1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
|
diff -urNp old/userguide/libnetpbm_ug.html new/userguide/libnetpbm_ug.html
--- old/userguide/libnetpbm_ug.html 2017-09-05 14:20:09.734743404 +0200
+++ new/userguide/libnetpbm_ug.html 2017-09-05 14:47:30.496705483 +0200
@@ -374,7 +374,7 @@ plain format.
<H2 id="reference">Reference</h2>
<p>The <a href="libnetpbm_image.html">Libnetpbm Netpbm Image
-Processing Manual</a> describes the the <b>libnetpbm</b> functions for
+Processing Manual</a> describes the <b>libnetpbm</b> functions for
processing image data.
<p>The <a href="libpm.html">Libnetpbm Utility Manual</a>
diff -urNp old/userguide/pamfunc.html new/userguide/pamfunc.html
--- old/userguide/pamfunc.html 2017-09-05 14:20:09.738743398 +0200
+++ new/userguide/pamfunc.html 2017-09-05 14:47:41.760644848 +0200
@@ -57,7 +57,7 @@ output image.
and bit string (such as and with 01001000). For the arithmetic functions, the
function arguments and results are the fraction that a sample is of the
maxval, i.e. normal interpretation of PAM tuples. But for the bit string
-functions, the value is the the bit string whose value as a binary cipher is
+functions, the value is the bit string whose value as a binary cipher is
the sample value, and the maxval indicates the width of the bit string.
<h4>Arithmetic functions</h4>
diff -urNp old/userguide/pbmtextps.html new/userguide/pbmtextps.html
--- old/userguide/pbmtextps.html 2017-09-05 14:20:09.736743401 +0200
+++ new/userguide/pbmtextps.html 2017-09-05 14:47:58.840553598 +0200
@@ -185,7 +185,7 @@ edge of the type. See <a href="#margins
<dt><b>-ascent=</b><i>n</i>
<dt><b>-descent=</b><i>n</i>
<dd>
-These options control the the margins added to the image, measured from
+These options control the margins added to the image, measured from
the text baseline. See <a href="#margins">Margins</a> for details.
<p>Sizes are in points, as a floating point number.
diff -urNp old/userguide/pbmtog3.html new/userguide/pbmtog3.html
--- old/userguide/pbmtog3.html 2017-09-05 14:20:09.735743403 +0200
+++ new/userguide/pbmtog3.html 2017-09-05 14:48:55.648255793 +0200
@@ -77,7 +77,7 @@ You cannot specify both.
<H2 id="history">HISTORY</H2>
<p>Before Netpbm 10.79 (June 2017), there was a different program by the same
-name in Netpbm, which was written by by Paul Haeberli
+name in Netpbm, which was written by Paul Haeberli
<<A HREF="mailto:paul@manray.sgi.com">paul@manray.sgi.com</A>> in 1989
and then modified extensively by others.
diff -urNp old/userguide/ppmtompeg.html new/userguide/ppmtompeg.html
--- old/userguide/ppmtompeg.html 2017-09-05 14:20:09.739743396 +0200
+++ new/userguide/ppmtompeg.html 1970-01-01 01:00:00.000000000 +0100
@@ -1,1291 +0,0 @@
-<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2//EN">
-<HTML>
-<HEAD>
-<TITLE>Ppmtompeg User Manual</TITLE>
-</HEAD>
-<BODY>
-<H1>Ppmtompeg</H1>
-Updated: 23 July 2006
-<BR>
-<A HREF="#index">Table Of Contents</A>
-
-<H2>NAME</H2>
-ppmtompeg - encode an MPEG-1 bitstream
-
-<H2 id="synopsis">SYNOPSIS</H2>
-
-<B>ppmtompeg</B>
-[<I>options</I>]
-<I>parameter-file</I>
-
-<H2 id="description">DESCRIPTION</H2>
-
-<p>This program is part of <a href="index.html">Netpbm</a>.
-
-<P><B>ppmtompeg</B> produces an MPEG-1 video stream. MPEG-1 is the
-first great video compression method, and is what is used in Video CDs
-(VCD). <b>ppmtompeg</b> originated in the year 1995. DVD uses a more
-advanced method, MPEG-2. There is an even newer method called MPEG-4
-which is also called Divx. I don't know where one finds that used.
-
-<p>There's technically a difference between a compression method for
-video and an actual file (stream) format for a movie, and I don't know
-if it can be validly said that the format of the stream
-<b>ppmtompeg</b> produces is MPEG-1.
-
-<p>Mencoder from the <a href="http://www.mplayerhq.hu">Mplayer
-package</a> is probably superior for most video format generation
-needs, if for no other reason than that it is more popular.
-
-<p>The programming library <a href="http://pm2v.free.fr"><b>PM2V</b></a>
-generates MPEG-2 streams.
-
-<p>Use <a href="http://www.mplayerhq.hu">Mplayer</a> (not part of Netpbm)
-to do the reverse conversion: to create a series of PNM files from an MPEG
-stream.
-
-<p><i>param_file</i> is a parameter file which includes a list of
-input files and other parameters. The file is described in detail
-below.
-
-<P>To understand this program, you need to understand something about
-the complex MPEG-1 format. One source of information about this
-standard format is the section Introduction to MPEG in the <a
-href="http://www.faqs.org/faqs/compression-faq">Compression FAQ</a>.
-
-<H2 id="options">OPTIONS</H2>
-
-<p>The <b>-gop</b>, <b>-combine_gops</b>, <b>-frames</b>, and
-<b>-combine_frames</b> options are all mutually exclusive.
-
-<DL COMPACT>
-<DT><B>-stat stat_file</B>
-
-<DD>This option causes <b>ppmtompeg</b> to append the statistics that
-it write to Standard Output to the file <I>stat_file</I> as well. The
-statistics use the following abbreviations: bits per block (bpb), bits
-per frame (bpf), seconds per frame (spf), and bits per second (bps).
-
-<p>These statistics include how many I, P, and B frames there were,
-and information about compression and quality.
-
-
-<DT><B>-quiet</b> <i>num_seconds</i>
-
-<DD> causes <b>ppmtompeg</b> not to report remaining time more often
-than every <i>num_seconds</i> seconds (unless the time estimate rises,
-which will happen near the beginning of the run). A negative value
-tells <b>ppmtompeg</b> not to report at all. 0 is the default
-(reports once after each frame). Note that the time remaining is an
-estimate and does not take into account time to read in frames.
-
-<DT><B>-realquiet</B> <DD> causes <b>ppmtompeg</b> to run silently,
-with the only screen output being errors. Particularly useful when
-reading input from stdin.
-
-<DT>
-<B>-no_frame_summary</B>
-
-<DD> This option prevents <b>ppmtompeg</b> from printing a summary
-line for each frame
-
-<DT><B>-float_dct</B>
-
-<DD> forces <b>ppmtompeg</b> to use a more accurate, yet more
-computationally expensive version of the DCT.
