setting the keyframe distance to 150 frames (5 seconds for 30 fps video). It may seem counter-intuitive, but more keyframes eat up more of your available bits and leave less for the in-between frames. Increasing the keyframe distance helps balance the available bits between keyframes and dependent frames. With such a low bitrate, that could be very important.
- Try increasing your max bitrate. You'll still get a file about the same size, but the encoder can allocate more bits in the spots that need it and fewer bits elsewhere. Screen recordings often have many spots where very few bits of data are needed, and the bits saved can be used for more complex frames.