User manual APPLE COMPRESSOR 2

[. . . ] Compressor 2 User Manual Apple Computer, Inc. © 2005 Apple Computer, Inc. All rights reserved. Under the copyright laws, this manual may not be copied, in whole or in part, without the written consent of Apple. Your rights to the software are governed by the accompanying software license agreement. The Apple logo is a trademark of Apple Computer, Inc. , registered in the U. S. [. . . ] Note: For short streams of 1 to 2 minutes or less, if you are using one pass VBR or one pass VBR Best, the average bit rate accuracy may be compromised by as much as 10 to 30 percent. Â "Two pass VBR": In this mode, Compressor reads through the entire source video file twice. In the first of these passes, Compressor analyzes the entire source video stream prior to transcoding it to determine the degree of encoding difficulty of each scene. It then creates a bit rate allocation plan that gives the higher bit rate to complex scenes and a lower bit rate to easy scenes, so as to average out to the specified average bit rate while ensuring that the specified maximum bit rate is not exceeded. In the second pass, Compressor does the actual compression, creating the MPEG-2 output video file according to its bit rate allocation plan. Like one pass VBR, the goal of two pass VBR is constant quality rather than constant bit rate. Unlike One-pass VBR, Two-pass VBR is able to establish an overview of where best to spend its bits across the entire source media file, before beginning the actual encoding. The result of this process is that transcoding time is almost twice that of one pass VBR. Although the benefit is not twice the quality, two pass VBR provides more consistent overall quality than one pass VBR, especially in source media files where the difference between the most and the least complex scenes is substantial. Â "Two pass VBR Best": This mode devotes more effort to its internal decision-making process than does two pass VBR. Encoding time for Two pass VBR Best is slower than it is for Two pass VBR, but it provides the best possible quality that the Compressor MPEG-2 encoder has to offer. This mode provides outstanding quality at bit rates of 3­3. 5 Mbps and above for standard definition (SD) video. Chapter 10 Creating MPEG-2 Output Files 135 Job Segmenting and Two Pass VBR If you choose a two-pass VBR mode, and you are using Compressor 2 or higher with distributed processing enabled, you may have to make a choice between speedier processing and ensuring the highest possible quality. The Apple Qmaster distributed processing system speeds up processing by distributing work to multiple processing nodes (computers). One way it does this is by dividing up the total amount of frames in a job into smaller segments. Each of the processing computers then works on a different segment. Since the nodes are working in parallel, the job is finished sooner than it would have been on a single computer. But with two-pass VBR (and multi-pass H. 264) each segment is treated individually so the bit-rate allocation generated in the first pass for any one segment does not include information from the segments processed on other computers. First, evaluate the encoding difficulty (complexity) of your source media. Then, decide whether or not to allow job segmenting (with the "Allow Job segmenting" checkbox at the top of the Encoder pane). If the distribution of simple and complex areas of the media is similar in any given segment as it is across the whole source media file, then you can get the same quality whether segmenting is turned on or not. In that case, it makes sense to allow segmenting to speed up the processing time. However, you may have a source media file with an uneven distribution of complex scenes. [. . . ] See workflows . compressor extension 86 configuration cluster controllers 245­246 service nodes 245­246 constant bit rates 137 constraining aspect ratio 47 Content is Original setting 97 copying items destinations 225, 231 settings 63, 74 Copyright Exists setting 97 cropping boundary 212 Cropping fields 201 cropping items frame sizes 131 images 47, 200­204, 217 . Cs code 104 customer support 243­244 D data rates 96, 169 Data Rate setting 96 dates batch submissions 84 transcodings 225 DAT sample rates 176 DC filters 99 decoders, stereo playback and 107 Default Destination pop-up menu 36, 230 Default Setting pop-up menu 35 Deinterlace pop-up menu 197 Deinterlacing filter 189 deinterlacing video 186­187, 189 deleting items batches from History table 84 destinations 225, 231 I-frames 221 markers 214 names from destinations 233 settings 63, 74 delta frames 168 Depth pop-up menu 167 Description field 75 Desktop folder 224 Destination field 236 destinations 223­232 See also settings assigning 19, 21­22, 32, 57, 68, 81­82 assigning pre-existing