Find "Frame Accurate" edit/cut/join software for downloaded mater

[kclgad]

For constant bitrate mpg-1, I know some software (e.g. MyFlix 3.0.5) can cut/join the file using "Frame Accurate" without re-encode whole file, quality only drop a bit around the cut/join point.

- Is there any other softwares have same "Frame Accurate" function to cut/join other file formats (downloaded material) ? e.g. asf, avi, mpg-1, mpg-2, variable bit rate mpg, mov, rm, rmvb, vob, wmv, etc (NOT need 1 software to handle all formats).

- Please mention is it need to re-encode whole file, and any drop of quality.

Thanks for any help.

[guns1inger]

Any video encoded with temporal compression (mpeg1, mpeg2, mpeg4 variants, wmv etc) will require encoding if the cut is not done on a I-frame. This is because of the nature of the compression, and it's reliance on the frames before and after it for the full image. Smarter software will only re-encode from the last I-frame, reducing the impact the re-encoding will have to a smaller section of the video, however this software tends to be limited to just mpeg1/mpeg2, and not download formats like real, wmv etc.

A lot of software will do frame accurate cuts, but will require complete re-encoding of the surviving segment. The Virtualdubs will load many of the formats you require, can out put some of them, but will only do I-frames cuts without re-encoding. For frame-accurate cuts it will re-encode the whole file.

The reason for this : the formats you have chosen, with the exception of a few that use the avi container, were necer designed for editing. They were designed to crush the crap out of a video for playback only. Heavy crushers for streaming, not so heavy for disc delivery. Editing was the last thing on the mind of the designers. The other reason they weren't concerned too much about editing - they realised that by the time the video had been compressed, the quality was such that few would want to use it for any other purpose because the quality was so low in comparison to the original. It is unfortunate that mpeg2 has become a compression format for cameras because it has these limitations as well.

However, to start you off

For mpeg1/2 and possibly VOB format, look at the Womble range of editors, or VideoRedo. Chances are you will have to demux the streams from the VOBs, but there is no loss of quality in doing this, and VOBs should only be watched, and nothing else.

For DV, lossless or uncompressed avi, pretty much anything will work, as there is no loss in the process, and DV is I-framed througout anyway.

For pretty much everything else you will be re-encoding the lot, and most of the software that will edit the likes of real is low quality stff anyway.

[redwudz]

Good post, guns1inger, and nice explanation.

[BiggerJim]

Well, now there is a solution: Some programms will achieve frame accurate cuts without reencoding the complete movie. They will reencode only the portion between the cut and the next keyframe. This is possible with:

Asfbin V 1.5 or later (for *.wmv) --> use -rkf option
VirtualDub V 1.7 or later --> use "Smart Rendering" (you have to have the appropriate codec to reencode the missing part)
Avidemux, I think starting with Version 2.3 or so --> use "Smart Copy"

If you are looking for a GUI for asfbin (it's only commandline), try cut assistant. IT can be used woth virtualdub and avidemux too, for that matter.