-
-<DT><B>-gop</b> <i>gop_num</i>
-<DD>
-causes <b>ppmtompeg</b> to encode only the numbered GOP (first GOP is 0). The
-parameter file is the same as for normal usage. The output file will be
-the normal output file with the suffix <b>.gop.</b><i>gop_num</i>.
-<b>ppmtompeg</b> does not output any sequence information.
-
-<DT><B>-combine_gops</B>
-
-<DD> causes <b>ppmtompeg</b> simply to combine some GOP files into a
-single MPEG output stream. <b>ppmtompeg</b> inserts a sequence header
-and trailer. In this case, the parameter file needs only to contain
-the SIZE value, an output file, and perhaps a list of input GOP
-files (see below).
-
-If you don't supply a list of input GOP files is used, then
-<b>ppmtompeg</b> assumes you're using the same parameter file you used
-when you created the input (with the <b>-gop</b> option) and
-calculates the corresponding gop filenames itself. If this is not the
-case, you can specify input GOP files in the same manner as normal
-input files -- except instead of using INPUT_DIR, INPUT, and
-END_INPUT, use GOP_INPUT_DIR, GOP_INPUT, and GOP_END_INPUT. If no
-input GOP files are specified, then the default is to use the output
-file name with suffix <b>.gop.</b><i>gop_num</i>, with <i>gop_num</i>
-starting from 0, as the input files.
-
-<p>Thus, unless you're mixing and matching GOP files from different
-sources, you can simply use the same parameter file for creating the
-GOP files (<b>-gop</b>) and for later turning them into an MPEG stream
-(<b>-combine_gops</b>).
-
-
-<DT><B>-frames <i>first_frame</i> <i>last_frame</i></B>
-
-<DD>This option causes <b>ppmtompeg</b> to encode only the frames numbered
-<i>first_frame</i> to <i>last_frame</i>, inclusive. The parameter
-file is the same as for normal usage. The output will be placed in
-separate files, one per frame, with the file names being the normal
-output file name with the suffix <b>.frame.</b><i>frame_num</i>. No
-GOP header information is output. (Thus, the parameter file need not
-include the GOP_SIZE value)
-
-<p>Use <b>ppmtompeg -combine_frames</b> to combine these frames later into
-an MPEG stream.
-
-
-<DT><B>-combine_frames</B>
-
-<DD> This option causes <b>ppmtompeg</b> simply to combine some
-individual MPEG frames (such as you might have created with an earlier
-run of <b>ppmtompeg -frames</b>) into a single MPEG stream. Sequence
-and GOP headers are inserted appropriately. In this case, the
-parameter file needs to contain only the SIZE value, the GOP_SIZE
-value, an output file, and perhaps a list of frame files (see below).
-
-<p>The parameter file may specify input frame files in the same manner
-as normal input files -- except instead of using INPUT_DIR, INPUT, and
-END_INPUT, use FRAME_INPUT_DIR, FRAME_INPUT, and FRAME_END_INPUT. If
-no input frame files are specified, then the default is to use the
-output file name with suffix <b>.frame.</b><i>frame_num</i>, with
-<i>frame_num</i> starting from 0, as the input files.
-
-
-
-<DT><B>-nice</B>
-
-<DD>This option causes <b>ppmtompeg</b> to run any remote processes
-"nicely," i.e. at low priority. (This is relevant only if you are
-running <b>ppmtompeg</b> in parallel mode. Otherwise, there are no
-remote processes). See 'man nice.'
-
-<DT><B>-max_machines <i>num_machines</i></B>
-
-<DD>This option causes <b>ppmtompeg</b> to use no more than
-<i>num_machines</i> machines as slaves for use in parallel encoding.
-
-<DT><B>-snr</B>
-
-<DD>This option causes <b>ppmtompeg</b> to include the signal-to-noise
-ratio in the reported statistics. Prints SNR (Y U V) and peak SNR (Y
-U V) for each frame. In summary, prints averages of luminance only
-(Y). SNR is defined as 10*log(variance of original/variance of
-error). Peak SNR is defined as 20*log(255/RMSE). Note that
-<b>ppmtompeg</b> runs a little slower when you use this option.
-
-<DT><B>-mse</B>
-
-<DD>This option causes <b>ppmtompeg</b> to report the mean squared
-error per block. It also automatically reports the quality of the
-images, so there is no need to specify <b>-snr</b> then.
-
-<DT><B>-bit_rate_info</b> <i>rate_file</i>
-
-<DD> This option makes <b>ppmtompeg</b> write bit rate information
-into the file <i>rate_file</i>. Bit rate information is bits per frame, and
-also bits per I-frame-to-I-frame.
-
-<DT><B>-mv_histogram</B>
-
-<DD> This option causes <b>ppmtompeg</b> to print a histogram of the
-motion vectors as part of statistics. There are three histograms --
-one for P frame, one for forward B frame, and one for backward B frame
-motion vectors.
-
-<p>The output is in the form of a matrix, each entry corresponding to one
-motion vector in the search window. The center of the matrix
-represents (0,0) motion vectors.
-
-<dt><b>-debug_sockets</b>
-
-<dd>This option causes <b>ppmtompeg</b> to print to Standard Output
-messages that narrate the communication between the machines when you run
-<b>ppmtompeg</b> in <a href="#parallel">parallel mode</a>.
-
-<dt><b>-debug_machines</b>
-
-<dd>This option causes <b>ppmtompeg</b> to print to Standard Output
-messages that narrate the progress of the conversion on the various
-machines when you run <b>ppmtompeg</b> in <a href="#parallel">parallel
-mode</a>.
-
-</DL>
-
-<H2 id="parmfile">PARAMETER FILE</H2>
-
-<P>The parameter file <strong>must</strong> contain the following
-lines (except when using the <b>-combine_gops</b> or <b>-combine_frames</b>
-options):
-
-<DL COMPACT>
-
-<DT><B>PATTERN</b> <i>pattern</i>
-
-<DD>This statement specifies the pattern (sequence) of I frames, P frames,
-and B frames. <i>pattern</i> is just a sequence of the letters I, P, and
-B with nothing between. Example:
-
-<pre>
- PATTERN IBBPBBPBBPBBPBB
-</pre>
-
-<p>See <a href="#ipb">I Frames, P Frames, B Frames</a>.
-
-<DT><B>OUTPUT</b> <i>output file</i>
-<DD>This names the file where the output MPEG stream goes.
-
-<DT><B>INPUT_DIR</b> <i>directory</i>
-
-<DD>This statement tells where the input images (frames) come from.
-If each frame is in a separate file, <i>directory</i> is the directory
-where they all are. You may use <b>.</b> to refer to the current
-directory. A null <i>directory</i> refers to the root directory of the
-system file tree.
