It would be helpful to me to be able to edit the files created by the streaming software I use that saves an .mp4 copy to the local hard drive. I want to be able to upload the video after trimming off the beginning and end to other non-streaming sites like vimeo and youtube but can't wait an hour, and take a quality hit, by re-compressing the video. I know that .mp4 is not an i-frame codec, but it seems like it should be possible to do edits at the nearest i-frame to where I want to cut and add the appropriate headers and such without processing the whole file. I can't figure out how to do this in Vegas even though it seems like it should be easy.

ther is no smart render of mp4 in vegas, nor come to that in any pro nle i'm aware of. apparently there are some 'basic' apps that will do so, ie. cut to cut and the like... google is your (evil) friend ;-)

mp4 is not a codec, it's a container file format. I guess you are talking about H.264 video in mp4 file.
Leslie is right - NLEs can't smart render this format. But there are tools that can do this:
SolveigMM Video Splitter (http://vegasaur.com/SolveigMM-Video-Splitter)

It would be helpful to me to be able to edit the files created by the streaming software I use that saves an .mp4 copy to the local hard drive. I want to be able to upload the video after trimming off the beginning and end to other non-streaming sites like vimeo and youtube but can't wait an hour, and take a quality hit, by re-compressing the video. I know that .mp4 is not an i-frame codec, but it seems like it should be possible to do edits at the nearest i-frame to where I want to cut and add the appropriate headers and such without processing the whole file. I can't figure out how to do this in Vegas even though it seems like it should be easy.

Try Avidemux: Avidemux - Main Page (http://fixounet.free.fr/avidemux/)

Fran

Thanks for the clarification about .mp4 not being a codec. I was really hoping that I was missing something about simple cut editing but I guess I was just reminiscing fondly the days when the DV codec could be cut without re-compresion. I'll look into these utility editing programs, but I long for the day when everything can be done in one place.

avidemux to the rescue! It is super easy to use and works well except I tried once to do a recompression to a specific size and it went over by 5%. The "copy" setting for output does a trim without compression and only takes a few seconds.

And the price is right!

Fran