Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
Next revision Both sides next revision
dvd_trip [2019/03/11 19:23]
beandog
dvd_trip [2019/03/11 19:26]
beandog
Line 9: Line 9:
 What it does: What it does:
  
-  * requires no arguments, will rip the longest track to trip_encode.mkv by default+  * requires no arguments, will rip the longest track to ''​trip_encode.mkv'' ​by default
   * rips the video track plus one audio track   * rips the video track plus one audio track
   * can select audio track by language or track id   * can select audio track by language or track id
Line 41: Line 41:
 CRF for x265 ranges from 0 to 51, with the default being 28. CRF for x265 ranges from 0 to 51, with the default being 28.
  
-In x265, changing the encoder speed is relative to filesize, not quality. In these presets, however, both CRF and encoding speed are adjusted for each one.+In x265, changing the encoder speed is relative to filesize, not quality. In these presets, however, both CRF and encoding speed are adjusted for each level.
  
 +==== x264 Encoding ====
  
 +CRF for x264 ranges from 0 to 51, with the default being 23.
 +
 +In x264, changing the encoder speed is relative to quality, not filesize. In these presets, however, both CRF and encoding speed are adjusted for each level.
 +
 +==== VPX Encoding ====
 +
 +The WebM project recommends doing a two-pass encode as the default options for creating video. I prefer doing a one-pass with a good CRF instead, and that is what's used here.
 +
 +VPX doesn'​t have a '​CRF'​ in the same sense that x264 and x265 do. Instead, you can set minimum and maximum quality scale levels. The lowest being 0, and the highest 63 (rc_min_quantizer and rc_max_quantizer).
 +
 +The values cannot be set to each other in an attempt to "​force"​ a specific quality level. The library requires that there be a minimium difference of 8 between the two values.
 +
 +In addition to setting the ranges, the rate control method is set to '​quality'​. The other options being VBR, CBR, and constrained quality.
 +
 +The default settings using libvpx as a one-pass, with no quality scales set is generally low-quality,​ with lots of blockiness, and so is used for the "​low"​ preset. Depending on your source, you may or may not get a good encode out of it, but setting it to defaults means you could get anything. The other presets set a minimum quality level.
 +
 +Using vpxenc, here is what the settings would look like for the low preset:
 +
 +<​code>​
 +vpxenc --end-usage=q --passes=1 --webm -o vpxenc.webm source.y4m
 +</​code>​

Navigation