[FFmpeg-devel] [PATCH] Newtek SpeedHQ decoder.

[Steinar H. Gunderson]

On Sun, Jan 08, 2017 at 01:45:07PM +0100, Paul B Mahol wrote:
>> +    memcpy(rbuf, buf, buf_size);
>> +    memset(rbuf + buf_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
> Huh?!? Is this needed at all?

After some discussion on IRC: It turns out that avcodec_decode_video2()
requires the input AVPacket to already have AV_INPUT_BUFFER_PADDING_SIZE
padding afterwards, and it essentially only sends this AVPacket down to the
decode() function pointer. I'd love if this were documented directly on
AVPacket and/or the decode function pointer, but it's a strong enough
guarantee that this can go safely.

Sending v3 shortly, and I've also started some fuzzing. It's gone through
~50M execs with afl already, but obviously needs to restart now that there's
been changed. (I made a tiny 16x32 frame as seed and adapted Kieran's fffuzz
to accept raw video, so it chugs along at ~650 execs/thread on 40
hyperthreads.)

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