-
-<p>To have <b>ppmtompeg</b> read all the frames serially from Standard
-Input, specify
-<pre>
- INPUT_DIR stdin
-</pre>
-
-<DT><B>INPUT</b>
-<DD>
-This line must be followed by a list of the input files (in display order)
-and then the line <B>END_INPUT</B>.
-
-<p>There are three types of lines between INPUT and END_INPUT. First,
-a line may simply be the name of an input file. Second, the line
-may be of the form <i>single_star_expr</i>
-<b>[</b><i>x</i><b>-</b><i>y</i><b>]</b>.
-<i>single_star_expr</i> can have a single <b>*</b> in it. It is
-replaced by all the numbers between x and y inclusive. So, for
-example, the line <b>tennis*.ppm [12-15]</b> refers to the files
-tennis12.ppm, tennis13.ppm, tennis14.ppm, tennis15.ppm.
-
-<p>Uniform zero-padding occurs, as well. For example, the line
-<b>football.*.ppm [001-130]</b> refers to the files football.001.ppm,
-football.002.ppm, ..., football.009.ppm, football.010.ppm, ...,
-football.130.ppm.
-
-<p>The third type of line is: <i>single_star_expr</i>
-<b>[</b><i>x</i><b>-</b><i>y</i><b>+</b><i>s</i><b>]</b>, where the
-line is treated exactly as above, except that we skip by <i>s</i>. Thus, the
-line <b>football.*.ppm [001-130+4]</b> refers to the files
-football.001.ppm, football.005.ppm, football.009.ppm,
-football.013.ppm, etc.
-
-<p>Furthermore, a line may specify a shell command to execute to
-generate lines to be interpreted as described above, as if those lines
-were in the parameter file instead. Use back ticks, like in the
-Bourne Shell, like this:
-
-<pre>
- `cat myfilelist`
-</pre>
-
-<p>
-If input is from Standard Input (per the <b>INPUT_DIR</b> statement),
-<b>ppmtompeg</b> ignores the <B>INPUT</b>/<b>END_INPUT</b> block, but
-it still must be present.
-
-<DT><b>BASE_FILE_FORMAT</b> {<b>PPM</b> | <b>PNM</b> | <b>YUV</b> |
- <b>JPEG</b> | <b>JMOVIE</b>}
-
-<DD><B>ppmtompeg</b> must convert all input files to one of the
-following formats as a first step of processing: PNM, YUV, JPEG(v4),
-or JMOVIE. (The conversion may be trivial if your input files are
-already in one of these formats). This line specifies which of the
-four formats. PPM is actually a subset of PNM. The separate
-specification is allowed for backward compatibility. Use PNM instead
-of PPM in new applications.
-
-<DT><b>INPUT_CONVERT</b> <i>conversion_command</i>
-
-<DD>You must specify how to convert a file to the base file format.
-If no conversion is necessary, then you would just say:
-
- <pre>
- INPUT_CONVERT *
- </pre>
-
-<p>Otherwise, <i>conversion_command</i> is a shell command that causes
-an image in the format your specified with <B>BASE_FILE_FORMAT</b> to
-be written to Standard Output. <b>ppmtompeg</b> executes the command
-once for each line between <b>INPUT</b> and <b>END_INPUT</b> (which is
-normally, but not necessarily, a file name). In the conversion
-command, <b>ppmtompeg</b> replaces each '*' with the contents of that
-line.
-
- If you had a bunch of gif files, you might say:
- <pre>
- INPUT_CONVERT giftopnm *
- </pre>
-
- If you have a bunch of separate a.Y, a.U, and a.V files (where
- the U and V have already been subsampled), then you might say:
-
- <pre>
- INPUT_CONVERT cat *.Y *.U *.V
- </pre>
-
-<p>Input conversion is not allowed with input from stdin, so use
-
- <pre>
- INPUT_CONVERT *
- </pre>
-
-as described above.
-
-<DT><b>SIZE</b> <i>width</i><b>x</b><i>height</i>
-
-<dd>
-
-<p><i>width</i> and <i>height</i> are the width and height of each
-frame in pixels.
-
-<p>When <b>ppmtompeg</b> can get this information from the input image
-files, it ignores the <b>SIZE</b> parameter and you may omit it.
-
-<p>When the image files are in YUV format, the files don't contain
-dimension information, so <b>SIZE</b> is required.
-
-<p>When <b>ppmtompeg</b> is running in parallel mode, not all of the
-processes in the network have access to the image files, so
-<b>SIZE</b> is required and must give the same dimensions as the
-input image files.
-
-<DT><b>YUV_SIZE</b> <i>width</i><b>x</b><i>height</i>
-
-<dd>This is an obsolete synonym of <b>SIZE</b>.
-
-<DT><b>YUV_FORMAT</B> {<b>ABEKAS</b> | <b>PHILLIPS</b> | <b>UCB</B> |
- <b>EYUV</b> | <i>pattern</i>}
-
-<DD>This is meaningful only when <b>BASE_FILE_FORMAT</b> specifies
-YUV format, and then it is required. It specifies the sub-format of
-the YUV class.
-
-
-<DT><b>GOP_SIZE</b> <i>n</i>
-
-<DD><i>n</i> is the number of frames in a Group of Pictures. Except that
-because a GOP must start with an I frame, <b>ppmtompeg</b> makes a GOP as
-much longer than <i>n</i> as it has to to make the next GOP start with an
-I frame.
-
-<p>Normally, it makes sense to make your GOP size a multiple of your
-pattern length (the latter is determined by the PATTERN parameter file
-statement).
-
-<p>See <a href="#gop">Group Of Pictures</a>.
-
-<DT><b>SLICES_PER_FRAME</b> <i>n</i>
-<dd><i>n</i> is roughly the number of slices per frame. Note, at
-least one MPEG player may complain if slices do not start at the left
-side of an image. To ensure this does not happen, make sure the
-number of rows is divisible by SLICES_PER_FRAME.
-
-<DT><b>PIXEL</b> {<b>FULL</b> | <b>HALF</b>}
-
-<dd>use half-pixel motion vectors, or just full-pixel ones It is
-usually important that you use half-pixel motion vectors, because it
-results in both better quality and better compression.
-
-
-<DT><b>RANGE</b> <i>n</i>
-<dd>Use a search range of <i>n</i> pixels in each of the four directions
-from a subject pixel. (So the search window is a square <i>n</i>*2 pixels
-on a side).
-
-<DT><b>PSEARCH_ALG</b> {<b>EXHAUSTIVE</B> | <b>TWOLEVEL</b> |
- <b>SUBSAMPLE</b> | <b>LOGARITHMIC</b>}
-
-<dd>This statement tells <b>ppmtompeg</b> what kind of search
- technique (algorithm) to use for P frames. You select the desired
- combination of speed and compression. <b>EXHAUSTIVE</b> gives the
- best compression, but <b>LOGARITHMIC</B> is the fastest.
