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software:sony-vegas-pro

This information is for Sony Vegas Pro 10, but much of it will also apply to Vegas Pro 11 and 12.

Color Space

  • Vegas Pro's working color space is RGB with a range of 0-255 in each of the R, G, and B channels.
  • In different places in the Vegas UI, the same full range is shown with a scale of 0-255, 0-1, or 0-100.
  • In 8-bit projects, RGB values are integers 0-255.
    • 8-bit mode is quite fast for editing, preview, and rendering.
  • In 32-bit projects, RGB values are 32-bit floating point values.
    • 32-bit mode is quite slow for editing, preview, and rendering when your project resolution is high.
    • 32-bit mode is more accurate and less prone to banding and other color precision artifacts - especially the cumulative errors of long filter chains.
    • 32-bit projects support values below 0 and above 255, and some filters allow access to these out-of-range values. For example, increasing the contrast could push a low value below 0, and decreasing the contrast could bring a below-0 value back above 0.
    • Compositing operates with 32-bit floating point precision in 32-bit projects.
    • Filters and media generators with green icons operate with 32-bit floating point precision in 32-bit projects; filters and media generators with a blue icon support only 8-bit integer precision.
    • In 32-bit full range projects, you should set the compositing gamma to 2.22, which means that Vegas's compositing and filters operate linearly on the encoded RGB values, same as in 8-bit and 32-bit video levels projects. Setting the compositing gamma to 1 changes the behavior of compositing and some filters in a way that you probably don't want (but perhaps is appropriate for video sources with a linear transfer function).
  • Projects can be switched freely between 8-bit mode, 32-bit video levels mode, and 32-bit full range mode, but filters may behave differently depending on how your input formats are mapped to RGB level ranges.
  • Most filters behave similarly in 8-bit and 32-bit modes, but a few like Color Balance behave quite differently when the color corrections are strong. If you are making strong corrections (e.g. for log footage), it's best to stick with either 8-bit or 32-bit mode for color correction and rendering.
  • By default Vegas Pro does no color management and makes no particular assumptions about the primary chromaticities or transfer function (“gamma”) of the RGB encoding: operations are linear on the RGB values, and the scopes and preview window show the full range of RGB values with no conversion or remapping.

Monitor Calibration

  • Typically your source video and delivery formats will be rec.709-encoded, so ideally your monitor should be calibrated to display rec.709 video as well.
  • Most computer monitors are calibrated for sRGB, which is very close to rec.709. They have the same primary chromaticites and white point. Rec.709's transfer function is approximately a power curve with a gamma of 2.4, compared to sRGB's transfer function which is a power function with a gamma of 2.2. The differences are small enough that you'll be fine to just calibrate your monitor for sRGB and ignore the differences - in fact the gamma would need to be changed by a larger amount than this small difference to account for different levels of ambient light in your editing environment.
  • I suggest calibrating your monitor using the excellent Lagom LCD test pages, even if you use a CRT or other type of monitor.
    • Use the Contrast page:
      • Set your monitor's contrast adjustment to the maximum, and then adjust the monitor's brightness and the individual R, G, and B gain and bias settings.
      • Make black, grey, and white appear with no tint.
      • Make the black background as dark as possible while still showing even contrast across each of the color ramps. There should be a visible difference in brightness between the black background and the leftmost rectangle of each gradient. As much as possible, the changes in apparent brightness from each rectangle to the next should be equal at every position in each gradient and between the gradients.
    • Use the Black level and White saturation pages to fine tune the black level, white level, and color balance. There should be a visible difference between every level.
    • Use the Gamma calibration page to adjust the gamma. Aim for a gamma between 2.2 and 2.4. Most good monitors calibrated for sRGB will be right around 2.2 out of the box. If your monitor doesn't have a gamma adjustment, your video card driver might, but beware that it might have separate color adjustments for 2D, 3D, and video surfaces. It's best to not change the gamma if you don't have to. An adjustment of the monitor's brightness adjustment is usually all that's needed to account for different ambient light conditions in your editing environment.

Level ranges and input/output conversion

  • By default, most operations in Vegas use the full 0-255 range of RGB values regardless of the project settings:
    • preview window
    • compositing
    • filters
    • still image import
    • media generators
    • full-screen preview (unless you enable the Studio RGB option in prefs, which uses 16-235)
    • Vectorscope (unless the Studio RGB option is selected, which uses 16-235)
    • Waveform scope (unless the Studio RGB option is selected, which uses 16-235)
    • Histogram (the Studio RGB option has no effect. It seems to be a bug)
    • RGB Parade (the Studio RGB option has no effect. It seems to be a bug)
  • Video input mapping to RGB level ranges, and video output mapping from RGB level ranges depends on the video format and the project setting. OOR means out-of-range preservation - that is, values above the channel's maximum and below the minimum are preserved (including superwhites and superblacks).
8-bit project
RGB levels / OOR
32-bit video levels
RGB levels / OOR
32-bit full range
RGB levels / OOR
YCbCr↔RGB
conversion matrix
.MPG MPEG-1/2 input 16-235 / yes 16-235 / yes 0-255 / yes rec.709 for proj 1358×764+
.MP4 MPEG-2 input 16-235 / yes 16-235 / yes 0-255 / yes rec.709 for hires file
.MP4 h.264 input 16-235 / yes 16-235 / yes 0-255 / yes rec.709 for anyres file
.MTS h.264 input 16-235 / yes 16-235 / yes 0-255 / yes rec.709
.MOV h.264 input † 0-255 / no 0-255 / no 0-255 / no rec.601
.MOV ProRes input † 0-255 / no 0-255 / no 0-255 / no rec.709
.MOV Cineform input * 16-235 / yes 16-235 / yes 16-235 / yes rec.709
.AVI Cineform input * 16-235 / yes 16-235 / yes 16-235 / yes rec.709
.AVI YUV-10 (v210) input * 16-235 / yes 16-235 / yes 0-255 / yes rec.709 for proj 1358×764+
Mainconcept MPEG-2 output16-235 / yes16-235 / yes 0-255 / yes rec.709
Mainconcept AVC/MP4 output16-235 / yes16-235 / yes 0-255 / yes rec.709
Sony YUV-10 (v210) AVI output *16-235 / yes16-235 / yes 0-255 / yes rec.709

