avcodec/itut35: always check the provider code and country code together

ITU-T T.35 provider codes are attributed by national bodies and it's possible to have collisions across countries. This is why the country code must always be checked as well. Use if statements rather than nested switches which would be unreadable.

Maryla Ustarroz-Calonge committed 1 year ago

Commit a3ec70b1 parent 088ace34 files · +52 −78Browse files

Showing the changes to libavcodec (4 of 4 files). Show all

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4 files

libavcodec/av1dec.c +12 −20
libavcodec/h2645_sei.c +9 −27
libavcodec/itut35.h +16 −5
libavcodec/libdav1d.c +15 −26

libavcodec/av1dec.c+12−20

 {
     GetByteContext gb;
     AV1DecContext *s = avctx->priv_data;
-    int ret, provider_code;
+    int ret, provider_code, country_code;
     bytestream2_init(&gb, itut_t35->payload, itut_t35->payload_size);
     provider_code = bytestream2_get_be16(&gb);
-    switch (provider_code) {
+    country_code = itut_t35->itu_t_t35_country_code ;
-    case ITU_T_T35_PROVIDER_CODE_ATSC: {
+    if (country_code == ITU_T_T35_COUNTRY_CODE_US && provider_code == 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
         default: // ignore unsupported identifiers
             break;
         }
-        break;
+    } else if (country_code == ITU_T_T35_COUNTRY_CODE_US && provider_code == ITU_T_T35_PROVIDER_CODE_SMTPE) {
-    }
-    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 != ITU_T_T35_COUNTRY_CODE_US ||
+        if (provider_oriented_code != 1 || application_identifier != 4)
-            provider_oriented_code != 1 || application_identifier != 4)
+            return 0; // ignore
-            break;
         hdrplus = av_dynamic_hdr_plus_create_side_data(frame);
         if (!hdrplus)
                                            bytestream2_get_bytes_left(&gb));
         if (ret < 0)
             return ret;
-        break;
+    } else if (country_code == ITU_T_T35_COUNTRY_CODE_US && provider_code == ITU_T_T35_PROVIDER_CODE_DOLBY) {
-    }
-    case ITU_T_T35_PROVIDER_CODE_DOLBY: {
         int provider_oriented_code = bytestream2_get_be32(&gb);
-        if (itut_t35->itu_t_t35_country_code != ITU_T_T35_COUNTRY_CODE_US ||
+        if (provider_oriented_code != 0x800)
-            provider_oriented_code != 0x800)
+            return 0; // ignore
-            break;
         ret = ff_dovi_rpu_parse(&s->dovi, gb.buffer, gb.buffer_end - gb.buffer,
                                 avctx->err_recognition);
         if (ret < 0) {
             av_log(avctx, AV_LOG_WARNING, "Error parsing DOVI OBU.\n");
-            break; // ignore
+            return 0; // ignore
         }
         ret = ff_dovi_attach_side_data(&s->dovi, frame);
         if (ret < 0)
             return ret;
-        break;
+    } else {
-    }
+        // ignore unsupported provider codes
-    default: // ignore unsupported provider codes
-        break;
     }
     return 0;