- <B>TWOLEVEL</B> is an exhaustive full-pixel search, followed by a
- local half- pixel search around the best full-pixel vector (the
- PIXEL option is ignored for this search technique).
-
-<DT><b>BSEARCH_ALG</b> {<b>SIMPLE</B> | <B>CROSS2</B> | <B>EXHAUSTIVE</B>}
-
-<dd>This statement tells <b>ppmtompeg</b> what kind of search
- technique (algorithm) to use for B frames. <b>SIMPLE</B> means
- find best forward and backward vectors, then interpolate.
- <B>CROSS2</B> means find those two vectors, then see what backward
- vector best matches the best forward vector, and vice versa.
- <b>EXHAUSTIVE</b> does an n-squared search and is
- <em>extremely</em> slow in relation to the others (<b>CROSS2</b>
- is about half as fast as <b>SIMPLE</B>).
-
-<DT><b>IQSCALE</b> <i>n</i>
-<dd>Use <i>n</i> as the qscale for I frames.
- See <a href="#qscale">Qscale</a>.
-
-<DT><b>PQSCALE</b> <i>n</i>
-<dd>Use <i>n</i> as the qscale for P frames.
- See <a href="#qscale">Qscale</a>.
-
-<DT><b>BQSCALE</b> <i>n</i>
-<dd>Use <i>n</i> as the qscale for B frames.
- See <a href="#qscale">Qscale</a>.
-
-<DT><b>REFERENCE_FRAME</b> {<B>ORIGINAL</B> | <b>DECODED</b>} <dd>This
-statement determines whether <b>ppmtompeg</b> uses the original images
-or the decoded images when computing motion vectors. Using decoded
-images is more accurate and should increase the playback quality of
-the output, but it makes the encoding take longer and seems to give
-worse compression. It also causes some complications with parallel
-encoding. (see the section on parallel encoding). One thing you can
-do as a trade-off is select <b>ORIGINAL</b> here, and lower the
-qscale (see <b>QSCALE</b> if the quality is not good enough.
-
-<table border="1" cellpadding="5" cellspacing="0"
-summary="comparison of original to decoded">
- <caption>Original or Decoded? (Normalized)</caption>
-<?makeman r c c c c c. ?>
-<?makeman _ ?>
- <tr align="center" bgcolor="#CCCCCC">
- <th>Reference</th>
- <th>Compression</th>
- <th>Speed</th>
- <th>Quality I</th>
- <th>Quality P</th>
- <th>Quality B</th>
- </tr>
- <tr>
- <td align="right">Decoded</td>
- <td align="center">1000</td>
- <td align="center">1000</td>
- <td align="center">1000</td>
- <td align="center">969</td>
- <td align="center">919</td>
- </tr>
- <tr>
- <td align="right">Original</td>
- <td align="center">885</td>
- <td align="center">1373</td>
- <td align="center">1000</td>
- <td align="center">912</td>
- <td align="center">884</td>
- </tr>
- </table>
-
-
-
-</dl>
-
-<p>The following lines are optional:
-
-<DL>
-
-<DT><B>FORCE_ENCODE_LAST_FRAME</B>
-
-<dd>This statement is obsolete. It does nothing.
-
-<p>Before Netpbm 10.26 (January 2005), <b>ppmtompeg</b> would drop
-trailing B frames from your movie, since a movie can't end with a B
-frame. (See <a href="#ipb">I Frames, P Frames, B Frames</a>.
-You would have to specify <b>FORCE_ENCODE_LAST_FRAME</b> to stop
-that from happening and get the same function that <b>ppmtompeg</b>
-has today.
-
-
-<DT><b>NIQTABLE</b>
-
-<dd>This statement specifies a custom non-intra quantization table.
-If you don't specify this statement, <b>ppmtompeg</b> uses a default
-non-intra quantization table.
-
-<p>
-The 8 lines immediately following <b>NIQTABLE</b> specify the quantization
-table. Each line defines a table row and consists of 8 integers,
-whitespace-delimited, which define the table columns.
-
-<DT><B>IQTABLE</b>
-
-<dd>This is analogous to NIQTABLE, but for the intra quantization table.
-
-<DT><b>ASPECT_RATIO</b> <i>ratio</i>
-
-<dd>This statement specifies the aspect ratio for <b>ppmtompeg</b> to
-specify in the MPEG output. I'm not sure what this is used for.
-
-<p><i>ratio</i> must be 1.0, 0.6735, 0.7031, 0.7615, 0.8055, 0.8437,
-0.8935, 0.9157, 0.9815, 1.0255, 1.0695, 1.0950, 1.1575, or 1.2015.
-
-<DT><b>FRAME_RATE</b> <i>rate</i>
-<dd>This specifies the frame rate for <b>ppmtompeg</b> to specify in the
-MPEG output. Some players use this value to determine the playback rate.
-
-<p><i>rate</i> must be 23.976, 24, 25, 29.97, 30, 50, 59.94, or 60.
-
-<DT><b>BIT_RATE</b> <i>rate</i>
-<DD>This specifies the bit rate for Constant Bit Rate (CBR) encoding.
-
-<p><i>rate</i> must be an integer.
-
-<DT><b>BUFFER_SIZE</b> <i>size</i>
-
-<dd>This specifies the value
-<b>ppmtompeg</b> is to specify in the MPEG output for the Video
-Buffering Verifier (VBV) buffer size needed to decode the sequence.
-
-<p>A Video Verifying Buffer is a buffer in which a decoder keeps the
-decoded bits in order to match the uneven speed of the decoding with
-the required constant playback speed.
-
-<p>As <b>ppmtompeg</b> encodes the image, it simulates the decoding
-process in terms of how many bits would be in the VBV as each frame gets
-decoded, assuming a VBV of the size you indicate.
-
-<P>If you specify the <b>WARN_VBV_UNDERFLOW</b> statement,
-<b>ppmtompeg</b> issues a warning each time the simulation underflows
-the buffer, which suggests that an underflow would occur on playback,
-which suggests the buffer is too small.
-
-<P>If you specify the <b>WARN_VBV_OVERFLOW</b> statement,
-<b>ppmtompeg</b> issues a warning each time the simulation overflows
-the buffer, which suggests that an overflow would occur on playback,
-which suggests the buffer is too small.
-
-<DT><B>WARN_VBV_UNDERFLOW</B>
-<DT><B>WARN_VBV_OVERFLOW</B>
-
-<dd>See <b>BUFFER_SIZE</b>.
-
-<p>These options were new in Netpbm 10.26 (January 2005). Before that,
-<b>ppmtompeg</b> issued the warnings always.
-
-</DL>
-
-
-The following statements apply only to parallel operation:
-
-<DL>
-
-<DT><b>PARALLEL</b>
-
-<dd>This statement, paired with <b>END PARALLEL</B>, is what causes
-<b>ppmtompeg</b> to operate in parallel mode. See <a
-href="#parallel">Parallel Operation</a>.
