avcodec/av1dec: use named constants for ITU-T T.35 metadata

Signed-off-by: James Almer <jamrial@gmail.com>

libavcodec/av1dec.c

@@ -34,6 +34,7 @@
 #include "decode.h"
 #include "hwaccel_internal.h"
 #include "internal.h"
+#include "itut35.h"
 #include "hwconfig.h"
 #include "profiles.h"
 #include "refstruct.h"
@@ -951,7 +952,7 @@ static int export_itut_t35(AVCodecContext *avctx, AVFrame *frame,
 
     provider_code = bytestream2_get_be16(&gb);
     switch (provider_code) {
-    case 0x31: { // atsc_provider_code
+    case ITU_T_T35_PROVIDER_CODE_ATSC: {
         uint32_t user_identifier = bytestream2_get_be32(&gb);
         switch (user_identifier) {
         case MKBETAG('G', 'A', '9', '4'): { // closed captions
@@ -975,12 +976,12 @@ static int export_itut_t35(AVCodecContext *avctx, AVFrame *frame,
         }
         break;
     }
-    case 0x3C: { // smpte_provider_code
+    case ITU_T_T35_PROVIDER_CODE_SMTPE: {
         AVDynamicHDRPlus *hdrplus;
         int provider_oriented_code = bytestream2_get_be16(&gb);
         int application_identifier = bytestream2_get_byte(&gb);
 
-        if (itut_t35->itu_t_t35_country_code != 0xB5 ||
+        if (itut_t35->itu_t_t35_country_code != ITU_T_T35_COUNTRY_CODE_US ||
             provider_oriented_code != 1 || application_identifier != 4)
             break;
 
@@ -994,9 +995,10 @@ static int export_itut_t35(AVCodecContext *avctx, AVFrame *frame,
             return ret;
         break;
     }
-    case 0x3B: { // dolby_provider_code
+    case ITU_T_T35_PROVIDER_CODE_DOLBY: {
         int provider_oriented_code = bytestream2_get_be32(&gb);
-        if (itut_t35->itu_t_t35_country_code != 0xB5 || provider_oriented_code != 0x800)
+        if (itut_t35->itu_t_t35_country_code != ITU_T_T35_COUNTRY_CODE_US ||
+            provider_oriented_code != 0x800)
             break;
 
         ret = ff_dovi_rpu_parse(&s->dovi, gb.buffer, gb.buffer_end - gb.buffer);

libavcodec/itut35.h

+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_ITUT35_H
+#define AVCODEC_ITUT35_H
+
+#define ITU_T_T35_COUNTRY_CODE_US 0xB5
+
+#define ITU_T_T35_PROVIDER_CODE_ATSC  0x31
+#define ITU_T_T35_PROVIDER_CODE_DOLBY 0x3B
+#define ITU_T_T35_PROVIDER_CODE_SMTPE 0x3C
+
+#endif /* AVCODEC_ITUT35_H */