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View Full Version : Good ratio of video to audio size?


Kent Wang
12th June 2003, 13:55
Before one can tune audio encode settings one has to figure out how much space to allot to the soundtrack. One doesn't want a near-perfect soundtrack with a shitty video stream, nor vice-versa, so a good ratio has to be found.

There a whole lot of variables, but let's assume Vorbis for the audio and Xvid for the video. One should also consider the scenarios for both 1CD and 2CD rips. I usually encode movies shorter than 2:10 for one CD and anything longer to 2 CD's. Of course, this changes wildly depending on the comp test. But for the 1CD scenario, lets assume a video stream where you can get a resolution of 448x288 with Bits/(Pixel*Frame)% of around 60%. For the 2CD scenario, assume a resolution of 576x368 at 65%.

What kind of video:audio ratio would you use for each of these scenarios? I've heard 600:100 for 1CD; that seems incredibly simple yet surprisingly accurate in my opinion.

Awatef
12th June 2003, 16:15
I don't care about ratios. Sound has to sound good no matter what, I won't cut 32kbps down just to respect a given ratio, because I know I won't see the extra 32k in the video.

Belgarath406
12th June 2003, 20:48
Same here.

As I store al my encoded movies on HD (I have about 450 movies on 4x160GB at the moment), I don't really care about file-size when I encode a movie.
As I choose quality above size (I watch my DivX movies on a 3 meter projector-screen, I always encode movies with the 384/448 Kbit 5.1 soundtrack or the DTS track and the resolution is always 720xXXX (XXX is whatever I get when the black bars at the top and bottom are cropped away).
As I also don't believe in cutting the movie up in CD-size chunks, this usually leads to a file-size between 1.3 and 2.0 Gb.

Belgarath

bond
12th June 2003, 22:18
@kent
forget what you heard/know (including video-audio-ratios, 1cd scenarios with a resolution of 448x... and your rule of thumb that movie length (+-2:10) is decisive whether to go for 1 or 2cds -> movies like lotr are exceptions of course)

thats my rule of thumb ;)
if you want to go for 1cd use vorbis or aac at 96kbps and the rest for the video-bitrate...