libavcodec/h2645_sei.c+9−27

         bytestream2_skipu(gb, 1);  // itu_t_t35_country_code_extension_byte
     }
-    if (country_code != ITU_T_T35_COUNTRY_CODE_US &&
-        country_code != ITU_T_T35_COUNTRY_CODE_UK &&
-        country_code != ITU_T_T35_COUNTRY_CODE_CN) {
-        av_log(logctx, AV_LOG_VERBOSE,
-               "Unsupported User Data Registered ITU-T T35 SEI message (country_code = %d)\n",
-               country_code);
-        return 0;
-    }
     /* itu_t_t35_payload_byte follows */
     provider_code = bytestream2_get_be16u(gb);
-    switch (provider_code) {
+    if (country_code == ITU_T_T35_COUNTRY_CODE_US && provider_code == ITU_T_T35_PROVIDER_CODE_ATSC) {
-    case ITU_T_T35_PROVIDER_CODE_ATSC: {
         uint32_t user_identifier;
         if (bytestream2_get_bytes_left(gb) < 4)
                    user_identifier);
             break;
         }
-        break;
+    } else if (country_code == ITU_T_T35_COUNTRY_CODE_UK && provider_code == ITU_T_T35_PROVIDER_CODE_LCEVC) {
-    }
-    case ITU_T_T35_PROVIDER_CODE_LCEVC: {
         if (bytestream2_get_bytes_left(gb) < 2)
             return AVERROR_INVALIDDATA;
         return decode_registered_user_data_lcevc(&h->lcevc, gb);
     }
 #if CONFIG_HEVC_SEI
-    case ITU_T_T35_PROVIDER_CODE_CUVA: {
+    else if (country_code == ITU_T_T35_COUNTRY_CODE_CN && provider_code == ITU_T_T35_PROVIDER_CODE_CUVA) {
         const uint16_t cuva_provider_oriented_code = 0x0005;
         uint16_t provider_oriented_code;
         if (provider_oriented_code == cuva_provider_oriented_code) {
             return decode_registered_user_data_dynamic_hdr_vivid(&h->dynamic_hdr_vivid, gb);
         }
-        break;
+    } else if(country_code == ITU_T_T35_COUNTRY_CODE_US && provider_code == ITU_T_T35_PROVIDER_CODE_SMTPE) {
-    }
-    case ITU_T_T35_PROVIDER_CODE_SMTPE: {
         // A/341 Amendment - 2094-40
         const uint16_t smpte2094_40_provider_oriented_code = 0x0001;
         const uint8_t smpte2094_40_application_identifier = 0x04;
             application_identifier == smpte2094_40_application_identifier) {
             return decode_registered_user_data_dynamic_hdr_plus(&h->dynamic_hdr_plus, gb);
         }
-        break;
+    } else if (country_code == ITU_T_T35_COUNTRY_CODE_US && provider_code == ITU_T_T35_PROVIDER_CODE_AOM) {
-    }
-    case 0x5890: { // aom_provider_code
         const uint16_t aom_grain_provider_oriented_code = 0x0001;
         uint16_t provider_oriented_code;
                                                 gb->buffer,
                                                 bytestream2_get_bytes_left(gb));
         }
-        break;
     }
-    unsupported_provider_code:
 #endif
-    default:
+    else {
+        unsupported_provider_code:
         av_log(logctx, AV_LOG_VERBOSE,
-               "Unsupported User Data Registered ITU-T T35 SEI message (provider_code = %d)\n",
+               "Unsupported User Data Registered ITU-T T35 SEI message (country_code = %d, provider_code = %d)\n",
-               provider_code);
+               country_code, provider_code);
-        break;
     }
     return 0;

libavcodec/itut35.h+16−5

@@ -23,10 +23,21 @@ · 22 unmodified lines
23	#define ITU_T_T35_COUNTRY_CODE_UK 0xB4	23	#define ITU_T_T35_COUNTRY_CODE_UK 0xB4
24	#define ITU_T_T35_COUNTRY_CODE_US 0xB5	24	#define ITU_T_T35_COUNTRY_CODE_US 0xB5
25		25
26	#define ITU_T_T35_PROVIDER_CODE_ATSC 0x31	26	// The Terminal Provider Code (or "Manufacturer Code") identifies the
27	#define ITU_T_T35_PROVIDER_CODE_CUVA 0x04	27	// manufacturer within a country. An Assignment Authority appointed by the
28	#define ITU_T_T35_PROVIDER_CODE_DOLBY 0x3B	28	// national body assigns this code nationally. The manufacturer code is always
29	#define ITU_T_T35_PROVIDER_CODE_LCEVC 0x50	29	// used in conjunction with a country code.
30	#define ITU_T_T35_PROVIDER_CODE_SMTPE 0x3C	30	// - CN providers
		31	#define ITU_T_T35_PROVIDER_CODE_CUVA 0x0004
		32	// - UK providers
		33	// V-Nova should be 0x5000 according to UK Register of Manufacturer Codes
		34	// https://www.cix.co.uk/~bpechey/H221/h221code.htm
		35	// but FFmpeg has been using 0x0050
		36	#define ITU_T_T35_PROVIDER_CODE_LCEVC 0x0050
		37	// - US providers
		38	#define ITU_T_T35_PROVIDER_CODE_ATSC 0x0031
		39	#define ITU_T_T35_PROVIDER_CODE_DOLBY 0x003B
		40	#define ITU_T_T35_PROVIDER_CODE_AOM 0x5890
		41	#define ITU_T_T35_PROVIDER_CODE_SMTPE 0x003C
31		42
32	#endif /* AVCODEC_ITUT35_H */	43	#endif /* AVCODEC_ITUT35_H */

