/* * Aura 2 decoder * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * Aura 2 decoder */ #include "avcodec.h"#include "internal.h"#include "libavutil/internal.h" static av_cold int aura_decode_init(AVCodecContext *avctx){    /* width needs to be divisible by 4 for this codec to work */    if (avctx->width & 0x3)        return AVERROR(EINVAL);    avctx->pix_fmt = AV_PIX_FMT_YUV422P;     return 0;} static int aura_decode_frame(AVCodecContext *avctx,                             void *data, int *got_frame,                             AVPacket *pkt){    AVFrame *frame = data;    uint8_t *Y, *U, *V;    uint8_t val;    int x, y, ret;    const uint8_t *buf = pkt->data;     /* prediction error tables (make it clear that they are signed values) */    const int8_t *delta_table = (const int8_t*)buf + 16;     if (pkt->size != 48 + avctx->height * avctx->width) {        av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",               pkt->size, 48 + avctx->height * avctx->width);        return AVERROR_INVALIDDATA;    }     /* pixel data starts 48 bytes in, after 3x16-byte tables */    buf += 48;     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)        return ret;     Y = frame->data[0];    U = frame->data[1];    V = frame->data[2];     /* iterate through each line in the height */    for (y = 0; y < avctx->height; y++) {        /* reset predictors */        val  = *buf++;        U[0] = val & 0xF0;        Y[0] = val << 4;        val  = *buf++;        V[0] = val & 0xF0;        Y[1] = Y[0] + delta_table[val & 0xF];        Y   += 2; U++; V++;         /* iterate through the remaining pixel groups (4 pixels/group) */        for (x = 1; x < (avctx->width >> 1); x++) {            val  = *buf++;            U[0] = U[-1] + delta_table[val >> 4];            Y[0] = Y[-1] + delta_table[val & 0xF];            val  = *buf++;            V[0] = V[-1] + delta_table[val >> 4];            Y[1] = Y[ 0] + delta_table[val & 0xF];            Y   += 2; U++; V++;        }        Y += frame->linesize[0] -  avctx->width;        U += frame->linesize[1] - (avctx->width >> 1);        V += frame->linesize[2] - (avctx->width >> 1);    }     *got_frame = 1;     return pkt->size;} AVCodec ff_aura2_decoder = {    .name           = "aura2",    .long_name      = NULL_IF_CONFIG_SMALL("Auravision Aura 2"),    .type           = AVMEDIA_TYPE_VIDEO,    .id             = AV_CODEC_ID_AURA2,    .init           = aura_decode_init,    .decode         = aura_decode_frame,    .capabilities   = AV_CODEC_CAP_DR1,    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,};