From 6e84a49ff43bc4b2abb7e35f25ece627e6d15a8c Mon Sep 17 00:00:00 2001 From: Cyril Concolato Date: Mon, 19 Feb 2024 10:04:29 -0800 Subject: [PATCH 1/5] add note for encryption description limit --- index.bs | 3 +++ 1 file changed, 3 insertions(+) diff --git a/index.bs b/index.bs index 964fc4b..436f55e 100644 --- a/index.bs +++ b/index.bs @@ -29,6 +29,7 @@ url: https://www.iso.org/standard/68960.html#; spec: ISOBMFF; type: property; text: pasp text: sgpd text: stsd + text: saiz url: https://www.webmproject.org/vp9/mp4/#; spec: VP9; type: property; text: SmDm @@ -619,6 +620,8 @@ Within protected samples, the following constraints apply: - A subsample SHALL be created for each tile that has a decode_tile structure whose size (including any trailing bits) is larger or equal to 16 bytes. If it is less than 16 bytes, per the rules above, the decode_tile structure is not encrypted and the corresponding bytes SHOULD be included in the [=BytesOfClearData=] field of a surrounding subsample, if any. - All other parts of [=Tile Group OBUs=] and [=Frame OBUs=] SHALL be unprotected . +NOTE: Version 1 of the [=saiz=] box as defined in [[ISOBMFF]] can only describe [=Sample Auxiliary Information=] whose size does not exceed 256 bytes. In the case of AV1 streams that use a large number of tiles or a large number of frames per sample, when following the encryption requirements defined in this section the size of corresponding Sample Auxiliary Information may exceed that limit. Until updates are made to ISOBMFF, authors are encouraged to avoid reaching the limit. + Subsample Encryption Illustration {#subsample-encryption-illustration} ------------------ Figure #1 illustrates Subsample based encryption of AV1. From 8344f2112bc21b7821a8c9520ef55353d5879272 Mon Sep 17 00:00:00 2001 From: Cyril Concolato Date: Mon, 19 Feb 2024 10:10:33 -0800 Subject: [PATCH 2/5] fix version number --- index.bs | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/index.bs b/index.bs index 436f55e..f66cb5a 100644 --- a/index.bs +++ b/index.bs @@ -17,6 +17,7 @@ Metadata Order: This version, !*, * 
 url: https://www.iso.org/standard/68960.html#; spec: ISOBMFF; type: dfn;
 	text: VisualSampleEntry
+	tetx: Sample Auxiliary Information
 
 url: https://www.iso.org/standard/68960.html#; spec: ISOBMFF; type: property;
 	text: bitr
@@ -620,7 +621,7 @@ Within protected samples, the following constraints apply:
 	    - A subsample SHALL be created for each tile that has a decode_tile structure whose size (including any trailing bits) is larger or equal to 16 bytes. If it is less than 16 bytes, per the rules above, the decode_tile structure is not encrypted and the corresponding bytes SHOULD be included in the [=BytesOfClearData=] field of a surrounding subsample, if any.
 		- All other parts of [=Tile Group OBUs=] and [=Frame OBUs=] SHALL be unprotected .
 
-NOTE: Version 1 of the [=saiz=] box as defined in [[ISOBMFF]] can only describe [=Sample Auxiliary Information=] whose size does not exceed 256 bytes. In the case of AV1 streams that use a large number of tiles or a large number of frames per sample, when following the encryption requirements defined in this section the size of corresponding Sample Auxiliary Information may exceed that limit. Until updates are made to ISOBMFF, authors are encouraged to avoid reaching the limit. 
+NOTE: Version 0 of the 'saiz' box as defined in [[ISOBMFF]] can only describe [=Sample Auxiliary Information=] whose size does not exceed 256 bytes. In the case of AV1 streams that use a large number of tiles or a large number of frames per sample, when following the encryption requirements defined in this section the size of corresponding Sample Auxiliary Information may exceed that limit. Until updates are made to ISOBMFF, authors are encouraged to avoid reaching the limit. 
 
 Subsample Encryption Illustration {#subsample-encryption-illustration}
 ------------------

From 8fba52cb22c38461b477651c43703c2181b7176c Mon Sep 17 00:00:00 2001
From: Cyril Concolato 
Date: Mon, 19 Feb 2024 10:11:42 -0800
Subject: [PATCH 3/5] fix typo

---
 index.bs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/index.bs b/index.bs
index f66cb5a..6da661a 100644
--- a/index.bs
+++ b/index.bs
@@ -17,7 +17,7 @@ Metadata Order: This version, !*, *
 
 url: https://www.iso.org/standard/68960.html#; spec: ISOBMFF; type: dfn;
 	text: VisualSampleEntry
-	tetx: Sample Auxiliary Information
+	text: Sample Auxiliary Information
 
 url: https://www.iso.org/standard/68960.html#; spec: ISOBMFF; type: property;
 	text: bitr

From bb83d022652456ee264919b9edd02c0465a1e187 Mon Sep 17 00:00:00 2001
From: Cyril Concolato 
Date: Mon, 4 Mar 2024 09:43:41 -0800
Subject: [PATCH 4/5] address comments

---
 index.bs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/index.bs b/index.bs
index 6da661a..f0e3bd8 100644
--- a/index.bs
+++ b/index.bs
@@ -621,7 +621,7 @@ Within protected samples, the following constraints apply:
 	    - A subsample SHALL be created for each tile that has a decode_tile structure whose size (including any trailing bits) is larger or equal to 16 bytes. If it is less than 16 bytes, per the rules above, the decode_tile structure is not encrypted and the corresponding bytes SHOULD be included in the [=BytesOfClearData=] field of a surrounding subsample, if any.
 		- All other parts of [=Tile Group OBUs=] and [=Frame OBUs=] SHALL be unprotected .
 
-NOTE: Version 0 of the 'saiz' box as defined in [[ISOBMFF]] can only describe [=Sample Auxiliary Information=] whose size does not exceed 256 bytes. In the case of AV1 streams that use a large number of tiles or a large number of frames per sample, when following the encryption requirements defined in this section the size of corresponding Sample Auxiliary Information may exceed that limit. Until updates are made to ISOBMFF, authors are encouraged to avoid reaching the limit. 
+NOTE: Version 0 of the 'saiz' box as defined in [[ISOBMFF]] can only describe [=Sample Auxiliary Information=] whose size does not exceed 255 bytes. In the case of AV1 streams that use a large number of tiles or a large number of frames per sample, when following the encryption requirements defined in this section the size of the corresponding Sample Auxiliary Information may exceed that limit. Until updates are made to [[ISOBMFF]], authors are encouraged to avoid reaching the limit.
 
 Subsample Encryption Illustration {#subsample-encryption-illustration}
 ------------------

From 41897d50d8b6db32c71ca84ba42148c812d88cc2 Mon Sep 17 00:00:00 2001
From: Cyril Concolato 
Date: Mon, 4 Mar 2024 10:21:37 -0800
Subject: [PATCH 5/5] update change log

---
 index.bs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/index.bs b/index.bs
index f0e3bd8..6500230 100644
--- a/index.bs
+++ b/index.bs
@@ -716,3 +716,5 @@ Changes since v1.2.0 release {#changelist}
 - Make assert-id's unique and add them to the previous version.
 - Add a note on the identification of the T.35 message.
 - Use undated reference for ISOBMFF.
+- Add note for encryption description limit.
+