* Supports 10-bit precision

† Quicktime h.264 and ProRes input boost the gamma by 1/0.88. Compensate by adding a Levels filter with 0.88 gamma (and no changes to the input and output limits) at the beginning of the filter chain. It is a documented bug in Quicktime

  • Vegas's handling of RGB levels is totally inconsistent and non-standard. You'll need to do different things in your project depending on your input and output formats, project settings, and preferences.
  • A levels filter with the “Studio RGB to Computer RGB” preset expands RGB levels from 16-235 to 0-255.
  • A Levels filter with the “Computer RGB to Studio RGB” preset compresses RGB levels from 0-255 to 16-235.
  • Mapping from input format ranges and mapping to output format ranges depends on the format, and here Vegas seems to follow standards:
    • 8-bit YCbCr: Y=16-235, Cb=16-240, Cr=16-240
    • 10-bit YCbCr: Y=64-940, Cb=64-960, Cr=64-960
    • 8-bit RGB: R=0-255, G=0-255, B=0-255
  • Quicktime .MOV input requires Quicktime to be installed. I use Quicktime Alternative 3.2.2.
  • Quicktime input suffers from precision errors that produce banding.
  • Cineform .MOV and .AVI input and output are enabled by installing the free GoPro Studio (version 2.0.0.285 tested). Vegas reads these files in 4:2:2 with 10-bit precision. The codec included with GoPro Studio is supposed to support output of up to 1920 x 1080.
  • .AVI input seems to support PCM audio of 16-bit precision at most.
  • Compensate for an incorrect YCbCr↔RGB conversion matrix by using 601<->709 Channel Blend filter values at the beginning or end of your filter chain.
  • If your output renderer allows out-of-range values, prevent out-of-range values by adding a Curves filter to the output: the default curve clips values below 0 and above 255. To clip values below 16 and above 235, add a “Studio RGB to Computer RGB” levels filter, then a default curve, then a “Computer RGB to Studio RGB” levels filter.

Rendering

  • Mainconcept MPEG-2 is my recommended renderer
    • It's fast and the quality is very good when you choose a high bit rate
    • It supports output of up to 80 Mbps CBR
    • It supports output greater than 4 GB
    • YouTube will accept this as input and convert it with no resampling or remapping of levels.
  • Mainconcept AVC/MP4 is not recommended
    • It's slow
    • The CBR option is broken. Instead you can choose VBR with max bit rate equal to average.
    • When the output reaches 4 GB, rendering fails.
  • If you want h.264 output, I recommend rendering first to Mainconcept MPEG-2 at a high bit rate, and then recompressing with ffmpeg.
  • If you want ProRes output, you can render to a Sony YUV-10 (v210) .AVI file, and then use ffmpeg to compress to ProRes. 10-bit precision is preserved this way and the output quality is excellent.
  • To resolve out-of-memory errors or black or silent events in the output:
    • Make sure you have plenty of free memory. Quit memory-hungry apps and services.
    • In video prefs, set dynamic RAM preview max to 0. This leaves more memory for rendering.
    • Close and re-open Vegas just before rendering.
  • 32-bit rendering
    • You must render video and audio separately. 32-bit rendering is hopelessly unreliable otherwise.
    • Render audio to a .WAV file, and mux it with your video outside of Vegas.

Settings & Switches

  • Resampling of video events means that frame blending will be used when the event frame rate doesn't match the output frame rate. If the difference is tiny, e.g. 30 fps to 29.970 fps, or when the difference is an integer ratio like 60 fps to 30 fps, you probably want to disable resampling so that frames are not blended.

Workflow Tips

  • To make fine adjustments to a filter slider, click it, hold down the CTRL key, and then turn your mouse's scroll wheel.
  • Video filters may be applied to source media, the timeline video events, video tracks, or to the video output (tools menu, video, video output FX).
  • A video filter applied to a track can be made to affect every track below it as well as the track itself (i.e. post-compositing instead of pre-compositing) by dragging the filter to the right of “compositing” in the filter chain.
  • While editing, set the project to 8-bit mode and/or reduce the project resolution to match your full-screen preview device, or to an even smaller size. This will make preview of filter adjustments much more responsive. Don't forget to change the project resolution back when you render.
  • To add a filter with a saved filter preset to multiple video events, select the events on the timeline, view Video FX, and then drag a preset onto the selected video events.
  • When adding video filters using the plug-in chooser, the filter chain can be saved as a filter package by clicking Save As in the plug-in chooser dialog.
  • To add a saved filter package to one or more events, view the plug-in manager, find the filter package and drag it onto the video event or onto multiple selected video events. Filters added this way use the filter's default.
software/sony-vegas-pro.txt · Last modified: 2013/10/18 07:27 by balazer