AVCHD thru Premiere CS4 encodes hiccups in audio

[ddane]

I need some help with a problem that I can’t seem to find any information about.

First the project - I have a player that I have developed in Flash that reads an audio-only FLV file and uses the FLV’s embedded cue points to load “slide images” as they are needed. The initial video has been shot with a Canon HF20. I am editing the files directly from the camera and from an external eSATA drive with Premiere Pro CS4. In Premiere, I am combining the MTS files and adding the cue points using the video to reference when the presenter changes the slides. The audio sounds perfect in Premiere. I then export the audio as an FLV (I have also tried using F4V to try and fix my problem).

Now the problem – The audio files, which vary in length from 2 minutes to 2 and a half hours, come out of the Adobe Media Encoder with spots of skipped audio (as if they had been dropped frames when encoding). A couple of times I’ve even had “misplaced” audio – where a second or two of audio from one part of the file plays in another section. Listening to the same file more than once shows the problem is in the file, not a playback error (such as something else being processed in the background causing the skip). Also, AME does not report any compiling errors for these files.

Here’s the technical stuff -
Original files are AVCHD from the Canon HF20. Premiere gives the files’ frame rate as 29.97 and audio format as 48000 Hz, compressed, Stereo and the project’s audio format as 48000 Hz, 32 bit floating point, Stereo.
I am encoding the files as audio only, bitrate 96kbps, Stereo for the FLVs and 44.1kHz, bitrate 96kbps, Stereo, using AAC for the F4Vs.
My computer’s specs are Pentium 4, 2.8 Ghz with 4 GB of RAM. XPPro with SP3. I am encoding the final FLV’s to an external 1 TB HD connected via eSATA.

I appreciate any help/advice that anyone might have on this. I know my computer isn’t the best for video editing, but the main reason for this setup was to process the camera’s digital files to audio. If the computer’s processor is what’s causing the hiccups, then I’ll need to upgrade. If you need any more info from me, please let me know. Thanks again!

[Baldrick]

Have you tried export to wav/pcm or some other audio format? To see if it sounds okey. Then can you try convert the wav/pcm.

And try also convert to mp4 with aac audio and see if sounds any different. It works fine in flash players.

[ddane]

I haven't tried any other formats due to encoding time. Some of the files are taking up to 8 hrs to encode. I have to start them to run while I'm gone because the render keeps me from being able to use the computer. We went to digital video to keep from having to go through digitizing and then encoding final files - lots of down time when processing multiple presentations.

I'll try the mp4 since it wouldn't require a second encode/render. Thanks for the suggestion.

I would like to find the problem, though, because we will eventually be using this setup to put video and audio up and would like to use the flv/f4v to do so.

[filmboss80]

A little tip: always encode short video clips until you find the best settings. That way you're not wasting lots of hours rendering.

[ddane]

That's part of the problem. The shorter clips aren't producing the hiccups. These are anywhere from 2 - 10 minutes long. The longer videos are producing the gliches when they are encoded at full or almost full length. If I encode just a short section of the longer videos, say 5 minutes or so, I don't get the hiccups. I made a point to encode a section in which I had heard the glitch in the full length version. It did not reproduce the hiccup when the short section was rendered.

[windstar]

Your computer isn't fast enough to handle adobe premiere and the type of file you are trying to work with. Check the requirements for the program. You need at least dual core(min) or quad core processor and as much memory as your mobo can handle.
Good luck