On Mon, May 21, 2018 at 9:25 AM, Jacob Trimble <modma...@google.com> wrote:
> On Mon, May 14, 2018 at 4:49 PM, Jacob Trimble <modma...@google.com> wrote:
>> On Tue, May 8, 2018 at 3:47 PM, Michael Niedermayer
>> <mich...@niedermayer.cc> wrote:
>>> On Mon, May 07, 2018 at 04:59:33PM -0700, Jacob Trimble wrote:
>>>> On Mon, May 7, 2018 at 3:18 PM, Michael Niedermayer
>>>> <mich...@niedermayer.cc> wrote:
>>>> > On Mon, Apr 23, 2018 at 11:03:57AM -0700, Jacob Trimble wrote:
>>>> >> While integrating my encryption info changes, I noticed a problem with
>>>> >> the init info structs. I implemented them as side-data on the Stream.
>>>> >> But this means there can only be one per stream. However, there can
>>>> >> be multiple 'pssh' atoms in a single stream (e.g. for key rotation or
>>>> >> multiple key systems). (sorry for not noticing sooner)
>>>> >>
>>>> >> Attached is a patch to fix this by making the init info a
>>>> >> singly-linked-list. It is ABI compatible and is still easy to use and
>>>> >> understand. The alternative would be to break ABI and have the
>>>> >> side-data methods return an array of pointers. I could do that
>>>> >> instead if that is preferable.
>>>> >
>>>> >> encryption_info.c | 154
>>>> >> +++++++++++++++++++++++++++++++++++-------------------
>>>> >> encryption_info.h | 5 +
>>>> >> 2 files changed, 106 insertions(+), 53 deletions(-)
>>>> >> e5eecc73a6997bbd11541771372d38ea9c3972a7
>>>> >> 0001-libavutil-encryption_info-Allow-multiple-init-info.patch
>>>> >> From bb941a77e882e93629d63d63059d0063b9519e29 Mon Sep 17 00:00:00 2001
>>>> >> From: Jacob Trimble <modma...@google.com>
>>>> >> Date: Mon, 23 Apr 2018 10:33:58 -0700
>>>> >> Subject: [PATCH] libavutil/encryption_info: Allow multiple init info.
>>>> >>
>>>> >> It is possible for there to be multiple encryption init info structure.
>>>> >> For example, to support multiple key systems or in key rotation. This
>>>> >> changes the AVEncryptionInitInfo struct to be a linked list so there
>>>> >> can be multiple structs without breaking ABI.
>>>> >>
>>>> >> Signed-off-by: Jacob Trimble <modma...@google.com>
>>>> >> ---
>>>> >> libavutil/encryption_info.c | 154 +++++++++++++++++++++++-------------
>>>> >> libavutil/encryption_info.h | 5 ++
>>>> >> 2 files changed, 106 insertions(+), 53 deletions(-)
>>>> >>
>>>> >> diff --git a/libavutil/encryption_info.c b/libavutil/encryption_info.c
>>>> >> index 20a752d6b4..9935c10d74 100644
>>>> >> --- a/libavutil/encryption_info.c
>>>> >> +++ b/libavutil/encryption_info.c
>>>> >> @@ -160,13 +160,16 @@ uint8_t *av_encryption_info_add_side_data(const
>>>> >> AVEncryptionInfo *info, size_t *
>>>> >> }
>>>> >>
>>>> >> // The format of the AVEncryptionInitInfo side data:
>>>> >> -// u32be system_id_size
>>>> >> -// u32be num_key_ids
>>>> >> -// u32be key_id_size
>>>> >> -// u32be data_size
>>>> >> -// u8[system_id_size] system_id
>>>> >> -// u8[key_id_size][num_key_id] key_ids
>>>> >> -// u8[data_size] data
>>>> >> +// u32be init_info_count
>>>> >> +// {
>>>> >> +// u32be system_id_size
>>>> >> +// u32be num_key_ids
>>>> >> +// u32be key_id_size
>>>> >> +// u32be data_size
>>>> >> +// u8[system_id_size] system_id
>>>> >> +// u8[key_id_size][num_key_id] key_ids
>>>> >> +// u8[data_size] data
>>>> >> +// }[init_info_count]
>>>> >>
>>>> >> #define FF_ENCRYPTION_INIT_INFO_EXTRA 16
>>>> >>
>>>> >> @@ -215,6 +218,7 @@ void
>>>> >> av_encryption_init_info_free(AVEncryptionInitInfo *info)
>>>> >> for (i = 0; i < info->num_key_ids; i++) {
>>>> >> av_free(info->key_ids[i]);
>>>> >> }
>>>> >> + av_encryption_init_info_free(info->next);
>>>> >> av_free(info->system_id);
>>>> >> av_free(info->key_ids);
>>>> >> av_free(info->data);
>>>> >> @@ -225,71 +229,115 @@ void
>>>> >> av_encryption_init_info_free(AVEncryptionInitInfo *info)
>>>> >> AVEncryptionInitInfo *av_encryption_init_info_get_side_data(
>>>> >> const uint8_t *side_data, size_t side_data_size)
>>>> >> {
>>>> >> - AVEncryptionInitInfo *info;
>>>> >> + AVEncryptionInitInfo *ret = NULL, *info;
>>>> >> uint64_t system_id_size, num_key_ids, key_id_size, data_size, i;
>>>> >> + uint64_t init_info_count;
>>>> >>
>>>> >> - if (!side_data || side_data_size < FF_ENCRYPTION_INIT_INFO_EXTRA)
>>>> >> - return NULL;
>>>> >> -
>>>> >> - system_id_size = AV_RB32(side_data);
>>>> > [...]
>>>> >> + init_info_count = AV_RB32(side_data);
>>>> >
>>>> > i may be missing something but this looks like the meaning of the first
>>>> > field changes, this thus doesnt look compatible to me
>>>>
>>>> It changes the binary format of the side-data, but that was explicitly
>>>> not part of ABI. The fields in the structs are unchanged. This would
>>>> only cause a problem if the side data bytes were stored out-of-band
>>>> from a different version of FFmpeg.
>>>
>>> yes, right.
>>> its side data that is neighter a C struct nor a well defined byte stream
>>> its a opaque block that can only be passed to libavutil which then
>>> translates
>>> it into a C struct.
>>> its not new but it still feels clumsy to use this as means to pass data
>>> around
>>>
>>
>> I know it's weird, but this was the design that was decided on when
>> this was added. Are there any changes you want for this patch?
>>
>>>
>>> [...]
>>> --
>>> Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>>>
>>> If you think the mosad wants you dead since a long time then you are either
>>> wrong or dead since a long time.
>>>
>>> _______________________________________________
>>> ffmpeg-devel mailing list
>>> ffmpeg-devel@ffmpeg.org
>>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>>
>
> PingAdded fix for issue found by Chrome's ClusterFuzz (http://crbug.com/846662). PTAL.
0001-libavutil-encryption_info-Allow-multiple-init-info-v4.patch
Description: Binary data
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