Video editing on a laptop
Project definition What I did
Capture and edit video using a laptop – burn edited video onto CD-ROM to show friends.
Gateway Solo 9100 XL – 233 MMX Pentium, 14.1" screen, 128 MB RAM, 5GB internal HD
Dazzle Parallel Port MPEG 1 encoder
Panasonic CW 7502 CD Burner (external SCSI)
Adaptec SlimSCSI 1480A
Adobe Premiere 4.2
Adobe Photoshop 4.0
Xing MPEG encoder
What I did
Shooting the video – I originally shot the video over the course of a three month windsurfing trip to Maui (Hawaii) in April-July 1997. It was all shot on the JVC GR-DV1 – I wasn’t paying particular attention to what I was shooting (much like any beginner videographer) and since the only piece of video capture hardware I owned at the time was a frame grabber it didn’t make much of a difference.
A year later in possesion of a more powerful computer and a better video capture card I decided to do things properly.
Disk space being at a premium (my 5 gig disk was partitioned for FAT16, two 2 gig partitions and one 1 gig.) Windows and apps were in one of the 2 gig partitions and documents and other assorted crap were in the 1 gig.
To keep things tidy I decided I’d keep to only one partition which left me with 2 GB of storage for all clips and the final movie.
(note that I performed all the standard tweaks to the win 95 system before starting capture – such as not running any real mode DOS programs or unneeded extensions like anti virus software – the only thing running other than needed software was explorer itself. These changes are well summarised in a doc on the adobe web site.)
The Dazzle card does not need an external power supply (the ps/2 mouse port supplies it with the 5V DC that it requires) and so is extremely easy to connect to the parallel port. I originally ran into problems as the card was not being recognised but on emailing Dazzle they quickly responded that Gateway had built non-standard parallel ports into their laptops. A replacement was provided within 7 days.
The Dazzle claims to capture 352x288 at a full 25fps and it did so with no problems – compression options for video allow for any value between 500kbps to 3Mbps. In my experience the software was a little unpredictable and often tended to freeze or drop frames at rates above 2.2 Mbps.
Since there was not much discernible difference I opted for 1.5 Mbps which worked with no problems.
Whilst capturing it is convenient to have a realtime preview of what it going on – since the parallel port is not fast enough for this kind of data throughput the dazzle only provides 4/5fps preview of the current action. This is annoying since to be sure you have the scene you want you either have to overcapture by a few seconds either side or check each clip after you capture it.
Since both of these solutions are time consuming it is also possible to position a TV near the camera, split the video signal and run one to the TV watching the ‘preview’ there but capturing to the hard drive.
However I had a PAL camera but I was in the US so I could not do that – instead I split the video signal and ran it through the TV-in port on my laptop (this connects to a primitive but functional TV card shipped as standard in all Gateway Solo 9100’s – it can see video but not capture it). I was able to view 25fps video from this TV card at the same time as the Dazzle software was capturing.
At the end of the long capture session (be ready for lots of reboots if things freeze – when a capture driver is dropped by the Dazzle software for whatever reason only a reboot fixes it) I was facing about 16 minutes worth of MPEG files.
The only additional raw material I made at this stage were WAV files for the soundtrack which I captured directly off the on board CD player.
My next problem was editing these files.
The only MPEG editors I had ever seen were frame accurate but pretty cheap pieces of software without a proper timeline – I had a copy of Premiere 4.2 and wanted to use it so I went searching for ways to get the movie into premiere.
An interesting point to note here is that MPEG is a lossy compression format so starting off with highly compressed footage and then perfoming edits on it, later rendering it out compressed again is NOT an optimal solution.
Given that I was doing this on a laptop I was not really in the market for optimal solution – I’d take what I could get but I insisted on using a good editor so one thing remained clear – I had to convert these MPEG clips into AVI’s.
