From: Maryla Ustarroz-Calonge via ffmpeg-devel <ffmpeg-devel@ffmpeg.org>
To: ffmpeg-devel@ffmpeg.org
Cc: Maryla Ustarroz-Calonge <maryla@google.com>
Subject: [FFmpeg-devel] [PATCH 2/3] avcodec/itut35: always check the provider code and country code together
Date: Tue, 5 Aug 2025 12:12:40 +0200
Message-ID: <20250805101241.947452-2-maryla@google.com> (raw)
In-Reply-To: <20250805101241.947452-1-maryla@google.com>
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.
Signed-off-by: Maryla Ustarroz-Calonge <maryla@google.com>
---
libavcodec/av1dec.c | 32 ++++++++++++--------------------
libavcodec/h2645_sei.c | 36 +++++++++---------------------------
libavcodec/itut35.h | 21 ++++++++++++++++-----
libavcodec/libdav1d.c | 41 +++++++++++++++--------------------------
4 files changed, 52 insertions(+), 78 deletions(-)
diff --git a/libavcodec/av1dec.c b/libavcodec/av1dec.c
index 8ff1bf394c..551f79fd7a 100644
--- a/libavcodec/av1dec.c
+++ b/libavcodec/av1dec.c
@@ -965,13 +965,13 @@ static int export_itut_t35(AVCodecContext *avctx, AVFrame *frame,
{
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) {
- case ITU_T_T35_PROVIDER_CODE_ATSC: {
+ country_code = itut_t35->itu_t_t35_country_code ;
+ 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
@@ -997,16 +997,13 @@ FF_ENABLE_DEPRECATION_WARNINGS
default: // ignore unsupported identifiers
break;
}
- break;
- }
- case ITU_T_T35_PROVIDER_CODE_SMTPE: {
+ } else if (country_code == ITU_T_T35_COUNTRY_CODE_US && provider_code == 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 ||
- provider_oriented_code != 1 || application_identifier != 4)
- break;
+ if (provider_oriented_code != 1 || application_identifier != 4)
+ return 0; // ignore
hdrplus = av_dynamic_hdr_plus_create_side_data(frame);
if (!hdrplus)
@@ -1016,28 +1013,23 @@ FF_ENABLE_DEPRECATION_WARNINGS
bytestream2_get_bytes_left(&gb));
if (ret < 0)
return ret;
- break;
- }
- case ITU_T_T35_PROVIDER_CODE_DOLBY: {
+ } else if (country_code == ITU_T_T35_COUNTRY_CODE_US && provider_code == 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 ||
- provider_oriented_code != 0x800)
- break;
+ if (provider_oriented_code != 0x800)
+ return 0; // ignore
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;
- }
- default: // ignore unsupported provider codes
- break;
+ } else {
+ // ignore unsupported provider codes
}
return 0;
diff --git a/libavcodec/h2645_sei.c b/libavcodec/h2645_sei.c
index d17c4fb5f9..fe567e1a53 100644
--- a/libavcodec/h2645_sei.c
+++ b/libavcodec/h2645_sei.c
@@ -158,20 +158,10 @@ static int decode_registered_user_data(H2645SEI *h, GetByteContext *gb,
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) {
- 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;
if (bytestream2_get_bytes_left(gb) < 4)
@@ -189,9 +179,7 @@ static int decode_registered_user_data(H2645SEI *h, GetByteContext *gb,
user_identifier);
break;
}
- break;
- }
- case ITU_T_T35_PROVIDER_CODE_LCEVC: {
+ } else if (country_code == ITU_T_T35_COUNTRY_CODE_UK && provider_code == ITU_T_T35_PROVIDER_CODE_LCEVC) {
if (bytestream2_get_bytes_left(gb) < 2)
return AVERROR_INVALIDDATA;
@@ -199,7 +187,7 @@ static int decode_registered_user_data(H2645SEI *h, GetByteContext *gb,
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;
@@ -213,9 +201,7 @@ static int decode_registered_user_data(H2645SEI *h, GetByteContext *gb,
if (provider_oriented_code == cuva_provider_oriented_code) {
return decode_registered_user_data_dynamic_hdr_vivid(&h->dynamic_hdr_vivid, gb);
}
- break;
- }
- case ITU_T_T35_PROVIDER_CODE_SMTPE: {
+ } else if(country_code == ITU_T_T35_COUNTRY_CODE_US && provider_code == 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;
@@ -234,9 +220,7 @@ static int decode_registered_user_data(H2645SEI *h, GetByteContext *gb,
application_identifier == smpte2094_40_application_identifier) {
return decode_registered_user_data_dynamic_hdr_plus(&h->dynamic_hdr_plus, gb);
}
- break;
- }
- case 0x5890: { // aom_provider_code