-
-<dt><b>END PARALLEL</b>
-
-<DD>This goes with <b>PARALLEL</b>.
-
-<DT><b>PARALLEL_TEST_FRAMES</b> <i>n</i>
-
-<dd>The master starts off by measuring each slave's speed. It does
-this by giving each slave <i>n</i> frames to encode and noting how
-long the slave takes to finish. These are not just test frames,
-though -- they're real frames and the results become part of the
-output.
-<b>ppmtompeg</b> is old and measures time in undivided seconds, so
-to get useful timings, specify enough frames that it will take at
-least 5 seconds to process them. The default is 10.
-
-<p>If you specify <b>FORCE_I_ALIGN</b>, <b>ppmtompeg</b> will increase
-the test frames value enough to maintain the alignment.
-
-<p>If there aren't enough frames for every slave to have the indicated
-number of test frames, <b>ppmtompeg</b> will give some slaves fewer.
-
-
-<DT><b>PARALLEL_TIME_CHUNKS</b> <i>t</i>
-
-<dd>When you specify this statement, the master attempts to feed work
-to the slaves in chunks that take <i>t</i> seconds to process. It uses
-the speed measurement it made when it started up (see PARALLEL_TEST_FRAMES)
-to decide how many frames to put in the chunk. This statement obviously
-doesn't affect the first batch of work sent to each slave, which is the
-one used to measure the slave's speed.
-
-<p>Smaller values of <i>t</i> increase communication, but improve load
-balancing. The default is 30 seconds.
-
-<p>You may specify only one of PARALLEL_TIME_CHUNKS, PARALLEL_CHUNK_TAPER,
-and PARALLEL_PERFECT. PARALLEL_CHUNK_TAPER is usually best.
-
-<DT><b>PARALLEL_CHUNK_TAPER</b>
-
-<DD>When you specify this statement, the master distributes work like
-with PARALLEL_TIME_CHUNKS, except that the master chooses the number
-of seconds for the chunks. It starts with a large number and, as it
-gets closer to finishing the job, reduces it. That way, it reduces
-scheduling overhead when precise scheduling isn't helpful, but still
-prevents a slave from finishing early after all the work has already
-been handed out to the other slaves, and then sitting idle while
-there's still work to do.
-
-<p>You may specify only one of PARALLEL_TIME_CHUNKS, PARALLEL_CHUNK_TAPER,
-and PARALLEL_PERFECT. PARALLEL_CHUNK_TAPER is usually best.
-
-
-<DT><b>PARALLEL_PERFECT</b>
-
-<dd>If this statement is present, <b>ppmtompeg</b> schedules on the
-assumption that each machine is about the same speed. The master will
-simply divide up the frames evenly between the slaves -- each
-slave gets the same number of frames. If some slaves are faster than
-others, they will finish first and remain idle while the slower slaves
-continue.
-
-<p>This has the advantage of minimal scheduling overhead. Where slaves
-have different speeds, though, it makes inefficient use of the fast
-ones. Where slaves are the same speed, it also has the disadvantage
-that they all finish at the same time and feed their output to the
-single Combine Server in a burst, which makes less efficient use of
-the Combine Server and thus can increase the total elapsed time.
-
-<p>You may specify only one of PARALLEL_TIME_CHUNKS, PARALLEL_CHUNK_TAPER,
-and PARALLEL_PERFECT. PARALLEL_CHUNK_TAPER is usually best.
-
-<DT><b>RSH</b> <i>remote_shell_command</i>
-
-<DD><b>ppmtompeg</b> executes the shell command
-<i>remote_shell_command</i> to start a process on another machine.
-The default command is <b>rsh</b>, and whatever command you specify
-must have compatible semantics. <b>ssh</b> is usually compatible.
-The command <b>ppmtompeg</b> uses is one like this:
-<b>ssh remote.host.com -l username shellcommand</b>.
-
-<p>Be sure to set up <b>.rhosts</b> files or SSH key authorizations
-where needed. Otherwise, you'll have to type in passwords.
-
-<p>On some HP machines, <b>rsh</b> is the restricted shell, and you want
-to specify <b>remsh</b>.
-
-<DT><b>FORCE_I_ALIGN</b>
-
-<dd>This statement forces each slave to encode a chunk of frames which
-is a multiple of the pattern length (see <b>PATTERN</b>). Since the
-first frame in any pattern is an I frame, this forces each chunk
-encoded by a slave to begin with an I frame.
-
-<p>This document used to say there was an argument to
-<b>FORCE_I_ALIGN</b> which was the number of frames <b>ppmtompeg</b>
-would use (and was required to be a multiple of the pattern length).
-But <b>ppmtompeg</b> has apparently always ignored that argument, and
-it does now.
-
-<DT><B>KEEP_TEMP_FILES</B>
-
-<dd>This statement causes <b>ppmtompeg</b> not to delete the temporary
-files it uses to transmit encoded frames to the combine server. This
-means you will be left with a file for each frame, the same as you
-would get with the <b>-frames</b> option.
-
-<p>This is mostly useful for debugging.
-
-<p>This works only if you're using a shared filesystem to communicate
-between the servers.
-
-<p>This option was new in Netpbm 10.26 (January 2005).
-
-</DL>
-
-
-<H3>Parameter File Notes</h3>
-
-<P> If you use the <b>-combine_gops</b> option, then you need to specify
-only the SIZE and OUTPUT values in the parameter file. In
-addition, the parameter file may specify input GOP files in the same
-manner as normal input files -- except instead of using INPUT_DIR,
-INPUT, and END_INPUT, use GOP_INPUT_DIR, GOP_INPUT, and GOP_END_INPUT.
-If you specify no input GOP files, then <b>ppmtompeg</b> uses by default the
-output file name with suffix <b>.gop.</b><i>gop_num</i>, with <i>gop_num</i>
-starting from 0, as the input files.
-
-<p>If you use the <b>-combine_frames</b> option, then you need to
-specify only the SIZE, GOP_SIZE, and OUTPUT values in the
-parameter file. In addition, the parameter file may specify input
-frame files in the same manner as normal input files -- except instead
-of using INPUT_DIR, INPUT, and END_INPUT, use FRAME_INPUT_DIR,
-FRAME_INPUT, and FRAME_END_INPUT. If no input frame files are
-specified, then the default is to use the output file name with suffix
-<b>.frame.</b><i>frame_num</i>, with <i>frame_num</i> starting from 0,
-as the input files.
-
-<p>Any number of spaces and tabs may come between each option and value. Lines
-beginning with <b>#</b> are ignored. Any other lines are ignored except for
-those between INPUT and END_INPUT. This allows you to use the same
-parameter file for normal usage and for <b>-combine_gops</b> and
-<b>-combine_frames</b>.
-
-<P>The file format is case-sensitive so all keywords should be in
-upper case.
-
-<P>The statements may appear in any order, except that the order within
-a block statement (such as INPUT ... END INPUT) is significant.