I noticed early on in this process that the performance of both the laptop hard drive and the Indeo codec makes it difficult for 25fps video files to be smoothly played from the hard drive so I decided the final video would be in MPEG. So the process will be
MPEG (captured) ---> AVI (edited in premiere) ------> MPEG (rendered out of premiere)
I went looking for software that could do this and for a few days drew total blanks on importing MPEGs into premiere. Exporting them from the timeline proved to be quite easy and efficient using Xing MPEG encoder but more on this later.
Eventually I found a company called Multimedia Lab that manufactured an MPEG import filter for premiere – I was very excited by this but annoyed upon installing to see that it was hopelessly slow.
It was slow to import the file and moving around the timeline was also slow – this was obviously a non solution.
If the files couldn’t be imported then they would have to be converted. Again – total blanks – Adobe tech support even mockingly suggested that starting with MPEG is not the way forward since most people end with it...
So when I found MainActor I was ecstatic – it was the missing piece of the puzzle. MainActor is made by a small multimedia company in Germany – it cost me 60 US dollars but it could convert between all known video formats including MPEG-> AVI and MPEG -> Quicktime.
Best of all it was easy to use as well as easily scriptable.
I would set it up to batch convert a folder of MPEG’s, leave the computer running overnight and in the morning I’d have a bunch of AVI’s – it wasn’t super fast but it worked and that was all that concerned me.
(In order to save time I sometimes clipped the MPEG’s before conversion – even if it was only a few seconds – I used a simple frame-based MPEG editor called IFilmEdit to do this.)
Discussion of general editing technique is not really the point of this summary so I keep this section concerned with laptop specific aspects of editing.
An early problem was the preview rate – premiere could manage about 12-15 fps if I was lucky (it could even do 20 or so fps on certain sections – very much depended on the specific clip arrangement) – I had multiple tracks of video as well as two 44.1 KHz audio tracks.
I had decided to go for maximum audio quality – knowing the MPEG compression would save me later.
Now fifteen fps is not bad for setting up an edit however it’s nice to be able to see the edited clips smoothly – the only way to this is to render out the section of the clips you are concerned with – using premiere’s make movie this took FOREVER but Xing excelled itself. It rendered out small MPEG’s in no time at all making it easy to see exact edits even on complicated effects.
Pretty soon everything was working according to plan and my first few edits were layed down – then I hit the "camcorder wall". The sound quality sucked. (I later counted the percentage of original soundtrack in the final edited movie and it was about 6%.)
The mike on the camera picks up the cameraman’s breathing as well as ambient noises of all kinds, wind etc etc.
So I quickly became aware that I would be a doing a lot of voiceover – which led me to another interesting problem. I wanted to do a voiceover in sync with certain events in the video which would mean that I would need to see a realtime 25fps preview of my edit while I was recording the voiceover.
Premiere could not give me this – at all. There were a few ways around this (an obvious one doing the best with what you have and roughly fitting the voiceover to the video) but I happened to come across my second cool piece of software – DDCLIP.
DDCLIP is essentially a multitrack media (sound and video and stills) sequencer – it’s very good for sound – it has four audio tracks that can interdependently record/playback so it could certainly handle the task at hand.
It was much faster than Premiere – it could handle previewing long sequences of AVI clips at 25fps whilst recording a voiceover track at the same time.
Using it in this fashion was a little pedantic since I ended up having to match my Premiere edits in its timeline first but it didn’t take too long after the first few attempts.
So that was about it – Photoshop was used to create some stills and title effects (since premiere’s titler is let’s face it – just awful) but the only thing that remained was to render the material out using Xing MPEG encoder.
It all came to a 100 MB MPEG file which contained 9min 15 seconds of video footage at 352x288 size, 25fps.
Even when played back resized to full screen the material didn’t look all that bad at all – I compared the quality to a commercially purchased Video CD and they were very similar.
(as an experiment I rendered out a movie with Indeo 5 with default settings – the render took about 10 times as long and produced a file about 10 times the size – the quality however was indistinguishable)
Nobody really wants to receive 100 MB attachments so I bought a CD burner and a cardbus SCSI controller for my laptop and proceeded to burn the clip on.
Friends received this days later and were easily able to play the clip directly from the CD.