libavcodec/libdav1d.c+15−26

                                    const Dav1dITUTT35 *itut_t35, AVCodecContext *c,
                                    AVFrame *frame) {
     GetByteContext gb;
-    int provider_code;
+    int provider_code, country_code;
     int res;
     bytestream2_init(&gb, itut_t35->payload, itut_t35->payload_size);
     provider_code = bytestream2_get_be16(&gb);
-    switch (provider_code) {
+    country_code = itut_t35->country_code;
-    case ITU_T_T35_PROVIDER_CODE_ATSC: {
+    if (country_code == ITU_T_T35_COUNTRY_CODE_US && provider_code == 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
             if (res < 0)
                 return res;
             if (!res)
-                break;
+                return 0;  // no cc found, ignore
             res = ff_frame_new_side_data_from_buf(c, frame, AV_FRAME_DATA_A53_CC, &buf);
             if (res < 0)
         default: // ignore unsupported identifiers
             break;
         }
-        break;
+    } else if (country_code == ITU_T_T35_COUNTRY_CODE_US && provider_code == ITU_T_T35_PROVIDER_CODE_SMTPE) {
-    }
-    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->country_code != ITU_T_T35_COUNTRY_CODE_US ||
+        if (provider_oriented_code != 1 || application_identifier != 4)
-            provider_oriented_code != 1 || application_identifier != 4)
+            return 0; // ignore
-            break;
         hdrplus = av_dynamic_hdr_plus_create_side_data(frame);
-        if (!hdrplus) {
+        if (!hdrplus)
-            res = AVERROR(ENOMEM);
+            return AVERROR(ENOMEM);
-            return res;
-        }
         res = av_dynamic_hdr_plus_from_t35(hdrplus, gb.buffer,
                                             bytestream2_get_bytes_left(&gb));
         if (res < 0)
             return res;
-        break;
+    } else if (country_code == ITU_T_T35_COUNTRY_CODE_US && provider_code == ITU_T_T35_PROVIDER_CODE_DOLBY) {
-    }
-    case ITU_T_T35_PROVIDER_CODE_DOLBY: {
         int provider_oriented_code = bytestream2_get_be32(&gb);
-        if (itut_t35->country_code != ITU_T_T35_COUNTRY_CODE_US ||
+        if (provider_oriented_code != 0x800)
-            provider_oriented_code != 0x800)
+            return 0; // ignore
-            break;
         res = ff_dovi_rpu_parse(&dav1d->dovi, gb.buffer, gb.buffer_end - gb.buffer,
                                 c->err_recognition);
         if (res < 0) {
             av_log(c, AV_LOG_WARNING, "Error parsing DOVI OBU.\n");
-            break; // ignore
+            return 0; // ignore
         }
         res = ff_dovi_attach_side_data(&dav1d->dovi, frame);
         if (res < 0)
             return res;
-        break;
+    } else {
+        // ignore unsupported provider codes
     }
-    default: // ignore unsupported provider codes
-        break;
-    }
     return 0;
 }

avcodec/itut35: always check the provider code and country code together

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