fasttimes
6th January 2003, 20:34
I was doing some testing with DivX, and noticed something neat.
Set the encoding mode to 1-pass quality based, and quantizer to 2, and the max keyframe interval to 1, and set the frame type to progressive. The results are virtually lossless, and are still only 1/10 or less the size of the original HuffUYV source AVI, making it 1/25 the size of an uncompressed YUV AVI!
For some reason, the encoder seems to destroy the interlacing, if the set the frame type to interlaced. Don't know why. Also, before I set keyframes to 1, I would get the occasional macroblocking, despite setting the quantization to the lowest setting of 2. There might be a less conservative number that would also work, thus allowing better compression by allowing the use of P frames. For example, I'd like to set max keyframe interval to 9999999, but then set a very low scene change threshhold. This might allow the extra compression, but without the risk of macroblocks. I also want to test exactly how the Psychovisual Enchantment setting effects the quality of the video.
I very well might use DivX as my archival codec. It's smaller than DV, and has the advantage of not being constrained by DV's constant bitrate encoding. The audio could be encoded in one of the lossless audio codecs out there, or high bitrate MP3, AAC, or AC-3 could be employed. The quality is there, in my testing, and seems to leave DV in the dust! Lastly, there is also the potential to play back an archival DVD-R DivX discs directly on the new generation of DivX players now appearing on the market.
This seems to be a very good way to archive analog captures! Anything to stay away from the evil DV format. :)
Set the encoding mode to 1-pass quality based, and quantizer to 2, and the max keyframe interval to 1, and set the frame type to progressive. The results are virtually lossless, and are still only 1/10 or less the size of the original HuffUYV source AVI, making it 1/25 the size of an uncompressed YUV AVI!
For some reason, the encoder seems to destroy the interlacing, if the set the frame type to interlaced. Don't know why. Also, before I set keyframes to 1, I would get the occasional macroblocking, despite setting the quantization to the lowest setting of 2. There might be a less conservative number that would also work, thus allowing better compression by allowing the use of P frames. For example, I'd like to set max keyframe interval to 9999999, but then set a very low scene change threshhold. This might allow the extra compression, but without the risk of macroblocks. I also want to test exactly how the Psychovisual Enchantment setting effects the quality of the video.
I very well might use DivX as my archival codec. It's smaller than DV, and has the advantage of not being constrained by DV's constant bitrate encoding. The audio could be encoded in one of the lossless audio codecs out there, or high bitrate MP3, AAC, or AC-3 could be employed. The quality is there, in my testing, and seems to leave DV in the dust! Lastly, there is also the potential to play back an archival DVD-R DivX discs directly on the new generation of DivX players now appearing on the market.
This seems to be a very good way to archive analog captures! Anything to stay away from the evil DV format. :)