img2: add j2c file extension

Some applications use the j2c extension for jpeg2000 codestream files.
Signed-off-by: NJean First <jeanfirst@gmail.com>
Signed-off-by: NMichael Niedermayer <michaelni@gmx.at>

libavformat/img2.c

@@ -85,6 +85,7 @@ static const IdStrMap img_tags[] = {
     { CODEC_ID_SUNRAST   , "im8"},
     { CODEC_ID_SUNRAST   , "im24"},
     { CODEC_ID_SUNRAST   , "sunras"},
+    { CODEC_ID_JPEG2000  , "j2c"},
     { CODEC_ID_JPEG2000  , "j2k"},
     { CODEC_ID_JPEG2000  , "jp2"},
     { CODEC_ID_JPEG2000  , "jpc"},
@@ -527,7 +528,7 @@ AVOutputFormat ff_image2_muxer = {
     .name           = "image2",
     .long_name      = NULL_IF_CONFIG_SMALL("image2 sequence"),
     .extensions     = "bmp,dpx,jls,jpeg,jpg,ljpg,pam,pbm,pcx,pgm,pgmyuv,png,"
-                      "ppm,sgi,tga,tif,tiff,jp2",
+                      "ppm,sgi,tga,tif,tiff,jp2,j2c",
     .priv_data_size = sizeof(VideoData),
     .video_codec    = CODEC_ID_MJPEG,
     .write_header   = write_header,