-
-<P><b>ppmtompeg</b> is prepared to handle up to 16 B frames between
-reference frames when encoding with input from stdin. (To build a
-modified <b>ppmtompeg</b> with a higher limit, change the constant
-B_FRAME_RUN in frame.c and recompile).
-
-<H2 id="general">GENERAL USAGE INFORMATION</H2>
-
-<H3 id="qscale">Qscale</h3>
-
-<p>The quantization scale values (qscale) give a trade-off between
-quality and compression. Using different Qscale values has very little
-effect on speed. The qscale values can be set separately for I, P, and
-B frames.
-
-<p>You select the qscale values with the <B>IQSCALE</b>,
-<b>PQSCALE</b>, and <b>BSCALE</b> parameter file statements.
-
-<p>A qscale value is an integer from 1 to 31. Larger numbers give
-better compression, but worse quality. In the following, the quality
-numbers are peak signal-to-noise ratio, defined as:
-<img src="ppmtompeg-snr.gif" alt="signal-to-noise formula" height="52" width="302">
-where MSE is the mean squared error.
-
-
-<p>Flower garden tests:
-
-<table border="1" cellpadding="5" cellspacing="0" summary="Qscale vs Quality">
- <caption>Qscale vs Quality</caption>
-<?makeman r r r r. ?>
-<?makeman _ ?>
- <tr align="center">
- <th>Qscale</th>
- <th>I Frames</th>
- <th>P Frames</th>
- <th>B Frames</th>
- </tr>
- <tr>
- <td align="right">1</td>
- <td align="right">43.2</td>
- <td align="right">46.3</td>
- <td align="right">46.5</td>
- </tr>
- <tr>
- <td align="right">6</td>
- <td align="right">32.6</td>
- <td align="right">34.6</td>
- <td align="right">34.3</td>
- </tr>
- <tr>
- <td align="right">11</td>
- <td align="right">28.6</td>
- <td align="right">29.5</td>
- <td align="right">30.0</td>
- </tr>
- <tr>
- <td align="right">16</td>
- <td align="right">26.3</td>
- <td align="right">26.8</td>
- <td align="right">28.6</td>
- </tr>
- <tr>
- <td align="right">21</td>
- <td align="right">24.7</td>
- <td align="right">25.0</td>
- <td align="right">27.9</td>
- </tr>
- <tr>
- <td align="right">26</td>
- <td align="right">23.5</td>
- <td align="right">23.9</td>
- <td align="right">27.5</td>
- </tr>
- <tr>
- <td align="right">31</td>
- <td align="right">22.6</td>
- <td align="right">23.0</td>
- <td align="right">27.3</td>
- </tr>
-</table>
-
-<table border="1" cellpadding="5" cellspacing="0"
-summary="Qscale vs Compression">
- <caption>Qscale vs Compression</caption>
-<?makeman r r r r. ?>
-<?makeman _ ?>
- <tr align="center">
- <th>Qscale</th>
- <th>I Frames</th>
- <th>P Frames</th>
- <th>B Frames</th>
- </tr>
- <tr>
- <td align="right">1</td>
- <td align="right">2</td>
- <td align="right">2</td>
- <td align="right">2</td>
- </tr>
- <tr>
- <td align="right">6</td>
- <td align="right">7</td>
- <td align="right">10</td>
- <td align="right">15</td>
- </tr>
- <tr>
- <td align="right">11</td>
- <td align="right">11</td>
- <td align="right">18</td>
- <td align="right">43</td>
- </tr>
- <tr>
- <td align="right">16</td>
- <td align="right">15</td>
- <td align="right">29</td>
- <td align="right">97</td>
- </tr>
- <tr>
- <td align="right">21</td>
- <td align="right">19</td>
- <td align="right">41</td>
- <td align="right">173</td>
- </tr>
- <tr>
- <td align="right">26</td>
- <td align="right">24</td>
- <td align="right">56</td>
- <td align="right">256</td>
- </tr>
- <tr>
- <td align="right">31</td>
- <td align="right">28</td>
- <td align="right">73</td>
- <td align="right">330</td>
- </tr>
-</table>
-
-
-<h3>Search Techniques</h3>
-
-<p>There are several different motion vector search techniques
-available. There are different techniques available for P frame
-search and B frame search. Using different search techniques present
-little difference in quality, but a large difference in compression
-and speed.
-
-<p>There are 4 types of P frame search: Exhaustive, TwoLevel,
-SubSample, and Logarithmic.
-
-<p>There are 3 types of B frame search: Exhaustive, Cross2, and
-Simple.
-
-The recommended search techniques are TwoLevel and Logarithmic for
-P frame search, and Cross2 and Simple for B frame search. Here are
-some numbers comparing the different search methods:
-
-<table border="1" cellpadding="5" cellspacing="0"
-summary="P frame motion vector search">
- <caption>P frame Motion Vector Search (Normalized)</caption>
-<?makeman r c c c. ?>
-<?makeman _ ?>
- <tr align="center">
- <th>Technique</th>
- <th>Compression<a href="#smallbetter"><sup>1</sup></a></th>
- <th>Speed <a href="#largefaster"><sup>2</sup></a></th>
- <th>Quality <a href="#largebetter"><sup>3</sup></a></th>
- </tr>
- <tr>
- <td align="right">Exhaustive</td>
- <td align="center">1000</td>
- <td align="center">1000</td>
- <td align="center">1000</td>
- </tr>
- <tr>
- <td align="right">SubSample</td>
- <td align="center">1008</td>
- <td align="center">2456</td>
- <td align="center">1000</td>
- </tr>
- <tr>
- <td align="right">TwoLevel</td>
- <td align="center">1009</td>
- <td align="center">3237</td>
- <td align="center">1000</td>
- </tr>
- <tr>
- <td align="right">Logarithmic</td>
- <td align="center">1085</td>
- <td align="center">8229</td>
- <td align="center">998</td>
- </tr>
-</table>
-
-<table border="1" cellpadding="5" cellspacing="0"
-summary="B frame motion vector search">
- <caption>B frame Motion Vector Search (Normalized)</caption>
-<?makeman r c c c. ?>
-<?makeman _ ?>
- <tr align="center">
- <th>Technique</th>
- <th>Compression<a href="#smallbetter"><sup>1</sup></a></th>
- <th>Speed<a href="#largefaster"><sup>2</sup></a></th>
- <th>Quality<a href="#largebetter"><sup>3</sup></a></th>
- </tr>
- <tr>
- <td align="right">Exhaustive</td>
- <td align="center">1000</td>
- <td align="center">1000</td>
- <td align="center">1000</td>
- </tr>
- <tr>
- <td align="right">Cross2</td>
- <td align="center">975</td>
- <td align="center">1000</td>
- <td align="center">996</td>
- </tr>
- <tr>
- <td align="right">Simple</td>
- <td align="center">938</td>
- <td align="center">1765</td>
- <td align="center">991</td>
- </tr>
-</table>
-
-<a name="smallbetter"> </a><sup>1</sup>Smaller numbers are better
-compression.
