I reply to your points below. I'm reproducing some of my reply to Chris O'Leary here:
When I refer to "Tailor", I mean FutureTel's frame-accurate MPEG editing engine, which is integrated into both the VideOh! and the Video Sphinx Pro products. Tailor is a cut-and-paste non-real-time frame-accurate MPEG editor. Tailor includes support for special effects, two of which (Fades and Titling or both) are integrated into ClipView 2.0. The current implementation of Effects is a complete re-encode (but a careful one, in the VBV sense) over the effect duration.
At 12:02 AM 10/3/98 PDT, Halstead W. G. York wrote:
>O.K. first of all, GRRRRRRRR.
(I guess the R's are interframes...)
>2nd, full spec MPEG-1 doesn't *have* all (or even most) it's frames. So you generally can't do frame based editing.
Correct, generally speaking.
>3rd, it is misleading in the extreme to call any proprietary I-frame only MPEG MPEG, because it still needs to be compressed as an MPEG-1 file *after editing*. I know that many of these editable formats do an intraframe subset of MPEG encoding when digitized, and that's cool, as it speeds up final MPEG compression. But, it is not a final delivery codec.
Agreed; I also detest liars and misrepresentation.
>4th, there are solutions out there that can re-produce a full frame-based timebase from a small GOP encode in a lossless fashion. However, they are all very expensive, and require fairly small GOP length (and therefore large file sizes).
I wonder if you are referring to the techniques being researched by (_inter alia_) the people on the Atlantic Project? They are presenting proposals for solving the all-digital studio dilemma of the next few years, whereby streaming MPEG-2 needs to be realtime spliced on the fly seamlessly and without appreciable generational loss. It is indeed do-able, and I mention this also so as to show that I am not a lone voice crying in the wilderness about MPEG editing; the Atlantic Project has big names and big bucks behind it - and it's all on the Web, down to a level of detail that will make your teeth ache. Go viddy it.
>If FutureTel is reproducing frames from final compressed MPEG files in real or near real time, then I apologize profusely. Otherwise, I feel that your statement is, from both a technical and a practical workflow perspective, misleading.
You've really no need to apologise, since I can't see what slander you've committed...
The misrepresentation reference certainly doesn't apply to Tailor. To reiterate, in its current incarnation Tailor is not billed as realtime - although it actually already is, and much more so, for a large number of the possible edit cases one finds - notably on long streams.
A final case in point: The VideoCD MPEG streams which Tailor can produce as a result of splicing together multiple VideoCD MPEG streams, or just trimming a single one.
The bitstream legality constraints for being able to burn a VideoCD CD-ROM, which is subsequently playable without problems on a Video CD player, are significantly tougher than the bitrate constraints generally applicable to streams piped into run-of-the-mill MPEG software decoders/players (the latter being a case Chris O'Leary brought up). We have seen no problems whatsoever in the playability of composite VideoCD streams which Tailor produced and which were burned onto VideoCD CD-ROM.
Cheers,
Andrew