[x264-devel] AVC Intra encoder based on libx264

[Jason Garrett-Glaser]

On Tue, Jan 31, 2012 at 2:00 AM, Joseph Artsimovich <joseph at mirriad.com> wrote:
> On 31/01/2012 00:42, Jason Garrett-Glaser wrote:
>>
>> ...
>>
>> I've written my own full
>> implementation, which can be found on my github
>> (https://github.com/DarkShikari/x264-devel).
>>
>> Testing welcome.
>
> Will do.  One thing I noticed being missing are custom scaling matrices and
> i_chroma_qp_offset = 3

Where in the spec does it list anything about those parameters?

> * Need to get rid of a SEI with x264 version info.

Where in the spec does it prohibit this?  In fact, the spec explicitly
states that arbitrary SEIs are okay.

> * Need to add two dummy SEIs. Avid decoder will choke if they are missing
> but doesn't seem to look inside.

Where in the spec does it say this?  It merely says room must be
reserved for such SEIs, not how one must reserve them.  In fact, the
spec explicitly suggests using zero bytes -- not even using NALs!  I
used a filler NAL because I felt it was less stupid, but either should
abide by the spec.

> * Frame size is wrong. For 50i, you generate frames of 546000 bytes. It
> should instead be 559104 + 512*19 =  568832. See my code in avci_encoder.cpp
> for more details.

1.  As far as I can tell from the spec, the 512 SEI bytes are
*included* in the frame size.  The frame size should be 559,104.
2.  The code requests a frame size of 559,104, not 546,000.  If you
can show me a case where it generates the wrong frame size, please do
so, but I tested a number of resolution/fps combinations and they
worked correctly.

Jason