-
-<a name="largefaster"> </a><sup>2</sup>Larger numbers mean faster
-execution.
-
-<a name="largebetter"> </a><sup>3</sup>Larger numbers mean better quality.
-
-<p>For some reason, Simple seems to give better compression, but it
-depends on the image sequence.
-
-<p>Select the search techniques with the <B>PSEARCH_ALG</B> and
-<B>BSEARCH_ALG</b> parameter file statements.
-
-
-<a name="gop"></a>
-<h3>Group Of Pictures (GOP)</h3>
-
-<p>A Group of Pictures (GOP) is a roughly independently decodable
-sequence of frames. An MPEG video stream is made of one or more
-GOP's. You may specify how many frames should be in each GOP with the
-<b>GOP_SIZE</b> parameter file statement. A GOP always starts with an
-I frame.
-
-<p>Instead of encoding an entire sequence, you can encode a single
-GOP. To do this, use the <b>-gop</b> command option. You can later
-join the resulting GOP files at any time by running <b>ppmtompeg</b>
-with the <b>-combine_gops</b> command option.
-
-
-<h3>Slices</h3>
-
-<p>A slice is an independently decodable unit in a frame. It can be
-as small as one macroblock, or it can be as big as the entire frame.
-Barring transmission error, adding slices does not change quality or
-speed; the only effect is slightly worse compression. More slices are
-used for noisy transmission so that errors are more recoverable. Since
-usually errors are not such a problem, we usually just use one slice
-per frame.
-
-<p>Control the slice size with the <B>SLICES_PER_FRAME</B> parameter
-file statement.
-
-<p>Some MPEG playback systems require that each slice consist of whole
-rows of macroblocks. If you are encoding for this kind of player, if
-the height of the image is H pixels, then you should set the
-SLICES_PER_FRAME to some number which divides H/16. For example, if
-the image is 240 pixels (15 macroblocks) high, then you should use
-only 15, 5, 3, or 1 slices per frame.
-
-<p>Note: these MPEG playback systems are really wrong, since the MPEG
-standard says this doesn't have to be so.
-
-
-
-<h3>Search Window</h3>
-
-<p>The search window is the window in which <b>ppmtompeg</b> searches
-for motion vectors. The window is a square. You can specify the size
-of the square, and whether to allow half-pixel motion vectors or not,
-with the <b>RANGE</b> and <b>PIXEL</B> parameter file statements.
-
-<h3 id="ipb">I Frames, P Frames, B Frames</h3>
-
-<p>In MPEG-1, a movie is represented as a sequence of MPEG frames,
-each of which is an I Frame, a P Frame, or a B Frame. Each represents
-an actual frame of the movie (don't get confused by the dual use of
-the word "frame." A movie frame is a graphical image. An MPEG frame
-is a set of data that describes a movie frame).
-
-<p>An I frame ("intra" frame) describes a movie frame in isolation --
-without respect to any other frame in the movie. A P frame
-("predictive" frame) describes a movie frame by describing how it
-differs from the movie frame described by the latest preceding I or
-P frame. A B frame ("bidirectional" frame) describes a movie frame by
-describing how it differs from the movie frames described by the
-nearest I or P frame before <em>and</em> after it.
-
-<p>Note that the first frame of a movie must be described by an I
-frame (because there is no previous movie frame) and the last movie
-frame must be described by an I or P frame (because there is no
-subsequent movie frame).
-
-<p>Beyond that, you can choose which frames are represented by which
-types. You specify a pattern, such as IBPBP and <b>ppmtompeg</b>
-simply repeats it over and over throughout the movie. The pattern
-affects speed, quality, and stream size. Here is a chart which shows
-some of the trade-offs:
-
-<table border="1" cellpadding="5" cellspacing="0"
-summary="Comparison of I/P/B Frames">
- <caption>Comparison of I/P/B Frames (Normalized)</caption>
-<?makeman r c c c. ?>
-<?makeman _ ?>
- <tr align="center">
- <th>Frame Type</th>
- <th>Size</th>
- <th>Speed</th>
- <th>Quality</th>
- </tr>
- <tr>
- <td align="right">I frames</td>
- <td align="center">1000</td>
- <td align="center">1000</td>
- <td align="center">1000</td>
- </tr>
- <tr>
- <td align="right">P frames</td>
- <td align="center">409</td>
- <td align="center">609</td>
- <td align="center">969</td>
- </tr>
- <tr>
- <td align="right">B frames</td>
- <td align="center">72</td>
- <td align="center">260</td>
- <td align="center">919</td>
- </tr>
- </table>
-
-(this is with constant qscale)
-
-<p>A standard sequence is IBBPBBPBBPBBPBB.
-
-<p>Select the sequence with the <B>PATTERN</B> parameter file statement.
-
-<p>Since the last MPEG frame cannot be a B frame (see above), if the
-pattern you specify indicates a B frame for the last movie frame of
-the movie, <b>ppmtompeg</b> makes it an I frame instead.
-
-<p>Before Netpbm 10.26 (January 2005), <b>ppmtompeg</b> instead drops
-the trailing B frames by default, and you need the
-<b>FORCE_ENCODE_LAST_FRAME</b> parameter file statement to make it do
-this.
-
-<p>The MPEG frames don't appear in the MPEG-1 stream in the same order that
-the corresponding movie frames appear in the movie -- the B frames come after
-the I and P frames on which they are based. For example, if the movie is
-4 frames that you will represent with the pattern IBBP, the MPEG-1 stream
-will start with an I frame describing movie frame 0. The next frame in
-the MPEG-1 stream is a P frame describing movie frame 3. The last two
-frames in the MPEG-1 stream are B frames describing movie frames 1 and 2,
-respectively.
-
-
-<h3>Specifying Input and Output Files</h3>
-
-<p>Specify the input frame images with the <B>INPUT_DIR</B>,
-<B>INPUT</B>, <B>END_INPUT</B>, <B>BASE_FILE_FORMAT</B>,
-<B>SIZE</B>, <B>YUV_FORMAT</B> and <b>INPUT_CONVERT</B> parameter
-file statements.
-
-<p>Specify the output file with the <b>OUTPUT</b> parameter file statement.
-
-
-<h3>Statistics</h3>
-
-<p><b>ppmtompeg</b> can generate a variety of statistics about the
-encoding. See the <b>-stat</b>, <b>-snr</b>, <b>-mv_histogram</b>,
-<b>-quiet</b>, <b>-no_frame_summary</b>, and <b>-bit_rate_info</b>
-options.
-
-
-<H2 id="parallel">PARALLEL OPERATION</H2>
-
-<P>You can run <b>ppmtompeg</b> on multiple machines at once, encoding
-the same MPEG stream. When you do, the machines are used as shown in
-the following diagram. We call this "parallel mode."
