Luch Machiavelli's List: video codec

• Let's stick with DV conversation for a moment. The instant the  image hits the chips on the DV camera, the media is compressed  to a ratio of 5:1 when it lays it to it's DV tape.
• You're basically getting 1/4th the color resolution from a perfect  source in comparison
• Additionally, going back to DV from an uncompressed  codec also looses 1/2 generation of quality.
• entire process  looses 1 full generation of quality loss
• 20 x 480, which is 6 pixels shorter than  the D1 size of 720 x 486 which all uncompressed 4:2:2 systems  use
• The worst thing to do is stretch the DV image vertically  to fit the 720 x 486 size
• You must keep the  vertical position in even numbered pairs.
• Once you get the positioning correct, you can now safely render  the DV clip to your uncompressed codec's best settings.
• you will sustain  the original DV artifacts it created when it was written to the  DV tape.
• When you capture DV via FireWire and  edit in DV mode, you're essentially editing the file that was  in the camera.
• So how can an uncompressed system make the quality worse? The  moment you step outside of FireWire and the DV codec,  you're going to loose generation quality
• Since uncompressed 4:2:2 systems use  their own codec
• DV clip needs to be converted to the uncompressed system's  native format
• capturing  it from your DV deck in real-time
• By decompressing the  DV codec to an uncompressed codec, you're losing 1/2 generation  of quality
• If you incorporate any graphics or animation  in your projects, your graphic clips will greatly benefit if  you edit in an uncompressed FCP timeline as opposed to taking  your graphics to a DV-based timeline edit

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• tools like the Ligos LSX-MPEG Suite offer professional-quality encoding from AVI to MPEG-1 and MPEG-2
• As a result, while DV format is great for editing since there is relatively light compression on each frame, the data size is much larger than more aggressive compression formats
• 11 GB (billion bytes) per hour of material.
• the DV and MPEG-2 formats would have required three separate steps: capturing the DV video, decompressing it, and then recompressing to MPEG-2.
• to store the original DV video, plus the raw uncompressed video, and then for the recompressed MPEG-2 video.
• , your capture board performed the analog to digital conversion, and often some form of compression, which meant the quality of the captured video was very dependent on the quality (and the cost) of the board
• with DV camcorders, the analog to digital conversion is done in the camcorder as you shoot the video, so the data stored on the DV tape is all digital.

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• Input: DivX uses temporal compression which is not suitable for editing. Using DivX files as source clips will cause you a lot of grief. Convert them to “uncompressed AVI” or “DV AVI” before importing them into Premiere Pro.
• Preferably, export your Premiere Pro project to an “uncompressed AVI” or “DV AVI” file and then use other software to encode to DivX.

• DV-AVI

• How do I use HandBrake to import my DVD into iMovie? ¶

   

   We strongly recommend against doing this. 

   

   MPEG-2 is a lossy source (meaning that visual data has been removed in order to compress the video). MPEG-4 (and H.264), the video codecs used by HandBrake, are also lossy. Since you will be using iMovie to render your content with yet another lossy codec, this represents a third generation of loss, which will make your final product look rather poor. 

   

   Instead, we recommend use of another tool (MPEG Streamclip is one solution

• Premiere exports several kind of avi, but the difference in general are
   
   1) DV-AVI: Very poorly compressed codec, will yield poor quality.
   2) AVI-No Compressor: Essentially uncompressed footage, but will play very slowly due to high data rate. Universally compatible.
   3) Uncompressed Microsoft AVI: Same as #2 except that it's encoded using a lossless codec that's only compatible with Adobe products.
• Premiere exports several kind of avi, but the difference in general are
   
   1) DV-AVI: Very poorly compressed codec, will yield poor quality.
   2) AVI-No Compressor: Essentially uncompressed footage, but will play very slowly due to high data rate. Universally compatible.
   3) Uncompressed Microsoft AVI: Same as #2 except that it's encoded using a lossless codec that's only compatible with Adobe products.

  • emphasis on "export"

• QuickTime is an architecture that allows you to access the content of multi-track digital media. DV Stream is a multiplexed file, video, audio, timecode and metadata are thrown together into one stream. That's the way the camera records it. If you work with DV Stream it becomes difficult to access audio, hence the many silly tricks you have to go through to do things with sound in iMovie. The tracks only get demuxed when you manually tell it to. The worst part is that the application never accesses the timecode data, just the silly time of day data. Without the timecode no project is ever recreatable without basically doing it from memory and guessing.