r.out.mpeg always fails because the output file name is empty

[paoloz]

Testing r.out.mpeg using North Carolina data set, smaller subset NC location (nc_basic_spm_grass7)

g.region rast=elevation

r.out.mpeg view1=elevation@PERMANENT,elevation_shade@PERMANENT output=./test.mpg

always fails with

r.out.mpeg view1=elevation@PERMANENT,elevation_shade@PERMANENT output=./test.mpg

Reading raster map <elevation@PERMANENT>...

Reading raster map <elevation_shade@PERMANENT>...

ERROR: Could not open output file!

WARNING: mpeg_encode ERROR

the reason is that the name of the output mpeg fie is not copied in the "outfile" variable, which is used to write the name of the output mpeg in the configuration file for "ppmtompeg"|"mpeg_encode" encoder. Therefore the name of the output mpeg is blank and the encoding always fail with "ERROR: Could not open output file!".

Tested with GRASS: 7.0.0, 7.4 svn (12/01/2018), 7.6.0, 7.6.1. Works in 6.4.6 because the variable is not empty, see lines 442-445 of grass-6.4.6/raster/r.out.mpeg/main.c.

A patch to solve the problem is attached.

Index: raster/r.out.mpeg/main.c =================================================================== --- raster/r.out.mpeg/main.c (revisione 74509) +++ raster/r.out.mpeg/main.c (copia di lavoro) @@ -6,6 +6,8 @@

• Brad Douglas <rez touchofmadness.com>, Markus Neteler <neteler itc.it>,
• Glynn Clements <glynn gclements.plus.com>, Hamish Bowman <hamish_b yahoo.com>,
• Jan-Oliver Wagner <jan intevation.de>, Paul Kelly <paul-grass stjohnspoint.co.uk>

+ * Paolo Zatelli <paolo.zatelli unitn.it> + *

• PURPOSE: combines a series of GRASS raster maps into a single MPEG-1
• COPYRIGHT: (C) 1999-2006, 2011 by the GRASS Development Team *

@@ -142,6 +144,9 @@

parse_command(viewopts, vfiles, &numviews, &frames);

+ /* output file */ + strcpy(outfile, out->answer); +

r_out = 0; if (conv->answer)

r_out = 1;