-
-<p><img src="ppmtompeg-par.gif" alt="ppmtompeg-par.gif">
-
-<p>To do parallel processing, put the statement
-
-<pre>
- PARALLEL
-</pre>
-
-in the parameter file, followed by a listing of the machines, one
-machine per line, then
-
-<pre>
- END_PARALLEL
-</pre>
-
-Each of the machine lines must be in one of two forms. If the machine
-has filesystem access to the input files, then the line is:
-
-<p>
-<i>machine</i> <i>user</i> <i>executable</i>
-
-<P>The executable is normally <b>ppmtompeg</b> (you may need to give
-the complete path if you've built for different architectures). If
-the machine does not have filesystem access to the input files, the line
-is:
-
-<P><b>REMOTE</b> <i>machine</i> <i>user</i> <i>executable</i>
-<i>parameter file</i>
-
-<p>The <b>-max_machines</b> command option limits the number of
-machines <b>ppmtompeg</b> will use. If you specify more machines in
-the parameter file than <b>-max_machines</b> allows, <b>ppmtompeg</b>
-uses only the machines listed first. This is handy if you want to
-experiment with different amounts of parallelism.
-
-<p>In general, you should use full path file names when describing
-executables and parameter files. This <em>includes</em> the parameter
-file argument on the original invocation of <b>ppmtompeg</b>.
-
-<p>All file names must be the same on all systems (so if e.g. you're
-using an NFS filesystem, you must make sure it is mounted at the same
-mountpoint on all systems).
-
-<P>Because not all of the processes involved in parallel operation
-have easy access to the input files, you must specify the <B>SIZE</B>
-parameter file statement when you do parallel operation.
-
-<p>The machine on which you originally invoke <b>ppmtompeg</b> is the
-master machine. It hosts a "combine server,", a
-"decode server," and a number of "i/o servers,"
-all as separate processes. The other machines in the network (listed
-in the parameter file) are slave machines. Each hosts a single
-process that continuously requests work from the master and does it.
-The slave process does the computation to encode MPEG frames. It
-processes frames in batches identified by the master.
-
-<p>The master uses a remote shell command to start a process on a
-slave machine. By default, it uses an <b>rsh</b> shell command to do
-this. But use the <b>RSH</b> parameter file statement to control
-this. The shell command the master executes remotely is
-<b>ppmtompeg</b>, but with options to indicate that it is to perform
-slave functions.
-
-<p>The various machines talk to each other over TCP connections. Each
-machine finds and binds to a free TCP port number and tells its
-partners the port number. These port numbers are at least 2048.
-
-<p>Use the PARALLEL_TEST_FRAMES, PARALLEL_TIME_CHUNKS, and
-PARALLEL_PERFECT parameter file statements to control the way the
-master divides up work among the slaves.
-
-<p>Use the <b>-nice</b> command option to cause all slave processes to run
-"nicely," i.e. as low priority processes. That way, this substantial and
-long-running CPU load will have minimal impact on other, possibly
-interactive, users of the systems.
-
-<A NAME="speed"> </A>
-<H2>SPEED</h2>
-
-<p>Here is a look at <b>ppmtompeg</b> speed, in single-node (not parallel)
-operation:
-
-<table border="1" cellpadding="5" cellspacing="0" summary="Compression speed">
- <caption>Compression Speed</caption>
-<?makeman r c. ?>
-<?makeman _ ?>
- <tr align="center">
- <th>Machine Type</th>
- <th>Macroblocks per second<sup>1</sup></th>
- </tr>
- <tr>
- <td align="right">HP 9000/755</td>
- <td align="center">280</td>
- </tr>
- <tr>
- <td align="right">DEC 3000/400</td>
- <td align="center">247</td>
- </tr>
- <tr>
- <td align="right">HP 9000/750</td>
- <td align="center">191</td>
- </tr>
- <tr>
- <td align="right">Sparc 10</td>
- <td align="center">104</td>
- </tr>
- <tr>
- <td align="right">DEC 5000</td>
- <td align="center">68</td>
- </tr>
-</table>
-<sup>1</sup>A macroblock is a 16x16 pixel square
-
-<p>The measurements in the table are with inputs and outputs via a
-conventional locally attached filesystem. If you are using a network
-filesystem over a single 10 MB/s Ethernet, that constrains your speed more
-than your CPU speed. In that case, don't expect to get better than 4
-or 5 frames per second no matter how fast your CPUs are.
-
-<p>Network speed is even more of a bottleneck when the slaves do not
-have filesystem access to the input files -- i.e. you declare them
-REMOTE.
-
-<p>Where I/O is the bottleneck, size of the input frames can make a big
-difference. So YUV input is better than PPM, and JPEG is better than
-both.
-
-<p>When you're first trying to get parallel mode working, be sure to
-use the <b>-debug_machines</b> option so you can see what's going on.
-Also, <b>-debug_sockets</b> can help you diagnose communication
-problems.
-
-
-<H2 id="authors">AUTHORS</H2>
-
-<UL>
-
-<LI>Kevin Gong - University of California, Berkeley, <A
-HREF="mailto:keving@cs.berkeley.edu">keving@cs.berkeley.edu</A>
-
-<LI>Ketan Patel - University of California, Berkeley, <A
-HREF="mailto:kpatel@cs.berkeley.edu">kpatel@cs.berkeley.edu</A>
-
-<LI>Dan Wallach - University of California, Berkeley, <A
-HREF="mailto:dwallach@cs.berkeley.edu">dwallach@cs.berkeley.edu</A>
-
-<LI>Darryl Brown - University of California, Berkeley, <A
-HREF="mailto:darryl@cs.berkeley.edu">darryl@cs.berkeley.edu</A>
-
-<LI>Eugene Hung - University of California, Berkeley, <A
-HREF="mailto:eyhung@cs.berkeley.edu">eyhung@cs.berkeley.edu</A>
-
-<LI>Steve Smoot - University of California, Berkeley, <A
-HREF="mailto:smoot@cs.berkeley.edu">smoot@cs.berkeley.edu</A>
-
-</UL>
-
-<HR>
-<A NAME="index"> </A>
-<H2>Table Of Contents</H2>
-<UL>
-<LI><A HREF="#synopsis">SYNOPSIS</A></LI>
-<LI><A HREF="#description">DESCRIPTION</A></LI>
-<LI><A HREF="#options">OPTIONS</A></LI>
-<LI><A HREF="#parmfile">PARAMETER FILE</A></LI>
-<LI><A HREF="#general">GENERAL USAGE INFORMATION</A></LI>
-<LI><A HREF="#parallel">PARALLEL OPERATION</A></LI>
-<LI><A HREF="#speed">SPEED</A></LI>
-<LI><A HREF="#authors">AUTHORS</A></LI>
-</UL>
-</BODY>
-</HTML>
|
