One of the threads in R.S.U. is getting off topic talking about video compression. I’ll answer one of the questions here where it’s not off topic.
The question was from Andrew’s thread: Andrew’s 8 minute movie…
The question was:
Here’s a description I wrote up for converting a MOV file from a digicam to an MPEG-1 file. The MOV files from a digicam are not very compressed. They’re a bit big to be posting online in the gallery. Converting them to a format like MPEG-1 will make them convenient to put in the gallery.
Here’s how to convert a MOV file from a digicam to an MPEG-1 file with TMPGEnc.
Install TMPGEnc and the QT Reader plugin
TMPGEnc
http://www.tmpgenc.net/e_main.html
QT Reader plugin
Start TMPGEnc
It will start up with the Project Wizard
Hit Cancel, we’re going to configure things manually since the presets don’t do what we want to do
For Video source click Browse
Find the source file (the MOV file) and click Open
Check the Output file name and make sure the name and path are what you want
For Stream type make sure it is set at “System (Video+Audio)”
Click on the Setting button
Select the Video tab
Stream type: MPEG-1 Video
Size: 320 x 240 pixels
Aspect ratio: 1:1 (VGA)
Frame rate: 30 fps
Rate control mode: 2-pass VBR(VBR)
Click on Setting for Rate control
Average bitrate: 500 kbits/sec
Maximum bitrate: 2000 kbits/sec
Minimum bitrate: 100 kbits/sec
Click OK
Motion search precision: Highest quality (very slow)
Note here: Pick a frame rate that is equal to or a multiple of the frame rate that the camera produces. If the camera does 10 fps or 15 fps then 30 fps will work well. If the camera does something like 12 fps then pick 24 fps for the frame rate. Check the camera’s documentation to find out its frame rate.
Click on the Advanced tab
Video source type: Non-interlace (progressive)
Click on the Audio tab
Stream type: MPEG-1 Audio Layer II
Sampling frequency: 32000 Hz
Channel mode: Mono
Bitrate: 64 kbits/sec (could go lower if you want)
Click OK
We’re done with the settings. Time to compress.
Click the Start button.
When it is done, play the output video and see how the quality is.
These settings got a 3900 KB MOV file from a digicam down to about a 1000 KB MPG file.
This is at an average bitrate of 500 kbits/sec. That was the point where the compression artifacts were starting to get noticeable. If you go lower than 500 kbits/sec you are going to want to keep an eye on the output quality to make sure it isn’t too blocky. You can go lower if you need a smaller file size.
Experiment with the average bitrate. 500 kbits/sec seemed to work OK on the sample clip I used. You can try a higher average bitrate of maybe 750 kbits/sec or even a little lower. The higher you go the better quality you are going to get, but the file size is going to get proportionally bigger.
If you have problems with the sound when converting the MOV file, go to the QuickTime settings and toggle the Sound Out settings from DirectSound to waveOut (or vice versa). I don’t know why that got things working for me, but it did.
Control Panel >> QuickTime
Select Sound Out in the QuickTime dropdown list
Toggle the playback device to/from DirectSound to waveOut (or vice versa)
From here you can import the MPG file to a program like VirtualDub to trim away parts of the video or do other basic editing. If your goal is to import it to an editing program you will want to use a higher bitrate (something like 2000 kbits/sec or 3000 kbits/sec or more would be good) to keep the quality up. Then once the editing is done compress the final version down to something smaller.