[FFmpeg-devel] [PATCH] avcodec: add Apple Pixlet decoder

[Paul B Mahol]

On 12/22/16, Michael Niedermayer <michael at niedermayer.cc> wrote:
> On Wed, Dec 21, 2016 at 09:16:40PM +0100, Paul B Mahol wrote:
>> Signed-off-by: Paul B Mahol <onemda at gmail.com>
>> ---
>>  Changelog               |   1 +
>>  doc/general.texi        |   1 +
>>  libavcodec/Makefile     |   1 +
>>  libavcodec/allcodecs.c  |   1 +
>>  libavcodec/avcodec.h    |   1 +
>>  libavcodec/codec_desc.c |   7 +
>>  libavcodec/pixlet.c     | 756
>> ++++++++++++++++++++++++++++++++++++++++++++++++
>>  libavformat/isom.c      |   2 +
>>  8 files changed, 770 insertions(+)
>>  create mode 100644 libavcodec/pixlet.c
> [...]
>> +static void reconstruction(AVCodecContext *avctx,
>> +                           int16_t *dest, unsigned width, unsigned
>> height, ptrdiff_t stride, int nb_levels,
>> +                           float *scaling_H, float *scaling_V, int
>> lowres)
>> +{
>> +    PixletContext *ctx = avctx->priv_data;
>> +    unsigned scaled_width, scaled_height;
>> +    float scale_H, scale_V;
>> +    int16_t *ptr, *tmp;
>> +    int i, j, k;
>> +
>> +    scaled_height = height >> nb_levels;
>> +    scaled_width  = width  >> nb_levels;
>> +    tmp = ctx->filter[0];
>> +
>> +    for (i = 0; i < nb_levels; i++) {
>> +        scaled_width  <<= 1;
>> +        scaled_height <<= 1;
>> +        scale_H = scaling_H[i + lowres];
>> +        scale_V = scaling_V[i + lowres];
>> +
>> +        ptr = dest;
>> +        for (j = 0; j < scaled_height; j++) {
>> +            filter(ptr, ctx->filter[1], scaled_width, scale_V);
>> +            ptr += stride;
>> +        }
>> +
>> +        for (j = 0; j < scaled_width; j++) {
>> +            ptr = dest + j;
>> +            for (k = 0; k < scaled_height; k++) {
>> +                tmp[k] = *ptr;
>> +                ptr += stride;
>> +            }
>> +
>> +            filter(tmp, ctx->filter[1], scaled_height, scale_H);
>> +
>> +            ptr = dest + j;
>> +            for (k = 0; k < scaled_height; k++) {
>> +                *ptr = tmp[k];
>> +                ptr += stride;
>> +            }
>> +        }
>> +    }
>> +}
>> +
>
>> +#define SQR(a) (a * a)
>
> missinng protection ()
>
> #define SQR(a) ((a) * (a))
>

Fixed locally, I also removed lowres support, can be readded if wanted. and
I changed code so it does not have so many memcpy calls.

Gonna apply, unless I see objections.