/*

  * Cirrus Logic AccuPak (CLJR) encoder

  * Copyright (c) 2003 Alex Beregszaszi
  *

  * 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

  * Cirrus Logic AccuPak encoder.

  */

 #include "libavutil/common.h"

 #include "libavutil/opt.h"

 
 #include "avcodec.h"

 #include "internal.h"

 #include "put_bits.h"

 typedef struct CLJRContext {

     AVClass        *avclass;
     int             dither_type;

 } CLJRContext;
 

 static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                         const AVFrame *p, int *got_packet)

 {

     CLJRContext *a = avctx->priv_data;

     PutBitContext pb;

     int x, y, ret;

     uint32_t dither= avctx->frame_number;

     static const uint32_t ordered_dither[2][2] =
     {
         { 0x10400000, 0x104F0000 },
         { 0xCB2A0000, 0xCB250000 },
     };

     if (avctx->width%4 && avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) {
          av_log(avctx, AV_LOG_ERROR,
                 "Widths which are not a multiple of 4 might fail with some decoders, "
                 "use vstrict=-1 / -strict -1 to use %d anyway.\n", avctx->width);
          return AVERROR_EXPERIMENTAL;
     }
 

     if ((ret = ff_alloc_packet2(avctx, pkt, 32*avctx->height*avctx->width/4, 0)) < 0)

         return ret;

     init_put_bits(&pb, pkt->data, pkt->size);

 
     for (y = 0; y < avctx->height; y++) {
         uint8_t *luma = &p->data[0][y * p->linesize[0]];
         uint8_t *cb   = &p->data[1][y * p->linesize[1]];
         uint8_t *cr   = &p->data[2][y * p->linesize[2]];

         uint8_t luma_tmp[4];

         for (x = 0; x < avctx->width; x += 4) {

             switch (a->dither_type) {
             case 0: dither = 0x492A0000;                       break;
             case 1: dither = dither * 1664525 + 1013904223;    break;

             case 2: dither = ordered_dither[ y&1 ][ (x>>2)&1 ];break;

             }

             if (x+3 >= avctx->width) {
                 memset(luma_tmp, 0, sizeof(luma_tmp));
                 memcpy(luma_tmp, luma, avctx->width - x);
                 luma = luma_tmp;
             }

             put_bits(&pb, 5, (249*(luma[3] +  (dither>>29)   )) >> 11);
             put_bits(&pb, 5, (249*(luma[2] + ((dither>>26)&7))) >> 11);
             put_bits(&pb, 5, (249*(luma[1] + ((dither>>23)&7))) >> 11);
             put_bits(&pb, 5, (249*(luma[0] + ((dither>>20)&7))) >> 11);

             luma += 4;

             put_bits(&pb, 6, (253*(*(cb++) + ((dither>>18)&3))) >> 10);
             put_bits(&pb, 6, (253*(*(cr++) + ((dither>>16)&3))) >> 10);

         }
     }

     flush_put_bits(&pb);

     pkt->size   = put_bits_count(&pb) / 8;
     pkt->flags |= AV_PKT_FLAG_KEY;
     *got_packet = 1;
     return 0;

 }
 

 #define OFFSET(x) offsetof(CLJRContext, x)
 #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
 static const AVOption options[] = {

     { "dither_type",   "Dither type",   OFFSET(dither_type),        AV_OPT_TYPE_INT, { .i64=1 }, 0, 2, VE},

     { NULL },
 };
 

 static const AVClass cljr_class = {

     .class_name = "cljr encoder",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 

 AVCodec ff_cljr_encoder = {

     .name           = "cljr",

     .long_name      = NULL_IF_CONFIG_SMALL("Cirrus Logic AccuPak"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_CLJR,

     .priv_data_size = sizeof(CLJRContext),

     .encode2        = encode_frame,

     .pix_fmts       = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV411P,
                                                    AV_PIX_FMT_NONE },

     .priv_class     = &cljr_class,

 };