destinations 68 in batches 26 changing 82 changing default 36, 230 compared to settings 61 creating 30, 226­229 deleting 225, 231 described 11, 27 Droplets 238, 239 duplicating 225, 231 DVD Studio Pro and 126, 232­233 file identifiers 225 local 224, 226, 226­228 names 224 open volume 226­228 remote 224, 226, 228­229 removing names from 233 temporary 81 TIFF output 184 types of 226 warnings 230 Destinations Inspector window 225 Destinations tab 38, 41, 224­225, 231­232 Destinations table 224 Dialog Normalization setting 97 digitizing sound 102 distributed processing choosing clusters 236 cluster segmenting 117 cluster storage 224 described 11 H. 264 output and 110 job segmenting 43­44, 130, 154, 165, 178, 183 multi-pass encoding and 112 scratch storage settings 35 two pass VBR and 136­138 distributing settings 75 DNS Domain settings 36 Dolby Digital encoder 12, 29, 106 Dolby Digital Professional Encoder pane 94­99 Dolby Digital Professional format 93, 106­107 converting audio to 100 described 10 Dolby Laboratories website 107 Dolby Surround Mode setting 97 downconversions 129 downloading movies 164, 165 downmixes 97, 107 drop frame timecode 132 Droplets 235­241 adding file identifiers 236 254 Index creating 33, 63, 238­239 described 10, 33 destinations 238 saving 63, 238 settings for 239, 240 surround sound settings 105 transcoding with 240­241 working with 33 Droplet window 52, 236­237 Duplicate button 63, 74 duplicating items destinations 225, 231 settings 63, 74 DV sample rates 176 DVCPRO HD format 202 DVD-5 discs 113 DVD option 118 DVDs bit rates 119 chapter markers 142 HD-resolution DVDs 128 minutes of video on 134 MPEG-1 output and 115 MPEG-1 settings 121, 123­126 sample rates 119, 176 SD video on 129 DVD Studio Pro 3:2 pull-downs 133 chapter markers 222 configuring MPEG-1 123­126 destinations for 126, 232­233 Dolby encoding options 95 meta-data 143, 151 MPEG-2 format and 10 DVD-Video format DVD Studio Pro and 95 MPEG-2 video streams and 128 open GOPs and 142 DVD-Video setting 95 encoding audio files 100 even fields 132, 189 Execute AppleScript on output option 205 exporting items chapter markers 144 Final Cut Pro projects 87 media with I-frames 50 QuickTime Export Component plug-ins 178 extensions See also names of specific file extensions channel identifiers and 104 Dolby Digital files 94 in File Extension field 43 in Summary table 42 Extras tab 143­144, 150, 151 F Fast forward and backward buttons 214 Fast Start option 165 field dominance 132, 146 Field Dominance pop-up menu 132 fields, output types of 132 File Extension field 43 file extensions. See extensions file formats See also names of specific formats described 28 extensions 43 file identifiers 225, 236 files AppleScript 207 audio 101­102 media. See source media files paths 229 File Selection dialog 207 Film Standard Compression setting 98 Filter controls 188 filters adding to settings 192­194 applying 46, 218 described 11, 27, 185­187 previewing 186, 218 reordering 46 settings 46, 73, 188­191 types of 189­191 uses for 185­187 working with 188­194 Filter setting 42 Filters list 188 Filters pane 46, 66, 70, 71, 188­194 Filters tab 192 Filters table 73 Final Cut Pro 3:2 pull-downs 133 E edit/cut markers 213, 215 editing 3:2 pull-downs 133 elementary streams 120, 143 emailing settings 75 email notification activating 48, 206 described 11, 204 preference 34 Email Notification to option 205 Enable Low Frequency Effects setting 97 Encoder pane See also names of specific Encoder panes modifying settings in 70, 71 overview 43, 66 Index 255 chapter markers and 144 interoperability with Compressor 11 quitting Compressor after batches 35 resubmitting projects 89 transcoding projects 87­89 FireWire website 14 flickering, removal of 189 folders, transcoded files 30 fonts 191 forced compression markers 144 forced I-frames 140, 142, 150, 220 Format option 170, 181 formats. See specific formats fps (frames per second) 111 Frame Controls pane modifying settings in 70, 71 overview 45, 196­198 Frame Controls tab 198 frame numbers 184 frame rates displaying 129 frame retiming and 45 H. 264 output 111 MPEG-1 116, 118 MPEG-2 132 MPEG-4 155 NTSC 131 QuickTime 168 settings 198 TIFF images 183 frames numbering 184 resizing 45 retiming 45 types of 140­142 frame size cropping and 131, 200­204 MPEG-1 116 MPEG-2 218 output files 47 scaling and 200, 200­204 settings 196 Frame size pop-up menu 201 Frame Sync rate 112 Full Bandwidth Channels settings 99 GOPs (group of pictures) adding I-frames to clips 150 closed 139, 141­142 MPEG-2 output files 149­150 open 139, 141­142 overview 140­142 settings 116, 138­140, 140­142 size 131, 139, 141 structure 139, 140­141 GOP Size pop-up menu 139, 149 GOP Structure pop-up menu 139, 149 GOP tab 138­140, 145, 149 Group button 63, 75 group folders 64, 75 group of pictures. [. . . ]