[FFmpeg-devel] [RFC][PATCH 3/3] tta: Add support for encrypted streams

James Almer jamrial at gmail.com
Tue Jan 29 02:23:29 CET 2013

On 28/01/13 11:27 AM, Michael Niedermayer wrote:
> On Mon, Jan 28, 2013 at 04:32:54AM -0300, James Almer wrote:
>> The code to decrypt data is added to the decoder, and
>> the code needed to provide the decrypt key is added
>> to the TTA demuxer.
>> Any other container that supports TTA streams will
>> need extra code to process the password and send it
>> to the decoder using packet side data (main extradata
>> is used for the TTA header).
> why is the password handling split between demuxer and decoder ?

Some containers supposedly don't store the TTA header (where the 
encryption flag is stored).

Then again the decoder seems to ignore any stream without the 
complete header inside the extradata, so i guess it's safe to do
it all within the decoder.

> [...]
>> @@ -44,7 +45,7 @@ typedef struct TTAFilter {
>>      int32_t qm[MAX_ORDER];
>>      int32_t dx[MAX_ORDER];
>>      int32_t dl[MAX_ORDER];
>> -} TTAFilter;
>> +} DECLARE_ALIGNED(16, , TTAFilter);
> this looks wrong
> why do you try to align the struct ?

That's how it's declared in libtta.
As i said before it appears to work the same without the alignment 
declaration, so i can remove it anyway.


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