+ } else if (country_code == ITU_T_T35_COUNTRY_CODE_US && provider_code == ITU_T_T35_PROVIDER_CODE_AOM) {
const uint16_t aom_grain_provider_oriented_code = 0x0001;
uint16_t provider_oriented_code;
@@ -252,15 +236,13 @@ static int decode_registered_user_data(H2645SEI *h, GetByteContext *gb,
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",
- provider_code);
- break;
+ "Unsupported User Data Registered ITU-T T35 SEI message (country_code = %d, provider_code = %d)\n",
+ country_code, provider_code);
}
return 0;
diff --git a/libavcodec/itut35.h b/libavcodec/itut35.h
index a75ef37929..414c76a4fa 100644
--- a/libavcodec/itut35.h
+++ b/libavcodec/itut35.h
@@ -23,10 +23,21 @@
#define ITU_T_T35_COUNTRY_CODE_UK 0xB4
#define ITU_T_T35_COUNTRY_CODE_US 0xB5
-#define ITU_T_T35_PROVIDER_CODE_ATSC 0x31
-#define ITU_T_T35_PROVIDER_CODE_CUVA 0x04
-#define ITU_T_T35_PROVIDER_CODE_DOLBY 0x3B
-#define ITU_T_T35_PROVIDER_CODE_LCEVC 0x50
-#define ITU_T_T35_PROVIDER_CODE_SMTPE 0x3C
+// The Terminal Provider Code (or "Manufacturer Code") identifies the
+// manufacturer within a country. An Assignment Authority appointed by the
+// national body assigns this code nationally. The manufacturer code is always
+// used in conjunction with a country code.
+// - CN providers
+#define ITU_T_T35_PROVIDER_CODE_CUVA 0x0004
+// - UK providers
+// V-Nova should be 0x5000 according to UK Register of Manufacturer Codes
+// https://www.cix.co.uk/~bpechey/H221/h221code.htm
+// but FFmpeg has been using 0x0050
+#define ITU_T_T35_PROVIDER_CODE_LCEVC 0x0050
+// - US providers
+#define ITU_T_T35_PROVIDER_CODE_ATSC 0x0031
+#define ITU_T_T35_PROVIDER_CODE_DOLBY 0x003B
+#define ITU_T_T35_PROVIDER_CODE_AOM 0x5890
+#define ITU_T_T35_PROVIDER_CODE_SMTPE 0x003C
#endif /* AVCODEC_ITUT35_H */
diff --git a/libavcodec/libdav1d.c b/libavcodec/libdav1d.c
index 51cc8837b0..4ade3701bf 100644
--- a/libavcodec/libdav1d.c
+++ b/libavcodec/libdav1d.c
@@ -390,14 +390,14 @@ static int parse_itut_t35_metadata(Libdav1dContext *dav1d, Dav1dPicture *p,
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) {
- case ITU_T_T35_PROVIDER_CODE_ATSC: {
+ country_code = itut_t35->country_code;
+ 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
@@ -407,7 +407,7 @@ static int parse_itut_t35_metadata(Libdav1dContext *dav1d, Dav1dPicture *p,
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)
@@ -423,51 +423,40 @@ FF_ENABLE_DEPRECATION_WARNINGS
default: // ignore unsupported identifiers
break;
}
- break;
- }
- case ITU_T_T35_PROVIDER_CODE_SMTPE: {
+ } else if (country_code == ITU_T_T35_COUNTRY_CODE_US && provider_code == 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 ||
- provider_oriented_code != 1 || application_identifier != 4)
- break;
+ if (provider_oriented_code != 1 || application_identifier != 4)
+ return 0; // ignore
hdrplus = av_dynamic_hdr_plus_create_side_data(frame);
- if (!hdrplus) {
- res = AVERROR(ENOMEM);
- return res;
- }
+ if (!hdrplus)
+ return AVERROR(ENOMEM);
res = av_dynamic_hdr_plus_from_t35(hdrplus, gb.buffer,
bytestream2_get_bytes_left(&gb));
if (res < 0)
return res;
- break;
- }
- case ITU_T_T35_PROVIDER_CODE_DOLBY: {
+ } else if (country_code == ITU_T_T35_COUNTRY_CODE_US && provider_code == 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 ||
- provider_oriented_code != 0x800)
- break;
+ if (provider_oriented_code != 0x800)
+ return 0; // ignore
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;
}
--
2.50.1.565.gc32cd1483b-goog
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next prev parent reply other threads:[~2025-08-05 10:13 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-05 10:12 [FFmpeg-devel] [PATCH 1/3] avcodec/libdav1d: move itut-t35 parsing to a separate function Maryla Ustarroz-Calonge via ffmpeg-devel
2025-08-05 10:12 ` Maryla Ustarroz-Calonge via ffmpeg-devel [this message]
2025-08-05 10:12 ` [FFmpeg-devel] [PATCH 3/3] avcodec/itut35: rename some provider codes Maryla Ustarroz-Calonge via ffmpeg-devel
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