/*
  * 012v decoder
  *
  * Copyright (C) 2012 Carl Eugen Hoyos
  *
  * 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
  */
 
 #include "avcodec.h"
 #include "internal.h"
 #include "libavutil/intreadwrite.h"
 
 static av_cold int zero12v_decode_init(AVCodecContext *avctx)
 {

     avctx->pix_fmt             = AV_PIX_FMT_YUV422P16;

     avctx->bits_per_raw_sample = 10;
 
     if (avctx->codec_tag == MKTAG('a', '1', '2', 'v'))

         avpriv_request_sample(avctx, "transparency");

 
     return 0;
 }
 
 static int zero12v_decode_frame(AVCodecContext *avctx, void *data,
                                 int *got_frame, AVPacket *avpkt)
 {

     int line, ret;

     const int width = avctx->width;

     AVFrame *pic = data;

     uint16_t *y, *u, *v;
     const uint8_t *line_end, *src = avpkt->data;
     int stride = avctx->width * 8 / 3;
 

     if (width <= 1 || avctx->height <= 0) {
         av_log(avctx, AV_LOG_ERROR, "Dimensions %dx%d not supported.\n", width, avctx->height);

         return AVERROR_INVALIDDATA;
     }

 
     if (   avctx->codec_tag == MKTAG('0', '1', '2', 'v')
         && avpkt->size % avctx->height == 0
         && avpkt->size / avctx->height * 3 >= width * 8)
         stride = avpkt->size / avctx->height;
 

     if (avpkt->size < avctx->height * stride) {
         av_log(avctx, AV_LOG_ERROR, "Packet too small: %d instead of %d\n",
                avpkt->size, avctx->height * stride);
         return AVERROR_INVALIDDATA;
     }
 

     if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)

         return ret;

     pic->pict_type = AV_PICTURE_TYPE_I;
     pic->key_frame = 1;
 

     line_end = avpkt->data + stride;

     for (line = 0; line < avctx->height; line++) {
         uint16_t y_temp[6] = {0x8000, 0x8000, 0x8000, 0x8000, 0x8000, 0x8000};
         uint16_t u_temp[3] = {0x8000, 0x8000, 0x8000};
         uint16_t v_temp[3] = {0x8000, 0x8000, 0x8000};
         int x;
         y = (uint16_t *)(pic->data[0] + line * pic->linesize[0]);
         u = (uint16_t *)(pic->data[1] + line * pic->linesize[1]);
         v = (uint16_t *)(pic->data[2] + line * pic->linesize[2]);
 
         for (x = 0; x < width; x += 6) {
             uint32_t t;
 
             if (width - x < 6 || line_end - src < 16) {
                 y = y_temp;
                 u = u_temp;
                 v = v_temp;
             }
 
             if (line_end - src < 4)
                 break;

             t = AV_RL32(src);

             src += 4;
             *u++ = t <<  6 & 0xFFC0;
             *y++ = t >>  4 & 0xFFC0;
             *v++ = t >> 14 & 0xFFC0;
 

             if (line_end - src < 4)

                 break;
 
             t = AV_RL32(src);
             src += 4;
             *y++ = t <<  6 & 0xFFC0;
             *u++ = t >>  4 & 0xFFC0;
             *y++ = t >> 14 & 0xFFC0;

 
             if (line_end - src < 4)

                 break;
 
             t = AV_RL32(src);
             src += 4;
             *v++ = t <<  6 & 0xFFC0;
             *y++ = t >>  4 & 0xFFC0;
             *u++ = t >> 14 & 0xFFC0;
 

             if (line_end - src < 4)

                 break;
 
             t = AV_RL32(src);
             src += 4;
             *y++ = t <<  6 & 0xFFC0;
             *v++ = t >>  4 & 0xFFC0;
             *y++ = t >> 14 & 0xFFC0;
 

             if (width - x < 6)

                 break;
         }

 
         if (x < width) {
             y = x   + (uint16_t *)(pic->data[0] + line * pic->linesize[0]);
             u = x/2 + (uint16_t *)(pic->data[1] + line * pic->linesize[1]);
             v = x/2 + (uint16_t *)(pic->data[2] + line * pic->linesize[2]);
             memcpy(y, y_temp, sizeof(*y) * (width - x));
             memcpy(u, u_temp, sizeof(*u) * (width - x + 1) / 2);
             memcpy(v, v_temp, sizeof(*v) * (width - x + 1) / 2);
         }
 
         line_end += stride;
         src = line_end - stride;

     }
 
     *got_frame = 1;
 
     return avpkt->size;
 }
 
 AVCodec ff_zero12v_decoder = {
     .name           = "012v",

     .long_name      = NULL_IF_CONFIG_SMALL("Uncompressed 4:2:2 10-bit"),

     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_012V,
     .init           = zero12v_decode_init,
     .decode         = zero12v_decode_frame,

     .capabilities   = AV_CODEC_CAP_DR1,

 };