Fix a typo that broke writing (and reading) PAM files.

Reported and reviewed by Derek Buitenhuis.

libavcodec/pamenc.c

@@ -78,7 +78,7 @@ static int pam_encode_frame(AVCodecContext *avctx, unsigned char *outbuf,
         return -1;
     }
     snprintf(s->bytestream, s->bytestream_end - s->bytestream,
-             "P7\nWIDTH %d\nHEIGHT %d\nDEPTH %d\nMAXVAL %d\nTUPLETYPE %s\nENDHDR\n",
+             "P7\nWIDTH %d\nHEIGHT %d\nDEPTH %d\nMAXVAL %d\nTUPLTYPE %s\nENDHDR\n",
              w, h, depth, maxval, tuple_type);
     s->bytestream += strlen(s->bytestream);
 

libavcodec/pnm.c

@@ -93,7 +93,9 @@ int ff_pnm_decode_header(AVCodecContext *avctx, PNMContext * const s)
             } else if (!strcmp(buf1, "MAXVAL")) {
                 pnm_get(s, buf1, sizeof(buf1));
                 maxval = strtol(buf1, NULL, 10);
-            } else if (!strcmp(buf1, "TUPLETYPE")) {
+            } else if (!strcmp(buf1, "TUPLTYPE") ||
+            // FFmpeg used to write invalid files
+                       !strcmp(buf1, "TUPLETYPE")) {
                 pnm_get(s, tuple_type, sizeof(tuple_type));
             } else if (!strcmp(buf1, "ENDHDR")) {
                 break;